查找使用阿拉丁产品的科研文献

Herb-drug interaction of Xingnaojing injection and Edaravone via pharmacokinetics, mixed inhibition of UGTs, and molecular docking

Dongli Qi,Huihui Li,Chunxia Liang,Peijin Peng,Zhen Yang,Yanquan Gao,Ziwei Li,Qingqing Zhang,Zhidong Liu

Background Xingnaojing injection (XNJ) is a famous emergency Traditional Chinese medicine (TCM) derived from the classical Chinese prescription named An-Gong-Niu-Huang Pill. XNJ is often used along with Edaravone injection (EDA) to treat acute ischemic stroke, they have a synergistic effect in improving patients' blood coagulation and neurological function. However, this combination also causes herb-drug interactions (HDIs), raising the risk of adverse reactions. At present, little is known about the pharmacokinetics and potential mechanism of XNJ combined with EDA. Purpose This study investigates the pharmacokinetics and potential mechanism of the HDIs between XNJ and EDA. Study design and methods The pharmacokinetic interactions between XNJ and EDA were studied by GC–MS in rats, and the inhibition of XNJ and (-)-borneol on UDP-glucuronosyltransferase (UGTs) were assayed by LC-MS/MS in vitro. In vitro-in vivo extrapolation ( IVIVE ) and molecular docking were performed to reveal the potential for HDIs. Results The AUC 0-∞ of (-)-borneol was increased by 1.25-fold in group EDA+XNJ 10 min later, and the C max of edaravone was increased by 1.6-fold in group XNJ+EDA 10 min later ( p < 0.05). XNJ and (-)-borneol inhibited UGTs-mediated edaravone metabolism in HLM and RLM with a similar inhibitory intensity, in which both of them have stronger inhibition in RLM. These findings demonstrated that (-)-borneol in XNJ mainly exerted UGTs inhibition, which was consistent with the pharmacokinetic assays. (-)-Borneol moderately inhibited UGT2B7 and UGT1A6 by a mixed inhibition mechanism, with K i values of 101.393 and 136.217 μM, respectively. Due to the blood concentration of injection was dramatically increased, the HDIs caused by the inhibitory effect of XNJ on UGTs should be highly emphasized. The binding energies of (-)-borneol and edaravone toward UGT2B7 were −6.254 and −6.643 kcal/mol, and the scores towards UGT1A6 were −5.220 and −6.469 kcal/mol, respectively. Moreover, (-)-borneol has similar free energies to many drugs metabolized by UGT2B7 and UGT1A6. Conclusions (-)-Borneol modulates the pharmacokinetic behavior of edaravone via mixed inhibition of UGT2B7 and UGT1A6. It provides a theoretical basis for the synergistic effect of XNJ and EDA combinations in clinical practice. When XNJ is used along with UGT2B7 and UGT1A6 substrates, it should be used clinically with caution.

Emodin-induced hepatotoxicity was exacerbated by probenecid through inhibiting UGTs and MRP2

Lili Wu,Yulian Chen,Han Liu,Zhikun Zhan,Zhi Liang,Tao Zhang,Zheng Cai,Ling Ye,Menghua Liu,Jie Zhao,Shuwen Liu,Lan Tang

Aggravating effect of probenecid (a traditional anti-gout agent) on emodin-induced hepatotoxicity was evaluated in this study. 33.3% rats died in combination group, while no death was observed in rats treated with emodin alone or probenecid alone, indicating that emodin-induced (150 mg/kg) hepatotoxicity was exacerbated by probenecid (100 mg/kg). In toxicokinetics-toxicodynamics (TK-TD) study, aspartate aminotransferase (AST) and systemic exposure (area under the serum concentration-time curve, AUC ) of emodin and its glucuronide were significantly increased in rats after co-administrated with emodin and probenecid for 28 consecutive days. Results showed that the increased AUC (increased by 85.9%) of emodin was mainly caused by the decreased enzyme activity of UDP-glucuronosyltransferases (UGTs, decreased by 11.8%–58.1%). In addition, AUC of emodin glucuronide was increased 5-fold, which was attributed to the decrease of multidrug-resistant-protein 2 (MRP2) protein levels (decreased by 54.4%). Similarly, in vitro experiments proved that probenecid reduced the cell viability of emodin-treated HepG2 cells through inhibiting UGT1A9, UGT2B7 and MRP2. Our findings demonstrated that emodin-induced hepatoxicity was exacerbated by probenecid through inhibition of UGTs and MRP2 in vivo and in vitro , indicating that gout patients should avoid taking emodin-containing preparations in combination with probenecid for a long time.

