Regulation of drug-metabolizing enzymes and efflux transporters by Astragali radix decoction and its main bioactive compounds: Implication for clinical drug-drug interactions

The role of efflux transporters in cytotoxicity and intracellular concentration of chlorpyrifos and chlorpyrifos oxon in human cell lines

In this study, we investigated the role of two efflux transporters, p-glycoprotein (P-gp) and breast cancer resistance protein (BCRP), in the cytotoxicity and intracellular accumulation of the organophosphate pesticide chlorpyrifos (CPF) and its active metabolite, CPF-oxon (CPFO), in a human-derived liver cell line (HepG2) and kidney epithelial cell line (HK-2). The cytotoxicity to CPF and CPFO differed between cell lines where HK-2 had lower IC50 values which could be attributed to lower basal expression and inducibility of metabolizing enzymes, transporters, and nuclear receptors in HK-2 cells. In HepG2 cells, co-exposure of CPF with a specific inhibitor of either P-gp or BCRP enhanced the cytotoxicity of CPF while co-exposure of CPFO with VRP enhanced the cytotoxicity of CPFO, suggesting the role of these transporters in the elimination CPF and CPFO. Inhibition of efflux transporters did not affect the cytotoxicity of CPF and CPFO in HK-2 cells. Co-incubation of CPF with P-gp and BCRP inhibitors increased the intracellular concentration of CPF in HepG2 cells suggesting that both transporters play a role in limiting the cellular accumulation of CPF in HepG2 cells. Our results provide evidence that inhibition of efflux transporters can enhance CPF-induced toxicity through enhanced cellular accumulation and raises additional questions regarding how pesticide-transporter interactions may influence toxicity of mixtures containing pesticides and other environmental chemicals.

Exploring the immunometabolic potential of Danggui Buxue Decoction for the treatment of IBD-related colorectal cancer

Danggui Buxue (DGBX) decoction is a classical prescription composed of Astragali Radix (AR) and Angelicae Sinensis Radix (ASR), used to enrich blood, and nourish Qi in Chinese medicine, with the potential to recover energy and stimulate metabolism. Chronic inflammation is a risk factor in the development of inflammatory bowel disease (IBD)-related colorectal cancer (CRC). More importantly, AR and ASR have anti-inflammatory and anti-cancer activities, as well as prefiguring a potential effect on inflammation-cancer transformation. We, therefore, aimed to review the immunometabolism potential of DGBX decoction and its components in this malignant transformation, to provide a helpful complement to manage the risk of IBD-CRC. The present study investigates the multifaceted roles of DGBX decoction and its entire components AR and ASR, including anti-inflammation effects, anti-cancer properties, immune regulation, and metabolic regulation. This assessment is informed by a synthesis of scholarly literature, with more than two hundred articles retrieved from PubMed, Web of Science, and Scopus databases within the past two decades. The search strategy employed utilized keywords such as "Danggui Buxue", "Astragali Radix", "Angelicae Sinensis Radix", "Inflammation", and "Metabolism", alongside the related synonyms, with a particular emphasis on high-quality research and studies yielding significant findings. The potential of DGBX decoction in modulating immunometabolism holds promise for the treatment of IBD-related CRC. It is particularly relevant given the heterogeneity of CRC and the growing trend towards personalized medicine, but the precise and detailed mechanism necessitate further in vivo validation and extensive clinical studies to substantiate the immunometabolic modulation and delineate the pathways involved.

Determination of vericiguat in rat plasma by UPLC-MS/MS and its application to drug interaction

Vericiguat (VER) is a novel soluble guanylate cyclase stimulator treating symptomatic chronic heart failure (HF), and it is a substrate of both transporters P-glycoprotein and breast cancer resistance protein (BCRP). Astragaloside IV (ASIV) is the main active ingredient in Radix Astragali (Huangqi), a traditional Chinese medicine widely used for HF treatment in China. ASIV's effect on the protein expression of P-glycoprotein and BCRP has been observed, its impact on VER metabolism remain uncertain. In the present study, male Sprague-Dawley rats were administered with 20 mg/kg ASIV and 1 mg/kg VER to study their pharmacokinetics. Blood samples were subject to liquid-liquid extraction, and riociguat was employed as the internal standard (IS). The analytical method involved a C18 column (XSelect® HSS T3 column, 2.1 × 100 mm, 2.5 μm) with a mobile phase of 0.1% formic acid and acetonitrile for gradient elution. The flow rate of the mobile phase was set at 0.2 mL/min, and 5 µL of the sample was used for analysis. The positive ion multi-response monitoring mode was utilized with a transition of m/z 427.4→109.1 for VER and m/z 423.3→109.1 for the IS. The method exhibited good linearity within the concentration range of 0.1 to 300 ng/mL (r = 0.9987), and all the validation processes were conducted in accordance with the requirements of biological analysis. The pharmacokinetic results revealed that ASIV did not significantly alter the main parameters of VER, except for Cmax, which decreased by 33.2% (P < 0.05). Overall, our study successfully established a selective, sensitive and repeatable ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis for detecting VER in rat plasma.

