Relevance of in vitro and clinical data for predicting CYP3A4-mediated herb-drug interactions in cancer patients

The acute toxic effect of Chinese medicine Fuzi is exacerbated in kidney yang deficiency mice due to metabolic difference

ETHNOPHARMACOLOGICAL RELEVANCE

The proper application of toxic medicines is one of the characteristics of traditional Chinese medicines, and the use of traditional Chinese medicines follows the principle of dialectical treatment. It is necessary to combine different "syndrome" or "disease" states with the toxicity of traditional Chinese medicines to form a reliable toxicity evaluation system. Fuzi, the lateral root of Aconitum carmichaelii Debx, is recognized as a panacea for kidney yang deficiency syndrome, however, its toxic effects significantly limit its clinical application.

AIM OF THE STUDY

Herein, our research aimed to explore the toxic effects of Fuzi on syndrome models, and tried to reveal the underlying mechanisms.

MATERIALS AND METHODS

Firstly, the mouse model of kidney yang deficiency syndrome was established through intramuscular injection of 25 mg/kg hydrocortisone per day for 10 consecutive days. Then, the acute toxicity of Fuzi in normal mice and kidney yang deficiency model mice was explored. Finally, the plasma metabolite concentrations and liver CYP3A4 enzyme activity were analyzed to reveal the possible mechanisms of the different pharmacological and toxicological effects of Fuzi in individuals with different physical constitutions.

RESULTS

It was found that the treatment with Fuzi (138 g/kg) had serious toxic effects on kidney yang deficiency mice, leading to the death of 80% of the mice, whereas it showed no lethal toxicity in normal mice. This indicates that Fuzi induced greater toxicity in kidney yang deficiency mice than in normal ones. The liver CYP3A4 enzyme activity in kidney yang deficiency mice was decreased by 20% compared to the controls, resulting in slower metabolism of the toxic diester diterpenoid alkaloids in Fuzi.

CONCLUSION

In conclusion, our study showed that changes of the metabolic enzyme activity in individuals with different syndromes led to different toxic effects of Chinese medicines, emphasizing the crucial importance of considering individual physical syndromes in the clinical application of traditional Chinese medicine, and the significance of conducting safety evaluations and dose predictions on animal models with specific syndromes for traditional Chinese medicines.

Advanced gastrointestinal stromal tumor: reliable classification of imatinib plasma trough concentration via machine learning

AIM

Patients with advanced gastrointestinal stromal tumors (GISTs) exhibiting an imatinib plasma trough concentration (IM Cmin) under 1100 ng/ml may show a reduced drug response rate, leading to the suggestion of monitoring for IM Cmin. Consequently, the objective of this research was to create a customized IM Cmin classification model for patients with advanced GISTs from China.

METHODS

Initial data and laboratory indicators from patients with advanced GISTs were gathered, and the above information was segmented into a training set, validation set, and testing set in a 6:2:2 ratio. Key variables associated with IM Cmin were identified to construct the classification model using the least absolute shrinkage and selection operator (LASSO) regression and forward stepwise binary logistic regression. Within the training and validation sets, nine ML classification models were constructed via the resampling method and underwent comparison through the Brier scores, the areas under the receiver-operating characteristic curve (AUROC), the decision curve, and the precision-recall (AUPR) curve to determine the most suitable model for this dataset. Two methods of internal validation were used to assess the most suitable model's classification performance: tenfold cross-validation and random split-sample validation (test set), and the value of the test set AUROC was used to evaluate the model's classification performance.

RESULTS

Six key variables (gender, daily IM dose, metastatic site, red blood cell count, platelet count, and percentage of neutrophils) were ultimately selected to construct the classification model. In the validation set, it is found by comparison that the Extreme Gradient Boosting (XGBoost) model has the largest AUROC, the lowest Brier score, the largest area under the decision curve, and the largest AUPR value. Furthermore, as evaluated via internal verification, it also performed well in the test set (AUROC = 0.725).

CONCLUSION

For patients with advanced GISTs who receive IM, initial data and laboratory indicators could be used to accurately estimate whether the IM Cmin is below 1100 ng/ml. The XGBoost model may stand a chance to assist clinicians in directing the administration of IM.

Fluorescence-Based High-Throughput Assays for Investigating Cytochrome P450 Enzyme-Mediated Drug-Drug Interactions

The cytochrome P450 enzymes (CYPs), a group of heme-containing enzymes, catalyze oxidative metabolism of a wide range of drugs and xenobiotics, as well as different endogenous molecules. Strong inhibition of human CYPs is the most common cause of clinically associated pharmacokinetic drug-drug/herb-drug interactions (DDIs/HDIs), which may result in serious adverse drug reactions, even toxicity. Accurate and rapid assessing of the inhibition potentials on CYP activities for therapeutic agents is crucial for the prediction of clinically relevant DDIs/HDIs. Over the past few decades, significant efforts have been invested into developing optical substrates for the human CYPs, generating a variety of powerful tools for high-throughput assays to detect CYP activities in biologic specimens and for screening of CYP inhibitors. This minireview focuses on recent advances in optical substrates developments for human CYPs, as well as their applications in screening CYP inhibitors and DDIs/HDIs studies. The examples for rational design and optimization of highly specific optical substrates for the target CYP enzyme, as well as applications in investigating CYP-mediated DDIs, are illustrated. Finally, the challenges and future perspectives in this field are proposed. Collectively, this review summarizes the reported optical-based biochemical assays for highly efficient CYP activities detection, which strongly facilitated the discovery of CYP inhibitors and the investigations on CYP-mediated DDIs. SIGNIFICANCE STATEMENT: Optical substrates for cytochrome P450 enzymes (CYPs) have emerged as powerful tools for the construction of high-throughput assays for screening of CYP inhibitors. This mini-review covers the advances and challenges in the development of highly specific optical substrates for sensing human CYP isoenzymes, as well as their applications in constructing fluorescence-based high-throughput assays for investigating CYP-mediated drug-drug interactions.

Advances in the care of breast cancer survivors

Breast cancer survivors may experience significant after effects from diagnoses of breast cancer and cancer directed therapies. This review synthesizes the evidence about optimal management of the sequelae of a diagnosis of breast cancer. It describes the side effects of chemotherapy and endocrine therapy and evidence based strategies for management of such effects, with particular attention to effects of therapies with curative intent. It includes strategies to promote health and wellness among breast cancer survivors, along with data to support the use of integrative oncology strategies. In addition, this review examines models of survivorship care and ways in which digital tools may facilitate communication between clinicians and patients. The strategies outlined in this review are paramount to supporting breast cancer survivors' quality of life.

