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Mawson AR. Understanding health disparities affecting people of West Central African descent in the United States: An evolutionary perspective. Evol Appl 2023; 16:963-978. [PMID: 37216026 PMCID: PMC10197229 DOI: 10.1111/eva.13549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/19/2023] [Accepted: 04/02/2023] [Indexed: 05/24/2023] Open
Abstract
Human populations adapting to diverse aspects of their environment such as climate and pathogens leave signatures of genetic variation. This principle may apply to people of West Central African descent in the United States, who are at increased risk of certain chronic conditions and diseases compared to their European counterparts. Less well known is that they are also at reduced risk of other diseases. While discriminatory practices in the United States continue to affect access to and the quality of healthcare, the health disparities affecting African Americans may also be due in part to evolutionary adaptations to the original environment of sub-Saharan Africa, which involved continuous exposure to the vectors of potentially lethal endemic tropical diseases. Evidence is presented that these organisms selectively absorb vitamin A from the host, and its use in parasite reproduction contributes to the signs and symptoms of the respective diseases. These evolutionary adaptations included (1) sequestering vitamin A away from the liver to other organs, to reduce accessibility to the invaders; and (2) reducing the metabolism and catabolism of vitamin A (vA), causing it to accumulate to subtoxic concentrations and weaken the organisms, thereby reducing the risk of severe disease. However, in the environment of North America, lacking vA-absorbing parasites and with a mainly dairy-based diet that is high in vA, this combination of factors is hypothesized to lead to the accumulation of vA and to increased sensitivity to vA as a toxin, which contribute to the health disparities affecting African Americans. vA toxicity is linked to numerous acute and chronic conditions via mitochondrial dysfunction and apoptosis. Subject to testing, the hypothesis suggests that the adoption of traditional or modified West Central African-style diets that are low in vA and high in vA-absorbing fiber hold promise for disease prevention and treatment, and as a population-based strategy for health maintenance and longevity.
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Affiliation(s)
- Anthony R. Mawson
- Department of Epidemiology and Biostatistics, School of Public Health, College of Health SciencesJackson State UniversityJacksonMississippiUSA
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2
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El Akil S, Elouilamine E, Ighid N, Izaabel EH. Explore the distribution of (rs35742686, rs3892097 and rs1065852) genetic polymorphisms of cytochrome P4502D6 gene in the Moroccan population. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2022. [DOI: 10.1186/s43042-022-00369-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Abstract
Background
The CYP2D6 gene encodes a crucial enzyme involved in the metabolic pathways of many commonly used drugs. It is a highly polymorphic gene inducing an interethnic and interindividual variability in disease susceptibility and treatment response. The aim of this study is to evaluate the frequency of the three CYP2D6 most investigated alleles (CYP2D6*3, CYP2D6*4, and CYP2D6*10 alleles) in Morocco compared to other populations.
This study enrolled 321 healthy Moroccan subjects. CYP2D6 genotypes and allele frequencies were assessed using a restriction fragment length polymorphism–polymerase chain reaction genotyping method. The Principal Component Analysis (PCA) and dendrogram were conducted to evaluate genetic proximity between Moroccans and other populations depending on CYP2D6 allele frequencies.
Results
According to the current study, the results observed the homozygous wild type of the three studied SNPs were predominant among the Moroccan population, while 1.4% of Moroccans carried the CYP2D6*4 allele responsible for a Poor Metabolizer phenotype and associated with low enzyme activity which may induce a treatment failure. The PCA and cluster dendrogram tools revealed genetic proximity between Moroccans and Mediterranean, European and African populations, versus a distancing from Asian populations.
Conclusion
The distribution of CYP2D6 polymorphisms within Morocco follows the patterns generally found among the Mediterranean, European and African populations. Furthermore, these results will help to lay a basis for clinical studies, aimed to introduce and optimize a personalized therapy in the Moroccan population.
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Relevance of CYP2D6 Gene Variants in Population Genetic Differentiation. Pharmaceutics 2022; 14:pharmaceutics14112481. [PMID: 36432672 PMCID: PMC9694252 DOI: 10.3390/pharmaceutics14112481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/09/2022] [Accepted: 11/10/2022] [Indexed: 11/18/2022] Open
Abstract
A significant portion of the variability in complex features, such as drug response, is likely caused by human genetic diversity. One of the highly polymorphic pharmacogenes is CYP2D6, encoding an enzyme involved in the metabolism of about 25% of commonly prescribed drugs. In a directed search of the 1000 Genomes Phase III variation data, 86 single nucleotide polymorphisms (SNPs) in the CYP2D6 gene were extracted from the genotypes of 2504 individuals from 26 populations, and then used to reconstruct haplotypes. Analyses were performed using Haploview, Phase, and Arlequin softwares. Haplotype and nucleotide diversity were high in all populations, but highest in populations of African ancestry. Pairwise FST showed significant results for eleven SNPs, six of which were characteristic of African populations, while four SNPs were most common in East Asian populations. A principal component analysis of CYP2D6 haplotypes showed that African populations form one cluster, Asian populations form another cluster with East and South Asian populations separated, while European populations form the third cluster. Linkage disequilibrium showed that all African populations have three or more haplotype blocks within the CYP2D6 gene, while other world populations have one, except for Chinese Dai and Punjabi in Pakistan populations, which have two.
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Ingelman-Sundberg M. Cytochrome P450 polymorphism: From evolution to clinical use. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2022; 95:393-416. [PMID: 35953162 DOI: 10.1016/bs.apha.2022.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The cytochromes P450s can be divided in two groups, those of high importance for endogenous functions being evolutionary quite stable and those participating in detoxification of drugs and other xenobiotics having less important endogenous functions. In the latter group extensive genetic diversity has been allowed and in addition this is of high importance for survival in different environments. The genetic polymorphisms in these genes have evolved to some extent based on dietary restrictions and environmental factors and have not been subject of conservation due to less importance for survival. In cases of high dietary selection events, gene multiplication and amplification events have been seen. The different variants in genes encoding drug metabolizing enzymes can be used as genetic biomarkers (pharmacogenomic labels) for adjustment of drug treatment leading to less adverse drug reactions and better response. Indeed, this has improved the use of personalized medicine, although the missing heredity seen based on twin studies indicates that there are indeed many more genetic variants to be discovered before one can achieve a satisfactory relationship between genotype and phenotype with respect to drug metabolism and toxicity.
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Affiliation(s)
- Magnus Ingelman-Sundberg
- Department of Physiology and Pharmacology, Section of Pharmacogenetics, Karolinska Institute, Stockholm, Sweden.
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Nthontho KC, Ndlovu AK, Sharma K, Kasvosve I, Hertz DL, Paganotti GM. Pharmacogenetics of Breast Cancer Treatments: A Sub-Saharan Africa Perspective. Pharmgenomics Pers Med 2022; 15:613-652. [PMID: 35761855 PMCID: PMC9233488 DOI: 10.2147/pgpm.s308531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 05/31/2022] [Indexed: 11/30/2022] Open
Abstract
Breast cancer is the most frequent cause of cancer death in low- and middle-income countries, in particular among sub-Saharan African women, where response to available anticancer treatment therapy is often limited by the recurrent breast tumours and metastasis, ultimately resulting in decreased overall survival rate. This can also be attributed to African genomes that contain more variation than those from other parts of the world. The purpose of this review is to summarize published evidence on pharmacogenetic and pharmacokinetic aspects related to specific available treatments and the known genetic variabilities associated with metabolism and/or transport of breast cancer drugs, and treatment outcomes when possible. The emphasis is on the African genetic variation and focuses on the genes with the highest strength of evidence, with a close look on CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A4/5, CYP19A1, UGT1A4, UGT2B7, UGT2B15, SLC22A16, SLC38A7, FcγR, DPYD, ABCB1, and SULT1A1, which are the genes known to play major roles in the metabolism and/or elimination of the respective anti-breast cancer drugs given to the patients. The genetic variability of their metabolism could be associated with different metabolic phenotypes that may cause reduced patients’ adherence because of toxicity or sub-therapeutic doses. Finally, this knowledge enhances possible personalized treatment approaches, with the possibility of improving survival outcomes in patients with breast cancer.
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Affiliation(s)
- Keneuoe Cecilia Nthontho
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana
- Botswana-University of Pennsylvania Partnership, Gaborone, Botswana
| | - Andrew Khulekani Ndlovu
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana
| | | | - Ishmael Kasvosve
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana
| | - Daniel Louis Hertz
- Department of Clinical Pharmacy, University of Michigan College of Pharmacy, Ann Arbor, MI, USA
| | - Giacomo Maria Paganotti
- Botswana-University of Pennsylvania Partnership, Gaborone, Botswana
- Division of Infectious Diseases, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Biomedical Sciences, Faculty of Medicine, University of Botswana, Gaborone, Botswana
- Correspondence: Giacomo Maria Paganotti, Botswana-University of Pennsylvania Partnership, PO Box 45498, Riverwalk Gaborone, Botswana, Tel +267 3555375, Email
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Zhou Y, Lauschke VM. Population pharmacogenomics: an update on ethnogeographic differences and opportunities for precision public health. Hum Genet 2022; 141:1113-1136. [PMID: 34652573 PMCID: PMC9177500 DOI: 10.1007/s00439-021-02385-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/05/2021] [Indexed: 11/25/2022]
Abstract
Both safety and efficacy of medical treatment can vary depending on the ethnogeographic background of the patient. One of the reasons underlying this variability is differences in pharmacogenetic polymorphisms in genes involved in drug disposition, as well as in drug targets. Knowledge and appreciation of these differences is thus essential to optimize population-stratified care. Here, we provide an extensive updated analysis of population pharmacogenomics in ten pharmacokinetic genes (CYP2D6, CYP2C19, DPYD, TPMT, NUDT15 and SLC22A1), drug targets (CFTR) and genes involved in drug hypersensitivity (HLA-A, HLA-B) or drug-induced acute hemolytic anemia (G6PD). Combined, polymorphisms in the analyzed genes affect the pharmacology, efficacy or safety of 141 different drugs and therapeutic regimens. The data reveal pronounced differences in the genetic landscape, complexity and variant frequencies between ethnogeographic groups. Reduced function alleles of CYP2D6, SLC22A1 and CFTR were most prevalent in individuals of European descent, whereas DPYD and TPMT deficiencies were most common in Sub-Saharan Africa. Oceanian populations showed the highest frequencies of CYP2C19 loss-of-function alleles while their inferred CYP2D6 activity was among the highest worldwide. Frequencies of HLA-B*15:02 and HLA-B*58:01 were highest across Asia, which has important implications for the risk of severe cutaneous adverse reactions upon treatment with carbamazepine and allopurinol. G6PD deficiencies were most frequent in Africa, the Middle East and Southeast Asia with pronounced differences in variant composition. These variability data provide an important resource to inform cost-effectiveness modeling and guide population-specific genotyping strategies with the goal of optimizing the implementation of precision public health.
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Affiliation(s)
- Yitian Zhou
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Volker M Lauschke
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 77, Stockholm, Sweden.
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany.
