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

Effect of eugenol on cytochrome P450 1A2, 2C9, 2D6, and 3A4 activity in human liver microsomes

This study aimed to provide an understanding of the influence of eugenol on CYP1A2, 2C9, 2D6, and 3A4 in human liver microsomes (HLM). Specific substrate for CYP1A2, 2C9, 2D6, and 3A4 were incubated in HLM with or without eugenol. The formation of their respective metabolites was assessed with HPLC analytical methods. Eugenol at 1, 10 and 100 µM levels inhibited the activity of CYP1A2 and CYP2C9 by 23.38 %, 23.57 %, 39.80 % and 62.82 %, 63.27 %, 67.70 % respectively. While, CYP2D6 and CYP3A4 activity was decreased by 40.70 %, 45.88 %, 62.68 % and 37.41 %, 42.58 % and 67.86 % at 1, 10 and 100 µM eugenol level respectively. The IC50 value of eugenol for CYP2D6 and CYP3A4 was calculated as 11.09 ± 3.49 µM and 13.48 ± 3.86 µM respectively. Potential herb-drug interactions was noted when eugenol is administered simultaneously with medications metabolized by these enzymes, most notably CYP2C9, CYP2D6 and CYP3A4.

Silymarin: Unveiling its pharmacological spectrum and therapeutic potential in liver diseases-A comprehensive narrative review

Liver diseases, encompassing conditions such as cirrhosis, present a substantial global health challenge with diverse etiologies, including viral infections, alcohol consumption, and non-alcoholic fatty liver disease (NAFLD). The exploration of natural compounds as therapeutic agents has gained traction, notably the herbal remedy milk thistle (Silybum marianum), with its active extract, silymarin, demonstrating remarkable antioxidant and hepatoprotective properties in extensive preclinical investigations. It can protect healthy liver cells or those that have not yet sustained permanent damage by reducing oxidative stress and mitigating cytotoxicity. Silymarin, a natural compound with antioxidant properties, anti-inflammatory effects, and antifibrotic activity, has shown potential in treating liver damage caused by alcohol, NAFLD, drug-induced toxicity, and viral hepatitis. Legalon® is a top-rated medication with excellent oral bioavailability, effective absorption, and therapeutic effectiveness. Its active component, silymarin, has antioxidant and hepatoprotective properties, Eurosil 85® also, a commercial product, has lipophilic properties enhanced by special formulation processes. Silymarin, during clinical trials, shows potential improvements in liver function, reduced mortality rates, and alleviation of symptoms across various liver disorders, with safety assessments showing low adverse effects. Overall, silymarin emerges as a promising natural compound with multifaceted hepatoprotective properties and therapeutic potential in liver diseases.

Changing Trends Towards Herbal Supplements: An Insight into Safety and Herb-drug Interaction

Herbs have been used as sustenance and medicine for a very long time, often in conjunction with other prescribed medications. Even though they are thought to be natural and secure, many of these herbs can interact with other medications and cause potentially dangerous adverse effects or decrease the benefits of the medication. The complex and diverse pharmacological functions carried out by the active ingredients in herbs unavoidably alter the pharmacokinetics of chemical drugs when administered in vivo. Drug transporter expression has a direct impact on how medications are absorbed, distributed, metabolized, and excreted in living organisms. Changes in substrate pharmacokinetics can affect the effectiveness and toxicity of a drug when the active ingredients of a herb inhibit or stimulate the expression of transporters. By reviewing published clinical and preclinical studies, this review aims to raise awareness of herbdrug interactions and discuss their evidence-based mechanisms and clinical consequences. More clinical information on herb-drug interactions is required to make choices regarding patient safety as the incidence and severity of herb-drug interactions are rising due to an increase in the use of herbal preparations globally.This review seeks to increase understanding of herb-drug interactions and explore their evidence-based mechanisms and clinical implications by reviewing published clinical and preclinical studies. The incidence and severity of herb-drug interactions are on the rise due to an increase in the use of herbal preparations worldwide, necessitating the need for more clinical data on these interactions in order to make decisions regarding patient safety. Healthcare workers and patients will become more alert to potential interactions as their knowledge of pharmacokinetic herb-drug interactions grows. The study's objective is to raise readers' awareness of possible interactions between herbal supplements and prescription medications who regularly take them.