Inhibition of aflatoxins on UDP-glucuronosyltransferases (UGTs)

Zuo Du,Zhen-Zhong Liu

Aflatoxins have been recognized as the most harmful mycotoxins leading to various toxic effects. The present study aims to determine the inhibition behavior of aflatoxins on the activity of the important phase II metabolizing enzymes, UDP-glucuronosyltransferases (UGTs), based on in vitro incubation system of recombinant human UGTs-catalyzed glucuronidation of 4-methylumbelliferone (4-MU). 100 μM AFB1 and AFG1 exhibited extensive inhibition towards UGT isoforms especially UGT1A7 and UGT1A8, with the inhibition ratios to be 71.38%, 72.95% and 72.79% for AFB1 to UGT1A7, AFB1 to UGT1A8 and AFG1 to UGT1A8, respectively. Molecular docking results showed that hydrogen bonds and hydrophobic contacts of the particular structure consisting of double furan ring with double bond contributed to the interaction of aflatoxins and UGTs. Kinetics analysis, including inhibition types and kinetics parameters ( K i ), and in vitro-in vivo extrapolation (IVIVE) indicated that there might be a medium possibility of inhibition on UGTs by aflatoxins in vivo . In conclusion, the present study indicated that aflatoxins could possibly disturb endogenous metabolism by inhibiting the activity of UGTs so as to exhibit toxic effects.

Investigation of UDP-glucuronosyltransferases (UGTs) Inhibitory Properties of Carvacrol

Rui-Hua Dong,Zhong-Ze Fang,Liang-Liang Zhu,Si-Cheng Liang,Guang-Bo Ge,Ling Yang,Ze-Yuan Liu

UDP-glucuronosyltransferases (UGTs), the most important phase II drug metabolizing enzymes (DMEs), could metabolize many drugs and various endogenous substances including bilirubin, steroid hormones, thyroid hormones, bile acids and fat-soluble vitamins. Evaluation of the inhibitory effects of compounds on UGTs is clinically important because inhibition of UGT isoforms could not only result in serious drug–drug interactions (DDIs), but also induce metabolic disorders of endogenous substances. The aim of the present study was to investigate the inhibitory effects of carvacrol on major UGT isoforms. The results showed that carvacrol could inhibit the activity of UGT1A9 with negligible effects on other UGT isoforms. When 4-methylumbelliferone (4-MU) was used as a nonspecific probe substrate and recombinant UGT enzymes were utilized as an enzyme resource, the inhibition of UGT1A9 was best fit to the competitive type and the inhibition kinetic parameter ( K i ) was calculated to be 5.7 µ m . Furthermore, another specific probe substrate, propofol, was employed to determine the inhibitory kinetics of UGT1A9, and the results demonstrated that the inhibitory type was noncompetitive. The inhibition kinetic parameter ( K i ) was determined to be 25.0 µ m . Because this substrate-dependent inhibition of UGT1A9 might confuse the in vitro–in vivo extrapolation, these in vitro inhibition kinetic parameters should be interpreted with special caution. Copyright © 2011 John Wiley & Sons, Ltd.

