Pharmacokinetic Herb-drug Interactions Research Articles

Evaluation of pharmacological and pharmacokinetic herb-drug interaction between irinotecan hydrochloride injection and Kangai injection in colorectal tumor-bearing mice and healthy rats

Introduction: Kangai (KA) injection, a Chinese herbal injection, is often used in combination with irinotecan (CPT-11) to enhance the effectiveness of anti-colorectal cancer treatment and alleviate side effects. However, the combined administration of this herb-drug pair remains controversial due to limited pre-clinical evidence and safety concerns. This study aimed to determine the pre-clinical herb-drug interactions between CPT-11 and KA injection to provide a reference for their clinical co-administration.Methods: In the pharmacological study, BALB/c mice with CT26 colorectal tumors were divided into four groups and treated with vehicle alone (0.9% saline), CPT-11 injection (100 mg/kg), KA injection (10 mL/kg), or a combination of CPT-11 and KA injection, respectively. The tumor volume of mice was monitored daily to evaluate the therapeutic effect. Daily body weight, survival rate, hematopoietic toxicity, immune organ indices, and gut toxicity were analyzed to study the adverse effects. Healthy Sprague-Dawley rats in the pharmacokinetic study were administered KA injection only (4 mL/kg), or a combination of CPT-11 injection (20 mg/kg) and KA injection, respectively. Six key components of KA injection (oxymatrine, matrine, ginsenoside Rb1, Rg1, Re, and astragaloside IV) in rat plasma samples collected within 24 h after administration were determined by LC-MS/MS.Results: The pharmacological study indicated that KA injection has the potential to enhance the anti-colorectal cancer efficacy of CPT-11 injection and alleviate the severe weight loss induced by CPT-11 injection in tumor-bearing mice. The pharmacokinetic study revealed that co-administration resulted in inhibition of oxymatrine metabolism in rats, evidenced by the significantly reduced Cmax and AUC0-t of its metabolite, matrine (p < 0.05), from 2.23 ± 0.24 to 1.38 ± 0.12 μg/mL and 8.29 ± 1.34 to 5.30 ± 0.79 μg h/mL, respectively. However, due to the similar efficacy of oxymatrine and matrine, this may not compromise the anti-cancer effect of this herb-drug pair.Discussion: This study clarified the pre-clinical pharmacology and pharmacokinetic benefits and risks of the CPT-11-KA combination and provided a reference for their clinical co-administration.

Biotransformation and brain distribution of the anti-COVID-19 drug molnupiravir and herb-drug pharmacokinetic interactions between the herbal extract Scutellaria formula-NRICM101

The aim of this study was to explore the effects of herbal drug pharmacokinetic interactions on the biotransformation of molnupiravir and its metabolite β-D-N4-hydroxycytidine (NHC) in the blood and brain. To investigate the biotransformation mechanism, a carboxylesterase inhibitor, bis(4-nitrophenyl)phosphate (BNPP), was administered. Not only molnupiravir but also the herbal medicine Scutellaria formula-NRICM101 is potentially affected by coadministration with molnupiravir. However, the herb-drug interaction between molnupiravir and the Scutellaria formula-NRICM101 has not yet been investigated. We hypothesized that the complex bioactive herbal ingredients in the extract of the Scutellaria formula-NRICM101, the biotransformation and penetration of the bloodbrain barrier of molnupiravir are altered by inhibition of carboxylesterase. To monitor the analytes, ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLCMS/MS) coupled with the microdialysis method was developed. Based on the dose transfer from humans to rats, a dose of molnupiravir (100 mg/kg, i.v.), molnupiravir (100 mg/kg, i.v.) + BNPP (50 mg/kg, i.v.), and molnupiravir (100 mg/kg, i.v.) + the Scutellaria formula-NRICM101 extract (1.27 g/kg, per day, for 5 consecutive days) were administered. The results showed that molnupiravir was rapidly metabolized to NHC and penetrated into the brain striatum. However, when concomitant with BNPP, NHC was suppressed, and molnupiravir was enhanced. The blood-to-brain penetration ratios were 2% and 6%, respectively. In summary, the extract of the Scutellaria formula-NRICM101 provides a pharmacological effect similar to that of the carboxylesterase inhibitor to suppress NHC in the blood, and the brain penetration ratio was increased, but the concentration is also higher than the effective concentration in the blood and brain.