Optimizing human performance in extreme environments through precision medicine: From spaceflight to high-performance operations on Earth

Humans operating in extreme environments often conduct their operations at the edges of the limits of human performance. Sometimes, they are required to push these limits to previously unattained levels. As a result, their margins for error in execution are much smaller than that found in the general public. These same small margins for error that impact execution may also impact risk, safety, health, and even survival. Thus, humans operating in extreme environments have a need for greater refinement in their preparation, training, fitness, and medical care. Precision medicine (PM) is uniquely suited to address the needs of those engaged in these extreme operations because of its depth of molecular analysis, derived precision countermeasures, and ability to match each individual (and his or her specific molecular phenotype) with any given operating context (environment). Herein, we present an overview of a systems approach to PM in extreme environments, which affords clinicians one method to contextualize the inputs, processes, and outputs that can form the basis of a formal practice. For the sake of brevity, this overview is focused on molecular dynamics, while providing only a brief introduction to the also important physiologic and behavioral phenotypes in PM. Moreover, rather than a full review, it highlights important concepts, while using only selected citations to illustrate those concepts. It further explores, by demonstration, the basic principles of using functionally characterized molecular networks to guide the practical application of PM in extreme environments. At its core, PM in extreme environments is about attention to incremental gains and losses in molecular network efficiency that can scale to produce notable changes in health and performance. The aim of this overview is to provide a conceptual overview of one approach to PM in extreme environments, coupled with a selected suite of practical considerations for molecular profiling and countermeasures.

Crude extract from Euphorbia prostrata extended curative period of glibenclemide in alloxan-induced diabetic rats

OBJECTIVES

Euphorbia prostrata is traditionally used alongside antidiabetic agents to manage diabetes. Bioactive ingredients of medicinal herbs may alter the overall pharmacokinetics of antidiabetic agents.

METHODS

We assessed hypoglycemic activities of ethanolic plant extract (EPE) singly and its effects on antidiabetic properties of gliclazide, glibenclemide and metformin in allaxonized rats. Varying concentrations of EPE (250 and 500 mg/kg) with or without metformin (10 mg/kg), glibenclemide (2 mg/kg) and gliclazide (5 mg/kg) were orally administered to evaluate herb-drug interaction.

RESULTS

The levels of blood glucose declined significantly after treatment with metformin, glibenclemide and gliclazide singly (p<0.01) or concomitantly with EPE (p<0.001). Concentration dependent mild to moderate reduction (5.2 and 10.0%) was registered in blood glucose for 250 and 500 mg/kg of EPE respectively. The overall reduction in blood glucose due to combined treatment with EPE and standard agents was additive. On the other hand, synergistic herb-drug interaction was registered for insulin levels in rats that received glibenclamide and gliclazide alongside EPE. Extract with metformin had antagonistic insulin outcome. Regarding the duration of hypoglycemic activities, periodical changes were similar in case of glibenclamide and gliclazide separately or in combination with EPE. However, in case of metformin with extract, the blood glucose continued to decline for 14 h and retained at 15.0% below the baseline values even after 24 h of treatment.

CONCLUSIONS

In conclusion, the extract itself had weak hypoglycemic effects but prolonged the therapeutic duration of metformin to more than 24 h when administered combinedly.

Safety of Onabotulinumtoxin A in Chronic Migraine: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Some 14% of global prevalence, based on high-income country populations, suffers from migraine. Chronic migraine is very disabling, being characterized by at least 15 headache days per month of which at least 8 days present the features of migraine. Onabotulinumtoxin A, targeting the machinery for exocytosis of neurotransmitters and neuropeptides, has been approved for use in chronic migraine since 2010. This systematic review and meta-analysis appraises the safety of onabotulinumtoxin A treatment for chronic migraine and the occurrence of treatment-related adverse events (TRAEs) in randomized, clinical studies in comparison with placebo or other comparators and preventative treatments according to the most updated Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 recommendations. The search retrieved 888 total records. Nine studies are included and seven were eligible for meta-analysis. The present study demonstrates that toxin produces more TRAEs than placebo, but less than oral topiramate, supporting the safety of onabotulinumtoxin A, and highlights the heterogeneity of the studies present in the literature (I² = 96%; p < 0.00001). This points to the need for further, adequately powered, randomized clinical trials assessing the safety of onabotulinumtoxin A in combination with the newest treatment options.