Genistein promotes the metabolic transformation of acetaminophen to glucuronic acid in human L-O2, HepG2 and Hep3b cells via the Nrf2/Keap1 pathway

Fan Yuan-jing,Wei Wei,Luo Jian-ping,Jin Yu-xia,Dai Zi-ling

This study aimed to explore the effects of genistein on regulating the activation of UGTs via the Nrf2/Keap1 pathway and to elucidate the underlying mechanisms of detoxification and hepatic protection. Experiments monitoring genistein-induced protection against acetaminophen-induced cell damage were performed in L-02, HepG2 and Hep3b cells. The results of the MTT, AST, ALT, LDH, GSH and GSSG assays showed that genistein evidently protected the cells from acetaminophen-induced injury in a dose-dependent manner. The control cells were treated with 10 mM acetaminophen without genistein to compare with the effects of the combination of acetaminophen and genistein on the expression of UGT1A1, 1A6 and 1A9, Nrf2 and Keap1 mRNAs, as well as the expression of Nrf2 and Keap1 proteins, which were tested by western blotting. The results showed that the expression of the Nrf2 mRNA and protein increased; in contrast, the expression levels of the Keap1 mRNA and protein were obviously reduced by genistein in a dose-dependent manner. Meanwhile, the expression of the UGT mRNA was increased, and UGT1A9 exhibited the highest expression among the three UGTs. Accordingly, the residual acetaminophen content was obviously reduced and acetaminophen glucuronidation increased after 24 hours of treatment with genistein in a dose-dependent manner.

Combined Pocket-Tunnel Diagnosis Guides Engineering of UGTs for Enhanced Sterol Glycosylation

Dai Jiawei,Gao Yawen,Zhang Lianghui,Wang Shuhao,Lu Yazhou,Bao Yingling,Zhu Linjiang,Chen Hanchi,Chen Xiaolong

Enzyme engineering drives green biocatalysis but lacks diagnostic tools to distinguish transport-limited from binding-limited catalytic bottlenecks, causing unnecessary trial and error. We developed the combined pocket-tunnel diagnosis (CPTD) framework to identify the rate-limiting step. It integrates static structural analysis with molecular dynamics to diagnose geometric and energetic barriers in the substrate transport and binding. Applying this to glycosyltransferase Bs YjiC for the synthesis of bulky sterol glycosides revealed a steric tunnel bottleneck. A compact 44 mutant library achieved 5.5-fold, 9.4-fold, and 4.3-fold activity enhancements for DHEA, pregnenolone, and diosgenin, respectively. Subsequent cavity engineering boosted diosgenin activity 9.29-fold and expanded the substrate scope to cholesterol. Comparative validation confirmed diagnostic accuracy, as a pocket-first strategy failed for both DHEA and pregnenolone and yielded only marginal gains for diosgenin. In contrast, the same pocket mutations produced substantially greater enhancements after the tunnel bottleneck was removed.

Inhibitory effects of tanshinones towards the catalytic activity of UDP-glucuronosyltransferases (UGTs)

Xu-Xin Zhang,Yun-Feng Cao,Li-Xuan Wang,Xiao-Lin Yuan,Zhong-Ze Fang

Contents: Danshen is a popular herb employed to treat cardiovascular and cerebrovascular diseases worldwide. Danshen–drug interaction has not been well studied.Objective: The inhibitory effects of four major tanshinones (tanshinone I, tanshinone IIA, cryptotanshinone, and dihydrotanshinone I) on UDP-glucuronosyltransferases (UGTs) isoforms were determined to better understand the mechanism of danshen–prescription drugs interaction.Materials and methods: In vitro recombinant UGTs-catalyzed 4-methylumbelliferone (4-MU) glucuronidation reaction was employed. Tanshinones (100 μM) was used to perform the initial screening of inhibition capability. High-performance liquid chromatography (HPLC) was used to separate 4-MU and its glucuronide. In vitro–in vivo extrapolation (IV–IVE) was employed to predict in vivo inhibition situation.Results: Cryptotanshinone inhibited UGT1A7 and UGT1A9 with IC50 values of 1.91 ± 0.27 and 0.27 ± 0.03 μM, respectively. Dihydrotanshinone I inhibited UGT1A9-catalyzed 4-MU glucuronidation reaction with the IC50 value of 0.72 ± 0.04 μM. The inhibition of cryptotanshinone towards UGT1A7 and UGT1A9 was best fit to competitive inhibition type, and UGT1A9 was non-competitively inhibited by dihydrotanshinone I. Using in vitro inhibition kinetic parameters (Ki) and in vivo maximum plasma concentration (Cmax) of cryptotanshinone and dihydrotanshinone I, the change of area-under-the-concentration–time curve (AUC) was predicted to be 0.4–4.2%, 3.7–56.3%, and 0.6–6.4% induced by cryptotanshinone and dihydrotanshinone inhibition towards UGT1A7 and UGT1A9, respectively.Discussion and conclusion: The inhibitory effects of tanshinones towards important UGT isoforms were evaluated in the present study, which provide helpful information for exploring the mechanism of danshen–clinical drugs interaction.