The importance and use of Amaranthus for crop diversification in the SADC region

Crop diversification is crucial for sustaining food security under current climatic conditions which limits crop productivity. It also provides an opportunity for the introduction of new food products and medicinal plants. Effective exploration of Amaranthus in the Southern African Development Community (SADC) region can provide economic and agricultural potential, high nutritional value and medicinal properties that can sustain communities. This review is focused on economic and agricultural potential, nutritional value, chemical composition, and medicinal properties of Amaranthus. Amaranthus is an underutilized, inexpensive vegetable with significant dietary minerals, vitamins, proteins, and bioactive compounds with potential health benefits. An agricultural-based approach of crop diversification has been suggested as a sustainable measure that can address food security, fight poverty and malnutrition under drought and heat stress. Nutritional, chemical composition, and medicinal properties of A. caudatus, A. hypochondriacus, A. cruentus, A. spinosus, A. dubius, A. blitum, A. virdis and A. hybridus, was reviewed. In addition, co-administration of herbal medicine by cancer patients and risk of herb-drug pharmacokinetic interactions was also highlighted. The future tolerance level to environmental stressors; investigation of the effect of processing and cooking methods on the nutrient content, bioactive compounds profile and nutraceutical properties of local species and varieties are also recommended in this review.

Pharmacokinetic herb-drug interactions: Altered systemic exposure and tissue distribution of ciprofloxacin, a substrate of multiple transporters, after combined treatment with Polygonum capitatum Buch.-Ham. ex D. Don extracts.

Background: Combination of Polygonum capitatum Buch.-Ham. ex D. Don extract (PCE) and ciprofloxacin (CIP) was commonly prescribed in the treatment of urinary tract infections. Their pharmacokinetic herb-drug interactions (HDIs) were focused in this study to assess potential impact on the safety and effectiveness. Methods: A randomized, three-period, crossover trial was designed to study the pharmacokinetic HDI between PCE and CIP in healthy humans. Their pharmacokinetic- and tissue distribution-based HDIs were also evaluated in rats. Gallic acid (GA) and protocatechuic acid (PCA) were chosen as PK-markers of PCE in humans and rats. Potential drug interaction mechanisms were revealed by assessing the effects of PCE on the activity and expression of multiple transporters, including OAT1/3, OCT2, MDR1, and BCRP. Results: Concurrent use of PCE substantially reduced circulating CIP (approximately 40%-50%) in humans and rats, while CIP hardly changed circulating GA and PCA. PCE significantly increased the tissue distribution of CIP in the prostate and testis of rats, but decreased in liver and lungs. Meanwhile, CIP significantly increased the tissue distribution of GA or PCA in the prostate and testis of rats, but decreased in kidney and heart. In the transporter-mediated in vitro HDI, GA and PCA presented inhibitory effects on OAT1/3 and inductive effects on MDR1 and BCRP. Conclusion: Multiple transporter-mediated HDI contributes to effects of PCE on the reduced systemic exposure and altered tissue distribution of CIP. More attention should be paid on the potential for PCE-perpetrated interactions.

Pharmacokinetic Herb-Drug Interactions of Glipizide with Andrographis paniculata (Burm. f.) and Andrographolide in Normal and Diabetic Rats by Validated HPLC Method.

Co-administered medicinal herbs can modify a drug’s pharmacokinetics (PK), effectiveness, and toxicity. Andrographis paniculata (Burm. f.) ethanolic extract (APE) and andrographolide (AND) (a potent CYP2C9 inducer/inhibitor) can alter the pharmacokinetic parameters of glipizide (GLZ). This study aimed to determine the potential pharmacokinetics of herb–drug interactions between GLZ and APE/AND in the plasma of normal and diabetic rats using the HPLC bioanalysis method. The glipizide bioanalytical method established with RP-HPLC/UV instrument was validated following the EMA guidelines. GLZ was administered alone and in combination with APE or AND to normal and diabetic rats. The GLZ pharmacokinetic parameters were estimated according to the correlation between concentration and sampling time using the PK solver program. A simple and rapid GLZ bioanalysis technique with a lower limit of quantitation of 25 ng/mL was developed and presented the following parameters: accuracy (error ≤ 15%), precision (CV ≤ 15%), selectivity, stability, and linearity (R2 = 0.998) at concentrations ranging 25–1500 ng/mL. APE administration significantly improved the Cmax and AUC0–t/AUC0–∞ GLZ values in normal and diabetic rats (p < 0.05). AND significantly reduced the bioavailability of GLZ in diabetic rats with small values of T 1/2, Cmax, and AUC0–t/AUC0–∞ (p < 0.05). This combination can be considered in administering medications because it can influence the pharmacological effects of GLZ.