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7
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Ballester P, Muriel J, Peiró AM. CYP2D6 phenotypes and opioid metabolism: the path to personalized analgesia. Expert Opin Drug Metab Toxicol 2022; 18:261-275. [PMID: 35649041 DOI: 10.1080/17425255.2022.2085552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Opioids play a fundamental role in chronic pain, especially considering when 1 of 5 Europeans adults, even more in older females, suffer from it. However, half of them do not reach an adequate pain relief. Could pharmacogenomics help to choose the most appropriate analgesic drug? AREAS COVERED The objective of the present narrative review was to assess the influence of cytochrome P450 2D6 (CYP2D6) phenotypes on pain relief, analgesic tolerability, and potential opioid misuse. Until December 2021, a literature search was conducted through the MEDLINE, PubMed database, including papers from the last 10 years. CYP2D6 plays a major role in metabolism that directly impacts on opioid (tramadol, codeine, or oxycodone) concentration with differences between sexes, with a female trend toward poorer pain control. In fact, CYP2D6 gene variants are the most actionable to be translated into clinical practice according to regulatory drug agencies and international guidelines. EXPERT OPINION CYP2D6 genotype can influence opioids' pharmacokinetics, effectiveness, side effects, and average opioid dose. This knowledge needs to be incorporated in pain management. Environmental factors, psychological together with genetic factors, under a sex perspective, must be considered when you are selecting the most personalized pain therapy for your patients.
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Affiliation(s)
- Pura Ballester
- Neuropharmacology on Pain (NED) group, Alicante Institute for Health and Biomedical Research (ISABIAL Foundation), Alicante, Spain
| | - Javier Muriel
- Neuropharmacology on Pain (NED) group, Alicante Institute for Health and Biomedical Research (ISABIAL Foundation), Alicante, Spain
| | - Ana M Peiró
- Neuropharmacology on Pain (NED) group, Alicante Institute for Health and Biomedical Research (ISABIAL Foundation), Alicante, Spain.,Clinical Pharmacology Unit, Department of Health of Alicante, General Hospital, Alicante, Spain
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8
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Stojanović Marković A, Zajc Petranović M, Tomas Ž, Puljko B, Šetinc M, Škarić-Jurić T, Peričić Salihović M. Untangling SNP Variations within CYP2D6 Gene in Croatian Roma. J Pers Med 2022; 12:jpm12030374. [PMID: 35330374 PMCID: PMC8951754 DOI: 10.3390/jpm12030374] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/18/2022] [Accepted: 02/23/2022] [Indexed: 02/06/2023] Open
Abstract
CYP2D6 is a highly polymorphic gene whose variations affect its enzyme activity. To assess whether the specific population history of Roma, characterized by constant migrations and endogamy, influenced the distribution of alleles and thus phenotypes, the CYP2D6 gene was sequenced using NGS (Next Generation Sequencing) method-targeted sequencing in three groups of Croatian Roma (N = 323) and results were compared to European and Asian populations. Identified single nucleotide polymorphisms (SNPs) were used to reconstruct haplotypes, which were translated into the star-allele nomenclature and later into phenotypes. A total of 43 polymorphic SNPs were identified. The three Roma groups differed significantly in the frequency of alleles of polymorphisms 6769 A > G, 6089 G > A, and 5264 A > G (p < 0.01), as well as in the prevalence of the five most represented star alleles: *1, *2, *4, *10, and *41 (p < 0.0001). Croatian Roma differ from the European and Asian populations in the accumulation of globally rare SNPs (6089 G > A, 4589 C > T, 4622 G > C, 7490 T > C). Our results also show that demographic history influences SNP variations in the Roma population. The three socio-culturally different Roma groups studied differ significantly in the distribution of star alleles, which confirms the importance of a separate study of different Roma groups.
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Affiliation(s)
- Anita Stojanović Marković
- Institute for Anthropological Research, 10000 Zagreb, Croatia; (A.S.M.); (M.Z.P.); (M.Š.); (T.Š.-J.)
| | - Matea Zajc Petranović
- Institute for Anthropological Research, 10000 Zagreb, Croatia; (A.S.M.); (M.Z.P.); (M.Š.); (T.Š.-J.)
| | - Željka Tomas
- Department for Translational Medicine, Srebrnjak Children’s Hospital, 10000 Zagreb, Croatia;
| | - Borna Puljko
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia;
- Department for Chemistry and Biochemistry, School of Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Maja Šetinc
- Institute for Anthropological Research, 10000 Zagreb, Croatia; (A.S.M.); (M.Z.P.); (M.Š.); (T.Š.-J.)
| | - Tatjana Škarić-Jurić
- Institute for Anthropological Research, 10000 Zagreb, Croatia; (A.S.M.); (M.Z.P.); (M.Š.); (T.Š.-J.)
| | - Marijana Peričić Salihović
- Institute for Anthropological Research, 10000 Zagreb, Croatia; (A.S.M.); (M.Z.P.); (M.Š.); (T.Š.-J.)
- Correspondence:
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Aklillu E, Engidawork E. The impact of catha edulis (vahl) forssk. ex endl. (celestraceae) (khat) on pharmacokinetics of clinically used drugs. Expert Opin Drug Metab Toxicol 2021; 17:1125-1138. [PMID: 34410209 DOI: 10.1080/17425255.2021.1971194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Catha edulis (Vahl) Forssk. ex Endl. (Celestraceae) is used as a recreational drug on daily basis for its euphoric and psychostimulant effects. It is also chewed by individuals who are on medications, raising the possibility of drug-khat interaction. However, limited data are available in the literature, although clinically significant interactions are expected, as khat contains a complex mixture of pharmacologically active constituents. AREAS COVERED It provides an overview of the phytochemistry, pharmacokinetics, pharmacodynamics, and pharmacogenetics of khat based on the literature mined from PubMed, Google Scholar, and Cochrane databases. It also presents a detailed account of drug-khat interactions with specific examples and their clinical significance. The interactions mainly occur at the pharmacokinetics level and particular attention is paid for the phases of absorption and cytochrome P450 enzyme-mediated metabolism. EXPERT OPINION Despite the increasing trend of khat chewing with medications among the populace and the potential risk for the occurrence of clinically significant interactions, there is paucity of data in the literature demonstrating the magnitude of the risk. The available data, however, clearly demonstrate that the consequence of drug-khat interaction is dependent on genotype. Genotyping, where feasible, could be used to improve clinical outcome and minimize adverse reactions.
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Affiliation(s)
- Eleni Aklillu
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital-Huddinge, Stockholm, Sweden
| | - Ephrem Engidawork
- Department of Pharmacology and Clinical Pharmacy, School of Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
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Ahmed JH, Makonnen E, Bisaso RK, Mukonzo JK, Fotoohi A, Aseffa A, Howe R, Hassan M, Aklillu E. Population Pharmacokinetic, Pharmacogenetic, and Pharmacodynamic Analysis of Cyclophosphamide in Ethiopian Breast Cancer Patients. Front Pharmacol 2020; 11:406. [PMID: 32390827 PMCID: PMC7191301 DOI: 10.3389/fphar.2020.00406] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 03/17/2020] [Indexed: 12/18/2022] Open
Abstract
Cyclophosphamide (CPA) containing chemotherapy regimen is the standard of care for breast cancer treatment in sub-Saharan Africa. Wide inter-individual variations in pharmacokinetics (PK) of cyclophosphamide (CPA) influence the efficacy and toxicity of CPA containing chemotherapy. Data on the pharmacokinetics (PK) profile of CPA and its covariates among black African patients is lacking. We investigated population pharmacokinetic/pharmacogenetic/pharmacodynamic (PK-PG-PD) of CPA in Ethiopian breast cancer patients. During the first cycle of CPA-based chemotherapy, the population PK parameters for CPA were determined in 267 breast cancer patients. Absolute neutrophil count was recorded at baseline and day 20 post-CPA administration. A population PK and covariate model analysis was performed using non-linear mixed effects modeling. Semi-mechanistic and empiric drug response models were explored to describe the relationship between the area under concentration-time curve (AUC), and neutrophil toxicity. One compartment model better described CPA PK with population clearance and apparent volume of distribution (VD) of 5.41 L/h and 46.5 L, respectively. Inter-patient variability in CPA clearance was 54.5%. Patients carrying CYP3A5*3 or *6 alleles had lower elimination rate constant and longer half-life compared to wild type carriers. CYP2C9 *2 or *3 carriers were associated with increased clearance of CPA. Patients who received 500 mg/m2 based CPA regimen were associated with a 32.3% lower than average clearance and 37.1% lower than average VD compared to patients who received 600 mg/m2. A 0.1 m2 unit increase in body surface area (BSA) was associated with a 5.6% increment in VD. The mean VD (33.5 L) in underweight group (BMI < 18.5 kg/m2) was significantly lower compared to those of overweight (48.1 L) or obese patients (51.9 L) (p < 0.001). AUC of CPA was positively correlated with neutropenic toxicity. In conclusion, we report large between-patient variability in clearance of CPA. CYP3A5 and CYP2C9 genotypes, BSA, BMI, and CPA dosage regimen influence PK of CPA. Plasma CPA exposure positively predicts chemotherapy-associated neutropenic toxicity.
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Affiliation(s)
- Jemal Hussien Ahmed
- Department of Pharmacology and Clinical Pharmacy, Addis Ababa University, Addis Ababa, Ethiopia.,Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Eyasu Makonnen
- Department of Pharmacology and Clinical Pharmacy, Addis Ababa University, Addis Ababa, Ethiopia.,Center for Innovative Drug Development and Therapeutic Trials, Addis Ababa University, Addis Ababa, Ethiopia
| | - Ronald Kuteesa Bisaso
- Department of Pharmacology and Therapeutics, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Jackson Kijumba Mukonzo
- Department of Pharmacology and Therapeutics, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Alan Fotoohi
- Division of Clinical Pharmacology, Department of Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Abraham Aseffa
- Non-Communicable Diseases (NCD) Research Directorate, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Rawleigh Howe
- Non-Communicable Diseases (NCD) Research Directorate, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Moustapha Hassan
- Experimental Cancer Medicine (ECM), Clinical Research Center (KFC), Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Eleni Aklillu
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
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Mugusi S, Habtewold A, Ngaimisi E, Amogne W, Yimer G, Minzi O, Makonnen E, Sudfeld C, Burhenne J, Aklillu E. Impact of Population and Pharmacogenetics Variations on Efavirenz Pharmacokinetics and Immunologic Outcomes During Anti-Tuberculosis Co-Therapy: A Parallel Prospective Cohort Study in Two Sub-Sahara African Populations. Front Pharmacol 2020; 11:26. [PMID: 32116703 PMCID: PMC7019112 DOI: 10.3389/fphar.2020.00026] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 01/10/2020] [Indexed: 01/02/2023] Open
Abstract
Efavirenz-based combination antiretroviral-therapy (cART) is the recommended regimen during tuberculosis (TB) therapy. In a multi-national parallel prospective-cohort study, we investigated the impact of population and pharmacogenetic variations for efavirenz pharmacokinetics, auto-induction, and immunologic outcome during antituberculosis treatment. A total of 921 treatment-naïve HIV patients with (196 Ethiopians and 231 Tanzanians) or without TB co-infection (285 Ethiopians and 209 Tanzanians) were enrolled and treated with efavirenz-based cART. TB-HIV patients started rifampicin-based anti-TB therapy 4 weeks before cART. Efavirenz plasma concentrations were measured on the 4th and 16th weeks of cART. Genotyping for CYP2B6, CYP3A5, ABCB1, UGT2B7, and SLCO1B1 was done. CD4 cells-count was measured at baseline, 12th, 24th, and 48th weeks of cART. Among HIV-only cohort, plasma efavirenz concentration and median CD4 cell count were significantly higher in Tanzanians than Ethiopians, and both CYP2B6 genotype and population-variation were significant predictors of efavirenz plasma concentration. Within-population analyses indicated a pronounced efavirenz autoinduction in Tanzanians as reflected by a significant decrease of plasma efavirenz concentration over time (p = 0.0001), but not in Ethiopians. Among TB-HIV cohort, there were no significant between-population differences in plasma efavirenz concentrations or CD4 cell-recovery, and CYP2B6 genotype but not population-variation was a significant predictor of efavirenz plasma exposure. In Tanzanian patients, short-term anti-TB co-treatment significantly reduced the mean plasma efavirenz concentration in CYP2B6*1/*1 genotype at week-4 (p = 0.005), but not at week-16 of cART. In Ethiopian patients, anti-TB cotreatment increased the mean plasma efavirenz concentration among CYP2B6*6 carriers at week-4 (p = 0.003) and week-16 (p = 0.035) of cART. In general, long-term anti-TB co-treatment increased plasma efavirenz concentration at week 16 of cART in both Ethiopians and Tanzanians being higher in CYP2B6*6/*6 > *1/*6 > *1/*1 genotypes. In TB-HIV patients, baseline body mass index (BMI), viral load, and WHO clinical-stage but not genotype, population-variation, or efavirenz concentration were significant predictors of immunologic outcome at week-48. In summary efavirenz auto-induction, pharmacokinetics, and the immunologic outcome are influenced by population-variation, anti-TB co-medication, and CYP2B6 genotype. CYP2B6 genotype is a significant predictor of efavirenz plasma exposure regardless of population-variation or antituberculosis co-treatment, but population-variation is insignificant during antituberculosis treatment. CYP2B6 genotype, population, and geographic differences need to be considered for efavirenz dosage-optimization.