Evaluation of Concomitant Use of Anticancer Drugs and Herbal Products: From Interactions to Synergic Activity

CAM is used by about 40% of cancer patients in Western Countries, with peaks of 80% for breast cancer patients. Cancer patients use CAM to boost immune function, to control cancer symptoms and treatment-related side effects, and to improve health-related quality of life (HR-QoL) and survival. Unfortunately, self-prescription of natural remedies in cancer patients can lead to unexpected toxicities and can reduce the effectiveness of cancer therapy. Although CAM usually refers to all the "natural or organic" products/methods that are generally considered less toxic, there are concerns about drug interactions, especially in patients participating in clinical trials with experimental agents. Despite the claims of the promising and potential benefits made by prescribers, many CAMs lack clear scientific evidence of their safety and efficacy. Given the widespread use of CAM-both clearly declared and overt-in this review, we focused on the most important known data on the risk of interactions between biologics and oncology drugs with the goal of opening up CAM in accordance with the meaning of integrative medicine.

Species Difference in the Metabolism of Mulberrin in Vitro and Its Inhibitory Effect on Cytochrome P450 and UDP-Glucuronosyltransferase Enzymes

This study aimed to evaluate the interspecies difference in metabolism of mulberrin and examine the interaction between mulberrin and CYP enzymes or recombinant human uridine 5'-diphosphate (UDP)-glucuronosyltransferase (UGT) enzymes. Liver microsomes from human (HLMs), Beagle dog (DLMs), minipig (PLMs), monkey (MLMs), rabbit (RLMs), rat (RAMs), and mouse (MIMs) were used to investigate metabolic diversity among different species. Additionally, recombinant human supersomes were used to confirm that metabolic enzymes are involved in the biotransformation of mulberrin. We also evaluated the influence of mulberrin on protein expression by Western blot analysis. Mulberrin metabolism showed significant interspecies differences. We found four and two metabolites in phase I and II reaction systems, respectively. In phase I metabolism profiles of mulberrin for HLMs, PLMs and MLMs conformed to the classic Michaelis-Menten kinetics, RAMs and MIMs followed biphasic kinetics; phase II reaction of mulberrin in HLMs, DLMs, PLMs, MLMs, RLMs, RAMs and MIMs followed biphasic kinetics. UGT1A1 were the major CYP isoforms responsible for the metabolism of mulberrin. Mulberrin showed potent inhibitory effects against CYP3A4, CYP2C9, CYP2E1, UGT1A1, UGT1A3 and UGT2B7 with IC₅₀ values of 54.21, 9.93, 39.12, 3.84, 2.01, 16.36 µM, respectively. According to Western blot analysis, mulberrin can upregulate the protein expression of CYP2C19, and downregulate the expression levels of CYP3A5 and CYP2C9 in HepG2 cells as concentration increased. The interspecies comparisons can help find other species with metabolic pathways similar to those in humans for future in vivo studies.

Hypericin and its anticancer effects: From mechanism of action to potential therapeutic application

BACKGROUND

Emerging studies indicate that hypericin has diverse pharmacological actions and exhibits potential for treatment of various types of cancer.

PURPOSE

The current review evaluates the pharmacological activity, associated molecular mechanism, and therapeutic application of hypericin as an anticancer agent according to the most recent state of knowledge with special emphasis on clinical trials and safety profile.

METHOD

This review follows The Preferred Reporting Items for Systematic Reviews criteria. Various databases, including PubMed, Scopus and Science Direct, were used to search and collect relevant literature. The major keywords used included the following: cancer, distribution, property, signaling pathway, pharmacological effect, treatment, prevention, in vitro and in vivo studies, toxicity, bioavailability, and clinical trials.

RESULTS

One hundred three articles met the established inclusion and exclusion criteria. Hypericin has shown anticancer activity against the expansion of several cell types including breast cancer, cervical cancer, colorectal cancer, colon cancer, hepatocellular carcinoma, stomach carcinoma, leukemia, lung cancer, melanoma, and glioblastoma cancer. Hypericin exerts its anticancer activity by inhibiting pro-inflammatory mediators, endothelial growth factor, fibroblast growth factor, cell adhesion, angiogenesis, and mitochondrial thioredoxin. It has also been shown to cause an increase in the levels of caspase-3 and caspase-4, arrest the cell cycle at metaphase leading to cancer cell apoptosis, and affect various protein and gene expression patterns.

CONCLUSION

Hypericin exhibits significant inhibitory activity against various types of in vitro and in vivo cancer models. However, well-designed, high quality, large-scale and multi-center randomized clinical studies are required to establish the safety and clinical utility of hypericin in cancer patients.

Real-world data on herb-drug interactions in oncology: A scoping review of pharmacoepidemiological studies

BACKGROUND

The concurrent use of conventional drugs and herbal medicines is becoming popular among patients with cancer. However, the potential risk of herb-drug interactions (HDI) remains under-addressed in the literature. Previous reviews have mainly focused on the prevalence of interactions, with less attention paid to the methods used by pharmacoepidemiological studies on evaluating HDI. This scoping review aims to summarize the existing pharmacoepidemiological studies that evaluate HDI using real-world data and to identify gaps to be addressed in future research.

METHODS

A comprehensive search was performed in nine English- and Chinese-language databases from their inception to May 2021. Gray literature and manual searches were conducted to identify additional studies. The recommended components of the pharmacoepidemiological studies and key findings related to HDI were summarized. The proportion (%) of patients with cancer at risk of HDI was estimated by combining data from eligible studies.

RESULTS

Twenty-eight studies were included in the review. More than half of these studies were cross-sectional studies (n = 18, 64.3%), followed by retrospective cohort studies (n = 5, 17.9%) and prospective cohort studies (n = 2, 7.1%). The three cancer drugs most commonly studied for their interaction potential with herbs were tamoxifen (n = 11, 39.3%), cyclophosphamide (n = 6, 21.4%), and paclitaxel (n = 6, 21.4%). Most cross-sectional studies identified potential HDI using tertiary databases and primary literature searches. Conversely, prospective and retrospective studies mainly investigated actual clinical outcomes, such as adverse events and secondary cancer occurrences. Most interaction outcomes identified using real-world data did not lead to negative clinical consequences. Collectively, 45.4% of herbal medicine users of the included studies were found to be at risk of HDI. We infer from this review that the common limitations of these studies were limited sample size, lack of data on herbal medicine use and details of HDI, and lack of evidence of HDI. Based on the study limitations, several recommendations to enrich the data sources and optimize the study designs were proposed.

CONCLUSIONS

There is a high demand for pharmacoepidemiological research on HDI, considering the increasing popularity of herbal medicine among patients with cancer. It is anticipated that emerging real-world data in this field can guide the development of safe and effective approaches to integrative oncology.

Molecular dynamics simulation and in vitro evaluation of herb-drug interactions involving dietary polyphenols and CDK inhibitors in breast cancer chemotherapy

Dietary polyphenols such as quercetin and curcumin have been extensively administered to patients with cancer in the form of herbal supplements. They may have a synergistic anticancer effect; however, a risk of pharmacokinetic interactions with selective CDK-4/6 inhibitors that are metabolized by the CYP3A4 enzyme exists. Considering these pharmacokinetic aspects, the current study examined the effects of curcumin and quercetin on human CYP3A4 to ascertain CYP3A4-mediated herb-drug interactions with CDK inhibitors. In this study, using in silico methods and CYP3A4 inhibition kinetics in human liver microsomes and recombinant CYP3A4 enzymes, the effects of concentration-dependent inhibition of CYP3A4 by quercetin and curcumin on CDK inhibitors metabolism were examined. Based on our in-silico docking findings, curcumin and quercetin were considerably bound to CYP3A4 protein and displace CDK inhibitors from the CYP3A4 substrate binding domain. The IC₅₀ values of curcumin and quercetin were 16.10 and 0.05 μM, respectively, for CYP3A4-mediated 1'-hydroxylation of midazolam. The dietary polyphenols prolonged the in vitro half-life of palbociclib and ribociclib by 6.4-fold and decreased their intrinsic microsomal clearance by approximately 4.6 times. Our findings indicate that curcumin and quercetin effectively cause herb-drug interactions and should be cautiously used to avoid therapeutic failure.