Everyday Evaluation of Herb/Dietary Supplement–Drug Interaction: A Pilot Study

A lack of reliable information hinders the clinician evaluation of suspected herb–drug interactions. This pilot study was a survey-based study conceived as a descriptive analysis of real-life experiences with herb–drug interaction from the perspective of herbalists, licensed health-care providers, and lay persons. Reported dietary supplement–drug interactions were evaluated against the resources most commonly cited for the evaluation of potential supplement–drug interactions. Disproportionality analyses were performed using tools available to most clinicians using data from the U.S. Federal Adverse Event Reporting System (FAERS) and the US Center for Food Safety and Applied Nutrition (CFSAN) Adverse Event Reporting System (CAERS). Secondary aims of the study included exploration of the reasons for respondent use of dietary supplements and qualitative analysis of respondent’s perceptions of dietary supplement–drug interaction. While agreement among reported supplement–drug interactions with commonly cited resources for supplement–drug interaction evaluation and via disproportionality analyses through FAERS was low, agreement using data from CAERS was high.

Amelioration of 5-Fluorouracil Induced Nephrotoxicity by Acacia catechu through Overcoming Oxidative Damage and Inflammation in Wistar Rats

AIM

The research intended to explore the possible nephroprotective potential of the ethyl acetate fraction derived from Acacia catechu leaves against nephrotoxicity brought about by 5-fluorouracil (5-FU) in Wistar rats.

BACKGROUND

While possessing strong anticancer properties, 5-FU is hindered in its therapeutic application due to significant organ toxicity linked to elevated oxidative stress and inflammation.

OBJECTIVE

The study is undertaken to conduct an analysis of the ethyl acetate fraction of A. catechu leaves both in terms of quality and quantity, examining its impact on different biochemical and histopathological parameters within the context of 5-FU-induced renal damage in rats and elucidation of the mechanism behind the observed outcomes.

METHODOLOGY

Intraperitoneal injection of 5-FU at a dosage of 20 mg/kg/day over 5 days was given to induce nephrotoxicity in rats. The evaluation of nephrotoxicity involved quantifying serum creatinine, urea, uric acid, and electrolyte concentrations. Furthermore, superoxide dismutase, catalase antioxidant enzymes, and TNF-α concentration in serum were also measured.

RESULTS

5-FU injection led to the initiation of oxidative stress within the kidneys, leading to modifications in renal biomarkers (including serum creatinine, urea, uric acid, and Na+, K+ levels), and a reduction in antioxidant enzymes namely superoxide dismutase and catalase. Notably, the presence of the inflammatory cytokine TNF-α was significantly elevated due to 5-FU. Microscopic examination of renal tissue revealed tubular degeneration and congestion. However, treatment involving the ethyl acetate fraction derived from A. catechu leaves effectively and dose-dependently reversed the changes observed in renal biomarkers, renal antioxidant enzymes, inflammatory mediators, and histopathological features, bringing them closer to normal conditions. The observed recuperative impact was mainly attributed to the antioxidant and antiinflammatory properties of the fraction.

CONCLUSION

The ethyl acetate fraction of A. catechu leaves exhibited a mitigating influence on the renal impairment caused by 5-FU, showcasing its potential as a nephroprotective agent capable of preventing and ameliorating 5-FU-induced nephrotoxicity.

Cytochrome P450 inhibition activities of non-standardized botanical products

ETHNOPHARMACOLOGICAL RELEVANCE

R-tab, H-tab and E-cap botanical products are used for the treatment of various ailments. R-tab is traditionally prescribed for improving urination, H-tab is for relieving piles, hemorrhoids, fissures, and rectal inflammation and E-cap is for regulating menstruation.

AIMS OF THE STUDY

To extract the botanical products and determine their potential interaction with the cytochrome P450 (CYP1A2, CYP2D6 and CYP3A4) enzymes.