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Affiliation(s)
- Sabina Mugusi
- Department of Clinical Pharmacology, School of Medicine, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.,Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, MA, United States
| | - Abiy Habtewold
- Department of Pharmaceutical Sciences, School of Pharmacy, William Carey University, Hattiesburg, MS, United States
| | - Eliford Ngaimisi
- Department of Clinical Pharmacy and Pharmacology, School of Pharmacy, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Wondwossen Amogne
- Department of Internal Medicine, School of Medicine, Addis Ababa University, Addis Ababa, Ethiopia
| | - Getnet Yimer
- Department of Pharmacology and Clinical Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Omary Minzi
- Department of Clinical Pharmacy and Pharmacology, School of Pharmacy, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Eyasu Makonnen
- Department of Pharmacology and Clinical Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.,Center for Innovative Drug Development and Therapeutic Trials for Africa (CDT Africa), College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Christopher Sudfeld
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, MA, United States
| | - Jürgen Burhenne
- Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Heidelberg, Germany
| | - Eleni Aklillu
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
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Albuquerque UP, do Nascimento ALB, Silva Chaves L, Feitosa IS, de Moura JMB, Gonçalves PHS, da Silva RH, da Silva TC, Ferreira Júnior WS. The chemical ecology approach to modern and early human use of medicinal plants. CHEMOECOLOGY 2020. [DOI: 10.1007/s00049-020-00302-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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13
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Ahmed JH, Makonnen E, Fotoohi A, Aseffa A, Howe R, Aklillu E. CYP2D6 Genotype Predicts Plasma Concentrations of Tamoxifen Metabolites in Ethiopian Breast Cancer Patients. Cancers (Basel) 2019; 11:cancers11091353. [PMID: 31547390 PMCID: PMC6770728 DOI: 10.3390/cancers11091353] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/30/2019] [Accepted: 09/06/2019] [Indexed: 12/15/2022] Open
Abstract
Tamoxifen displays wide inter-individual variability (IIV) in its pharmacokinetics and treatment outcome. Data on tamoxifen pharmacokinetics and pharmacogenetics from black African breast cancer patient populations is lacking. We investigated the pharmacokinetic and pharmacogenetic profile of tamoxifen and its major active metabolite, endoxifen, in Ethiopian breast cancer patients. A total of 81 female breast cancer patients on adjuvant tamoxifen therapy were enrolled. Tamoxifen (Tam) and its major metabolites, N-desmethyltamoxifen (NDM), 4-hydroxy-tamoxifen (4-HT), and (Z)-endoxifen (E) were quantified using LC-MS/MS. Genotyping for CYP2D6, CYP2C9, CYP2C19, CYP3A5, POR, and ABCB1 and UGT2B15 and copy number variation for CYP2D6 were done. The proportion of patients with low endoxifen level (<5.9 ng/mL) was 35.8% (median concentration 7.94 ng/mL). The allele frequency of CYP2D6 gene deletion (*5) and duplication (*1×N or *2×N) was 4.3% and 14.8%, respectively. Twenty-six percent of the patients carried duplicated or multiplicated CYP2D6 gene. An increase in CYP2D6 activity score was associated with increased endoxifen concentration and MRE/NDM (p < 0.001). The IIV in endoxifen concentration and MRE/NDM was 74.6% and 59%, respectively. CYP2D6 diplotype explained 28.2% and 44% of the variability in absolute endoxifen concentration and MRE/NDM, respectively. The explanatory power of CYP2D6 diplotype was improved among ABCB1c.4036G carriers (43% and 65.2%, respectively for endoxifen concentration and MRE/NDM) compared to A/A genotype. CYP2C9, CYP2C19, and CYP3A5 genotypes had no significant influence on endoxifen concentration or MRE/NDM. In conclusion, we report a high rate of low endoxifen level as well as large IIV in tamoxifen and its metabolite concentrations. CYP2D6 is significant predictor of plasma endoxifen level in a gene-dose dependent manner.
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Affiliation(s)
- Jemal Hussien Ahmed
- Department of Pharmacology and Clinical Pharmacy, Addis Ababa University, Addis Ababa P.O. Box 9086, Ethiopia.
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm 141 86, Sweden.
| | - Eyasu Makonnen
- Department of Pharmacology and Clinical Pharmacy, Addis Ababa University, Addis Ababa P.O. Box 9086, Ethiopia.
- Center for Innovative Drug Development and Therapeutic Trials, Addis Ababa University, Addis Ababa P.O. Box 9086, Ethiopia.
| | - Alan Fotoohi
- Division of Clinical Pharmacology, Department of Medicine, Karolinska Institutet, Solna Stockholm 171 76, Sweden.
| | - Abraham Aseffa
- Armauer Hansen Research Institute, Addis Ababa P.O. Box 1005, Ethiopia.
| | - Rawleigh Howe
- Armauer Hansen Research Institute, Addis Ababa P.O. Box 1005, Ethiopia.
| | - Eleni Aklillu
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm 141 86, Sweden.
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Bolaji OO, Adehin A, Adeagbo BA. Pharmacogenomics in the Nigerian population: the past, the present and the future. Pharmacogenomics 2019; 20:915-926. [DOI: 10.2217/pgs-2019-0046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The Nigerian population exhibits huge ethnic and genetic diversity, typical of African populations, which can be harnessed for improved drug-response and disease management. Existing data on genes relevant to drug response, so far generated for the population, indeed confirm the prevalence of some clinically significant pharmacogenes. These reports detail prevailing genetic alleles and metabolic phenotypes of vital drug metabolizing monooxygenases, transferases and drug transporters. While the utilization of existing pharmacogenomic data for healthcare delivery remains unpopular, several past and on-going studies suggest that a future shift toward genotype-stratified dosing of drugs and disease management in the population is imminent. This review discusses the present state of pharmacogenomics in Nigeria and the potential benefits of sustained research in this field for the population.
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Affiliation(s)
- Oluseye O Bolaji
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Ayorinde Adehin
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria
- Institute of Biomedical & Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, PR China
| | - Babatunde A Adeagbo
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria
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Zhang F, Finkelstein J. Inconsistency in race and ethnic classification in pharmacogenetics studies and its potential clinical implications. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2019; 12:107-123. [PMID: 31308725 PMCID: PMC6612983 DOI: 10.2147/pgpm.s207449] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 05/30/2019] [Indexed: 12/11/2022]
Abstract
Introduction Racial and ethnic categories are frequently used in pharmacogenetics literature to stratify patients; however, these categories can be inconsistent across different studies. To address the ongoing debate on the applicability of traditional concepts of race and ethnicity in the context of precision medicine, we aimed to review the application of current racial and ethnic categories in pharmacogenetics and its potential impact on clinical care. Methods One hundred and three total pharmacogenetics papers involving the CYP2C9, CYP2C19, and CYP2D6 genes were analyzed for their country of origin, racial, and ethnic categories used, and allele frequency data. Correspondence between the major continental racial categories promulgated by National Institutes of Health (NIH) and those reported by the pharmacogenetics papers was evaluated. Results The racial and ethnic categories used in the papers we analyzed were highly heterogeneous. In total, we found 66 different racial and ethnic categories used which fall under the NIH race category “White”, 47 different racial and ethnic categories for “Asian”, and 62 different categories for “Black”. The number of categories used varied widely based on country of origin: Japan used the highest number of different categories for “White” with 17, Malaysia used the highest number for “Asian” with 24, and the US used the highest number for “Black” with 28. Significant variation in allele frequency between different ethnic subgroups was identified within 3 major continental racial categories. Conclusion Our analysis showed that racial and ethnic classification is highly inconsistent across different papers as well as between different countries. Evidence-based consensus is necessary for optimal use of self-identified race as well as geographical ancestry in pharmacogenetics. Common taxonomy of geographical ancestry which reflects specifics of particular countries and is accepted by the entire scientific community can facilitate reproducible pharmacogenetic research and clinical implementation of its results.
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Affiliation(s)
- Frederick Zhang
- Center for Bioinformatics and Data Analytics, Columbia University Irving Medical Center, New York, NY, USA
| | - Joseph Finkelstein
- Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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Effects of Khat (Catha edulis) use on catalytic activities of major drug-metabolizing cytochrome P450 enzymes and implication of pharmacogenetic variations. Sci Rep 2018; 8:12726. [PMID: 30143732 PMCID: PMC6109098 DOI: 10.1038/s41598-018-31191-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 08/14/2018] [Indexed: 12/24/2022] Open
Abstract
In a one-way cross-over study, we investigated the effect of Khat, a natural amphetamine-like psychostimulant plant, on catalytic activities of five major drug-metabolizing cytochrome P450 (CYP) enzymes. After a one-week Khat abstinence, 63 Ethiopian male volunteers were phenotyped using cocktail probe drugs (caffeine, losartan, dextromethorphan, omeprazole). Phenotyping was repeated after a one-week daily use of 400 g fresh Khat leaves. Genotyping for CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP3A5 were done. Urinary cathinone and phenylpropanolamine, and plasma probe drugs and metabolites concentrations were quantified using LC-MS/MS. Effect of Khat on enzyme activities was evaluated by comparing caffeine/paraxanthine (CYP1A2), losartan/losartan carboxylic acid (CYP2C9), omeprazole/5-hydroxyomeprazole (CYP2C19), dextromethorphan/dextrorphan (CYP2D6) and dextromethorphan/3-methoxymorphinan (CYP3A4) metabolic ratios (MR) before and after Khat use. Wilcoxon-matched-pair-test indicated a significant increase in median CYP2D6 MR (41%, p < 0.0001), and a marginal increase in CYP3A4 and CYP2C19 MR by Khat. Repeated measure ANOVA indicated the impact of CYP1A2 and CYP2C19 genotype on Khat-CYP enzyme interactions. The median MR increased by 35% in CYP1A2*1/*1 (p = 0.07) and by 40% in carriers of defective CYP2C19 alleles (p = 0.03). Urinary log cathinone/phenylpropanolamine ratios significantly correlated with CYP2D6 genotype (p = 0.004) and CYP2D6 MR (P = 0.025). Khat significantly inhibits CYP2D6, marginally inhibits CYP3A4, and genotype-dependently inhibit CYP2C19 and CYP1A2 enzyme activities.