Phytotherapy in Integrative Oncology-An Update of Promising Treatment Options

Modern phytotherapy is part of today's conventional evidence-based medicine and the use of phytopharmaceuticals in integrative oncology is becoming increasingly popular. Approximately 40% of users of such phytopharmaceuticals are tumour patients. The present review provides an overview of the most important plants and nature-based compounds used in integrative oncology and illustrates their pharmacological potential in preclinical and clinical settings. A selection of promising anti-tumour plants and ingredients was made on the basis of scientific evidence and therapeutic practical relevance and included Boswellia, gingko, ginseng, ginger, and curcumin. In addition to these nominees, there is a large number of other interesting plants and plant ingredients that can be considered for the treatment of cancer diseases or for the treatment of tumour or tumour therapy-associated symptoms. Side effects and interactions are included in the discussion. However, with the regular and intended use of phytopharmaceuticals, the occurrence of adverse side effects is rather rare. Overall, the use of defined phytopharmaceuticals is recommended in the context of a rational integrative oncology approach.

Consensus guidelines for improving patients' understanding of invasive fungal disease and related risk prevention in the haematology/oncology setting, 2021

Patients with invasive fungal disease (IFD) are at significant risk of morbidity and mortality. A productive partnership between patients, their carers/families, and the multidisciplinary team managing the infection and any underlying conditions, is essential. Sharing information and addressing knowledge gaps are required to ensure those at risk of IFD avoid infection, while those with suspected or confirmed infection optimise their therapy and avoid toxicities. This new addition to the Australian and New Zealand consensus guidelines for the management of IFD and antifungal use in the haematology/oncology setting outlines the key information needs of patients and their carers/families. It specifically addresses risk factor reduction, antifungal agents and adherence, and the risks and benefits of complementary and alternative therapies. Knowledge gaps are also identified to help inform the future research agenda.

Targeting Drug Chemo-Resistance in Cancer Using Natural Products

Cancer is one of the leading causes of death globally. The development of drug resistance is the main contributor to cancer-related mortality. Cancer cells exploit multiple mechanisms to reduce the therapeutic effects of anticancer drugs, thereby causing chemotherapy failure. Natural products are accessible, inexpensive, and less toxic sources of chemotherapeutic agents. Additionally, they have multiple mechanisms of action to inhibit various targets involved in the development of drug resistance. In this review, we have summarized the basic research and clinical applications of natural products as possible inhibitors for drug resistance in cancer. The molecular targets and the mechanisms of action of each natural product are also explained. Diverse drug resistance biomarkers were sensitive to natural products. P-glycoprotein and breast cancer resistance protein can be targeted by a large number of natural products. On the other hand, protein kinase C and topoisomerases were less sensitive to most of the studied natural products. The studies discussed in this review will provide a solid ground for scientists to explore the possible use of natural products in combination anticancer therapies to overcome drug resistance by targeting multiple drug resistance mechanisms.

Nanoparticulate Drug Delivery Strategies to Address Intestinal Cytochrome P450 CYP3A4 Metabolism towards Personalized Medicine

Drug dosing in clinical practice, which determines optimal efficacy, toxicity or ineffectiveness, is critical to patients' outcomes. However, many orally administered therapeutic drugs are susceptible to biotransformation by a group of important oxidative enzymes, known as cytochrome P450s (CYPs). In particular, CYP3A4 is a low specificity isoenzyme of the CYPs family, which contributes to the metabolism of approximately 50% of all marketed drugs. Induction or inhibition of CYP3A4 activity results in the varied oral bioavailability and unwanted drug-drug, drug-food, and drug-herb interactions. This review explores the need for addressing intestinal CYP3A4 metabolism and investigates the opportunities to incorporate lipid-based oral drug delivery to enable precise dosing. A variety of lipid- and lipid-polymer hybrid-nanoparticles are highlighted to improve drug bioavailability. These drug carriers are designed to target different intestinal regions, including (1) local saturation or inhibition of CYP3A4 activity at duodenum and proximal jejunum; (2) CYP3A4 bypass via lymphatic absorption; (3) pH-responsive drug release or vitamin-B12 targeted cellular uptake in the distal intestine. Exploitation of lipidic nanosystems not only revives drugs removed from clinical practice due to serious drug-drug interactions, but also provide alternative approaches to reduce pharmacokinetic variability.

A Comparative Study on Anticancer Effects of the Alhagi maurorum and Amygdalus haussknechtii Extracts Alone and in Combination with Docetaxel on 4T1 Breast Cancer Cells

Medicinal plants have long been studied due to their anticancer effects and use of them is commonly increased as a complementary and alternative medicine (CAM therapies) among patients with cancer. In this study, Alhagi maurorum (A.m) and Amygdalus haussknechtii (A.h) extracts were evaluated for their effects on inhibiting the growth of 4T1 breast cancer cells. Based on MTT assay results, the IC50s of A.m and A.h extracts were 57 µg/ml and 85 µg/ml, respectively. Then the cell migration, gene expression, and degree of apoptosis after 48 hours in each treated group with A.m and A.h extracts alone or in combination with docetaxel (DTX) on 4T1 cells were evaluated. A.m had a synergistic behavior with DTX (CI < 1). A.h reduced DTX IC50 but presented CI > 1. Cell migration assay showed that each extract alone or in combination with DTX prevented the migration of 4T1 cells. The Ao/EB staining and flowcytometry results confirmed that, in combination therapy, A.m + DTX and A.h + DTX induced apoptosis close to the level of DTX. Real-time PCR analysis showed that A.m + DTX (IC50 + IC25) downregulated the mRNA expression of HIF-1α and FZD7. A.m + DTX (IC50 + IC10) group decreased the expression of HIF-1α. Moreover, in A.h + DTX (IC50 + IC25) group, β-Catenin and FZD7 were downregulated and upregulated, respectively. Generally, our findings suggest that the combination of A.m and DTX possesses synergistic antitumor effects on 4T1 cells, which may be a valuable choice for CAM therapies. A.h has an acceptable antitumor activity but not in combination with DTX.