Potential herb‒drug interactions between anti-COVID-19 drugs and traditional Chinese medicine

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread worldwide. Effective treatments against COVID-19 remain urgently in need although vaccination significantly reduces the incidence, hospitalization, and mortality. At present, antiviral drugs including Nirmatrelvir/Ritonavir (PaxlovidTM), Remdesivir, and Molnupiravir have been authorized to treat COVID-19 and become more globally available. On the other hand, traditional Chinese medicine (TCM) has been used for the treatment of epidemic diseases for a long history. Currently, various TCM formulae against COVID-19 such as Qingfei Paidu decoction, Xuanfei Baidu granule, Huashi Baidu granule, Jinhua Qinggan granule, Lianhua Qingwen capsule, and Xuebijing injection have been widely used in clinical practice in China, which may cause potential herb-drug interactions (HDIs) in patients under treatment with antiviral drugs and affect the efficacy and safety of medicines. However, information on potential HDIs between the above anti-COVID-19 drugs and TCM formulae is lacking, and thus this work seeks to summarize and highlight potential HDIs between antiviral drugs and TCM formulae against COVID-19, and especially pharmacokinetic HDIs mediated by metabolizing enzymes and/or transporters. These well-characterized HDIs could provide useful information on clinical concomitant medicine use to maximize clinical outcomes and minimize adverse and toxic effects.

QiShenYiQi pills, a Chinese patent medicine, increase bioavailability of atorvastatin by inhibiting Mrp2 expression in rats

CONTEXT

Atorvastatin (ATV) and QiShenYiQi pills (QSYQ), a Chinese patent medicine, are often co-prescribed to Chinese cardiovascular patients. The effects of QSYQ on the pharmacokinetics of ATV have not been studied.

OBJECTIVE

We investigated the influence of QSYQ on the pharmacokinetics of ATV and its metabolites upon oral or intravenous administration of ATV to rats.

MATERIALS AND METHODS

Sprague-Dawley rats (n = 5/group) were pre-treated with oral QSYQ (675 mg/kg) or vehicle control for 7 days and then orally administrated ATV (10 mg/kg) or intravenously administrated ATV (2 mg/kg). Serum concentrations of ATV and metabolites were determined by ultra-high performance liquid chromatography tandem mass spectrometry. Expression of metabolic enzymes and transporters in jejunum and ileum were measured by quantitative real-time PCR and Western blot.

RESULTS

QSYQ resulted in an increase of AUC_0-12 h of ATV from 226.67 ± 42.11 to 408.70 ± 161.75 ng/mL/h and of C_max of ATV from 101.46 ± 26.18 to 198.00 ± 51.69 ng/mL and in an increased of para-hydroxy atorvastatin from 9.07 ± 6.20 to 23.10 ± 8.70 ng/mL in rats administered ATV orally. No change was observed in rats treated intravenously. The expression of multidrug resistance-associated protein 2 mRNA and protein decreased in ileum, and the mRNA of P-glycoprotein decreased in jejunum, though no change in protein expression was found.

DISCUSSION AND CONCLUSIONS

QSYQ increased bioavailability of ATV administered orally through inhibiting the expression of Mrp2 in ileum. Clinicians should pay close attention to potential drug-drug interactions between ATV and QSYQ.

Aidi injection altered the activity of CYP2D4, CYP1A2, CYP2C19, CYP3A2, CYP2E1 and CYP2C11 in normal and diethylnitrosamine-induced hepatocellular carcinoma in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Aidi injection (ADI), a traditional chinese medicine preparation, is widely used in combination with chemotherapy for the treatment of various malignant tumors, such as hepatocellular carcinoma (HCC). Studies have shown that changes in cytochrome P450 (CYP450) activity in disease states would affect the metabolism of drugs in vivo, especially liver diseases. However, the changes of Aidi injection on the activities of CYP2D4, CYP1A2, CYP2C19, CYP3A2, CYP2E1 and CYP2C11 in normal and HCC states are still unknown.

AIM OF THE STUDY

The cocktail probe drugs method was used to investigate the effects of ADI on the activity of CYP2D4, CYP1A2, CYP2C19, CYP3A2, CYP2E1 and CYP2C11 in normal and HCC rats.

MATERIALS AND METHODS

The HCC rats was induced by diethylnitrosamine (DEN). Then, both normal and HCC rats were randomly divided into 2 groups (n = 6). They were given saline or ADI (10 mL/kg/d, i.p) for 2 weeks, respectively. On the fifteenth day, cocktail probe mixing solution, including metoprolol (10 mg/kg), caffeine (1.0 mg/kg), omeprazole (2.0 mg/kg), midazolam (2.0 mg/kg), chlorzoxazone (4.0 mg/kg) and tolbutamide (0.5 mg/kg), was injected into tail vein of all rats in each group. The blood sample was obtained at specified time. After the protein is precipitated, six probe drugs are analyzed by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS).

RESULTS

Compared with control group, the activity of CYP3A2 and CYP2E1 was significantly lower in the ADI group. Compared with the model group, the activities of CYP1A2, CYP3A2, CYP2E1, and CYP2C11 enzymes in the ADI model group were significantly reduced. Additionally, the activity of CYP2D4, CYP1A2, CYP2C19, CYP3A2, CYP2E1 and CYP2C11 enzymes in model group was significantly lower than control group.