Pharmacokinetic interaction of Jiaotai Pills and Fluoxetine in rats with CUMS-induced depression

A high-performance liquid chromatography-tandem mass spectrometry(LC-MS/MS) was developed for simultaneously determining the components(magnoflorine, jatrorrhizine, berberrubine, coptisine, berberine) of Jiaotai Pills and Fluoxetine in plasma of rats with chronic unpredictable mild stress(CUMS)-induced depression to investigate the pharmacokinetic herb-drug interaction of Jiaotai Pills and Fluoxetine in the rats. The six components showed good linear relationship within the corresponding concentration ranges, and the method showed high specificity, accuracy, precision, and stability. Their pharmacokinetic parameters were calculated by DAS 3.2.2, and the results showed that the in vivo metabolic processes of the six components accorded with the characteristics of non-compartmental model. When Jiaotai Pills and Fluoxetine were used together, the AUC_(0-t), AUC_(0-∞), C_(max), and C_(av) of magnoflorine all significantly increased(P&lt;0.05), while the pharmacokinetic trend of berberrubine was opposite to that of magnoflorine, as manifested by the decrease in AUC_(0-t), AUC_(0-∞), T_(max), C_(max), and C_(av)(P&lt;0.01, P&lt;0.05). The pharmacokinetic characteristics of jatrorrhizine, coptisine, and berberine followed the trend of berberrubine. There was no significant difference in the pharmacokinetic characteristics of Fluoxetine in the single or combination groups. This study suggests that the enhanced antidepressant efficacy of Jiaotai Pills and Fluo-xetine may be attributed to the pharmacokinetic interaction.

The Chinese herb Styrax triggers pharmacokinetic herb-drug interactions via inhibiting intestinal CYP3A.

Human cytochrome P450 3A4 (hCYP3A4) is a predominant enzyme to trigger clinically relevant drug/herb-drug interactions (DDIs or HDIs). Although a number of herbal medicines have been found with strong anti-hCYP3A4 effects in vitro, the in vivo modulatory effects of herbal medicines on hCYP3A4 and their potential risks to trigger HDIs are rarely investigated. Herein, we demonstrate a case study to efficiently find the herbal medicine(s) with potent hCYP3A4 inhibition in vitro and to accurately assess the potential HDIs risk in vivo. Following screening over 100 herbal medicines, the Chinese herb Styrax was found with the most potent hCYP3A4 inhibition in HLMs. In vitro assays demonstrated that Styrax could potently inhibit mammalian CYP3A in liver and intestinal microsomes from both humans and rats. In vivo pharmacokinetic assays showed that Styrax (i.g., 100 mg/kg) significantly elevated the plasma exposure of two CYP3A-substrate drugs (midazolam and felodipine) when midazolam or felodipine was administered orally. By contrast, the plasma exposure of either midazolam or felodipine was hardly affected by Styrax (i.g.) when the victim drug was administered intravenously. Further investigations demonstrated that seven pentacyclic triterpenoid acids (PTAs) in Styrax were key substances responsible for CYP3A inhibition, while these PTAs could be exposed to intestinal tract at relatively high exposure levels but their exposure levels in rat plasma and liver were extremely low. These findings well explained why Styrax (i.g.) could elevate the plasma exposure of victim drugs only when these agents were orally administrated. Collectively, our findings demonstrate that Styrax can modulate the pharmacokinetic behavior of CYP3A-substrate drugs via inhibiting intestinal CYP3A, which is very helpful for the clinical pharmacologists to better assess the HDIs triggered by Styrax or Styrax-related herbal products.