Nutraceuticals: Transformation of Conventional Foods into Health Promoters/Disease Preventers and Safety Considerations

Nutraceuticals are essential food constituents that provide nutritional benefits as well as medicinal effects. The benefits of these foods are due to the presence of active compounds such as carotenoids, collagen hydrolysate, and dietary fibers. Nutraceuticals have been found to positively affect cardiovascular and immune system health and have a role in infection and cancer prevention. Nutraceuticals can be categorized into different classes based on their nature and mode of action. In this review, different classifications of nutraceuticals and their potential therapeutic activity, such as anti-cancer, antioxidant, anti-inflammatory and anti-lipid activity in disease will be reviewed. Moreover, the different mechanisms of action of these products, applications, and safety upon consumers including current trends and future prospect of nutraceuticals will be included.

Clinical implications of food-drug interactions with small-molecule kinase inhibitors

During the past two decades, small-molecule kinase inhibitors have proven to be valuable in the treatment of solid and haematological tumours. However, because of their oral administration, the intrapatient and interpatient exposure to small-molecule kinase inhibitors (SMKIs) is highly variable and is affected by many factors, such as concomitant use of food and herbs. Food-drug interactions are capable of altering the systemic bioavailability and pharmacokinetics of these drugs. The most important mechanisms underlying food-drug interactions are gastrointestinal drug absorption and hepatic metabolism through cytochrome P450 isoenzymes. As food-drug interactions can lead to therapy failure or severe toxicity, knowledge of these interactions is essential. This Review provides a comprehensive overview of published studies involving food-drug interactions and herb-drug interactions for all registered SMKIs up to Oct 1, 2019. We critically discuss US Food and Drug Administration (FDA) and European Medicines Agency (EMA) guidelines concerning food-drug interactions and offer clear recommendations for their management in clinical practice.

Pharmacokinetic Interactions between Herbal Medicines and Drugs: Their Mechanisms and Clinical Relevance

The therapeutic efficacy of a drug or its unexpected unwanted side effects may depend on the concurrent use of a medicinal plant. In particular, constituents in the medicinal plant extracts may influence drug bioavailability, metabolism and half-life, leading to drug toxicity or failure to obtain a therapeutic response. This narrative review focuses on clinical studies improving knowledge on the ability of selected herbal medicines to influence the pharmacokinetics of co-administered drugs. Moreover, in vitro studies are useful to anticipate potential herbal medicine-drug interactions. In particular, they help to elucidate the cellular target (metabolic or transporter protein) and the mechanism (induction or inhibition) by which a single constituent of the herbal medicine acts. The authors highlight the difficulties in predicting herbal–drug interactions from in vitro data where high concentrations of extracts or their constituents are used and pharmacokinetics are missed. Moreover, the difficulty to compare results from human studies where different kinds of herbal extracts are used is discussed. The herbal medicines discussed are among the best sellers and they are reported in the “Herbal Medicines for Human Use” section of the European Medicinal Agency (EMA).

Preclinical Herb-Drug Pharmacokinetic Interaction of Panax ginseng Extract and Selegiline in Freely Moving Rats

Selegiline, an inhibitor of monoamine oxidase B, is prescribed during the early stages of Parkinson's disease. The nutritional herbal medicine Panax ginseng C.A. Meyer has been reported to show potential neuroprotective activity; however, the herb-drug pharmacokinetic interaction between selegiline and P. ginseng extract has not been characterized. Our hypothesis is that the ginseng extract and selegiline produce pharmacokinetic interactions at certain doses. To investigate this hypothesis, a validated ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed to monitor selegiline in rat plasma. Experimental rats were divided into groups treated with selegiline alone (10 mg/kg, i.v.; 30 mg/kg, p.o.), with the low-dose ginseng extract (1 g/kg, p.o., for 5 consecutive days) or with the high-dose ginseng extract (3 g/kg, p.o., for 5 consecutive days). The pharmacokinetic results demonstrated that the oral bioavailability of selegiline alone was approximately 18%; however, when rats were pretreated with low and high doses of the ginseng extract, the bioavailability of selegiline was 7.2 and 29%, respectively. These results suggested that the ginseng extract may produce a biphasic pharmacokinetic phenomenon. In summary, ginseng alters the oral bioavailability of selegiline, and these observations might provide preclinical information concerning the pharmacokinetic interactions between selegiline and herbal supplements.

Potential Interactions of Biologically Based Complementary Medicine in Gynecological Oncology

OBJECTIVE

The aim of this study was to assess the potential risks of interactions between biologically based complementary and alternative medication (BB-CAM) and conventional drugs during systemic therapy in breast and gynecological cancer patients by analyzing the actual CAM-drug combinations from individual patients' records.

METHODS

From September 2014 to December 2014 and from February 2017 to May 2017, all patients (n = 717) undergoing systemic therapy at the Gynecologic Oncology Day Care Unit in the Gynecology and Obstetrics Department of the Technical University of Munich, Germany, were asked to participate in a questionnaire about all their medications. To assess the potential risk of CAM-drug interactions (CDIs), we initially utilized the Lexicomp drug interaction database. This assessment was then expanded with a systematic search of other digital databases, such as the National Center for Complementary and Integrative Health, Memorial Sloan Kettering Cancer Center, PubMed, and MEDLINE as well as the Cochrane Library.

RESULTS

Among 448 respondents, 74.1% reported using BB-CAM simultaneously with their systemic therapy. The assessment showed 1 patient with a potentially clinically relevant CDI, where the interaction was based on a self-medicated combination of Echinacea and cyclophosphamide. Furthermore, 81 patients (18.1%) were thought to have interactions because of a combination of BB-CAMs and cytochrome P450 3A4-metabolized anticancer drugs.

CONCLUSIONS

Our data demonstrated high overall use of BB-CAMs by cancer patients undergoing systemic therapy. The analyses showed only 1 clinically relevant CDI.

Trends in Complementary and Alternative Medicine Use among Patients with Prostate Cancer

PURPOSE

We explored the prevalence and trends of self-reported complementary and alternative medicine use among patients with prostate cancer using CaPSURE™ (Cancer of the Prostate Strategic Urologic Research Endeavor).

MATERIALS AND METHODS

A total of 7,989 CaPSURE participants completed questionnaires between 1996 and 2016 on the use of nearly 70 complementary and alternative medicine types. Participants were defined as users if they indicated that they had ever used complementary and alternative medicines. To evaluate trends among 7,696 patients with newly diagnosed prostate cancer we considered complementary and alternative medicine use within 24 months of diagnosis and calculated the percent change in complementary and alternative medicine use between groups defined by the year of diagnosis.

RESULTS

Of patients with prostate cancer 56% reported complementary and alternative medicine use on at least 1 questionnaire. Multivitamin and omega-3 fatty acid use was common at 40% and 24% of patients, respectively. Compared to nonusers greater proportions of complementary and alternative medicine users were college educated, had a higher household income and lived in the West and Midwest. Median prostate specific antigen at diagnosis was 5.8 (IQR 4.4-8.4) and 6.2 ng/ml (IQR 4.7-10.1) among users and nonusers, respectively (p <0.01). Between those diagnosed in 1996 to 2000 and 2011 to 2016, complementary and alternative medicine use increased 128% from 24% to 54%. When comparing participants diagnosed in 2006 to 2010 with those diagnosed in 2011 to 2016, a 108% increase was seen in supplemental vitamin D use and a -48% decrease was seen in supplemental vitamin E use.