CONCLUSIONS

ADI can inhibit a lot of CYP450 enzyme, so it may reduce the dosage of chemotherapeutic drugs to reach the required plasma concentration of chemotherapeutic drugs, which is of great significance for the combination of anti-tumor chemotherapeutic drugs and is worthy of further in-depth study and clinical attention.

Systematic Evaluation of Toxicity of Aconite Based on Bibliometric Method

AIM

Based on the bibliometric method, the toxicity of aconite is analyzed and evaluated.

METHODS

Studies on the toxicity of aconite were retrieved from CNKI, CQVIP, Chinese Biomedical Literature Service System, and PubMed, ranging from January 1985 to November 2020. All those studies were formed into the Database of Literature of Toxicity of Aconite (DLTA). Studies on the toxicity of aconite were retrieved from CNKI, CQVIP, SinoMed, and PubMed, respectively. Collecting relevant information in DLTA, we analyzed the hotspots, factors and mechanism of aconite toxicity, and attenuation methods.

RESULTS

A total of 445 studies on the toxicity of aconite have been collected. "Compatibility attenuation" and "Processing attenuation" have been the hotspots of aconite toxicity in recent years. Many studies support that the main toxic reactions of aconite are heart damage, liver toxicity, nephrotoxicity, and neurotoxicity. The toxic effect of aconite is related to the effect on the central nervous system. Exciting the vagus nerve reduces the autonomy of the sinus node and damages myocardial cells. The decoction time, dosage, and administration of aconite are the main factors of the toxicity of aconite. There are few studies about the effect of the origin of aconite and the specifications of the medicinal materials on toxicity. Therefore, it is impossible to analyze its relevance. At present, the commonly used methods to reduce the toxicity of aconite mainly include three methods: drug compatibility, processing, and decoction. The most common compatibility with aconite medicines includes licorice, dried ginger, ginseng, and ephedra. Black sliced aconite, steamed slices, and fried slices are less toxic than other processed products. Aconite decoction for more than 60 minutes can basically reach the safe range, and more than 2 hours of decoction may cause the loss of active ingredients.

CONCLUSIONS

The research on the mechanisms of aconite dosage-efficacy-toxicity, compatibility, processing, liver toxicity, and nephrotoxicity is still not comprehensive and in-depth. Researchers should perfect toxicity studies of aconite, remove the constraints that affect its clinical application, and promote the clinical use of aconite safely and reasonably.

Effect and molecular mechanism research of Astragalus membranaceus on inhibiting intestinal absorption of six alkaloids of Aconitum carmichaelii in spleen deficiency rats

Objective

To investigate the effect and the mechanism of Astragalus membranaceus (Huangqi in Chinese, HQ) extract on the intestinal absorption of six alkaloids of Aconitum carmichaelii (Fuzi in Chinese, FZ) in rats with spleen deficiency and provide novel insights into the application of HQ on modulating intestinal barrier.

Methods

Four-week-old male Sprague-Dawley rats were fed with Xiaochengqi Decoction to induce the spleen deficiency model for 40 d. Single-pass intestinal perfusion model were used to study the effects of HQ extract on the absorption of alkaloids. Protein expression and mRNA levels of MRP2 and BCRP and tight junction proteins (TJ, including Claudin-1, Occludin and ZO-1) were measured using Western blot and real-time PCR, respectively. The location and expression of TJ protein was also investigated by the immunofluorescence method.

Results

Compared with the normal group, the protein expression of MRP2, BCRP and TJ proteins in the model group were significantly down-regulated. After oral administration of HQ, the alkaloid absorption in intestinal villi was inhibited, MRP2, BCRP and TJ proteins were up-regulated, the green fluorescence staining of Claudin-1, Occludin, and ZO-1 was enhanced, and a thick layer of mucus was deposited on the surface of the epithelium of the intestinal cavity.

Conclusion

HQ as an intestinal barrier modulator improves the physiological changes of the intestinal environment of spleen deficiency to reduce the absorption of toxic components, leading to a decrease in the absorption of drug-like molecules.

Pharmaceutical Values of Calycosin: One Type of Flavonoid Isolated from Astragalus

Astragalus is a popular Materia Medica in China, and it could be applied in the treatment of various diseases. It contains a variety of chemically active ingredients, such as saponins, flavonoids, and polysaccharides. Plant-derived bioactive chemicals are considered natural, safe, and beneficial. Among the infinite plant-identified and isolated molecules, flavonoids have been reported to have positive effects on human health. Calycosin is the most important active flavonoid substance identified predominantly within this medicinal plant. In recent years, calycosin has been reported to have anticancer, antioxidative, immune-modulatory, and estrogenic-like properties. This review collected recent relevant literatures on calycosin and summarized its potential pharmaceutical properties and working mechanism involved, which provided solid basis for future clinical research.