Pharmacokinetic herb-drug interactions between Aidi injection and doxorubicin in rats with diethylnitrosamine-induced hepatocellular carcinoma

BackgroundAidi Injection (ADI), a Chinese herbal preparation with anti-cancer activity, is used for the treatment of hepatocellular carcinoma (HCC). Several clinical studies have shown that co-administration of ADI with doxorubicin (DOX) is associated with reduced toxicity of chemotherapy, enhanced clinical efficacy and improved quality of life for patients. However, limited information is available about the herb-drug interactions between ADI and DOX. The study aimed to investigate the pharmacokinetic mechanism of herb-drug interactions between ADI and DOX in a rat model of HCC.MethodsExperimental HCC was induced in rats by oral administration of diethylnitrosamine. The HCC rats were pretreated with ADI (10 mL/kg, intraperitoneal injection) for 14 consecutive days prior to administration of DOX (7 mg/kg, intravenous injection) to investigate pharmacokinetic interactions. Plasma concentrations of DOX and its major metabolite, doxorubicinol (DOXol), were determined using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).ResultsPreadministration of ADI significantly altered the pharmacokinetics of DOX in HCC rats, leading to increased plasma concentrations of both DOX and DOXol. The area under the plasma drug concentration-time curve (AUCs) of DOX and DOXol in rats pretreated with ADI were 3.79-fold and 2.92-fold higher, respectively, than those in control rats that did not receive ADI.ConclusionsIncreased levels of DOX and DOXol were found in the plasma of HCC rats pretreated with ADI.

TO STUDY THE PHARMACOKINETIC HERB-DRUG INTERACTION OF MOMORDICA CHARANTIA FRUIT EXTRACT AND PURE CHARANTIN WITH NATEGLINIDE IN RATS

Objective: Momordica charantia fruit extract and antidiabetic drug Nateglinide might be used simultaneously in the treatment of diabetes, so the objective of this study was to investigate pharmacokinetic herb-drug interactions of Momordica charantia fruit extract and pure charantin with nateglinide in rats. Methods: After oral co-administration of Momordica charantia fruit extract (250 mg/kg) and Charantin (10 mg/kg) with nateglinide in rats, drug concentration parameters peak plasma concentration (Cmax), time to reach peak plasma concentration (tmax), elimination half-life (t1/2), apparent volume of distribution (Vd), plasma clearance (Cl), and area under the curve (AUC) were calculated by using the non-compartment model. Results: NAT was absorbed into the circulatory system and reached its peak concentration approximately 2 h after being administered individually. tmax of groups co-administered NAT+MCE has been changed to 4h. A significant decrease in Cmax of NAT from 16.28 µg/ml to 11.37 µg/ml and 10.37 µg/ml with NAT with charantin and NAT with MCE groups, respectively. AUC of NAT decreased from 84.53 h/µg/ml to 53.63 h/µg/ml and 47.17 h/µg/ml by co-administration with Charantin and MCE respectively. Co-administration of nateglinide with Charantin and Momordica charantia fruit extract decreased systemic exposure level of nateglinide in vivo with decreasing Cmax and AUC and an increase in t1/2, Cl and Vd. Conclusion: From this study, it can be concluded that nateglinide, Momordica charantia fruit extract, and pure Charantin existed pharmacokinetic herb-drug interactions in the rat which has to be correlated with the anti-diabetic study. Further studies should be done to understand the effect of other herbal ingredients of Momordica charantia fruit extract on nateglinide as well as to predict the herb-drug interaction in humans.

Black Cumin (Nigella sativa L.): A Comprehensive Review on Phytochemistry, Health Benefits, Molecular Pharmacology, and Safety.

Mounting evidence support the potential benefits of functional foods or nutraceuticals for human health and diseases. Black cumin (Nigella sativa L.), a highly valued nutraceutical herb with a wide array of health benefits, has attracted growing interest from health-conscious individuals, the scientific community, and pharmaceutical industries. The pleiotropic pharmacological effects of black cumin, and its main bioactive component thymoquinone (TQ), have been manifested by their ability to attenuate oxidative stress and inflammation, and to promote immunity, cell survival, and energy metabolism, which underlie diverse health benefits, including protection against metabolic, cardiovascular, digestive, hepatic, renal, respiratory, reproductive, and neurological disorders, cancer, and so on. Furthermore, black cumin acts as an antidote, mitigating various toxicities and drug-induced side effects. Despite significant advances in pharmacological benefits, this miracle herb and its active components are still far from their clinical application. This review begins with highlighting the research trends in black cumin and revisiting phytochemical profiles. Subsequently, pharmacological attributes and health benefits of black cumin and TQ are critically reviewed. We overview molecular pharmacology to gain insight into the underlying mechanism of health benefits. Issues related to pharmacokinetic herb–drug interactions, drug delivery, and safety are also addressed. Identifying knowledge gaps, our current effort will direct future research to advance potential applications of black cumin and TQ in health and diseases.