CONCLUSIONS

Many patients with prostate cancer reported complementary and alternative medicine use. Multivitamins and omega-3 fatty acids were commonly ingested and vitamin D use increased dramatically from 2006 to 2010 compared to 2011 to 2016. These data can guide clinical discussions and decision making such as nutritionist referral and help prioritize future research.

P450 enzymes-based metabolic interactions between monarch drugs and the other constituent herbs: A strategy to explore compatibility mechanism of Sangju-Yin

BACKGROUND

Herbal compatibility of compound formulas can enhance therapeutic effects or reduce side effects of the monarch drugs, but majority of compatibility mechanisms are still unknown. Sangju-Yin, a well-known Chinese compound formula, is currently used to treat common cold in clinical.

PURPOSE

In this study, we proposed a strategy to explore the compatibility mechanism of Sangju-Yin by investigating P450 enzymes-based metabolic interactions between monarch drugs and the other constituent herbs.

METHODS

Under the guidance of traditional Chinese medicine theory, the constituent herbs of Sangju-Yin were divided into four groups, including monarch drugs, monarch drugs with addition of minister drugs, monarch drugs with addition of minister and adjuvant drugs, as well as the whole recipe, namely monarch drugs with addition of minister, adjuvant and conductant drugs. Their effects on rats in vivo P450 (CYP1A2, CYP2A3, CYP2C6, CYP2C11 and CYP3A1) activities after oral administration were evaluated using probe drug assay based on LC-MS/MS. Moreover, effects of the four groups of herbs on mRNA expression of P450 enzymes after oral administration, as well as in vitro P450 activities after co-incubation, were investigated to explore the underlying mechanisms.

RESULTS

Comparing with monarch drugs, addition of different constituent herbs significantly enhanced CYP1A2 and CYP2C6 activities, and inhibited CYP2A3 and CYP3A1 activities, indicating their possible influences on plasma concentrations of active constituents in the monarch drugs. Mechanism study suggested that these herbs affected P450 activities by transcriptional regulation and/or direct interaction with the enzymes.

CONCLUSION

This study clarified the compatibility mechanism of Sangju-Yin from the aspect of P450 enzymes-based metabolic interactions, which would benefit better understanding of the therapeutic basis of Sangju-Yin.

Interaction between phytotherapy and oral anticancer agents: prospective study and literature review

Cancer is becoming more prevalent in elderly patient. Due to polypharmacy, older adults with cancer are predisposed to drug-drug interactions. There is also an increasing interest in the use of complementary and alternative medicine (CAM). Thirty to seventy percent of patients with cancer have used CAM. Through pharmaceutical counseling sessions, we can provide advices on herb-drug interactions (HDI). All the patients seen in pharmaceutical counseling sessions were prospectively included. Information was collected during these sessions: prescribed medication (oral anticancer agents (OAA) and other drugs), CAM (phytotherapy especially), and use of over-the-counter (OTC) drugs. If pharmacist considered an interaction or an intervention clinically relevant, the oncologist was notified. Then, a literature review was realized to identify the potential HDI (no interactions, precautions for use, contraindication). Among 201 pharmacist counseling sessions, it resulted in 104 interventions related to 46 HDI, 28 drug-drug interactions and 30 others (wrong dosage, omission…). To determine HDI, we review 73 medicinal plants which are used by our patients with cancer and 31 OAA. A total of 1829 recommendations were formulated about 59 (75%) medical plants and their interaction with an OAA. Herb-drug interactions should not be ignored by healthcare providers in their management of cancer patients in daily practice.

Complementary medicine use during cancer treatment and potential herb-drug interactions from a cross-sectional study in an academic centre

Complementary medicine (CM) is used by one third to one half of cancer patients throughout the world. The objective of this study was to describe the prevalence of CM use and the potential for interactions with cancer treatments in an academic oncology centre. A cross-sectional study was conducted among patients undergoing current cancer treatment. Among 132 included patients, 56% had used CM since their cancer diagnosis and 45% were using CM during cancer treatment at the time of the survey. The main CM used were green tea (35%), herbal tea (35%), homeopathy (27%), dietary supplements (27%), and herbal medicines (27%). A small majority of patients (58%) spontaneously mentioned the use of CM to their oncologist. Of 42 identified combinations of concomitant use of biologically based CM and anticancer agents among the study patients, the potential for pharmacokinetic interactions of clinical relevance was not expected in 17 combinations (40%), hypothetical and deemed unlikely in 23 (55%), and of probable low clinical relevance in 2 (5%). Considering the high prevalence of CM use, active enquiries should be made by healthcare professionals to detect symptoms that may relate to CM tolerance and effects or that suggest interactions between CM and cancer treatments.

Enzyme Kinetics and Molecular Docking Studies on Cytochrome 2B6, 2C19, 2E1, and 3A4 Activities by Sauchinone

Sauchinone, an active lignan isolated from the aerial parts of Saururus chinensis (Saururaceae), exhibits anti-inflammatory, anti-obesity, anti-hyperglycemic, and anti-hepatic steatosis effects. As herb–drug interaction (HDI) through cytochrome P450s (CYPs)-mediated metabolism limits clinical application of herbs and drugs in combination, this study sought to explore the enzyme kinetics of sauchinone towards CYP inhibition in in vitro human liver microsomes (HLMs) and in vivo mice studies and computational molecular docking analysis. In in vitro HLMs, sauchinone reversibly inhibited CYP2B6, 2C19, 2E1, and 3A4 activities in non-competitive modes, showing inhibition constant (K_i) values of 14.3, 16.8, 41.7, and 6.84 μM, respectively. Also, sauchinone time-dependently inhibited CYP2B6, 2E1 and 3A4 activities in vitro HLMs. Molecular docking study showed that sauchinone could be bound to a few key amino acid residues in the active site of CYP2B6, 2C19, 2E1, and 3A4. When sibutramine, clopidogrel, or chlorzoxazone was co-administered with sauchinone to mice, the systemic exposure of each drug was increased compared to that without sauchinone, because sauchinone reduced the metabolic clearance of each drug. In conclusion, when sauchinone was co-treated with drugs metabolized via CYP2B6, 2C19, 2E1, or 3A4, sauchinone–drug interactions occurred because sauchinone inhibited the CYP-mediated metabolic activities.