MATERIALS AND METHODS

R-tab, H-tab and E-cap botanical products were first extracted using solvents and analyzed using HPLC and LC-MS/MS. The effects of methanol extracts on the cytochrome induction and inhibition activities were determined using a series of in vitro assays, including multiplex RT-qPCR, CYP activity assays (P450-Glo™) and LC-MS/MS-based assays. For the CYP induction assay, omeprazole, rifampicin and dexamethasone were used as CYP1A2, CYP2D6 and CYP3A4 inducers, respectively. Ketoconazole and acetaminophen were used as positive and negative controls for the CYP3A4 inhibition assay, whereas furafylline and ketoconazole were used as positive and negative controls for the CYP1A2 inhibition assay.

RESULTS

All three botanical products did not show any significant induction in CYP1A2, CYP2D6 and CYP3A4 mRNA expression. By contrast, R-tab inhibited the mRNA expression of CYP1A2 significantly from the lowest concentration of 0.01 μg/mL, while, H-tab inhibited the mRNA expression of CYP1A2 and CYP3A4 from 0.1 μg/mL. Based on the P450 Glo assays, E-cap extract inhibited the metabolic activity of CYP1A2 with an IC₅₀ value of 37.24 μg/mL. On the other hand, R-tab, H-tab and E-cap showed inhibitory effects on the CYP3A4 enzymatic activity with IC₅₀ values of 17.42, 18.20 and 20.60 μg/mL, respectively. However, using the LC-MS/MS-based methods, the concentration-dependent effects of R-tab and H-tab extracts on the metabolism of testosterone appeared to be more prominent, with IC₅₀ values of 51.90 and 56.90 μg/mL as compared with the rest of the results, which were all above 100 μg/mL CONCLUSION: The CYP3A4 mRNA and enzymatic activity were moderately inhibited by R-tab and H-tab. Methanol extract of botanical products in solid dosage forms can be evaluated for their herb-drug interaction risks using in vitro assays and may provide the minimum data required for safety labeling.

Advances in Pharmacokinetic Mechanisms of Transporter-Mediated Herb-Drug Interactions

As the use of herbs has become more popular worldwide, there are increasing reports of herb-drug interactions (HDIs) following the combination of herbs and drugs. The active components of herbs are complex and have a variety of pharmacological activities, which inevitably affect changes in the pharmacokinetics of chemical drugs in vivo. The absorption, distribution, metabolism, and excretion of drugs in vivo are closely related to the expression of drug transporters. When the active components of herbs inhibit or induce the expression of transporters, this can cause changes in substrate pharmacokinetics, resulting in changes in the efficacy and toxicity of drugs. In this article, the tissue distribution and physiological functions of drug transporters are summarized through literature retrieval, and the effects of herbs on drug transporters and the possible mechanism of HDIs are analyzed and discussed in order to provide ideas and a reference for further guiding of safe clinical drug use.

Effects of Palmitoylethanolamide (PEA) on Nociceptive, Musculoskeletal and Neuropathic Pain: Systematic Review and Meta-Analysis of Clinical Evidence

Some 30−50% of the global population and almost 20% of the European population actually suffer from chronic pain, which presents a tremendous burden to society when this pain turns into a disability and hospitalization. Palmitoylethanolamide (PEA) has been demonstrated to improve pain in preclinical contexts, but an appraisal of clinical evidence is still lacking. The present study aimed at addressing the working hypothesis for the efficacy of PEA for nociceptive musculoskeletal and neuropathic pain in the clinical setting. The systematic search, selection and analysis were performed in agreement with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 recommendations. The primary outcome was pain reduction, as measured by a pain assessment scale. The secondary outcome was improvement in quality of life and/or of parameters of function. The results obtained for a total of 933 patients demonstrate the efficacy of PEA over the control (p < 0.00001), in particular in six studies apart from the two randomized, double-blind clinical trials included. However, the results are downgraded due to the high heterogeneity of the studies (I2 = 99%), and the funnel plot suggests publication bias. Efficacy in achieving a reduction in the need for rescue medications and improvement in functioning, neuropathic symptoms and quality of life are reported. Therefore, adequately powered randomized, double-blind clinical trials are needed to deepen the domains of efficacy of add-on therapy with PEA for chronic pain. PROSPERO registration: CRD42022314395.