Preclinical study of simultaneous pharmacokinetic and pharmacodynamic herb-drug interactions between Yin-Chen-Hao-Tang and spironolactone

BackgroundThe prevalence and therapeutic effects of the use of herbal remedies for chronic liver diseases make the combined administration of herbal products with conventional treatment unable to be ignored. This study investigated the pharmacokinetic and pharmacodynamic herb-drug interactions between the herbal formula Yin-Chen-Hao-Tang (YCHT) and spironolactone.MethodsA selective high-performance liquid chromatography (HPLC) method was developed and validated for the detection of spironolactone and its metabolite canrenone in rat urine. The interaction study was conducted by collecting urine samples after oral administration of spironolactone alone or in combination with YCHT for 5 days. Urine pharmacokinetic parameters and urinary sodium, potassium, volume, and weight were analyzed.ResultsThe results revealed significant increases in the cumulative amount and the area under the rate curve (AURC) of the metabolite canrenone after pretreatment with the high dose of YCHT. The urine weight and volume were significantly reduced dose-dependently as a result of pretreatment with YCHT. The urinary sodium-to-potassium ratio, which indicates diuretic effects, was also reduced in the high-dose YCHT condition.ConclusionsHerb-drug pharmacokinetic and pharmacodynamic interactions between YCHT and spironolactone were observed in the study. The herb-drug interaction that appeared with a single dose of spironolactone should be considered when patients are being treated with a continuous administration of this drug.

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.

Herb drug interaction of Tinospora cordifolia (Willd.) Miers extract and Glimepiride: In vivo and in silico studies

Tinospora cordifolia (Willd.) Miers (TC), family Menispermaceae is a well-known traditional herb reported in traditional Indian literature for the treatment of various disorders such as diabetes and cardiovascular diseases. Berberine, the chief active constituent of TC is reported to possess anti-diabetic potential along with other isoquinoline alkaloids. TC and its active constituent berberine both have been reported to be potent CYP2C9 inhibitor, thereby raising herb drug interaction (HDI) potential on co-administration with drugs metabolized through the CYP pathway. The present study evaluated the pharmacokinetic HDI of TC hydroalcoholic extract with Glimepiride (GP) after oral co-administration in Wistar rats using in vivo pharmacokinetic and in silico studies. After oral co-administration of TC extract (100 mg/kg) with GP (20 mg/kg) in rats, drug concentrations in plasma were determined using HPLC method. The main pharmacokinetic parameters of Cmax, Tmax, AUC, Vd, CL, and MRT0-t were calculated using Win Nonlin software. Also in silico molecular docking study using CYP2C9 (PDB ID: 1R90) as target protein and phytoconstituents (isoquinoline alkaloids) of TC as ligands were carried out using Auto Dock Vina 1.1.2 to determine their CYP2C9 interaction potential. The PK interactions studies demonstrated an increase in the systemic levels of GP. A significant increase in Cmax, AUC0-t and MRT0-t of GP (p<0.01) was observed, along with a substantial decrease in Vd and CL. In silico molecular docking studies on CYP2C9 demonstrated high inhibition potential of berberine (binding affinity: -9.6 kcal/mol) with formation of two hydrogen bonds with Ser 209 and Asn 474 in the active site of enzyme, complementing the literature reports as well as our in vivo PK findings. The results obtained from in vivo and in silico studies proposed that, for a co-administration of GP and TC extract, there exists a potentially significant PK HDI. This knowledge concerning potential HDI of GP might prove helpful for healthcare professionals as well as diabetic patients on GP therapy. It eventually warrants further studies to predict the pharmacokinetics and pharmacodynamics of GP in humans in case of HDI.

Simultaneous Determination of Schisandrin and Promethazine with Its Metabolite in Rat Plasma by HPLC-MS/MS and Its Application to a Pharmacokinetic Study.