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Aklillu E, Carrillo JA, Makonnen E, Bertilsson L, Djordjevic N. N-Acetyltransferase-2 (NAT2) phenotype is influenced by genotype-environment interaction in Ethiopians. Eur J Clin Pharmacol 2018; 74:903-911. [PMID: 29589062 PMCID: PMC5999125 DOI: 10.1007/s00228-018-2448-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 03/14/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND OBJECTIVES N-acetyltransferase 2 (NAT2) metabolize several drugs including isoniazid. We investigated the effect of genotype, geographical difference, and smoking habit on NAT2 phenotype in Ethiopians. METHODS Genotyping for NAT2 191G > A, 341 T > C, 590G > A, and 857G > A was performed in 163 unrelated healthy Ethiopians (85 living in Ethiopia and 78 living in Sweden). The NAT2 phenotype was determined using caffeine as a probe and log AFMU/(AFMU + 1X + 1 U) urinary metabolic ratio (MR) as an index. RESULTS The frequencies of NAT2*4, *5, *6, *7, and *14 haplotypes were 14.1, 48.5, 30.1, 5.5, and 1.8%, respectively. The frequencies of rapid (NAT2*4/*4), intermediate (heterozygous *4), and slow (no *4 allele) acetylator genotypes were 1.8, 24.6, and 73.6%, respectively. The distribution NAT2 MR was bimodal with 70% being phenotypically slow acetylators. NAT2 genotype (p < 0.0001) and country of residence (p = 0.004) independently predicted NAT2 phenotype. Controlling for the effect of genotype, ethnic Ethiopians living in Ethiopia had significantly higher NAT2 MR than those living in Sweden (p = 0.006). NAT2 genotype-phenotype concordance rate was 75%. Distinct country-of-residence-based genotype-phenotype discordance was observed. The proportion of phenotypically determined rapid acetylators was significantly higher and slow acetylators was lower in Ethiopians living in Ethiopia (39% rapid, 61% slow) than in Sweden (20% rapid, 80% slow). Sex and smoking had no significant effect on NAT2 MR. CONCLUSIONS We report a high prevalence of NAT 2 slow acetylators in Ethiopians and a conditional NAT2 genotype-phenotype discordance implicating a partial phenotype conversion and metabolic adaptation. Gene-environment interactions regulate NAT2 phenotype.
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Affiliation(s)
- Eleni Aklillu
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Huddinge C1:68, SE-141 86, Stockholm, Sweden.
| | - Juan Antonio Carrillo
- Division of Clinical Pharmacology, Department of Medical and Surgical Therapeutics, Medical School, University of Extremadura, Badajoz, Spain
| | - Eyasu Makonnen
- Department of Pharmacology, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Leif Bertilsson
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Huddinge C1:68, SE-141 86, Stockholm, Sweden
| | - Natasa Djordjevic
- Department of Pharmacology and Toxicology, Faculty of Medical Sciences, University of Kragujevac, Svetozara Markovica 69, Kragujevac, 34 000, Serbia
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18
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Engidawork E. Pharmacological and Toxicological Effects of Catha edulis F. (Khat). Phytother Res 2017; 31:1019-1028. [PMID: 28557133 DOI: 10.1002/ptr.5832] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 04/19/2017] [Accepted: 04/20/2017] [Indexed: 01/02/2023]
Abstract
Khat chewing is deeply rooted in the culture and tradition of communities in khat belt countries, and its consumption is spread to other countries through the suitcase trade. The aim of this article is to review current knowledge on the chemistry, social, pharmacology and toxicology of khat and its use. Khat produces effect invariably in every system, which is harmful or beneficial in some instances. Harmful effects are observed in heavy users, although firm evidence is lacking. Chewing khat acutely elicits states of euphoria, which is followed by low mood. Khat contains alkaloids with psychostimulant properties, but the effect cannot be totally explained by these alkaloids. It is also not clear whether the effect produced in some organs like liver could be attributed to khat or pesticides sprayed during farming. Although the evidence indicates that khat has adverse effects in most organs, our understanding of the complex interaction between use and effect is incomplete, and causal relationships have not yet been described. Moreover, khat has positioned itself well in the social, economic and political arena. Thus, a multidisciplinary research is required to understand the different dimensions and come up with ways that maximize the benefit while minimizing the risk. Copyright © 2017 John Wiley & Sons, Ltd.
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Affiliation(s)
- Ephrem Engidawork
- Department of Pharmacology and Clinical Pharmacy, School of Pharmacy, College of Health Sciences, Addis Ababa University, P.O Box 1176, Addis Ababa, Ethiopia
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Pantano F, Tittarelli R, Mannocchi G, Zaami S, Ricci S, Giorgetti R, Terranova D, Busardò FP, Marinelli E. Hepatotoxicity Induced by "the 3Ks": Kava, Kratom and Khat. Int J Mol Sci 2016; 17:580. [PMID: 27092496 PMCID: PMC4849036 DOI: 10.3390/ijms17040580] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 02/18/2016] [Accepted: 04/11/2016] [Indexed: 12/23/2022] Open
Abstract
The 3Ks (kava, kratom and khat) are herbals that can potentially induce liver injuries. On the one hand, growing controversial data have been reported about the hepatotoxicity of kratom, while, on the other hand, even though kava and khat hepatotoxicity has been investigated, the hepatotoxic effects are still not clear. Chronic recreational use of kratom has been associated with rare instances of acute liver injury. Several studies and case reports have suggested that khat is hepatotoxic, leading to deranged liver enzymes and also histopathological evidence of acute hepatocellular degeneration. Numerous reports of severe hepatotoxicity potentially induced by kava have also been highlighted, both in the USA and Europe. The aim of this review is to focus on the different patterns and the mechanisms of hepatotoxicity induced by “the 3Ks”, while trying to clarify the numerous aspects that still need to be addressed.
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Affiliation(s)
- Flaminia Pantano
- Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, 00161 Rome, Italy.
| | - Roberta Tittarelli
- Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, 00161 Rome, Italy.
| | - Giulio Mannocchi
- Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, 00161 Rome, Italy.
| | - Simona Zaami
- Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, 00161 Rome, Italy.
| | - Serafino Ricci
- Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, 00161 Rome, Italy.
| | - Raffaele Giorgetti
- Section of Legal Medicine, Università Politecnica delle Marche, 60121 Ancona, Italy.
| | - Daniela Terranova
- Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, 00161 Rome, Italy.
| | - Francesco P Busardò
- Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, 00161 Rome, Italy.
| | - Enrico Marinelli
- Department of Anatomical, Histological, Forensic and Orthopedic Sciences, Sapienza University of Rome, 00161 Rome, Italy.
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Abstract
The use of khat (Catha edulis) while on medication may alter treatment outcome. In particular, the influence of khat on the metabolic activities of drug-metabolizing enzymes is not known. We performed a comparative 1-way crossover study to evaluate the effect of khat on cytochrome P450 (CYP)2D6 and CYP3A4 enzyme activity. After 1 week of khat abstinence, baseline CYP2D6 and CYP3A4 metabolic activities were determined in 40 Ethiopian male volunteers using 30 mg dextromethorphan (DM) as a probe drug and then repeated after 1 week of daily use of 400 g fresh khat leaves. Urinary concentrations of cathinone and cathine were determined to monitor the subjects' compliance to the study protocol. Genotyping for CYP2D6*3 and CYP2D6*4 was done. Plasma DM, dextrorphan and 3-methoxymorphinan concentrations were quantified. CYP2D6 and CYP3A4 enzyme activities were assessed by comparing plasma log DM/dextrorphan and log DM/methoxymorphinan metabolic ratio (MR) respectively in the presence and absence of khat. Cytochrome 2D6 MR was significantly increased from baseline by concurrent khat use (paired t test, P = 0.003; geometric mean ratio, 1.38; 95% confidence interval [95% CI], 1.12-1.53). Moreover, the inhibition of CYP2D6 activity by khat was more pronounced in CYP2D6*1/*1 compared with CYP2D6*1/*4 genotypes (P = 0.01). A marginal inhibition of CYP3A4 activity in the presence of khat was observed (P = 0.24). The mean percentage increase of CYP2D6 and CYP3A4 MR from baseline by khat use was 46% (95% CI, 20-72) and 31% (95% CI, 8-54), respectively. This is the first report linking khat use with significant inhibition of CYP2D6 metabolic activity in humans.
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Interethnic variation of CYP2C19 alleles, 'predicted' phenotypes and 'measured' metabolic phenotypes across world populations. THE PHARMACOGENOMICS JOURNAL 2015; 16:113-23. [PMID: 26503820 DOI: 10.1038/tpj.2015.70] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 07/15/2015] [Accepted: 08/19/2015] [Indexed: 02/08/2023]
Abstract
The present study evaluates the worldwide frequency distribution of CYP2C19 alleles and CYP2C19 metabolic phenotypes ('predicted' from genotypes and 'measured' with a probe drug) among healthy volunteers from different ethnic groups and geographic regions, as well as the relationship between the 'predicted' and 'measured' CYP2C19 metabolic phenotypes. A total of 52 181 healthy volunteers were studied within 138 selected original research papers. CYP2C19*17 was 42- and 24-fold more frequent in Mediterranean-South Europeans and Middle Easterns than in East Asians (P<0.001, in both cases). Contrarily, CYP2C19*2 and CYP2C19*3 alleles were more frequent in East Asians (30.26% and 6.89%, respectively), and even a twofold higher frequency of these alleles was found in Native populations from Oceania (61.30% and 14.42%, respectively; P<0.001, in all cases), which may be a consequence of genetic drift process in the Pacific Islands. Regarding CYP2C19 metabolic phenotype, poor metabolizers (PMs) were more frequent among Asians than in Europeans, contrarily to the phenomenon reported for CYP2D6. A correlation has been found between the frequencies of CYP2C19 poor metabolism 'predicted' from CYP2C19 genotypes (gPMs) and the poor metabolic phenotype 'measured' with a probe drug (mPMs) when subjects are either classified by ethnicity (r=0.94, P<0.001) or geographic region (r=0.99, P=0.002). Nevertheless, further research is needed in African and Asian populations, which are under-represented, and additional CYP2C19 variants and the 'measured' phenotype should be studied.