Transcriptome profiling and RNA interference reveals relevant detoxification genes in Monochamus alternatus response to (+)-α-pinene

Xuanyu He,Zhaodong Hao,Hui Li,Tian Xu,Ruixu Chen,Xiaohong Xia,Shouyin Li,Dejun Hao

Understanding the mechanism of insect resistance to toxic effects of phytochemicals can provide an insight into plant–herbivore interactions. Monochamus alternatus Hope, a main vector of pine wood nematode ( Bursaphelenchus xylophilus ), prefers to infest masson pine ( Pinus massoniana Lamb) and causes huge economic and environmental losses. α-Pinene is the primary component of resin produced by masson pine and plays a crucial role in defending against herbivorous insects, but its defensive effects on M . alternatus larvae are barely known. Here, we explored the physiological metabolism in M . alternatus larvae that were fumigated with (+)-α-pinene, (-)-α-pinene, β-pinene, (R)-(+)-limonene, myrcene and (-)-α-phellandrene. (+)-α-Pinene showed the highest fumigant toxicity to M . alternatus larvae among these monoterpenes, and the fourth instar larvae possessed the highest resistance to this compound at the larval stage. Comparative transcriptome analysis detected 423 up-regulated and 311 down-regulated genes in the larvae fumigated with (+)-α-pinene, which were mainly related to detoxification, energy and protein metabolism. Among the differentially expressed genes encoding for detoxification enzymes, 14 P450s, 13 UGTs, 1GSTs and 3ABCs were dramatically up-regulated in the larvae fumigated with (+)-α-pinene. Silencing of P450s via RNA interference led to an increased mortality in the larval fumigated with (+)-α-pinene. Piperonyl butoxide exposure significantly increased the mortality and inhibited the expressions of P450s, UGTs and ABCs in the larvae fumigated with (+)-α-pinene. These results suggested an important role of P450s in the resistance of M . alternatus larvae to (+)-α-pinene fumigation, which may facilitate the understanding of terpenoid detoxification in M . alternatus larvae.

Identification of UGTs and BCRP as potential pharmacokinetic determinants of the natural flavonoid alpinetin

Chunli Qi,Jiangnan Fu,Huinan Zhao,Huijie Xing,Dong Dong,Baojian Wu

Effects of diosmetin on nine cytochrome P450 isoforms, UGTs and three drug transporters in vitro

Jun-Jun Chen,Jing-Xian Zhang,Xiang-Qi Zhang,Mei-Juan Qi,Mei-Zhi Shi,Jiao Yang,Ke-Zhi Zhang,Cheng Guo,Yong-Long Han