This study aimed to develop a selective, simple, and sensitive HPLC-MS/MS method for the simultaneous determination of schisandrin and promethazine (PMZ) with its metabolite in rat plasma, which was further used for a pharmacokinetic herb-drug interaction study. HPLC-MS/MS analyses were performed on an Agilent Technologies 1290 LC and a 6410 triple quadrupole mass spectrometer. The following parameters, the lower limit of quantification (LLOQ), calibration curve, accuracy, precision, stability, matrix effect, and recovery, were validated. The linear range of the developed method for PMZ, its metabolite promethazine sulfoxide (PMZSO), and schisandrin in rat plasma was 0.5–200 ng/mL (R2 > 0.995), with an LLOQ of 0.5 ng/mL, which completely met the determination requirements of biosamples. The intra- and interday precision (RSD, %) was below 13.31% (below 16.67% for the LLOQ) in various plasma, whose accuracy (bias, %) was from −8.52% to 11.40%, which were both within an acceptable range. This method was successfully applied to a pharmacokinetic herb-drug interaction study after oral administration of PMZ with or without S. chinensis water extract. The results demonstrated that coadministration with the S. chinensis water extract might affect the pharmacokinetic behaviors of PMZ. In turn, when taken together with PMZ, the pharmacokinetic parameters of schisandrin, the main active component of S. chinensis, were also affected. The method established in the current study was selective, simple, sensitive, and widely available with good linearity, high accuracy and precision, and a stable sample preparation process. Moreover, this analytical method provides a significant approach for the investigation of herb-drug interaction between S. chinensis and PMZ. The potential pharmacokinetic herb-drug interaction of PMZ- and schisandrin-containing preparations should be noted.

The Herb-Drug Pharmacokinetic Interaction of Fluoxetine and Its Metabolite Norfluoxetine with a Traditional Chinese Medicine in Rats by LC-MS/MS.

Background Fluoxetine (FLU) is the first-line and widely used medication for depression. The combination of Chaihu Shugan san (CSGS) and FLU is commonly used to enhance antidepressant effects and reduce side effects. Objective The primary objective of this study was to investigate the potential pharmacokinetic effect of CSGS on FLU. Materials and Methods Thirty-two healthy adult male Sprague-Dawley (SD) rats were randomly divided into four groups, the fluoxetine group and multiple dose groups A, B, and C. The rats in the different groups were orally administered with a combination of FLU and different doses of CSGS for 14 d. On the fifteenth day, serial blood samples were taken from the caudal vein before the administration and at 0.25, 0.5, 0.75, 1, 2, 4, 6, 8, 10, 12, 24, 36, and 48 h after the administration. A liquid-liquid extraction method was applied to extract the analytes from serum. Then, the concentrations of FLU and its metabolite, norfluoxetine (NOF), were determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The pharmacokinetic parameters were calculated by DAS 3.2.8 program and compared by statistic analysis. Results Compared with the FLU group, the FLU and NOF area under the plasma concentration-time curve (AUC) (0–∞) in multiple dose group C was significantly increased, while the NOF AUCs (0–∞) in multiple dose group A and multiple dose group B were decreased. Compared with the FLU group, the NOF clearance (CL) in multiple dose group C was decreased, while the CL in multiple dose groups A and B was increased. Discussion and Conclusion There were some differences in pharmacokinetic parameters between the FLU group and multiple dose groups, and CSGS can affect the pharmacokinetics of fluoxetine.

Rhinacanthin-C Mediated Herb-Drug Interactions with Drug Transporters and Phase I Drug-Metabolizing Enzymes.