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Hatta FH, Lundblad M, Ramsjo M, Kang JH, Roh HK, Bertilsson L, Eliasson E, Aklillu E. Differences inCYP2C9Genotype and Enzyme Activity Between Swedes and Koreans of Relevance for Personalized Medicine: Role of Ethnicity, Genotype, Smoking, Age, and Sex. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2015; 19:346-53. [DOI: 10.1089/omi.2015.0022] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Fazleen H.M. Hatta
- Department of Laboratory Medicine, Karolinska Institutet, Division of Clinical Pharmacology, Karolinska University Hospital, Huddinge, Sweden
- Integrative Pharmacogenomics Institute (iPROMISE), Faculty of Pharmacy, Universiti Teknologi MARA, Selangor, Malaysia
| | - Mia Lundblad
- Department of Laboratory Medicine, Karolinska Institutet, Division of Clinical Pharmacology, Karolinska University Hospital, Huddinge, Sweden
| | - Margareta Ramsjo
- Department of Laboratory Medicine, Karolinska Institutet, Division of Clinical Pharmacology, Karolinska University Hospital, Huddinge, Sweden
| | - Ju-Hee Kang
- Department of Clinical Pharmacology, Inha University School of Medicine and Clinical Pharmacology, Inha University Hospital, Inha University, Incheon, Korea
| | - Hyung-Keun Roh
- Department of Internal Medicine, Division of Clinical Pharmacology, Gachon University Hospital, Incheon, Korea
| | - Leif Bertilsson
- Department of Laboratory Medicine, Karolinska Institutet, Division of Clinical Pharmacology, Karolinska University Hospital, Huddinge, Sweden
| | - Erik Eliasson
- Department of Laboratory Medicine, Karolinska Institutet, Division of Clinical Pharmacology, Karolinska University Hospital, Huddinge, Sweden
| | - Eleni Aklillu
- Department of Laboratory Medicine, Karolinska Institutet, Division of Clinical Pharmacology, Karolinska University Hospital, Huddinge, Sweden
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Chaudhry AS, Prasad B, Shirasaka Y, Fohner A, Finkelstein D, Fan Y, Wang S, Wu G, Aklillu E, Sim SC, Thummel KE, Schuetz EG. The CYP2C19 Intron 2 Branch Point SNP is the Ancestral Polymorphism Contributing to the Poor Metabolizer Phenotype in Livers with CYP2C19*35 and CYP2C19*2 Alleles. Drug Metab Dispos 2015; 43:1226-35. [PMID: 26021325 DOI: 10.1124/dmd.115.064428] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 05/28/2015] [Indexed: 12/13/2022] Open
Abstract
CYP2C19 rs12769205 alters an intron 2 branch point adenine leading to an alternative mRNA in human liver with complete inclusion of intron 2 (exon 2B). rs12769205 changes the mRNA reading frame, introduces 87 amino acids, and leads to a premature stop codon. The 1000 Genomes project (http://browser.1000genomes.org/index.html) indicated rs12769205 is in linkage disequilibrium with rs4244285 on CYP2C19*2, but found alone on CYP2C19*35 in Blacks. Minigenes containing rs12769205 transfected into HepG2 cells demonstrated this single nucleotide polymorphism (SNP) alone leads to exon 2B and decreases CYP2C19 canonical mRNA. A residual amount of CYP2C19 protein was detectable by quantitative proteomics with tandem mass spectrometry in CYP2C19*2/*2 and *1/*35 liver microsomes with an exon 2 probe. However, an exon 4 probe, downstream from rs12769205, but upstream of rs4244285, failed to detect CYP2C19 protein in livers homozygous for rs12769205, demonstrating rs12769205 alone can lead to complete loss of CYP2C19 protein. CYP2C19 genotypes and mephenytoin phenotype were compared in 104 Ethiopians. Poor metabolism of mephenytoin was seen in persons homozygous for both rs12769205 and rs4244285 (CYP2C19*2/*2), but with little effect on mephenytoin disposition of CYP2C19*1/*2, CYP2C19*1/*3, or CYP2C19*1/*35 heterozygous alleles. Extended haplotype homozygosity tests of the HapMap Yorubans (YRI) showed both haplotypes carrying rs12769205 (CYP2C19*35 and CYP2C19*2) are under significant natural selection, with CYP2C19*35 having a higher relative extended haplotype homozygosity score. The phylogenetic tree of the YRI CYP2C19 haplotypes revealed rs12769205 arose first on CYP2C19*35 and that rs4244285 was added later, creating CYP2C19*2. In conclusion, rs12769205 is the ancestral polymorphism leading to aberrant splicing of CYP2C19*35 and CYP2C19*2 alleles in liver.
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Affiliation(s)
- Amarjit S Chaudhry
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee (A.S.C., E.G.S.); Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington (B.P., Y.S., A.F., K.E.T.); Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee (D.F., Y.F., S.W., G.W.); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm, Sweden (E.A.); and Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (S.C.S.)
| | - Bhagwat Prasad
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee (A.S.C., E.G.S.); Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington (B.P., Y.S., A.F., K.E.T.); Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee (D.F., Y.F., S.W., G.W.); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm, Sweden (E.A.); and Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (S.C.S.)
| | - Yoshiyuki Shirasaka
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee (A.S.C., E.G.S.); Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington (B.P., Y.S., A.F., K.E.T.); Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee (D.F., Y.F., S.W., G.W.); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm, Sweden (E.A.); and Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (S.C.S.)
| | - Alison Fohner
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee (A.S.C., E.G.S.); Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington (B.P., Y.S., A.F., K.E.T.); Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee (D.F., Y.F., S.W., G.W.); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm, Sweden (E.A.); and Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (S.C.S.)
| | - David Finkelstein
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee (A.S.C., E.G.S.); Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington (B.P., Y.S., A.F., K.E.T.); Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee (D.F., Y.F., S.W., G.W.); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm, Sweden (E.A.); and Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (S.C.S.)
| | - Yiping Fan
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee (A.S.C., E.G.S.); Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington (B.P., Y.S., A.F., K.E.T.); Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee (D.F., Y.F., S.W., G.W.); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm, Sweden (E.A.); and Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (S.C.S.)
| | - Shuoguo Wang
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee (A.S.C., E.G.S.); Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington (B.P., Y.S., A.F., K.E.T.); Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee (D.F., Y.F., S.W., G.W.); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm, Sweden (E.A.); and Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (S.C.S.)
| | - Gang Wu
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee (A.S.C., E.G.S.); Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington (B.P., Y.S., A.F., K.E.T.); Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee (D.F., Y.F., S.W., G.W.); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm, Sweden (E.A.); and Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (S.C.S.)
| | - Eleni Aklillu
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee (A.S.C., E.G.S.); Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington (B.P., Y.S., A.F., K.E.T.); Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee (D.F., Y.F., S.W., G.W.); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm, Sweden (E.A.); and Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (S.C.S.)
| | - Sarah C Sim
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee (A.S.C., E.G.S.); Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington (B.P., Y.S., A.F., K.E.T.); Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee (D.F., Y.F., S.W., G.W.); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm, Sweden (E.A.); and Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (S.C.S.)
| | - Kenneth E Thummel
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee (A.S.C., E.G.S.); Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington (B.P., Y.S., A.F., K.E.T.); Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee (D.F., Y.F., S.W., G.W.); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm, Sweden (E.A.); and Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (S.C.S.)
| | - Erin G Schuetz
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee (A.S.C., E.G.S.); Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington (B.P., Y.S., A.F., K.E.T.); Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee (D.F., Y.F., S.W., G.W.); Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, Stockholm, Sweden (E.A.); and Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden (S.C.S.)
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Steere B, Baker JAR, Hall SD, Guo Y. Prediction of in vivo clearance and associated variability of CYP2C19 substrates by genotypes in populations utilizing a pharmacogenetics-based mechanistic model. Drug Metab Dispos 2015; 43:870-83. [PMID: 25845826 DOI: 10.1124/dmd.114.061523] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 04/06/2015] [Indexed: 12/18/2022] Open
Abstract
It is important to examine the cytochrome P450 2C19 (CYP2C19) genetic contribution to drug disposition and responses of CYP2C19 substrates during drug development. Design of such clinical trials requires projection of genotype-dependent in vivo clearance and associated variabilities of the investigational drug, which is not generally available during early stages of drug development, but is essential for CYP2C19 substrates with multiple clearance pathways. This study evaluated the utility of pharmacogenetics-based mechanistic modeling in predicting such parameters. Hepatic CYP2C19 activity and variability within genotypes were derived from in vitro S-mephenytoin metabolic activity in genotyped human liver microsomes (N = 128). These data were then used in mechanistic models to predict genotype-dependent disposition of CYP2C19 substrates (i.e., S-mephenytoin, citalopram, pantoprazole, and voriconazole) by incorporating in vivo clearance or pharmacokinetics of wild-type subjects and parameters of other clearance pathways. Relative to the wild-type, the CYP2C19 abundance (coefficient of variation percentage) in CYP2C19*17/*17, *1/*17, *1/*1, *17/null, *1/null, and null/null microsomes was estimated as 1.85 (117%), 1.79 (155%), 1.00 (138%), 0.83 (80%), 0.38 (130%), and 0 (0%), respectively. The subsequent modeling and simulations predicted, within 2-fold of the observed, the means and variabilities of urinary S/R-mephenytoin ratio (36 of 37 genetic groups), the oral clearance of citalopram (9 of 9 genetic groups) and pantoprazole (6 of 6 genetic groups), and voriconazole oral clearance (4 of 4 genetic groups). Thus, relative CYP2C19 genotype-dependent hepatic activity and variability were quantified in vitro and used in a mechanistic model to predict pharmacokinetic variability, thus allowing the design of pharmacogenetics and drug-drug interaction trials for CYP2C19 substrates.
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Affiliation(s)
- Boyd Steere
- Research IT Informatics (B.S.), Clinical Diagnostic Laboratory (J.A.R.B.), and Drug Disposition (S.D.H., Y.G.), Eli Lilly and Company, Indianapolis, Indiana
| | - Jessica A Roseberry Baker
- Research IT Informatics (B.S.), Clinical Diagnostic Laboratory (J.A.R.B.), and Drug Disposition (S.D.H., Y.G.), Eli Lilly and Company, Indianapolis, Indiana
| | - Stephen D Hall
- Research IT Informatics (B.S.), Clinical Diagnostic Laboratory (J.A.R.B.), and Drug Disposition (S.D.H., Y.G.), Eli Lilly and Company, Indianapolis, Indiana
| | - Yingying Guo
- Research IT Informatics (B.S.), Clinical Diagnostic Laboratory (J.A.R.B.), and Drug Disposition (S.D.H., Y.G.), Eli Lilly and Company, Indianapolis, Indiana
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Alessandrini M, Pepper MS. Priority pharmacogenetics for the African continent: focus on CYP450. Pharmacogenomics 2014; 15:385-400. [PMID: 24533717 DOI: 10.2217/pgs.13.252] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Countries in Africa have a high burden of communicable disease, and are experiencing an increase in noncommunicable diseases due to the effects of globalization, industrialization and urbanization. The costs incurred through adverse drug reactions and nonresponsiveness to therapy further aggravates the situation, and the application of pharmacogenetic principles is likely to provide some relief. Having undertaken an extensive evaluation of CYP450 reports in Africa, our objective was to map out areas of need based on regional disease burdens. The data confirms a paucity of CYP450 reports and illustrates large regions for which no population information exists. There is a dire need to address the health problems of Africa, and wide-scale pharmacogenetic profiling of these populations will add significantly to improving patient care on the continent. Priority pharmacogenetics for the African continent gives precedence to the profiling of clinically relevant pharmacogenetic biomarkers, and defines the immediate need in the context of disease burden.