Traditional Chinese herbal medicine Astragalus Radix and its effects on intestinal absorption of aconite alkaloids in rats

Objective

Methods

Results

Conclusion

Molecular mechanisms of astragaloside‑IV in cancer therapy (Review)

Radix Astragali (RA) is widely used in traditional Chinese medicine (TCM), and astragaloside IV (AS-IV) is the most critical component of RA. Previous studies have demonstrated that AS-IV exerts effects on the myocardium, nervous system and endocrine system, among others. In the present review article, data from studies conducted over the past 20 years were collated, which have evaluated the effects of AS-IV on tumors. The mechanisms of action of AS-IV on malignant cells both in vivo and in vitro were summarized and it was demonstrated that AS-IV plays a vital role, particularly in inhibiting tumor growth and metastasis, promoting the apoptosis of tumor cells, enhancing immune function and preventing drug resistance. Moreover, AS-IV controls several epithelial-mesenchymal transformation (EMT)-related and autophagy-related pathways, such as the phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT), Wnt/β-catenin, mitogen-activated protein kinase (MAPK)/extracellular regulated protein kinase (ERK) and transforming growth factor-β (TGF-β)/SMAD signaling pathways, which are commonly affected in the majority of tumors. The present review provides new perspectives on the functions of AS-IV and its role as an adjuvant treatment in cancer chemotherapy.

Calycosin: a Review of its Pharmacological Effects and Application Prospects

Introduction: Calycosin (CA), a typical phytoestrogen extracted from root of Astragalus membranaceus. On the basis of summarizing the pharmacological and pharmacokinetic studies of CA in recent years, we hope to provide useful information for CA about treating different diseases and to make suggestions for future research.Areas covered: We collected relevant information (January 2014 to March 2020) on CA via the Internet database. Keywords searched includ pharmacology, pharmacokinetics and toxicology, and the number of effective references was 118. CA is a phytoestrogen with wide range of pharmacological activities. By affecting PI3K/Akt/mTOR, WDR7-7-GPR30, Rab27B-β-catenin-VEGF, etc. signaling pathway, CA showed the effect of anticancer, anti-inflammatory, anti-osteoporosis, neuroprotection, hepatoprotection, etc. Therefore, CA is prospective to be used in the treatment of many diseases.Expert opinion: Research shows that CA has a therapeutic effect on a variety of diseases. We think CA is a promising natural medicine. Therefore, we propose that the research directions of CA in the future include the following. Carrying out clinical research trials in order to find the most suitable medicinal concentration for different diseases; Exploring the synergistic mechanism of CA in combination with other drugs; Exploring ways to increase the blood circulation concentration of CA.

Influence of astragaloside IV on pharmacokinetics of triptolide in rats and its potential mechanism

Context: It is common to combine two or more drugs in clinics in China. Triptolide (TP) has been used primarily for the treatment of inflammatory and autoimmune diseases. Astragaloside IV (AS-IV) has been applied with many other drugs, due to its various pharmacological effects. AS-IV and TP can be used together for the treatment of diseases in clinics in China.Objective: This study investigates the effects of astragaloside IV (AS-IV) on the pharmacokinetics of TP in rats and its potential mechanism.Materials and methods: The pharmacokinetics of orally administered triptolide (2 mg/kg) with or without AS-IV pre-treatment (100 mg/kg/day for 7 d) were investigated. Additionally, the effects of AS-IV on the transport of triptolide were investigated using the Caco-2 cell transwell model.Results: The results indicated that when the rats were pre-treated with AS-IV, the C_max of triptolide decreased from 418.78 ± 29.36 to 351.31 ± 38.88 ng/mL, and the AUC_0-t decreased from 358.83 ± 19.56 to 252.23 ± 15.75 μg/h/L. The Caco-2 cell transwell experiments indicated that AS-IV could increase the efflux ratio of TP from 2.37 to 2.91 through inducing the activity of P-gp.Discussion and conclusions: In conclusion, AS-IV could decrease the system exposure of triptolide when they are co-administered, and it might work through decreasing the absorption of triptolide by inducing the activity of P-gp.

Marked decrease of tacrolimus blood concentration caused by compound Chinese herbal granules in a patient with refractory nephrotic syndrome

WHAT IS KNOWN AND OBJECTIVE

The blood concentration of tacrolimus can be affected by co-administrated drugs. The objective is to draw more attention to herb-drug interactions in China, where herbal medicines are commonly used.

CASE DESCRIPTION

The blood concentration of tacrolimus in a girl with refractory nephrotic syndrome decreased nearly a half despite no change in dose. Nebulizer therapy, cyclophosphamide and a compound Chinese herbal medicine were the only additional treatments than usual.

WHAT IS NEW AND CONCLUSION

The most possible cause of the decrease in tacrolimus concentration was the administration of Radix Astragali among compound Chinese herbal medicine granules.

A novel approach of targeting refractory epilepsy: Need of an hour

The refractory epilepsy adds to the global burden of epilepsy as about 25 % of all patients with epilepsy present drug-resistant epilepsy. The P-glycoprotein (P-gp) plays a vital role in the mechanism of resistance in epilepsy. The AED levels in the brain are regulated by the P-gp transport. The upregulation of P-gp results in low concentration of AEDs inside the brain parenchyma and thus leads to resistance. There are three main conditions which lead to decrease transport of AEDs in refractory epilepsy. First being AEDs as substrate of P-gp; secondly, the elevated expression of P-gp in patients with drug resistant epilepsy as compared to drug-responsive patients; thirdly, the low brain AED concentration in refractory epilepsy in comparison to drug-responsive epilepsy. Therefore, determination of P-gp substrate should be a criterion for the selection of new AED for management of refractory epilepsy. This review highlights various tools which help in identification of P-gp substrates and also illustrates a concept of using various novel non-P-gp substrates which can cross the blood brain barrier and leads to enhanced accumulation inside the brain. Hence, these non P-gp substrates can be used as an add on treatment for the management of resistant epilepsy.