Rhinacanthin-C is a major active constituent in Rhinacanthus nasutus (L.) Kurz, a plant widely used in herbal remedies. Its potential for pharmacokinetic herb-drug interaction may exist with drug transporters and drug metabolizing enzymes. This study assessed the possibility for rhinacanthin-C-mediated drug interaction by determining its inhibitory effects against major human efflux and influx drug transporters as well as various human cytochrome P450(CYP) isoforms. Rhinacanthin-C demonstrated a moderate permeability through the Caco-2 monolayers [Papp (AP-to-BL) = 1.26 × 10-6 cm/s]. It significantly inhibited transport mediated by both P-glycoprotein (P-gp) (IC50 = 5.20 µM) and breast cancer resistance protein (BCRP) (IC50 = 0.83 µM) across Caco-2 and BCRP-overexpressing Madin-Darby canine kidney II cells (MDCKII) cells. This compound also strongly inhibited uptake mediated by organic anion-transporting polypeptide 1B1 (OATP1B1) (IC50 = 0.70 µM) and OATP1B3 (IC50 = 3.95 µM) in OATP1B-overexpressing HEK cells. In addition to its inhibitory effect on these drug transporters, rhinacanthin-C significantly inhibited multiple human CYP isoforms including CYP2C8 (IC50 = 4.56 µM), 2C9 (IC50 = 1.52 µM), 2C19 (IC50 = 28.40 µM), and 3A4/5 (IC50 = 53 µM for midazolam and IC50 = 81.20 µM for testosterone), but not CYP1A2, 2A6, 2B6, 2D6, and 2E1. These results strongly support a high propensity for rhinacanthin-C as a perpetrator of clinical herb-drug interaction via inhibiting various influx and efflux drug transporters (i.e., P-gp, BCRP, OATP1B1, and OATP1B3) and CYP isoforms (i.e., CYP2C8, CYP2C9, and CYP2C19). Thus, the potential for significant pharmacokinetic herb-drug interaction should be addressed when herbal products containing rhinacanthin-C are to be used in conjunction with other prescription drugs.

High degree of pharmacokinetic compatibility exists between the five-herb medicine XueBiJing and antibiotics comedicated in sepsis care

Managing the dysregulated host response to infection remains a major challenge in sepsis care. Chinese treatment guideline recommends adding XueBiJing, a five-herb medicine, to antibiotic-based sepsis care. Although adding XueBiJing further reduced 28-day mortality via modulating the host response, pharmacokinetic herb–drug interaction is a widely recognized issue that needs to be studied. Building on our earlier systematic chemical and human pharmacokinetic investigations of XueBiJing, we evaluated the degree of pharmacokinetic compatibility for XueBiJing/antibiotic combination based on mechanistic evidence of interaction risk. Considering both XueBiJing‒antibiotic and antibiotic‒XueBiJing interaction potential, we integrated informatics-based approach with experimental approach and developed a compound pair-based method for data processing. To reflect clinical reality, we selected for study XueBiJing compounds bioavailable for drug interactions and 45 antibiotics commonly used in sepsis care in China. Based on the data of interacting with drug metabolizing enzymes and transporters, no XueBiJing compound could pair, as perpetrator, with the antibiotics. Although some antibiotics could, due to their inhibition of uridine 5′-diphosphoglucuronosyltransferase 2B15, organic anion transporters 1/2 and/or organic anion-transporting polypeptide 1B3, pair with senkyunolide I, tanshinol and salvianolic acid B, the potential interactions (resulting in increased exposure) are likely desirable due to these XueBiJing compounds' low baseline exposure levels. Inhibition of aldehyde dehydrogenase by 7 antibiotics probably results in undesirable reduction of exposure to protocatechuic acid from XueBiJing. Collectively, XueBiJing/antibiotic combination exhibited a high degree of pharmacokinetic compatibility at clinically relevant doses. The methodology developed can be applied to investigate other drug combinations.

Potential Pharmacokinetic Herb-Drug Interactions: Have we Overlooked the Importance of Human Carboxylesterases 1 and 2?

Herbal products have grown steadily across the globe and have increasingly been incorporated into western medicine for healthcare aims, thereby causing potential pharmacokinetic Herb-drug Interactions (HDIs) through the inhibition or induction of drug-metabolizing enzymes and transporters. Human Carboxylesterases 1 (CES1) and 2 (CES2) metabolize endogenous and exogenous chemicals including many important therapeutic medications. The growing number of CES substrate drugs also underscores the importance of the enzymes. Herein, we summarized those potential inhibitors and inducers coming from herbal constituents toward CES1 and CES2. We also reviewed the reported HDI studies focusing on herbal products and therapeutic agents metabolized by CES1 or CES2. We searched in PubMed for manuscript published in English after Jan 1, 2000 combining terms "carboxylesterase 1", "carboxylesterase 2", "inhibitor", "inducer", "herb-drug interaction", "inhibitory", and "herbal supplement". We also searched specific websites including FDA and EMA. The data of screened papers were analyzed and summarized. The results showed that more than 50 natural inhibitors of CES1 or CES2, including phenolic chemicals, triterpenoids, and tanshinones were found from herbs, whereas only few inducers of CES1 and CES2 were reported. Systemic exposure to some commonly used drugs including oseltamivir, irinotecan, and clopidogrel were changed when they were co-administered with herb products such as goldenseal, black cohosh, ginger, St. John's Wort, curcumin, and some Chinese compound formula in animals. Nonclinical and clinical studies on HDIs are warranted in the future to provide safety information toward better clinical outcomes for the combination of herbal products and conventional drugs.