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Affiliation(s)
- Marco Alessandrini
- Department of Immunology & The Institute for Cellular & Molecular Medicine, Faculty of Health Sciences, University of Pretoria, South Africa
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Dandara C, Swart M, Mpeta B, Wonkam A, Masimirembwa C. Cytochrome P450 pharmacogenetics in African populations: implications for public health. Expert Opin Drug Metab Toxicol 2014; 10:769-85. [PMID: 24588448 DOI: 10.1517/17425255.2014.894020] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Africa harbors a disproportionate burden of disease when taking into account the triple challenge caused by HIV/AIDS, tuberculosis (TB) and malaria, against a backdrop of an increasing burden of noncommunicable diseases. More than 80% of therapeutic drugs used in the management of these diseases/conditions are metabolized by CYP enzymes that exhibit genetic polymorphisms. AREAS COVERED There is variability in the expression and activities of CYPs resulting in interindividual differences in the response to standard doses of therapeutic drugs, due to genetic polymorphisms, which exhibit both quantitative and qualitative differences between racial and between ethnic groups. The review aims to evaluate the implications of the genetic variation in CYPs on the public health of Africans. The CYPs reviewed here metabolize most of the commonly used therapeutic drugs and include CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 3A4 and 3A5. Allele frequencies are compared between African ethnic groups and among populations of African, Asian and European origin. Data are obtained from our own studies and literature. EXPERT OPINION The variability in the pattern of genetic variation between populations translates into differences in drug response. Understanding CYP variability improves rational drug use and has public health significance.
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Affiliation(s)
- Collet Dandara
- University of Cape Town, Faculty of Health Sciences, Pharmacogenetics and Cancer Research Group, Division of Human Genetics, Department of Clinical Laboratory Sciences , Anzio Road Observatory, 7925, Cape Town , South Africa +27 21 406 6506 ;
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28
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Aklillu E, Djordjevic N, Carrillo JA, Makonnen E, Bertilsson L, Ingelman-Sundberg M. High CYP2A6 enzyme activity as measured by a caffeine test and unique distribution of CYP2A6 variant alleles in Ethiopian population. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2013; 18:446-53. [PMID: 24380444 DOI: 10.1089/omi.2013.0140] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
CYP2A6 metabolizes clinically relevant drugs, including antiretroviral and antimalarial drugs of major public health importance for the African populations. CYP2A6 genotype-phenotype relationship in African populations, and implications of geographic differences on enzyme activity, remain to be investigated. We evaluated the influence of CYP2A6 genotype, geographical differences, gender, and cigarette smoking on enzyme activity, using caffeine as a probe in 100 healthy unrelated Ethiopians living in Ethiopia, and 72 living in Sweden. CYP2A6 phenotype was estimated by urinary 1,7-dimethyluric acid (17U)/1,7-dimethylxanthine or paraxanthine (17X) ratio. The frequencies of CYP2A6*1B, *1D, *2, *4, *9, and *1x2 in Ethiopians were 31.3, 29.4, 0.6, 0.6, 2.8, and 0.3%, respectively. The overall mean±SD for log 17U/17X was 0.12±0.24 and coefficient of variation 199%. No significant difference in the mean log 17U/17X ratio between Ethiopians living in Sweden versus Ethiopia was observed. Analysis of variance revealed CYP2A6 genotype (p=0.04, F=2.01) but not geographical differences, sex, or cigarette smoking as predictors of CYP2A6 activity. Importantly, the median (interquartile range) of 17U/17X ratio in Ethiopians 1.35 (0.99 to 1.84) was 3- and 11-fold higher than the previously reported value in Swedes 0.52 (0.27 to 1.00) and Koreans 0.13 (0.0 to 0.35), respectively (Djordjevic et al., 2013). Taken together, we report here the relevance of CYP2A6 genotype for enzyme activity in this Ethiopian sample, as well as high CYP2A6 activity and unique distribution of the CYP2A6 variant alleles in Ethiopians as compared other populations described hitherto. Because Omics biomarker research is rapidly accelerating in Africa, CYP2A6 pharmacogenetics and clinical pharmacology observations reported herein for the Ethiopian populations have clinical and biological importance to plan for future rational therapeutics efforts in the African continent as well as therapeutics as a global science.
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Affiliation(s)
- Eleni Aklillu
- 1 Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska University Hospital , Karolinska Institutet, Stockholm, Sweden
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Montané Jaime LK, Lalla A, Steimer W, Gaedigk A. Characterization of the CYP2D6 gene locus and metabolic activity in Indo- and Afro-Trinidadians: discovery of novel allelic variants. Pharmacogenomics 2013; 14:261-76. [PMID: 23394389 DOI: 10.2217/pgs.12.207] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The highly polymorphic CYP2D6 gene has extensively been studied in many populations, but there is a void of knowledge regarding CYP2D6 pharmacogenetics and activity in populations with unique ancestries and admixture, such as those residing in Trinidad and Tobago. MATERIALS & METHODS 167 healthy Indo- and 103 Afro-Trinidadians were phenotyped with dextromethorphan and extensively genotyped. Gene resequencing was performed to resolve cases with genotype/phenotype discordance. RESULTS CYP2D6 activity did not differ between the Indo-Trinidadians and Afro-Trinidadians. Poor metabolizers were, however, more frequent in the Indo-Trinidadians (4.19 vs 1.94%), and unique allele frequency patterns were observed. Two novel nonfunctional allelic variants were found among the Indo-Trinidadians in two discordant cases. CYP2D6*100 is characterized by a single nucleotide deletion and CYP2D6*101 by a 19-bp deletion; both cause frameshifts. CONCLUSION Our study underscores the importance of thoroughly characterizing the genetic make up of unique populations when considering pharmacogenetic testing for individualized therapy.
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Affiliation(s)
- Lazara Karelia Montané Jaime
- Pharmacology Unit, Department of Paraclinical Sciences, Faculty of Medical Sciences, The University of The West Indies, St Augustine, Trinidad & Tobago.
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St John-Smith P, McQueen D, Edwards L, Schifano F. Classical and novel psychoactive substances: rethinking drug misuse from an evolutionary psychiatric perspective. Hum Psychopharmacol 2013; 28:394-401. [PMID: 23881888 DOI: 10.1002/hup.2303] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2012] [Accepted: 02/04/2013] [Indexed: 11/08/2022]
Abstract
In this article, ontogenetic and phylogenetic causes of drug abuse and links to human emotional development are considered. Some evolutionary perspectives (e.g. that under certain conditions, consumption of otherwise toxic alkaloids may confer both physical and cultural advantages) are reviewed. As described in the 'mismatch theory', the capacity of the human genome to evolve defences against toxins has been outstripped by the pace of cultural change and technological development, such as purposeful fermentation of alcohol and more recently distillation of alcohol; purification and chemical manipulation of plant alkaloids; and the engineering of entirely novel psychoactive substances (NPS). The functions of the neurobiological substrates that mediate substance misuse and dependence are reviewed. Reasons are given why NPSs present greater cause for concern than plant-derived substances of abuse. We argue that evolutionary biology provides an important orientation for the research agenda in substance misuse.
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Affiliation(s)
- Paul St John-Smith
- Hertsmere Community Mental Health Team, Hertfordshire Partnership Foundation Trust, Borehamwood, UK.
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Alessandrini M, Asfaha S, Dodgen TM, Warnich L, Pepper MS. Cytochrome P450 pharmacogenetics in African populations. Drug Metab Rev 2013; 45:253-75. [PMID: 23590174 DOI: 10.3109/03602532.2013.783062] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The Cytochrome P450 (CYP450) family of enzymes is involved in the oxidative metabolism of many therapeutic drugs, carcinogens and various endogenous substrates. These enzymes are highly polymorphic at an inter-individual and inter-ethnic level. Polymorphisms or genetic variations account for up to 30% of inter-individual differences seen in a variety of drug responses. The frequencies of the different metabolizer categories (slow, intermediate, extensive and ultra-rapid), the distribution of genetic variants, genotype-phenotype correlations and the clinical importance of the CYP450 enzymes have been extensively documented in Caucasian and Oriental populations. Limited data exists for African populations, despite the fact that this knowledge is critically important for these populations who experience a heavy burden of communicable and non-communicable diseases. In addition, the costs incurred through adverse drug reactions and non-responsiveness to therapy could be reduced through the wide-scale application of pharmacogenetics. This review provides an overview and investigation of CYP450 genotypic and phenotypic reports published from 1980 to present in African populations. Our findings confirm the high degree of variability that is expected when comparing individuals of African origin to other ethnic groups and also highlight the distribution of clinically relevant CYP450 alleles amongst the various African populations. The notable discordance in genotypic and phenotypic data amongst African populations exemplifies the need for in-depth and well-orchestrated molecular and pharmacological investigations of these populations in the future, for which whole genome sequencing and association studies will be critical.
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Affiliation(s)
- Marco Alessandrini
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
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Djordjevic N, Carrillo JA, Ueda N, Gervasini G, Fukasawa T, Suda A, Jankovic S, Aklillu E. N-acetyltransferase-2 (NAT2) Gene Polymorphisms and Enzyme Activity in Serbs: Unprecedented High Prevalence of Rapid Acetylators in a White Population. J Clin Pharmacol 2013; 51:994-1003. [DOI: 10.1177/0091270010377630] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Abstract
Genetic variation influences the absorption and efflux of drugs in the intestine, the metabolism of drugs in the liver and the effects of these drugs on their target proteins. Indeed, variations in genes whose products have a role in the pathophysiology of nonmalignant gastrointestinal diseases, such as IBD, have been shown to affect the response of patients to therapy. This Review provides an overview of pharmacogenetics in the management of nonmalignant gastrointestinal diseases on the basis of data from clinical trials. Genetic variants that have the greatest effect on the management of patients with IBD involve the metabolism of thiopurines. Variation in drug metabolism by cytochrome P450 enzymes also requires attention so as to avoid drug interactions in patients receiving tricyclic antidepressants and PPIs. Few genotyping tests are currently used in the clinical management of patients with nonmalignant gastrointestinal diseases, owing to a lack of data from clinical trials showing their effectiveness in predicting nonresponse or adverse outcomes. However, pharmacogenetics could have a beneficial role in enabling pharmacotherapy for nonmalignant gastrointestinal diseases to be targeted to the individual patient.
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Affiliation(s)
- Michael Camilleri
- College of Medicine, Mayo Clinic, Charlton, 8–110, 200 First Street, South West, Rochester, MN 55905, USA
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Dodgen TM, Cromarty AD, Pepper MS. Quantitative plasma analysis using automated online solid-phase extraction with column switching LC-MS/MS for characterising cytochrome P450 2D6 and 2C19 metabolism. J Sep Sci 2011; 34:1102-10. [DOI: 10.1002/jssc.201000920] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 02/12/2011] [Accepted: 02/17/2011] [Indexed: 12/18/2022]
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Abstract
Medico-legal autopsy is the primary method in determining the cause and manner of death when the death is suspected to be unnatural. In some of these autopsies, the death remains ambiguous, even after a complete autopsy including histological investigation and toxicological screenings. In cases where there are no morphological abnormalities, medico-legal genetics may offer additional means to provide knowledge of possible genetic mutations, which may have initiated the process or predisposed the individual to stress risk conditions leading to death. One class of ambiguous deaths consists of drug-related deaths where the interpretation of the toxicological results are not clear. In such situations post mortem genotyping and the analysis of metabolite rations may provide an insight to the findings. A few cases demonstrating the potential strength of pharmacogenetics in medico-legal context has been published. However, there is a paramount need for serious scientific studies before the field of post mortem pharmacogenetics can be utilized in routine medico-legal analyses casework and brought routinely into courtroom.