Multiple circulating alkaloids and saponins from intravenous Kang-Ai injection inhibit human cytochrome P450 and UDP-glucuronosyltransferase isozymes: potential drug-drug interactions

BACKGROUND

Kang-Ai injection is widely used as an adjuvant therapy drug for many cancers, leukopenia, and chronic hepatitis B. Circulating alkaloids and saponins are believed to be responsible for therapeutic effects. However, their pharmacokinetics (PK) and excretion in vivo and the risk of drug-drug interactions (DDI) through inhibiting human cytochrome P450 (CYP) and UDP-glucuronosyltransferase (UGT) enzymes remain unclear.

METHODS

PK and excretion of circulating compounds were investigated in rats using a validated ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS) method. Further, the inhibitory effects of nine major compounds against eleven CYP and UGT isozymes were assayed using well-accepted specific substrate for each enzyme.

RESULTS

After dosing, 9 alkaloids were found with C max and t 1/2 values of 0.17-422.70 μmol/L and 1.78-4.33 h, respectively. Additionally, 28 saponins exhibited considerable systemic exposure with t 1/2 values of 0.63-7.22 h, whereas other trace saponins could be negligible or undetected. Besides, over 90% of alkaloids were excreted through hepatobiliary and renal excretion. Likewise, astragalosides and protopanaxatriol (PPT) type ginsenosides also involved in hepatobiliary and/or renal excretion. Protopanaxadiol (PPD) type ginsenosides were mainly excreted to urine. Furthermore, PPD-type ginsenosides were extensively bound (f u-plasma approximately 1%), whereas astragalosides and PPT-type ginsenosides displayed f u-plasma values of 12.35% and 60.23-87.36%, respectively. Moreover, matrine, oxymatrine, astragaloside IV, ginsenoside Rg1, ginsenoside Re, ginsenoside Rd, ginsenoside Rc, and ginsenoside Rb1 exhibited no inhibition or weak inhibition against several common CYP and UGT enzymes IC50 values between 8.81 and 92.21 μM. Through kinetic modeling, their inhibition mechanisms towards those CYP and UGT isozymes were explored with obtained Ki values. In vitro-in vivo extrapolation showed the inhibition of systemic clearance for CYP or UGT substrates seemed impossible due to [I]/Ki no more than 0.1.

CONCLUSIONS

We summarized the PK behaviors, excretion characteristics and protein binding rates of circulating alkaloids, astragalosides and ginsenosides after intravenous Kang-Ai injection. Furthermore, weak inhibition or no inhibition towards these CYP and UGT activities could not trigger harmful DDI when Kang-Ai injection is co-administered with clinical drugs primarily cleared by these CYP or UGT isozymes.

Pharmacokinetic interaction between a Chinese herbal formula Huosu Yangwei oral liquid and apatinib in vitro and in vivo

Objectives

This study aimed to evaluate the inhibitory effects of Huosu Yangwei oral liquid (HSYW) on cytochrome P450 enzymes (CYPs) and to investigate whether this herbal medicine could modulate the pharmacokinetic behaviour of the co-administered CYP-substrate drug apatinib.

Methods

Cytochrome P450 enzymes inhibition assays were conducted in human liver microsomes (HLM) by a LC-MS/MS method for simultaneous determination of the oxidative metabolites of eight probe substrates for hepatic CYPs. The modulatory effects of HSYW on the oxidative metabolism of apatinib were investigated in both HLM and rat liver microsomes (RLM). The influences of HSYW on the pharmacokinetic behaviour of apatinib were investigated in rats.

Key findings

Huosu Yangwei oral liquid inhibited all tested CYPs in human liver preparations, with the IC50 values ranged from 0.3148 to 2.642 mg/ml. HSYW could also inhibit the formation of two major oxidative metabolites of apatinib in liver microsomes from both human and rat. In-vivo assays demonstrated that HSYW could significantly prolong the plasma half-life of apatinib by 7.4-fold and increase the AUC0–inf (nm·h) of apatinib by 43%, when HSYW (10 ml/kg) was co-administered with apatinib (10 mg/kg) in rats.

Conclusions

Huosu Yangwei oral liquid could inhibit mammalian CYPs and modulated the metabolic half-life of apatinib both in vitro and in vivo.