Inhibitory Effect of Sauchinone on UDP-Glucuronosyltransferase (UGT) 2B7 Activity

Herb-drug interaction (HDI) limits clinical application of herbs and drugs, and inhibition of herbs towards uridine diphosphate (UDP)-glucuronosyltransferases (UGTs) has gained attention as one of the important reasons to cause HDIs. Sauchinone, an active lignan isolated from aerial parts of Saururus chinensis (Saururacease), possesses anti-oxidant, anti-inflammatory, and anti-viral activities. In pharmacokinetics of sauchinone, sauchinone is highly distributed to the liver, forming extensive metabolites of sauchinone via UGTs in the liver. Thus, we investigated whether sauchinone inhibited UGTs to explore potential of sauchinone-drug interactions. In human liver microsomes (HLMs), sauchinone inhibited activities of UGT1A1, 1A3, 1A6, and 2B7 with IC₅₀ values of 8.83, 43.9, 0.758, and 0.279 μM, respectively. Sauchinone also noncompetitively inhibited UGT1A6 and 2B7 with K_i values of 1.08 and 0.524 μM, respectively. In in vivo interaction study using mice, sauchinone inhibited UGT2B7-mediated zidovudine metabolism, resulting in increased systemic exposure of zidovudine when sauchinone and zidovudine were co-administered together. Our results indicated that there is potential HDI between sauchinone and drugs undergoing UGT2B7-mediated metabolism, possibly contributing to the safe use of sauchinone and drug combinations.

In vitro inhibitory effects of major bioactive constituents of Andrographis paniculata, Curcuma longa and Silybum marianum on human liver microsomal morphine glucuronidation: A prediction of potential herb-drug interactions arising from andrographolide, curcumin and silybin inhibition in humans

This study aimed to investigate the liver microsomal inhibitory effects of silybin, silychristin, andrographolide, and curcumin by using morphine as an in vitro UGT2B7 probe substrate, and predict the magnitude of the herb-drug interaction arising from these herbal constituents' inhibition in vivo. Studies were performed in the incubation with and without bovine serum albumin (BSA). Andrographolide and curcumin showed a marked inhibition on morphine 3- and 6-glucuronidation with IC50 of 50&87 and 96&111 μM, respectively. In the presence of 2%BSA, andrographolide also showed a strong inhibition on morphine 3- and 6-glucuronidation (IC50 4.4&21.6 μM) whereas curcumin showed moderate inhibition (IC50 338&333 μM). In the absence and presence of 2%BSA, morphine 3- and 6-glucuronidation was moderately inhibited by silybin (IC50 583&862 and 1252&1421 μM, respectively), however was weakly inhibited by silychristin (IC50 3527&3504 and 1124&1530 μM, respectively). The Ki of andrographolide, curcumin and silybin on morphine 3- and 6-glucuronidation were 7.1&9.5, 72.7&65.2, and 224.5&159.7 μM, respectively, while the respective values generated from the system containing 2%BSA were 2.4&3.1, 96.4&108.8, and 366.3&394.5 μM. Using the in vitro and in vivo extrapolation approach, andrographolide was herbal component that may have had a potential interaction in vivo when it was co-administered with morphine.

Screening of cytochrome P450 3A4 inhibitors via in silico and in vitro approaches

Cytochrome P450 3A4 (CYP3A4) is an important member of the CYP family and responsible for metabolizing a broad range of drugs. It is necessary to establish virtual screening models for predicting CYP3A4 inhibitors.

Toxicity Potential of Nutraceuticals

By the turn of the twenty-first century, the use of nutraceuticals became increasingly popular in both humans and animals due to their easy access, cost-effectiveness, and tolerability with a wide margin of safety. While some nutraceuticals are safe, others have a toxic potential. For a large number of nutraceuticals, no toxicity/safety data are available due to a lack of pharmacological/toxicological studies. The safety of some nutraceuticals can be compromised via contamination with toxic plants, metals, mycotoxins, pesticides, fertilizers, drugs of abuse, etc. Knowledge of pharmacokinetic/toxicokinetic studies appears to play a pivotal role in safety and toxicity assessment of nutraceuticals. Interaction studies are essential to determine efficacy, safety, and toxicity when nutraceuticals and therapeutic drugs are used concomitantly. This chapter describes various aspects of nutraceuticals, particularly their toxic potential, and the factors influencing their safety.

The potent mechanism-based inactivation of CYP2D6 and CYP3A4 with fusidic acid in in vivo bioaccumulation

1. The accumulation of fusidic acid (FA) after multiple doses of FA has been reported on in previous studies but the related mechanisms have not been clarified fully. In the present study, we explain the mechanisms related to the mechanism-based inactivation of CYP2D6 and CYP3A4. 2. The irreversible inhibitory effects of FA on CYP2D6 and CYP3A4 were examined via a series of experiments, including: (a) time-, concentration- and NADPH-dependent inactivation, (b) substrate protection in enzyme inactivation and (c) partition ratio with recombinant human CYP enzymes. Metoprolol α-hydroxylation and midazolam 1'-hydroxylation were used as marker reactions for CYP2D6 and CYP3A4 activities, and HPLC-MS/MS measurement was also utilised. 3. FA caused to the time- and concentration-dependent inactivation of CYP2D6 and CYP3A4. About 55.8% of the activity of CYP2D6 and 75.8% of the activity of CYP3A4 were suppressed after incubation with 10 μM FA for 15 min. K_I and k_inact were found to be 2.87 μM and 0.033 min^-1, respectively, for CYP2D6, while they were 1.95 μM and 0.029 min^-1, respectively, for CYP3A4. Inhibition of CYP2D6 and CYP3A4 activity was found to require the presence of NADPH. Substrates of CYP2D6 and CYP3A4 showed that the enzymes were protected against the inactivation induced by FA. The estimated partition ratio for the inactivation was 7 for CYP2D6 and 12 for CYP3A4. 4. FA is a potent mechanism-based inhibitor of CYP2D6 and CYP3A4, which may explain the accumulation of FA in vivo.

Muscadine Grape Skin Extract (MPX) in Men with Biochemically Recurrent Prostate Cancer: A Randomized, Multicenter, Placebo-Controlled Clinical Trial

Purpose: MuscadinePlus (MPX), a commercial preparation of pulverized muscadine grape skin, was evaluated as a therapeutic option for men with biochemically recurrent (BCR) prostate cancer wishing to defer androgen deprivation therapy.Experimental Design: This was a 12-month, multicenter, placebo-controlled, two-dose, double-blinded trial of MPX in 125 men with BCR prostate cancer, powered to detect a PSA doubling time (PSADT) difference of 6 months (low dose) and 12 months (high dose) relative to placebo. Participants were stratified (baseline PSADT, Gleason score) and randomly assigned 1:2:2 to receive placebo, 500 mg MPX (low), or 4,000 mg MPX (high) daily. Correlates included superoxide dismutase-2 (SOD2) genotype, lipid peroxidation, and polyphenol pharmacokinetics.Results: The evaluable population included 112 patients, all treated for at least 6 months and 62% treated for 12 months. No significant difference was found in PSADT change between control and treatment arms (P = 0.81): control 0.9 months (n = 20; range, 6.7-83.1), low dose 1.5 months (n = 52; range, 10.3-87.2), high dose 0.9 months (n = 40; range, 27.3-88.1). One high-dose patient experienced objective response. No drug-related CTCAE grade 3-4 adverse events were seen. In a preplanned exploratory analysis, PSADT pre-to-post increase was significant in the 27 (26%) genotyped patients with SOD2 Alanine/Alanine genotype (rs4880 T>C polymorphism) on MPX (pooled treatment arms; 6.4 months, P = 0.02), but not in control (1.8 months, P = 0.25).Conclusions: Compared with placebo, MPX did not significantly prolong PSADT in BCR patients over two different doses. Exploratory analysis revealed a patient population with potential benefit that would require further study. Clin Cancer Res; 24(2); 306-15. ©2017 AACR.