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Affiliation(s)
- A Sajantila
- Hjelt Institute, Department of Forensic Medicine, P.O. Box 14, University of Helsinki, Finland.
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36
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Evolution of detoxifying systems: the role of environment and population history in shaping genetic diversity at human CYP2D6 locus. Pharmacogenet Genomics 2011; 20:485-99. [PMID: 20520586 DOI: 10.1097/fpc.0b013e32833bba25] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The transition from food collection to food production (FP) modified the nature of selective pressures, and several studies illustrate that genetic adaptation to new lifestyle has occurred in humans since the agricultural revolution. Here we test the hypothesis that high levels of genetic variation at CYP2D6, a locus coding for a detoxifying enzyme of the cytochrome P450 complex, reflect this change. METHODS We compared DNA sequences and predicted the levels of enzyme activity across 10 African, Asian and European populations, six of which currently rely on hunting and gathering (HG) while four on food production (FP). RESULTS AND CONCLUSION HG and FP showed similar levels of CYP2D6 diversity, but displayed different substitution patterns at coding DNA sites possibly related to selective differences. Comparison with variation at presumably neutral independent loci confirmed this finding, despite the confounding effects of population history, resulting in higher overall variation in Africans than in Eurasians. The differences between HG and FP populations suggest that new lifestyle and dietary habits acquired in the transition to agriculture affected the variation pattern at CYP2D6, leading to an increase in FP populations of the frequency of alleles that are associated with a slower rate of metabolism. These alleles reached a balanced co-existence with other important and previously selected variants. We suggest that the pronounced substrate-dependent activity of most of these enzymes expanded the spectrum of the metabolic response.
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Cytochrome P450-2D6 extensive metabolizers are more vulnerable to methamphetamine-associated neurocognitive impairment: preliminary findings. J Int Neuropsychol Soc 2010; 16:890-901. [PMID: 20727252 PMCID: PMC3543816 DOI: 10.1017/s1355617710000779] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
While neuropsychological deficits are evident among methamphetamine (meth) addicts, they are often unrelated to meth exposure parameters such as lifetime consumption and length of abstinence. The notion that some meth users develop neuropsychological impairments while others with similar drug exposure do not, suggests that there may be individual differences in vulnerability to the neurotoxic effects of meth. One source of differential vulnerability could come from genotypic variability in metabolic clearance of meth, dependent on the activity of cytochrome P450-2D6 (CYP2D6). We compared neuropsychological performance in 52 individuals with a history of meth dependence according with their CYP2D6 phenotype. All were free of HIV or hepatitis C infection and did not meet dependence criteria for other substances. Extensive metabolizers showed worse overall neuropsychological performance and were three times as likely to be cognitively impaired as intermediate/poor metabolizers. Groups did not differ in their demographic or meth use characteristics, nor did they evidence differences in mood disorder or other substance use. This preliminary study is the first to suggest that efficient meth metabolism is associated with worse neurocognitive outcomes in humans, and implicates the products of oxidative metabolism of meth as a possible source of brain injury.
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Videau O, Delaforge M, Levi M, Thévenot E, Gal O, Becquemont L, Beaune P, Bénech H. Biochemical and analytical development of the CIME cocktail for drug fate assessment in humans. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2010; 24:2407-2419. [PMID: 20658680 DOI: 10.1002/rcm.4641] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Phenotyping based on drug metabolism activity appears to be informative regarding mechanism-based interactions during drug development. We report here the first steps of the development of the innovative CIME cocktail. This cocktail is designed not only for the major cytochrome P450, with caffeine, amodiaquine, tolbutamide, omeprazole, dextromethorphan and midazolam as substrates of CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6 and CYP3A, respectively, but also phase II enzymes UGT 1A1/6/9 with acetaminophen, P-gp and OATP1B1 with digoxin and rosuvastatin, and renal function with memantine. An assay combining ultra-performance liquid chromatography using a 1.7 microm particle size column with tandem mass spectrometry (UPLC/MS/MS) was set up for the simultaneous quantification of the 20 substrates and metabolites after extraction from human plasma using solid-phase extraction. The method was validated in the spirit of the FDA guidelines. Mean accuracy ranged from 87.7 to 115%, the coefficient of variance (CV%) of intra- and inter-run from 1.7 to 16.4% and from 1.6 to 14.9%, respectively, and for the limit of quantification (LOQ) with ten lots of plasma, accuracy ranged from 84 to 115% and CV% precision was <16%. Short-term stability was evaluated in eluate (4 h, room temperature), plasma (24 h, room temperature), the autosampler (24 h, 4 degrees C) and in three freeze/thaw cycles in plasma. All except three analytes were stable under these conditions. For the three others a specific process can be followed. This robust, fast and sensitive assay in human plasma provides an analytical tool for ten-probe drugs of the CIME cocktail. Clinical samples will be assayed in the near future using this new assay method.
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Affiliation(s)
- Orianne Videau
- CEA, Pharmacology and Immunoanalysis Unit, DSV/iBiTecS, 91191 Gif-Sur-Yvette Cedex, France
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Ingelman-Sundberg M, Sim SC. Pharmacogenetic biomarkers as tools for improved drug therapy; emphasis on the cytochrome P450 system. Biochem Biophys Res Commun 2010; 396:90-4. [PMID: 20494117 DOI: 10.1016/j.bbrc.2010.02.162] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Accepted: 02/24/2010] [Indexed: 11/19/2022]
Abstract
Important interindividual differences in drug pharmacokinetics cause absence of drug response or adverse drug reactions in significant fractions of the populations. The identification of the major enzymes participating, and the elucidation of the genetic basis for this variation in particular among cytochromes P450, provide tools for a personalized medicine treatment, which can make drug therapy much more effective at a lower cost. Much of the pioneering work linking drug metabolizing phenotype to genetic polymorphism among the P450 enzymes has been carried out at Karolinska Institutet. In this review we give a background and description of this work as well as the important implications for future medicine.
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Affiliation(s)
- Magnus Ingelman-Sundberg
- Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, SE-17177 Stockholm, Sweden.
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Jetter A, Fätkenheuer G, Frank D, Klaassen T, Seeringer A, Doroshyenko O, Kirchheiner J, Hein W, Schömig E, Fuhr U, Wyen C. Do activities of cytochrome P450 (CYP)3A, CYP2D6 and P-glycoprotein differ between healthy volunteers and HIV-infected patients? Antivir Ther 2010; 15:975-83. [DOI: 10.3851/imp1648] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Affiliation(s)
- Shu-Feng Zhou
- Discipline of Chinese Medicine, School of Health Sciences, RMIT University, Victoria, Australia.
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Lötsch J, Rohrbacher M, Schmidt H, Doehring A, Brockmöller J, Geisslinger G. Can extremely low or high morphine formation from codeine be predicted prior to therapy initiation? Pain 2009; 144:119-24. [PMID: 19395173 DOI: 10.1016/j.pain.2009.03.023] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 03/24/2009] [Accepted: 03/24/2009] [Indexed: 10/20/2022]
Abstract
Activation of codeine by O-demethylation into morphine is a prerequisite for its analgesic effects and severe toxicity. Identifying patients in whom morphine is formed either at extremely low or at extremely high amounts may improve efficacy and safety of codeine therapy. To assess how well this identification is possible, we compared the performance of current CYP2D6 phenotype association systems (traditional genotype-based classification, a recently proposed CYP2D6 activity score, and the plasma dextromethorphan metabolic ratio) in 57 healthy Caucasians after oral administration of 30 mg dextromethorphan hydrobromide or 50 mg codeine. Most subjects (87.5%) at the lower 15% of morphine formation from codeine and thus likely to not to respond to codeine therapy were correctly identified by CYP2D6 genotype- or phenotype-based systems. In contrast, in subjects at the upper 15% of morphine formation being at risk for opioid toxicity, CYP2D6 genotyping predicted only the 50% who carried gene duplication, whereas dextromethorphan-based phenotyping identified 67.5% of the subjects with high morphine formation. However, satisfactory prediction (87.5%) of high morphine formation was only achieved when combining genotyping with phenotyping. In conclusion, insufficient morphine formation from codeine and thus likely failure of analgesia can currently be well predicted. However, to make codeine therapy safe, extremely high morphine formation has to be predicted as well, which has to be obtained at the effort of combining genotyping with phenotyping.
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Affiliation(s)
- Jörn Lötsch
- pharmazentrum frankfurt/ZAFES, Institute of Clinical Pharmacology, Johann Wolfgang Goethe-University, Theodor Stern Kai 7, D-60590 Frankfurt am Main, Germany.
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The pharmacokinetics of codeine and its metabolites in Blacks with sickle cell disease. Eur J Clin Pharmacol 2009; 65:651-8. [PMID: 19357842 DOI: 10.1007/s00228-009-0646-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Accepted: 03/11/2009] [Indexed: 10/20/2022]
Abstract
PURPOSE We conducted a prospective, open-label study in 54 adult subjects with sickle cell disease to determine the relationship between morphine concentrations, cytochrome P450 (CYP) 2D6 genotype, and clinical outcomes. METHODS A blood sample was obtained for genotyping and serial blood samples were drawn to measure codeine and its metabolites in the plasma before and after oral codeine sulfate 30 mg. Codeine and its metabolites were measured by liquid chromatography-tandem mass spectrometry (LC-MS). CYP2D6 genetic testing included four single nucleotide polymorphisms (SNP) indicative of three variant alleles: *17 (1023T); *29 (1659A, 3183A); and *41 (2988A) alleles. RESULTS Thirty subjects (group I) had a mean (standard deviation) maximal morphine concentration of 2.0 (1.0) ng/ml. Morphine was not measurable in the remaining 24 subjects (group II). Nine (30%) subjects in group I and 11 (46%) subjects in group II carried a variant *17, *29, or *41 allele (p = 0.23); one (3%) subject in group I and 5 (21%) subjects in group II were homozygous for *17 or *29 allele (p = 0.07). Emergency room visits (group I 1.5 +/- 1.8 vs. group II 2.1 +/- 4.3, p = NS) did not differ based on metabolic status, but more hospital admissions (0.9 +/- 1.4 vs. 2.2 +/- 4.1, p = 0.05) were documented in patients with no measurable morphine concentrations. CONCLUSIONS We conclude that Blacks with sickle cell disease without measurable plasma morphine levels after a single dose of codeine were not more likely to be a carrier of a single variant allele commonly associated with reduced CYP2D6 metabolic capacity; however, homozygosity for a variant CYP2D6 allele may result in reduced metabolic capacity. Furthermore, it appears that subjects without measurable morphine concentrations were more likely to be admitted to the hospital for an acute pain crisis.