Astragaloside IV enhances cisplatin chemosensitivity in hepatocellular carcinoma by suppressing MRP2

Decreased chemosensitivity among tumor cells is often an obstacle in cisplatin (Cis) chemotherapy. Overexpression of multidrug resistance-associated protein 2 (MRP2) is a key mechanism underlying decreased Cis chemosensitivity and resistance. Astragaloside IV (AS IV) is an important component derived from the well-known traditional Chinese herb Astragalus membranaceus. The aim of this study was to explore the role of AS IV in enhancing the antitumor effect of Cis by suppressing MRP2 expression in HepG2 cells and H22 tumor-bearing mice. After co-treatment of HepG2 cells with Cis and AS IV, we assessed the effects on cell proliferation and apoptosis. Tumor growth and apoptosis assessment were performed to assess chemosensitivity in H22 tumor-bearing mice. We used western blotting, immunofluorescence assays, and immunohistochemistry assays to detect MRP2 expression in HepG2 cells, H22 tumor tissues and mouse kidney tissues. AS IV enhanced Cis chemosensitivity by increasing tumor cell apoptosis and slowing tumor growth in vitro and in vivo. MRP2 overexpression in tumor cells was induced by Cis, which contributes to decreased chemosensitivity and Cis resistance. Co-administration of AS IV suppressed MRP2 expression in tumor tissues, which might be an important mechanism for enhancing Cis chemosensitivity in hepatocellular carcinoma. Moreover, AS IV alleviated Cis-induced kidney injury in mice without changing MRP2 expression. In total, AS IV enhanced the antitumor effect of Cis against hepatocellular carcinoma by suppressing MRP2 expression in tumor cells. The results provide a new insight into the combined use of a chemotherapy drug and natural ingredients to treat cancer.

Effects of astragaloside IV on the pharmacokinetics of omeprazole in rats

Context: Omeprazole and astragaloside IV (AS-IV) are widely used for the treatment of gastric ulcers in China clinics. Objective: This study investigates the effects of AS-IV on the pharmacokinetics of omeprazole in rats. Materials and methods: The pharmacokinetics of orally administered omeprazole (2 mg/kg), with or without AS-IV (100 mg/kg/day for 7 days) pretreatment, were investigated in male Sprague-Dawley rats (two groups of six animals each) using LC-MS/MS. A Caco-2 cell transwell model and rat liver microsome incubation systems were also used to support the in vivo pharmacokinetic data and investigate its potential mechanism. Results: The results indicated that co-administration of AS-IV could decrease the systemic exposure of omeprazole significantly (p < 0.05), including AUC_0-t (717.20 ± 177.63 vs. 1166.25 ± 186.65 ng h/mL) and C_max (272.35 ± 25.81 vs. 366.34 ± 32.57 ng/mL). The t_1/2 of omeprazole also decreased significantly (1.78 ± 0.15 vs. 2.23 ± 0.27 h, p < 0.05). The efflux ratio of omeprazole across the Caco-2 cell transwell model increased significantly from 1.73 to 2.67 (p < 0.05), and the metabolic stability of omeprazole was decreased from 42.6 ± 7.8 to 26.2 ± 5.1 min with the pretreatment of AS-IV (p < 0.05). Discussion and conclusions: AS-IV could decrease the systemic exposure of omeprazole in rats when AS-IV and omeprazole were co-administered, and it might exert these effects through decreasing the absorption of omeprazole by inducing P-gp, or through accelerating the metabolism of omeprazole in rat liver by inducing the activity of CYP3A4.

Astragali radix and its main bioactive compounds activate the Nrf2-mediated signaling pathway to induce P-glycoprotein and breast cancer resistance protein

ETHNOPHARMACOLOGICAL RELEVANCE

Astragali radix (Huang Qi, HQ), a well-known Chinese herbal medicine, is widely coadministered with many other drugs for treating diseases. The potential herb-drug interactions (HDIs) possibly occur during the combination therapy. P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) are the crucial targets that mediate the production of HDIs. We previously observed that HQ and its three main bioactive compounds, including Astragaloside IV (AS-IV), calycosin (CS) and formononetin (FMNT), could significantly induce the expression of P-gp and BCRP in HepG2 cells in vitro. However, their modulations on the function of P-gp and BCRP remain unknown; their impact on these two proteins expression in vivo is not clear; the exact regulatory mechanism has also not yet been explored.

AIM OF THE STUDY

This study aimed to investigate the impact of HQ, AS-IV, CS and FMNT on P-gp and BCRP in vivo, and the exact regulatory mechanism involved. The effects of HQ and these compounds on the function of P-gp and BCRP were also studied.

MATERIALS AND METHODS

Wild-type C57BL/6 mice and nuclear factor E2-related factor-2 knockout (Nrf2^-/-) C57BL/6 mice were orally treated with HQ, AS-IV, CS or FMNT. The protein levels of P-gp and BCRP in the liver of mice were measured by using Western blot and immunohistochemistry. The mRNA levels were measured by using real-time PCR. The activation of the drugs on the antioxidant response element (ARE)-luciferin activity was studied by using reporter assay in a stably transfected HepG2-C8 cells. The efflux activity of P-gp and BCRP in HepG2 cells were tested by using flow cytometer with typical probes.

RESULTS

HQ, AS-IV, CS and FMNT significantly upregulated the P-gp and BCRP expression in the liver of wild-type mice. The induction was significantly reversed in the Nrf2^-/- mice. HQ and these compounds significantly increased the Nrf2 expression in wild-type mice. HQ and these compounds also markedly enhanced the ARE-luciferin activity and promoted the nuclear translocation of Nrf2 in cells. Besides, HQ and these compounds significantly enhanced the efflux activity of P-gp and BCRP, and increased the intracellular ATP levels.