Analgesic Characteristics of NanoBEO Released by an Airless Dispenser for the Control of Agitation in Severe Dementia

Chronic pain is one of the most common causes of the need for clinical evaluation, acquiring more importance in the elderly with cognitive impairment. Reduced self-reporting capabilities cause unrelieved pain contributing to the development of agitation. Safe and effective pain treatment can afford the management of agitation without the serious increase in death risk associated with neuroleptics. To this aim, the essential oil of bergamot (BEO), proven by rigorous evidence to have strong preclinical anti-nociceptive and anti-allodynic properties, has been engineered (NanoBEO, patent EP 4003294) to allow randomized, double-blind, placebo-controlled trials (BRAINAID, NCT04321889). The present study: (1) assesses the analgesic effects of a single therapeutic dose of NanoBEO, as supplied by an airless dispenser for clinical translation, in models of inflammatory, neuropathic, and sensitization types of pain relevant to clinic; (2) provides a dose-response analysis of the efficacy of NanoBEO on scratching behavior, a typical behavioral disturbance occurring in dementia. A single therapeutic dose of NanoBEO confirms efficacy following thirty minutes pre-treatment with capsaicin and on the central sensitization phase induced by formalin. Moreover, it has an ID50 of 0.6312 mg and it is efficacious on static and dynamic mechanical allodynia. Altogether, the gathered results strengthen the potential of NanoBEO for clinical management of pain and agitation.

Pharmacotechnological Advances for Clinical Translation of Essential Oils for the Treatment of Pain and Agitation in Severe Dementia

The demand for natural products is steadily increasing, and pharmacotechnological engineering is needed to allow rigorous investigation of their efficacy and safety in clinical conditions representing still unmet needs. Among aged patients affected by dementia, up to 80% of residents in nursing homes suffer from chronic pain and 97% from fluctuant neuropsychiatric symptoms (NPS), of which the most challenging is agitation. It is, at least in part, due to undertreated pain and treated with antipsychotics almost doubling the risk of death. In the frame of a scoping review assessing the existence of essential oils undergoing engineering pharmacotechnological processes using solid lipid nanoparticle delivery systems for clinical translation in pain and/or neuropsychiatric symptoms of dementia following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR), here we identified that the sole essential oil engineered to overcome the criticisms of aromatherapy clinical trials in pain and dementia is the essential oil of bergamot (BEO). Therefore, we present the process leading to the actually ongoing randomized, double-blind, placebo-controlled NCT04321889 clinical trial to assess the efficacy and safety of intervention with bergamot in the management of agitation and pain in severe dementia to be followed also for the proof of concept of efficacy and safety of other essential oils.

Inhibitory effects of Triphala on CYP isoforms in vitro and its pharmacokinetic interactions with phenacetin and midazolam in rats

Context

Direct evidence of Triphala-drug interactions has not been provided to date.

Objective

This study was aimed to determine the effects of Triphala on cytochrome P450 (CYP) isoforms and P-glycoprotein (P-gp) in vitro, and to investigate pharmacokinetic interactions of Triphala with CYP-probes in rats.

Materials and methods

Effects of Triphala on the activities of CYP isoforms and P-gp were examined using human liver microsomes (HLMs) and Caco-2 cells, respectively. Pharmacokinetic interactions between Triphala and CYP-probes (i.e., phenacetin and midazolam) were further examined in rats.

Results

Triphala extract inhibited the activities of CYP isoforms in the order of CYP1A2>3A4>2C9>2D6 with the IC₅₀ values of 23.6 ± 9.2, 28.1 ± 9.8, 30.41 ± 16.7 and 93.9 ± 27.5 μg/mL, respectively in HLMs. It exhibited a non-competitive inhibition of CYP1A2 and 2C9 with the K_i values of 23.6 and 30.4 μg/mL, respectively, while its inhibition on CYP3A4 was competitive manner with the Ki values of 64.9 μg/mL. The inhibitory effects of Triphala on CYP1A2 and 3A4 were not time-dependent. Moreover, Triphala did not affect the P-gp activity in Caco-2 cells. Triphala, after its oral co-administration at 500 mg/kg, increased the bioavailabilities of phenacetin and midazolam by about 61.2% and 40.7%, respectively, in rats.