Noncompetitive inhibition of human CYP2C9 in vitro by a commercial Rhodiola rosea product

A commercial Rhodiola rosea (R. rosea) product has previously demonstrated CYP2C9 inhibition in humans. The purpose of this study was to provide in vitro inhibitory data for this particular interaction and to classify the mechanism of the interaction. Another aim was to examine the in vitro influence of ethanol on the CYP2C9 activity. Human CYP2C9 (wild type) isolated from a baculovirus‐infected cell system was incubated with 0.8 μmol/L losartan for 20 min. Sulfaphenazole was used as a positive control. The commercial R. rosea product “Arctic Root” was used as test inhibitor. Formation of the CYP2C9‐produced losartan metabolite EXP‐3174 was determined by validated LC‐MS/MS methodology. Possible mechanism‐based (irreversible) inhibition was evaluated using time‐ and NADPH‐dependent inhibition assays. Kinetic constants (K_m, V_max, and K_i) were calculated from a Lineweaver‐Burk plot. Mode of inhibition was determined. CYP2C9 was inhibited by “Arctic Root” with an IC₅₀ (extract concentration yielding 50% reduction in enzyme activity) of 19.2 ± 2.7 μg/mL. Inhibitor concentrations of 20 μg/mL and 40 μg/mL yielded K_i values of 16.37 μg/mL and 5.59 μg/mL, respectively. The Lineweaver‐Burk plot showed noncompetitive inhibition mode. No time‐ or NADPH‐dependent inhibition was observed. The presence of ethanol inhibited CYP2C9 activity in a concentration‐dependent manner. In conclusion, the commercial R. rosea product “Arctic Root” demonstrated noncompetitive inhibition of CYP2C9 in vitro. Further work identifying the constituents responsible for this inhibition is needed.

Correlative analysis of plasma SN-38 levels and DPD activity with outcomes of FOLFIRI regimen for metastatic colorectal cancer with UGT1A1 *28 and *6 wild type and its implication for individualized chemotherapy

It remains uncertain whether there is an correlation between clinical pharmacokinetic parameters and outcomes for metastatic colorectal cancer especially with UGT1A1 *28 and *6 wild type (*1/*1-*1/*1) for serious events associated with Irinotecan are largely excluded. This study retrospectively analyzed the relationship between Irinotecan metabolite levels and outcomes of UGT1A1 *1/*1-*1/*1 genotype arrangement. Blood samples (n = 244) were collected for analysis of plasma DPD activity (before first chemotherapy) and SN-38 levels (1.5 and 49 hour after CPT-11 administration). Clinical variables such as toxicity and outcomes were then assessed. Of the *1/*1 -*1/*1 genotype combination, the median progression free survival of the C_{SN-38 1.5 h} > 50.24 ng/ml subset was remarkably longer than that of the C_{SN-38 1.5 h} ≤ 50.24 ng/ml subset. However, there were no differences between the C_{SN-38 49 h} > 15.25 ng/ml subgroup and the ≤ 15.25 ng/ml group. It was lower DPD activity that responsible for the relatively higher incidence of bone marrow hypocellular, diarrhea, and oral mucositis in the C_{SN-38 1.5 h} > 50.24 ng/ml and C_{SN-38 49 h} > 15.25 ng/ml subsets. Therefore, plasma SN-38 levels is related to outcomes for UGT1A1 *1/*1-*1/*1 genotype, to improve efficacy, patients with C_{SN-38 1.5 h} lower than 50.24 ng/ml, CPT-11 dosage could be added in next chemmotherapy on SN-38 plasma level monitoring. Additionally, in patients with DPD activity below 3.18 before treatment, appropriate reduction of 5-FU dose could be considered to minimize the incidence of adverse events.

Practical considerations when designing and conducting clinical pharmacokinetic herb–drug interaction studies

Pharmacokinetic herb–drug interaction (HDI) research has been ongoing for almost two decades and a significant body of information has been published on the subject, yet much of it is contradictory. Some of this disparity stems from the botanical dosage form itself, as product quality and dosage form performance can vary significantly among brands. Unless products are adequately characterized, HDI study results can be misleading. The purpose of this report is to identify several common weaknesses inherent in many prospective clinical HDI studies and to provide guidance in addressing these shortcomings. Topics such as study design, pharmacokinetic end points, product quality, dosage form performance, gauging clinical relevance, and efforts to minimize dietary influences while improving compliance are discussed.

In vitro inhibition of cytochrome P-450 activities and quantification of constituents in a selection of commercial Rhodiola rosea products

CONTEXT

Rhodiola rosea L. (Crassulaceae) products are popular natural remedies with a worldwide distribution. Recent studies have revealed potent CYP inhibition by R. rosea extracts both in vitro and in vivo, but information on in vitro CYP inhibition by commercial products are lacking. Variations in commercial R. rosea product quality have also been published.

OBJECTIVE

This study evaluates the variation of in vitro CYP inhibition potential and product quality of six commercially available R. rosea products.

MATERIALS AND METHODS

Human CYPs isolated from baculovirus-infected cell system were incubated with testosterone (CYP3A4), dextromethorphan (CYP2D6) or phenacetin (CYP1A2). Positive CYP inhibitors ketoconazole (CYP3A4), quinidine (CYP2D6) and β-naphtoflavone (CYP1A2) were used as controls. Quantification of rosavin, rosarin, rosin, tyrosol and salidroside were used to evaluate R. rosea content.

RESULTS

IC₅₀ values ranged from 7.2-106.6 μg/mL for CYP3A4, 13.0-186.1 μg/mL for 2D6 and 10.7-116.0 μg/mL for 1A2. The tincture formulation of R. rosea was the strongest inhibitor giving the lowest IC₅₀ values of 7.2 ± 0.7, 13 ± 1.7 and 10.7 ± 5.6 μg/mL, respectively. CYP3A4 was significantly more inhibited by the different products than CYP1A2 (p < .05). One of the six products did not contain any rosavin, rosarin or rosin and is not a R. rosea product. Constituent concentrations were not linked to enzyme inhibition.

DISCUSSION AND CONCLUSION

The present results show a large variation in inhibitory potential between the products. Several of the products demonstrate similar inhibition levels as the product Arctic Root already proven to inhibit CYP enzyme activity in man.