Enhanced Intestinal Permeability and Plasma Concentration of Metformin in Rats by the Repeated Administration of Red Ginseng Extract.

We aimed to assess the potential herb–drug interactions between Korean red ginseng extract (RGE) and metformin in rats in terms of the modulation of metformin transporters, such as organic cation transporter (Oct), multiple toxin and extrusion protein (Mate), and plasma membrane monoamine transporter (Pmat). Single treatment of RGE did not inhibit the in vitro transport activity of OCT1/2 up to 500 µg/mL and inhibited MATE1/2-K with high IC50 value (more than 147.8 µg/mL), suggesting that concomitant used of RGE did not directly inhibit OCT- and MATE-mediated metformin uptake. However, 1-week repeated administration of RGE (1.5 g/kg/day) (1WRA) to rats showed different alterations in mRNA levels of Oct1 depending on the tissue type. RGE increased intestinal Oct1 but decreased hepatic Oct1. However, neither renal Oct1/Oct2 nor Mate1/Pmat expression in duodenum, jejunum, ileum, liver, and kidney were changed in 1WRA rats. RGE repeated dose also increased the intestinal permeability of metformin; however, the permeability of 3-O-methyl-d-glucose and Lucifer yellow was not changed in 1WRA rats, suggesting that the increased permeability of metformin by multiple doses of RGE is substrate-specific. On pharmacokinetic analysis, plasma metformin concentrations following intravenous injection were not changed in 1WRA, consistent with no significant change in renal Oct1, Oct2, and mate1. Repeated doses of RGE for 1 week significantly increased the plasma concentration of metformin, with increased half-life and urinary excretion of metformin following oral administration of metformin (50 mg/kg), which could be attributed to the increased absorption of metformin. In conclusion, repeated administration of RGE showed in vivo pharmacokinetic herb–drug interaction with metformin, with regard to its plasma exposure and increased absorption in rats. These results were consistent with increased intestinal Oct1 and its functional consequence, therefore, the combined therapeutic efficacy needs further evaluation before the combination and repeated administration of RGE and metformin, an Oct1 substrate drug.

In-vitro assessment of CYP3A4 and CYPC29 inhibition potential of Lupeol using human liver microsomes

Background: Lupeol is a dietary triterpene, possesses numerous biological activities. Lupeol is currently under development for chemotherapy and chemoprevention. The aim of present study was to determine the potential inhibitory effect of Lupeol on cytochrome P450 (CYP3A4 and CYP2C9 isozymes) activities in human liver microsomes (HLM).&#x0D; Methods: The inhibition studies were conducted using testosterone 6β-hydroxylase (CYP3A4), and diclofenac 4’-Hydroxylase (CYP2C9) activity assay using positive control Ketoconazole and Sulphaphenazole, respectively. Inhibition study was performed by incubating lupeol (0 to 20 μM) with human liver microsomes, and the metabolite formation was analyzed by liquid chromatography-Tandem Mass Spectrometry (LC-MS/MS).&#x0D; Results: Luepol did not inhibit CYP3A4 and CYP2C9 isozymes mediated activities in human liver microsomes up to a maximum tested concentration of 20µM based on solubility under tested invitro conditions.&#x0D; Conclusions: Lupeol is not an inhibitor of the CYP3A4 and CYP2C9 isozymes. IC50 is greater than highest tested concentration as well as physiological concentration, where effect was measured with confidence. Therefore, clinically relevant pharmacokinetic herb-drug interactions are unlikely to occur between Lupeol and co-administered substrates of these CYP isozymes. Looking at the spectrum of biological activities and CYP inhibition potential of Lupeol; Lupeol can be used as adjuvant/ chemotherapy agent/ chemopreventive agent in therapy.&#x0D; Keywords: Lupeol, HLM, CYP3A4 and CYP2C9, Inhibition, herb–drug interactions