Diosmetin (3′, 5, 7-trihydroxy-4′-methoxyflavone), a natural flavonoid from traditional Chinese herbs, has been used in various medicinal products because of its anticancer, antimicrobial, antioxidant, estrogenic and anti-inflammatory activity. However, flavonoids could affect the metabolic enzymes and cause drug-drug interactions (DDI), reducing the efficacy of co-administered drugs and potentially resulting in serious adverse reactions. To evaluate its potential to interact with co-administered drugs, the IC 50 value of phase I cytochrome P450 enzymes (CYPs), phase II UDP-glucuronyltransferases (UGTs) and hepatic uptake transporters (organic cation transporters (OCTs), organic anion transporter polypeptides (OATPs) and Na + -taurocholate cotransporting polypeptides (NTCPs)) were examined in vitro by LC-MS/MS. Diosmetin showed strong inhibition of CYP1A2 in a concentration-dependent manner. The intensity of the inhibitory effect was followed by CYP2C8 , CYP2C9 , CYP2C19 and CYP2E1 . For CYP2A6 , CYP2B6 , CYP2D6 and CYP3A4 , diosmetin was found to have no significant inhibitory effects, and the induction effect on CYPs was not significant. For UGTs, diosmetin had a minimal inhibitory effect. In addition, the inhibitory effects of diosmetin on OATP and OCT1 were weak, and it had little effect on NTCP. This finding indicated that drug-drug interactions induced by diosmetin may occur through co-administration of drugs metabolized by CYP1A2.

Effects of azadirachtin on detoxification-related gene expression in the fat bodies of the fall armyworm, Spodoptera frugiperda

Yu Haikuo,Yang Xianmei,Dai Jinghua,Li Yuning,Veeran Sethuraman,Lin Jintian,Shu Benshui

The fall armyworm, Spodoptera frugiperda, has become a worldwide pest and threatens world food production. A previous study indicated that azadirachtin, the most effective botanical insecticide for S. frugiperda , inhibits larval growth of the insect. The effect of azadirachtin on the tissues of the larvae, however, remains to be determined. In this study, the effects of azadirachtin on the structure of fat bodies were analyzed. Comparative transcriptomic analysis was conducted between controls and samples treated with 0.1 μg/g azadirachtin for 7 days to explore potential relevant mechanisms. The expression of 5356 genes was significantly affected after azadirachtin treatment, with 3020 up-regulated and 2336 down-regulated. Among them, 137 encode detoxification enzymes, including 53 P450s , 20 GSTs , 27 CarEs , 16 UGTs , and 12 ABC transporters . Our results indicated that azadirachtin could destroy fat body structure and change the mRNA levels of detoxification-related genes. The up-regulated genes encoding detoxification enzymes might be related to detoxifying azadirachtin. Our results elucidate a preliminary mechanism of azadirachtin detoxification in the fat bodies of S. frugiperda larvae.

Four novel Cit7GlcTs functional in flavonoid 7-O-glucoside biosynthesis are vital to flavonoid biosynthesis shunting in citrus

Yuan Ziyu,Li Gu,Zhang Huixian,Peng Zhaoxin,Ding Wenyu,Wen Huan,Zhou Hanxin,Zeng Jiwu,Chen Jiajing,Xu Juan

Citrus fruits have abundant flavonoid glycosides (FGs), an important class of natural functional and flavor components. However, there have been few reports about the modification of UDP-glycosyltransferases (UGTs) on flavonoids in citrus. Notably, in flavonoid biosynthesis, 7-O-glucosylation is the initial and essential step of glycosylation prior to the synthesis of flavanone disaccharides, the most abundant and iconic FGs in citrus fruits. Here, based on the accumulation of FGs observed at the very early fruit development stage of two pummelo varieties, we screened six novel flavonoid 7-O-glucosyltransferase genes (7GlcTs) via transcriptomic analysis and then characterized them in vitro. The results revealed that four Cg7GlcTs possess wide catalytic activities towards various flavonoid substrates, with CgUGT89AK1 exhibiting the highest catalytic efficiency. Transient overexpression of CgUGT90A31 and CgUGT89AK1 led to increases in FG synthesis in pummelo leaves. Interestingly, these two genes had conserved sequences and consistent functions across different germplasms. Moreover, CitUGT89AK1 was found to play a role in the response of citrus to Huanglongbing infection by promoting FG production. The findings improve our understanding of flavonoid 7-O-glucosylation by identifying the key genes, and may help improve the benefits of flavonoid biosynthesis for plants and humans in the future.