CONCLUSIONS

Our results proved that HQ and its main bioactive compounds could induce the P-gp and BCRP expression through the activation of the Nrf2-mediated signaling pathway. HQ and these compounds also significantly enhanced the efflux activity of P-gp and BCRP, and the increased intracellular ATP levels were likely involved in the increased P-gp and BCRP function. These results suggested that potentially HDIs likely occurred when HQ was used concomitantly with other drugs that are substrates of P-gp and BCRP.

Aconitum alkaloids, the major components of Aconitum species, affect expression of multidrug resistance-associated protein 2 and breast cancer resistance protein by activating the Nrf2-mediated signalling pathway

BACKGROUND

Aconitum alkaloids from Aconitum species are often used to treat arthritis and rheumatic diseases but have the drawback of high toxicity. Identifying their pharmacokinetic behaviour is important for the safe clinical application of Aconitum species. Efflux transporters (ETs), including P-glycoprotein (P-gp), multidrug resistance-associated protein 2 (MRP2), and breast cancer resistance protein (BCRP), have important functions in regulating the pharmacokinetic behaviours of drugs and in herb-herb or herb-drug interactions (HDIs). The Aconitum alkaloids regulate P-gp expression and function, but their effects on MRP2 and BCRP expression remain unknown.

PURPOSE

To determine the effects of three Aconitum alkaloids, aconitine (AC), benzoylaconine (BAC), and aconine, on MRP2 and BCRP.

METHODS

The levels of the protein and mRNA expression of MRP2 and BCRP in vivo and in vitro were measured via Western blotting and real-time PCR, respectively. Fluorescence signals of MRP2 and BCRP were detected via confocal fluorescence microscopy. A reporter assay using HepG2-C8 cells, which were generated by transfecting plasmids containing the antioxidant response element (ARE)-luciferin gene into HepG2 cells, was used to examine the ARE-luciferin activity. The transport activities of MRP2 and BCRP were tested via flow cytometry using substrate probes.

RESULTS

The Aconitum alkaloids significantly up-regulated MRP2 and BCRP expression, accompanied by a marked increase in nuclear factor E2-related factor-2 (Nrf2) expression in the jejunum, ileum, and colon of FVB mice, in the order AC < BAC < aconine. In the in vitro model, the Aconitum alkaloids increased MRP2 and BCRP expression in Caco-2 and LS174T cells, in the order AC < BAC < aconine. Additionally, these alkaloids promoted the translocation of Nrf2 from the cytoplasm to the nucleus and significantly increased ARE-luciferin activity in HepG2-C8 cells. Luteolin, a potent inhibitor of Nrf2, markedly prevented MRP2 and BCRP expression from being induced by the three Aconitum alkaloids. The efflux activity of MRP2 was also significantly increased in cells receiving the same treatment.

CONCLUSIONS

The tested Aconitum alkaloids significantly increased the expression of MRP2 and BCRP by activating the Nrf2-mediated signalling pathway and enhanced the efflux activity of MRP2. The potential for herb-herb interactions or HDIs exists when Aconitum species are co-administered with substrate drugs that are transported via MRP2 and BCRP. Therefore, the Aconitum alkaloids may be used as quality indicators for the herbs of Aconitum species.

Effects of calycosin against high-fat diet-induced nonalcoholic fatty liver disease in mice

BACKGROUND AND AIM

Nonalcoholic fatty liver disease (NAFLD) has become a major health concern worldwide. The present study was designed to investigate the effects of calycosin against high-fat diet (HFD)-induced NAFLD in mice.

METHODS

C57BL/6 J male mice were fed with HFD to induce NAFLD model and treated with or without calycosin for 12 weeks. The levels of ALT, AST, insulin, and adiponectin were measured using biochemical methods. Hemotoxylin and eosin staining and Oil Red O staining were used to determine the liver histopathology changes and measure the degree of lipid accumulation respectively. Glucose tolerance tests and insulin tolerance tests were performed followed by quantitative insulin sensitivity check index determination. Western blot and quantitative real-time polymerase chain reaction were used to explore the potential mechanism involved in the beneficial effects of calycosin.

RESULTS

Calycosin effectively decreased the levels of ALT and AST, increased the levels of adiponectin and insulin. Hemotoxylin and eosin staining indicated calycosin treatment remarkably improved liver injury. Oil Red O staining indicated calycosin treatment remarkably improved lipid accumulation. Quantitative insulin sensitivity check index in HFD fed mice was significantly lower than in the standard chow fed mice. Further, calycosin suppressed phosphoenolpyruvate carboxykinase, glucose-6-phosphatase, sterol-regulatory element binding protein 1c, and FASN involved in gluconeogenesis and triglyceride synthesis. Calycosin increased glycogen synthase kinase 3 beta, glucose transporter 4, and phosphorylated insulin receptor substrates 1 and 2 expressions involved in glucose metabolism. The aforementioned beneficial effects of calycosin against HFD-induced NAFLD may be attributed to farnesoid X receptor activation.

CONCLUSION

Calycosin could produce the favorable effects against HFD-induced NAFLD in mice.