Discussion and conclusions

Increases observed in the bioavailabilities of phenacetin and midazolam after oral co-administration of Triphala in rats provided a direct line of evidence to show Triphala-drug interactions via inhibition of CYP1A and CYP3A activities, respectively. These results, together with the lack of time-dependency of CYP 1A2 and 3A4 inhibition in vitro, suggested that the inhibitory effect of Triphala is primarily reversible.

Translational Value of the Transdermal Administration of Bergamot Essential Oil and of Its Fractions

The essential oil of bergamot (BEO) has consistently proven antinociceptive and antiallodynic properties. Accordingly, the analgesic efficacy of the decolored essential oil (DEC), with higher levels of limonene, and the deterpenated (DET) fraction, with higher levels of linalool and linalyl acetate, was investigated using a formalin test after inhalation. The present study was aimed at characterizing the effects of BEO, its components with the highest pharmacological activity (represented by linalool, limonene, and linalyl acetate), and its DEC and DET fractions on the formalin test after transdermal administration relevant to clinical translation through topical application. To this aim, the schedule of intervention involved administration immediately after formalin injection or as a 5 min pretreatment followed by washout in ddY-strain mice. This study demonstrates, for the first time, the significant analgesic effect of all three constituents in the first and second phases, accounting for the efficacy of the essential oil in the formalin test. While all fractions revealed equal activity toward the phytocomplex in the early phase, the reduction in time of licking/biting during the late phase was more markedly induced by DEC. Moreover, pretreatment with BEO and its fractions followed by washout did not produce a significant reduction in licking/biting time in both phases of formalin-induced nociceptive response.

Pharmacological Treatment of Pain and Agitation in Severe Dementia and Responsiveness to Change of the Italian Mobilization–Observation–Behavior–Intensity–Dementia (I-MOBID2) Pain Scale: Study Protocol

Up to 80% of Alzheimer’s disease (AD) patients in nursing homes experiences chronic pain and 97% develops fluctuant neuropsychiatric symptoms (NPS). Agitation, associated with unrelieved pain, is managed through antipsychotics and may increase the risk of death. Evidence is accumulating in favor of analgesia for a safer, effective therapy of agitation. The Italian version of Mobilization–Observation–Behavior–Intensity–Dementia, I-MOBID2, recently validated in the Italian setting, shows: good scale content validity index (0.89), high construct validity (Spearman rank-order correlation Rho = 0.748), reliable internal consistency (Cronbach’s α coefficient = 0.751), good-excellent inter-rater (intraclass correlation coefficient, ICC = 0.778) and test-retest (ICC = 0.902) reliability, and good inter-rater and test-retest agreement (Cohen’s K = 0.744) with 5.8 min completion time. This study intends to identify the responsiveness of the I-MOBID2 based on COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) recommendations, assessing the a priori hypotheses of (1) the efficacy of painkillers administered to severe AD patients after proper pain assessment and (2) the effect of reduction of the Cohen-Mansfield Agitation Inventory (CMAI) score and of agitation rescue medications. This protocol is approved by Calabria Region Ethics Committee protocol No. 31/2017 and follows the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guidelines.

Potential pharmacokinetic and pharmacodynamic herb-drug interactions of Andrographis paniculata (Burm. f.) and andrographolide: A systematic review

Introduction: Herb–drug interactions (HDIs) in pharmacokinetics and pharmacodynamics can occur when natural compounds are used in combination with drugs. This study aimed to review the potential interaction of Andrographis paniculata (Burm. f.) extract (APE) and its primary compound andrographolide (AND) with several drugs exhibiting various pharmacological activities.Methods: In this systematic review, articles were collected from international databases such as PubMed, Science Direct, Springer Link, and Scopus until August 2021. The following keywords were used: Andrographis paniculata, andrographolide, HDI, drug interaction, pharmacokinetics, and pharmacology. This review was written in accordance with the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA), SYRCLE’s risk of bias (RoB) tool for animal intervention studies, and Cochrane RoB 2 tool to analyze the RoB for qualitative assessment.Results: Twelve articles were included in accordance with the inclusion and exclusion criteria of this study. Five studies explored the potential of HDIs for combining APE with drugs and AND with theophylline, etoricoxib, nabumetone, naproxen, and tolbutamide. Five studies focused on AND in combination with aminophylline and doxofylline, meloxicam, glyburide, glimepiride, metformin, and warfarin. Two studies tested the combination of APE with gliclazide and midazolam. The HDI mechanism involving the inhibition or induction of cytochrome P450 enzyme expression was dominant in influencing the drug’s pharmacokinetic profile. Pharmacological studies on the combination of several drugs, particularly anti-inflammatory and antidiabetic drugs, showed a synergistic activity.Conclusion: APE and AND have potential pharmacokinetic and pharmacodynamic HDIs with various drugs. This study can be used as a therapeutic consideration in clinical aspects related to the possibility of HDIs of A. paniculata (Burm. f.).