Screening of drug metabolizing enzymes for fusidic acid and its interactions with isoform-selective substrates in vitro

1. Fusidic acid (FA) is widely used for the treatment of infections of sensitive osteomyelitis or skin and soft tissue caused by bacteria. However, the role of cytochrome P450s (CYPs) in the metabolism of FA is unclear. In the present study, we screened the main CYPs for the metabolism of FA and studied its interactions with isoform-selective substrates in vitro. 2. The main CYP450s were screened according to the inhibitory effect of specific inhibitors on the metabolism of FA in human liver microsomes (HLMs) or recombinant CYP isoforms. Enzyme kinetic parameters including K_i, K_i', V_max, and IC₅₀ were calculated to determine the potential of FA to affect CYP-mediated metabolism of isoform-selective substrates. 3. FA metabolism rate was inhibited by 49.8% and 83.1% under CYP2D6, CYP3A4 selective inhibitors in HLMs. In recombinant experiment, the inhibitory effects on FA metabolism were 83.3% for CYP2D6 and 58.9% for CYP3A4, respectively. FA showed inhibition on CYP2D6 and CYP3A4 with K_is of 13.9 and 38.6 μM, respectively. Other CYP isoforms including CYP1A2, CYP2A6, CYP2C9, CYP2E1, and CYP2C19 showed minimal or no effect on the metabolism of FA. 4. FA was primarily metabolized by CYP2D6 and CYP3A4 and showed a noncompetitive inhibition on CYP2D6 and a mixed competitive inhibition on CYP3A4. Drug-drug interactions between FA and other chemicals, especially with substrates of CYP2D6 and CYP3A4, are phenomena that clinicians need to be aware of and cautious about.

Metabolic profile and safety of piperlongumine

Piperlongumine (PPL), a natural plant product, has been extensively studied in cancer treatment going up on clinical trials. Since the first report related to its use on cancer research (in 2011) around 80 papers have been published in less than 10 years, but a gap still remaining. There are no metabolism studies of PPL in human organism. For the lack of a better view, here, the CYP450 in vitro oxidation of PPL was described for the first time. In addition, the enzymatic kinetic data, the predicted in vivo parameters, the produced metabolites, the phenotyping study and possible piperlongumine-drug interactions in vivo is presented.

Drug-drug interactions of cytostatics with regular medicines in lung cancer patients

Background Lung cancer patients have a high risk for drug-drug interactions, as they use numerous types of concomitant medicines including antineoplastic agents, cancer treatment co-medication, and medicines aimed at several types of comorbidities. Objective The primary objective of this study is to determine the incidence and the clinical relevance of the drug-drug interactions between antineoplastic agents and regular medication used by lung cancer patients. Secondary objectives are (i) to determine the effectiveness of the medication review by the hospital pharmacists concerned, (ii) to establish which patients are most at risk of drug-drug interactions and (iii) to determine whether physicians comply with advice given by hospital pharmacists. Setting This prospective study was undertaken in a Dutch hospital pharmacy, at Onze Lieve Vrouwe Gasthuis (OLVG), Amsterdam. Methods All lung cancer patients receiving one or more cytotoxic agents during the period 21 June 2010 till 2 December 2014 at OLVG were included. The medication list of the patients was obtained electronically from the community pharmacy and checked for interactions by a hospital pharmacist. Interactions that required intervention according to the national database were the only ones taken into account. Interventions were recorded in the patients' electronic charts. All medication reviews were cross-checked and analyzed by an independent pharmacist at the end of the study period. Main outcome measure Prevalence and clinical relevance of drug-drug interactions between antineoplastic agents and other types of medication in lung cancer patients. Results A total of 298 lung cancer patients were included in this study. In 53 patients (18%), a total of 73 interactions with potential clinical relevance were found. The most frequent interaction was between cytostatics and coumarins while the most relevant one was between cisplatin and furosemide. According to statistical analysis, gender as well as the number of drugs prescribed were significant predictors for drug-drug interactions. Eighty-four percent of the interactions were discovered by pharmacists during daily routine. In 92% of the cases, the pulmonary physicians complied with the advice of the pharmacist. Conclusion Eighteen percent of lung cancer patients treated with cytotoxic therapy had one or more relevant drug-drug interactions. This study shows that medication surveillance by a hospital pharmacist is necessary to prevent possible negative drug-drug interactions. Further research should focus on the clinical outcome of the interactions as well as on interactions between cytostatics and alternative medicines and/or over-the-counter medicines.

Interaction effects on cytochrome P450 both in vitro and in vivo studies by two major bioactive xanthones from Halenia elliptica D. Don

The major components, 1-hydroxy-2,3,5-trimethoxy-xanthone (HM-1) and 1,5-dihydroxy-2,3-dimethoxy-xanthone (HM-5) isolated from Halenia elliptica D. Don (Gentianaceae), could cause vasodilatation in rat coronary artery with different mechanisms. In this work, high-performance liquid chromatography coupled to ion trap time-of-flight mass spectrometry (LCMS-IT-TOF) was used to clarify the metabolic pathways, and CYP450 isoform involvement of HM-1 and HM-5 were also studied in rat. At the same time, in vivo inhibition effects of HM-1 and ethyl acetate extracts from origin herb were studied. Three metabolites of HM-5 were found in rat liver microsomes (RLMs); demethylation and hydroxylation were the major phase I metabolic reactions for HM-5. Multiple CYP450s were involved in metabolism of HM-1 and HM-5. The inhibition study showed that HM-5 inhibited Cyp1a2, 2c6 and 2d2 in RLMs. HM-1 inhibited activities of Cyp1a2, Cyp2c6 and Cyp3a2. In vivo experiment demonstrated that both HM-1 and ethyl acetate extracts could inhibit Cyp3a2 in rats. In conclusion, the metabolism of xanthones from the origin herb involved multiple CYP450 isoforms; in vitro, metabolism of HM-5 was similar to that of its parent drug HM-1, but their inhibition effects upon CYP450s were different; in vivo, Cyp3a2 could be inhibited by HM-1 and ethyl acetate extracts.

Screening of Drug Metabolizing Enzymes for the Ginsenoside Compound K In Vitro: An Efficient Anti-Cancer Substance Originating from Panax Ginseng

Ginsenoside compound K (CK), a rare ginsenoside originating from Panax Ginseng, has been found to possess unique pharmacological activities specifically as anti-cancers. However, the role of cytochrome P450s (CYPs) in the metabolism of CK is unclear. In this study, we screened the CYPs for the metabolism of CK in vitro using human liver microsomes (HLMs) or human recombinant CYPs. The results showed that CK inhibited the enzyme activities of CYP2C9 and CYP3A4 in the HLMs. The K_m and V_max values of CK were 84.20±21.92 μM and 0.28±0.04 nmol/mg protein/min, respectively, for the HLMs; 34.63±10.48 μM and 0.45±0.05 nmol/nmol P450/min, respectively, for CYP2C9; and 27.03±5.04 μM and 0.68±0.04 nmol/nmol P450/min, respectively, for CYP3A4. The IC₅₀ values were 16.00 μM and 9.83 μM, and K_i values were 14.92 μM and 11.42μM for CYP2C9 and CYP3A4, respectively. Other human CYP isoforms, including CYP1A2, CYP2A6, CYP2D6, CYP2E1, and CYP2C19, showed minimal or no effect on CK metabolism. The results suggested that CK was a substrate and also inhibitors for both CYP2C9 and CYP3A4. Patients using CK in combination with therapeutic drugs that are substrates of CYP2C9 and CYP3A4 for different reasons should be careful, although the inhibiting potency of CK is much poorer than that of enzyme-specific inhibitors.