LC-MS/MS quantification of sulfotransferases is better than conventional immunogenic methods in determining human liver SULT activities: implication in precision medicine

This study aims to determine whether enzyme activities are correlated with protein amounts and mRNA expression levels of five major human sulfotransferase (SULT) enzymes in 10 matched pericarcinomatous and hepatocellular carcinoma liver samples. The MRM UHPLC-MS/MS method, Western blot and RT-PCR were used along with SULT activity measurement using probe substrates. The LC-MS/MS method was specific for all five tested SULTs, whereas Western blot was specific for only two isoforms. The activities of SULT1A1, SULT1B1, SULT1E1 and SULT2A1 in 9 of 10 samples showed a significant decrease in tumor tissues relative to matched pericarcinomatous tissues, whereas the activities of SULT1A3 in 7 of 10 samples increased. The turnover numbers of SULTs did not change, except for SULT1A1. A generally high degree of correlations was observed between SULT activities and protein amounts (r² ≥ 0.59 except one), whereas a low degree of correlations was observed between SULT activities and mRNA expression levels (r² ≤ 0.48 except one). HCC reduced the SULT activities via impaired protein amounts. LC-MS/MS quantification of SULTs is highly reliable measurement of SULT activities, and may be adopted for implementing precision medicine with respect to drugs mainly metabolized by SULTs in healthy and HCC patients.

Calycosin improves cognitive function in a transgenic mouse model of Alzheimer's disease by activating the protein kinase C pathway

The major pathological changes in Alzheimer's disease are beta amyloid deposits and cognitive impairment. Calycosin is a typical phytoestrogen derived from radix astragali that binds to estrogen receptors to produce estrogen-like effects. Radix astragali Calycosin has been shown to relieve cognitive impairment induced by diabetes mellitus, suggesting calycosin may improve the cognitive function of Alzheimer's disease patients. The protein kinase C pathway is upstream of the mitogen-activated protein kinase pathway and exerts a neuroprotective effect by regulating Alzheimer's disease-related beta amyloid degradation. We hypothesized that calycosin improves the cognitive function of a transgenic mouse model of Alzheimer's disease by activating the protein kinase C pathway. Various doses of calycosin (10, 20 and 40 mg/kg) were intraperitoneally injected into APP/PS1 transgenic mice that model Alzheimer's disease. Calycosin diminished hippocampal beta amyloid, Tau protein, interleukin-1beta, tumor necrosis factor-alpha, acetylcholinesterase and malondialdehyde levels in a dose-dependent manner, and increased acetylcholine and glutathione activities. The administration of a protein kinase C inhibitor, calphostin C, abolished the neuroprotective effects of calycosin including improving cognitive ability, and anti-oxidative and anti-inflammatory effects. Our data demonstrated that calycosin mitigated oxidative stress and inflammatory responses in the hippocampus of Alzheimer's disease model mice by activating the protein kinase C pathway, and thereby improving cognitive function.

Spica prunellae and its marker compound rosmarinic acid induced the expression of efflux transporters through activation of Nrf2-mediated signaling pathway in HepG2 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Spica prunellae (SP) is a well-known traditional Chinese medicinal herb with properties of antihypertensive, antihyperglycemic, antiviral, anti-inflammatory, and antitumor activities. This herb is also popularly consumed as a food additive in some drinks or other food forms for treating pyreticosis. Rosmarinic acid (RA) is the marker compound from SP, which possesses anti-oxidative and anti-inflammatory functions.

AIM OF THE STUDY

This study aims to investigate the regulatory effect of the water extract of SP (WESP) and RA on efflux transports (ETs), including P-glycoprotein (p-gp), multidrug resistance-associated protein 2 (MRP2), and breast cancer resistance protein (BCRP) in HepG2 cell line. Results would provide beneficial information for the proper application of SP in clinics.

MATERIALS AND METHODS

HepG2 cells were treated with different doses of the tested drugs for 24 or 96h. MTT assay was used to examine cell viability. The protein and mRNA levels of the ETs were measured by using Western blot and real-time PCR, respectively. Reporter assay was used to study the antioxidant response element (ARE)-luciferin activity by using HepG2-C8 cells, which were generated by transfecting plasmid containing ARE-luciferin gene into HepG2 cells. The transport activities of ETs were tested by using substrate probes.

RESULTS

WESP significantly (p<0.05) increased the expression of ETs in a dose-dependent manner. The increase caused by WESP was stronger than RA alone. Both WESP and RA promoted the translocation of nuclear factor E2-related factor-2 (Nrf2) from cytoplasm to the nucleus as well as significantly (p<0.05) enhanced the ARE-luciferin activity. WESP and RA also enhanced the efflux activity of P-gp and MRP2, accompanied by marked increase (p<0.05) in the intracellular ATP levels.

CONCLUSIONS

WESP could significantly induce the expression of ETs through the activation of Nrf2-mediated signaling pathway in HepG2 cells. RA could be one of the active compounds responsible for the induction. WESP and RA also enhanced the efflux activity of P-gp and MRP2, and the increased intracellular ATP levels were likely involved in this induction. Results of this study provide a better understanding of the regulation of SP on ETs and the underlying molecular mechanism. Results indicated that potential drug-drug interactions may exist when SP is co-administered with other substrate drugs that are transported via the ETs, especially P-gp and MRP2, thereby providing beneficial information for appropriate use of SP for clinical therapy.