Pharmacogenetics and Precision Medicine Approaches for the Improvement of COVID-19 Therapies

Many drugs are being administered to tackle coronavirus disease 2019 (COVID-19) pandemic situations without establishing clinical effectiveness or tailoring safety. A repurposing strategy might be more effective and successful if pharmacogenetic interventions are being considered in future clinical studies/trials. Although it is very unlikely that there are almost no pharmacogenetic data for COVID-19 drugs, however, from inferring the pharmacokinetic (PK)/pharmacodynamic(PD) properties and some pharmacogenetic evidence in other diseases/clinical conditions, it is highly likely that pharmacogenetic associations are also feasible in at least some COVID-19 drugs. We strongly mandate to undertake a pharmacogenetic assessment for at least these drug–gene pairs (atazanavir–UGT1A1, ABCB1, SLCO1B1, APOA5; efavirenz–CYP2B6; nevirapine–HLA, CYP2B6, ABCB1; lopinavir–SLCO1B3, ABCC2; ribavirin–SLC28A2; tocilizumab–FCGR3A; ivermectin–ABCB1; oseltamivir–CES1, ABCB1; clopidogrel–CYP2C19, ABCB1, warfarin–CYP2C9, VKORC1; non-steroidal anti-inflammatory drugs (NSAIDs)–CYP2C9) in COVID-19 patients for advancing precision medicine. Molecular docking and computational studies are promising to achieve new therapeutics against SARS-CoV-2 infection. The current situation in the discovery of anti-SARS-CoV-2 agents at four important targets from in silico studies has been described and summarized in this review. Although natural occurring compounds from different herbs against SARS-CoV-2 infection are favorable, however, accurate experimental investigation of these compounds is warranted to provide insightful information. Moreover, clinical considerations of drug–drug interactions (DDIs) and drug–herb interactions (DHIs) of the existing repurposed drugs along with pharmacogenetic (e.g., efavirenz and CYP2B6) and herbogenetic (e.g., andrographolide and CYP2C9) interventions, collectively called multifactorial drug–gene interactions (DGIs), may further accelerate the development of precision COVID-19 therapies in the real-world clinical settings.

Unpredictable adverse effects of herbal products

Herbal products are being increasingly used all over the world for preventive and therapeutic purposes because of the belief of their safety. They have become an important part of health care system in many countries since they can easily be purchased in the health food stores or online. However, the lack of sufficient study on their efficacy and toxicity, inadequate controls of their availability, reduce their safety. Unlike conventional drugs, herbal products are not regulated for purity and potency. Herbal products contain substances which can induce or inhibit enzymes that take part in drug metabolism. Therefore the concurrent use of drugs with some medicinal plants can cause serious adverse effects and can also decrease the efficacy of the therapy. Particularly, drugs with narrow therapeutic index and plants which can affect drug metabolizing enzymes when used together, may lead to unpredictable adverse reactions. Impurities, contaminants and adulterants found in the herbal products, are the most common malpractises in herbal raw-material trade. In this review the unpredictable adverse effects of herbal products due to their possible interactions with drugs and also due to the adulteration and contamination with prohibited chemicals will be discussed in detail.