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Miura J, Obua C, Abbo C, Kaneko S, Tateishi T. Cytochrome P450 2C19 genetic polymorphisms in Ugandans. Eur J Clin Pharmacol 2008; 65:319-20. [PMID: 19002442 DOI: 10.1007/s00228-008-0583-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2008] [Accepted: 10/20/2008] [Indexed: 11/25/2022]
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González I, Peñas-Lledó EM, Pérez B, Dorado P, Álvarez M, LLerena A. Relation between CYP2D6 phenotype and genotype and personality in healthy volunteers. Pharmacogenomics 2008; 9:833-40. [DOI: 10.2217/14622416.9.7.833] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Objectives: Our group has previously show that interindividual variability in CYP2D6 hydroxylation capacity was related to personality differences in cognitive social anxiety. Thus, we aimed to analyze whether this relationship between personality and CYP2D6 phenotype and genotype was found in a similar population of healthy volunteers from a different latitude and culture by using the same methodology. Methods: A total of 253 university students and staff from Havana Psychiatric Hospital and Calixto García Medical School in Cuba completed the Karolinska Scales of Personality (KSP), and were evaluated on debrisoquine hydroxylation capacity and CYP2D6 genotypes. KSP scores were compared between four groups, divided according to their CYP2D6 metabolic capacity: one of poor and three of extensive metabolizers. Furthermore, KSP scores were compared between another four different groups divided according to their number of CYP2D6 active genes: zero, one, two, and more than two. Results: In Cubans, the differences in cognitive social anxiety-related personality traits across the four CYP2D6 hydroxylation capacity groups were strikingly similar to those found in Spaniards. These differences also came out to be significant for psychic anxiety (p = 0.02) and socialization (p = 0.02). The same pattern of results obtained for the subscales of psychic anxiety, socialization, psychasthenia and inhibition of aggression with regard to phenotype in both the Cuban and Spanish studies were seen with regard to CYP2D6 genotypes. Conclusions: Corroborating these results further strengthens evidence of the relationship between CYP2D6 metabolic capacity and personality. In this population of healthy Cuban volunteers, the CYP2D6 hydroxylation capacity was related to the degree of anxiety and socialization. These results support the postulated reduction of serotonin in CYP2D6 poor metabolizers, which may be associated with a cluster of behavioral traits (e.g., anxiety, impulsivity). Thus, research is warranted to determine CYP2D6 functional implications for interindividual differences in vulnerability to neuropsychiatric diseases and drug response.
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Affiliation(s)
- Idilio González
- Hospital Psiquiátrico de La Habana, Cuba
- Faculty of Medicine, University of Extremadura & Clinical Research Centre (CICAB), Hospital Infanta Cristina, Servicio Extremeño de Salud. Avda. de Elvas, s/n. E-06080, Badajoz, Spain
| | - Eva M Peñas-Lledó
- Faculty of Medicine, University of Extremadura & Clinical Research Centre (CICAB), Hospital Infanta Cristina, Servicio Extremeño de Salud. Avda. de Elvas, s/n. E-06080, Badajoz, Spain
| | - Bárbaro Pérez
- Facultad de Ciencias Médicas Calixto García, Instituto Superior de Ciencias Médicas de La Habana, Cuba
| | - Pedro Dorado
- Facultad de Ciencias Médicas Calixto García, Instituto Superior de Ciencias Médicas de La Habana, Cuba
| | - Mayra Álvarez
- Faculty of Medicine, University of Extremadura & Clinical Research Centre (CICAB), Hospital Infanta Cristina, Servicio Extremeño de Salud. Avda. de Elvas, s/n. E-06080, Badajoz, Spain
| | - Adrián LLerena
- Faculty of Medicine, University of Extremadura & Clinical Research Centre (CICAB), Hospital Infanta Cristina, Servicio Extremeño de Salud. Avda. de Elvas, s/n. E-06080, Badajoz, Spain
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Sirugo G, Hennig BJ, Adeyemo AA, Matimba A, Newport MJ, Ibrahim ME, Ryckman KK, Tacconelli A, Mariani-Costantini R, Novelli G, Soodyall H, Rotimi CN, Ramesar RS, Tishkoff SA, Williams SM. Genetic studies of African populations: an overview on disease susceptibility and response to vaccines and therapeutics. Hum Genet 2008; 123:557-98. [PMID: 18512079 DOI: 10.1007/s00439-008-0511-y] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Accepted: 05/07/2008] [Indexed: 01/13/2023]
Abstract
Africa is the ultimate source of modern humans and as such harbors more genetic variation than any other continent. For this reason, studies of the patterns of genetic variation in African populations are crucial to understanding how genes affect phenotypic variation, including disease predisposition. In addition, the patterns of extant genetic variation in Africa are important for understanding how genetic variation affects infectious diseases that are a major problem in Africa, such as malaria, tuberculosis, schistosomiasis, and HIV/AIDS. Therefore, elucidating the role that genetic susceptibility to infectious diseases plays is critical to improving the health of people in Africa. It is also of note that recent and ongoing social and cultural changes in sub-Saharan Africa have increased the prevalence of non-communicable diseases that will also require genetic analyses to improve disease prevention and treatment. In this review we give special attention to many of the past and ongoing studies, emphasizing those in Sub-Saharan Africans that address the role of genetic variation in human disease.
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Affiliation(s)
- Giorgio Sirugo
- Medical Research Council Laboratories, Fajara, The Gambia, West Africa.
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Fuhr U, Jetter A, Kirchheiner J. Appropriate phenotyping procedures for drug metabolizing enzymes and transporters in humans and their simultaneous use in the "cocktail" approach. Clin Pharmacol Ther 2007; 81:270-83. [PMID: 17259951 DOI: 10.1038/sj.clpt.6100050] [Citation(s) in RCA: 174] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Phenotyping for drug metabolizing enzymes and transporters is used to assess quantitatively the effect of an intervention (e.g., drug therapy, diet) or a condition (e.g., genetic polymorphism, disease) on their activity. Appropriate selection of test drug and metric is essential to obtain results applicable for other substrates of the respective enzyme/transporter. The following phenotyping metrics are recommended based on the level of validation and on practicability: CYP1A2, paraxanthine/caffeine in plasma 6 h after 150 mg caffeine; CYP2C9, tolbutamide plasma concentration 24 h after 125 mg tolbutamide; CYP2C19, urinary excretion of 4'-OH-mephenytoin 0-12 h after 50 mg mephenytoin; CYP2D6, urinary molar ratio debrisoquine/4-OH-debrisoquine 0-8 h after 10 mg debrisoquine; and CYP3A4, plasma clearance of midazolam after 2 mg midazolam (all drugs given orally).
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Affiliation(s)
- U Fuhr
- Department of Pharmacology, Clinical Pharmacology Unit, University of Cologne, Cologne, Germany.
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Ozdemir V, Aklillu E, Mee S, Bertilsson L, Albers LJ, Graham JE, Caligiuri M, Lohr JB, Reist C. Pharmacogenetics for off-patent antipsychotics: reframing the risk for tardive dyskinesia and access to essential medicines. Expert Opin Pharmacother 2006; 7:119-33. [PMID: 16433578 DOI: 10.1517/14656566.7.2.119] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
First-generation antipsychotics (FGAs) induce tardive dyskinesia, a debilitating involuntary hyperkinetic movement disorder, in 20-50% of individuals with a psychotic illness during chronic treatment. There is presently no curative treatment or definitive predictive test for tardive dyskinesia. The authors note that the three antipsychotic drugs enlisted in the most recent (14th) World Health Organization Model List of Essential Medicines--chlorpromazine, fluphenazine and haloperidol--belong to the FGA therapeutic class. In this regard, the need to choose between the competing objectives of ensuring global access to affordable and efficacious medicines, such as FGAs, and the formidable long-term risk for tardive dyskinesia, may create an ethical conundrum. Pharmacogenetics has thus far been conceptually framed as a tool to individualize therapy with new drugs under patent protection. However, the authors suggest that pharmacogenetics may also improve access to pharmacotherapy through the reintroduction of affordable second-line generic drugs or FGAs with suboptimal safety, as first-line therapy, in targeted subpopulations in whom they present a lower risk for tardive dyskinesia. To impact positively on global public health and distributive justice, a directory complementary to the essential medicines library--one that enlists the 'essential biomarkers' required for optimal pharmacotherapy--may benefit patients who do not have adequate access to new antipsychotic medications. This review discusses pharmacogenetic associations of tardive dyskinesia that are in part supported by meta-analyses and the oxidative stress-neuronal degeneration hypothesis.
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Affiliation(s)
- Vural Ozdemir
- VA Long Beach Healthcare System, Southern California Institute for Research and Education, Department of Psychiatry and Human Behavior, College of Medicine, University of California, Irvine, Long Beach, CA 90822, USA.
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Gaedigk A, Bhathena A, Ndjountché L, Pearce RE, Abdel-Rahman SM, Alander SW, Bradford LD, Rogan PK, Leeder JS. Identification and characterization of novel sequence variations in the cytochrome P4502D6 (CYP2D6) gene in African Americans. THE PHARMACOGENOMICS JOURNAL 2005; 5:173-82. [PMID: 15768052 PMCID: PMC1440720 DOI: 10.1038/sj.tpj.6500305] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cytochrome P4502D6 (CYP2D6) genotyping reliably predicts poor metabolizer phenotype in Caucasians, but is less accurate in African Americans. To evaluate discordance we have observed in phenotype to genotype correlation studies, select African American subjects were chosen for complete resequencing of the CYP2D6 gene including 4.2 kb of the CYP2D7-2D6 intergenic region. Comparisons were made to a CYP2D6(*)1 reference sequence revealing novel SNPs in the upstream, coding and intervening sequences. These sequence variations, defining four functional alleles (CYP2D6(*)41B, (*)45A and B and (*)46), were characterized for their ability to influence splice site strength, transcription level or catalytic protein activity. Furthermore, their frequency was determined in a population of 251 African Americans. A -692(TGTG) deletion (CYP2D6(*)45B) did not significantly decrease gene expression, nor could any other upstream SNP explain a genotype-discordant case. CYP2D6(*)45 and (*)46 have a combined frequency of 4% and can be identified by a common SNP. Carriers are predicted to exhibit an extensive or intermediate CYP2D6 phenotype.
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Affiliation(s)
- A Gaedigk
- Division of Clinical Pharmacology and Experimental Therapeutics, Children's Mercy Hospital & Clinics, Kansas City, MO 64108, USA.
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Ingelman-Sundberg M. Genetic polymorphisms of cytochrome P450 2D6 (CYP2D6): clinical consequences, evolutionary aspects and functional diversity. THE PHARMACOGENOMICS JOURNAL 2005; 5:6-13. [PMID: 15492763 DOI: 10.1038/sj.tpj.6500285] [Citation(s) in RCA: 734] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
CYP2D6 is of great importance for the metabolism of clinically used drugs and about 20-25% of those are metabolised by this enzyme. In addition, the enzyme utilises hydroxytryptamines as endogenous substrates. The polymorphism of the enzyme results in poor, intermediate, efficient or ultrarapid metabolisers (UMs) of CYP2D6 drugs. It is plausible that the UM genotype, where more than one active gene on one allele occurs, is the outcome of selective dietary selection in certain populations in North East Africa. The UM phenotype affects 5.5% of the population in Western Europe. A hypothesis for the evolutionary basis behind selection for CYP2D6 gene duplications is presented in relation to selection for Cyp6 variants in insecticide resistant Drosophila strains. The polymorphism of CYP2D6 significantly affects the pharmacokinetics of about 50% of the drugs in clinical use, which are CYP2D6 substrates. The consequences of the polymorphism at ordinary drug doses can be either adverse drug reactions or no drug response. Examples are presented where CYP2D6 polymorphism affects the efficacy and costs of drug treatment. Predictive CYP2D6 genotyping is estimated by the author to be beneficial for treatment of about 30-40% of CYP2D6 drug substrates, that is, for about 7-10% of all drugs clinically used, although prospective clinical studies are necessary to evaluate the exact benefit of drug selection and dosage based on the CYP2D6 genotype.
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Affiliation(s)
- M Ingelman-Sundberg
- Division of Molecular Toxicology, IMM, Karolinska Institutet, Stockholm, Sweden.
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