Herb-Drug Interactions: Worlds Intersect with the Patient at the Center

This review examines three bodies of literature related to herb-drug interactions: case reports, clinical studies, evaluations found in six drug interaction checking resources. The aim of the study is to examine the congruity of resources and to assess the degree to which case reports signal for further study. A qualitative review of case reports seeks to determine needs and perspectives of case report authors. Methods: Systematic search of Medline identified clinical studies and case reports of interacting herb-drug combinations. Interacting herb-drug pairs were searched in six drug interaction resources. Case reports were analyzed qualitatively for completeness and to identify underlying themes. Results: Ninety-nine case-report documents detailed 107 cases. Sixty-five clinical studies evaluated 93 mechanisms of interaction relevant to herbs reported in case studies, involving 30 different herbal products; 52.7% of these investigations offered evidence supporting reported reactions. Cohen's kappa found no agreement between any interaction checker and case report corpus. Case reports often lacked full information. Need for further information, attitudes about herbs and herb use, and strategies to reduce risk from interaction were three primary themes in the case report corpus. Conclusions: Reliable herb-drug information is needed, including open and respectful discussion with patients.

Pharmacokinetic and pharmacodynamic interaction of Rosuvastatin calcium with guggulipid extract in rats

Background & objectives

Rosuvastatin calcium (RC) is a potent and competitive synthetic inhibitor of HMG-CoA reductase used for the treatment of dyslipidemia. Guggulipid obtained from Commiphora mukul is used in the treatment of a wide variety of diseases such as atherosclerosis, hypercholesterolemia, rheumatism, and obesity. The present study evaluates the pharmacokinetic and pharmacodynamic interactions between RC and the standardized guggulipid extract in rats.

Materials and methods

The guggulipid extract was standardized for the presence of guggulsterones. The pharmacokinetic interaction was determined after a single dose administration of RC alone or in combination with the guggulipid extract or after multiple-dose administration of RC alone or RC along with the guggulipid extract for 14 days. To determine the pharmacodynamic interaction, RC and guggulipid extract were administered to hyperlipidemic rats for 14 days. The level of significance was determined using unpaired student’s t-test, one way ANOVA, the post-ANOVA Tukey test.

Results

Standardization of guggulipid extract showed it contains 7.5%w/w of guggulsterones. Guggulipid extract increased the bioavailability of RC in both single-dose and multiple-dose studies. Guggulipid extract reduced the rate of absorption (Ka) of RC but showed an increase in maximum serum concentration (Cmax). An in-vitro study using isolated rat intestine revealed that guggulipid extract decreased the rate of absorption of RC in the intestinal lumen. The hypolipidemic activity of RC was augmented by the guggulipid extract in hyperlipidemic rats.

Interpretation & conclusion

Therefore it is concluded that guggulipid extract increases the bioavailability of RC by delaying its Ka and augments its hypolipidemic action. However, it is recommended that a combination of RC with guggulipid extract should be used only after an adverse effect(s) of this combination are determined.

Impacts of Drug Interactions on Pharmacokinetics and the Brain Transporters: A Recent Review of Natural Compound-Drug Interactions in Brain Disorders

Natural compounds such as herbal medicines and/or phyto-compounds from foods, have frequently been used to exert synergistic therapeutic effects with anti-brain disorder drugs, supplement the effects of nutrients, and boost the immune system. However, co-administration of natural compounds with the drugs can cause synergistic toxicity or impeditive drug interactions due to changes in pharmacokinetic properties (e.g., absorption, metabolism, and excretion) and various drug transporters, particularly brain transporters. In this review, natural compound–drug interactions (NDIs), which can occur during the treatment of brain disorders, are emphasized from the perspective of pharmacokinetics and cellular transport. In addition, the challenges emanating from NDIs and recent approaches are discussed.

Multifaceted Factors Causing Conflicting Outcomes in Herb-Drug Interactions

Metabolic enzyme and/or transporter-mediated pharmacokinetic (PK) changes in a drug caused by concomitant herbal products have been a primary issue of herb and drug interactions (HDIs), because PK changes of a drug may result in the alternation of efficacy and toxicity. Studies on HDIs have been carried out by predictive in vitro and in vivo preclinical studies, and clinical trials. Nevertheless, the discrepancies between predictive data and the clinical significance on HDIs still exist, and different reports of HDIs add to rather than clarify the confusion regarding the use of herbal products and drug combinations. Here, we briefly review the underlying mechanisms causing PK-based HDIs, and more importantly summarize challenging issues, such as dose and treatment period effects, to be considered in study designs and interpretations of HDI evaluations.