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Ethnopharmacological communication

Mechanism-based inhibition of Alantolactone on human cytochrome P450 3A4 in vitro and activity of hepatic cytochrome P450 in mice Chong-Zhen Qin a,e,f, Qiao-Li Lv a,e,f, Na-Yiyuan Wu a,e,f, Lin Cheng a,e,f, Yun-Chen Chu b, Tang-Yuan Chu c, Lei Hu a,e,f, Yu Cheng a,e,f, Xue Zhang d, Hong-Hao Zhou a,e,f,n a

Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, PR China Department of Molecular Biology and Human Genetics, Tzu Chi University. No 701 Sec 3 Chun Yang Rd. Hualian City, Taiwan c Department of Obstetrics and Gynecology, Buddhist Tzu Chi General Hospital, Tzu Chi University, Hualien, Taiwan; Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan d Institute of Life Sciences, Chongqing Medical University, Chongqing 400016, China e Institute of Clinical Pharmacology, Central South University, Changsha 410008, PR China f Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, PR China b

art ic l e i nf o

a b s t r a c t

Article history: Received 25 November 2014 Received in revised form 20 March 2015 Accepted 28 March 2015

Ethnopharmacological relevance: Alantolactone (AL), one of the main active ingredients in Inula helenium L., has been included in various prescriptions of traditional Chinese medicine. The effects of AL on cytochrome P450 (CYP450) were still unclear. This study evaluated the inhibitory effect of AL on cytochrome P450s in vitro and in vivo. Materials and methods: The inhibitory effects of AL on the CYPs activity were evaluated in human liver microsomes (HLMs) and recombinant cDNA-expressed enzymes incubation system, and then determined by LC-MS/MS based CYPs probe substrate assay. C57BL/6 mice were treated AL orally (0, 25, 50, 100 mg/kg) for 15 days. The inhibitory effects of AL on major Cyps in mice were examined at both the mRNA and enzyme activity levels. Results: AL showed a potent inhibitory effect on CYP3A4 activity with IC50 values of 3.599 (HLMs) and 3.90 (recombinant CYP3A4) μM, respectively. AL strongly decreased CYP3A4 activity in a dose-dependent but not time-dependent way in HLMs. Results from typical Lineweaver–Burk plots showed that AL could inhibit CYP3A4 activity noncompetitively, with a Ki value of 1.09 μM in HLMs. Moreover, activity of CYP2C19 could also be inhibited by AL with IC50 of 36.82 μM. Other CYP450 isoforms were not markedly affected by AL. The inhibition was also validated by in vivo study of mice. AL significantly decreased mRNA expression of Cyp2c and 3a family. Conclusion: The study indicates that herb–drug interaction should be paid more attention between AL and drugs metabolized by CYP3A4. & 2015 Published by Elsevier Ireland Ltd.

Keywords: Alantolactone CYP3A4 Human liver microsomes Noncompetitive inhibition Drug–drug interaction Chemical compounds studied in this article: : Alantolactone PubChem CID: 72724

1. Introduction Herbal medicines are widely used in treatment of different diseases worldwide because of the efficacy and low toxicity. However, potential of herb–drug interactions rises when they are co-administered with other drugs (Lau et al., 2013; Pal and Mitra, 2006). The underlying mechanism for herb–drug interactions has been studied, and modulation of drug metabolism by cytochrome P450 (CYP) has been implicated as the major causes (Guengerich, 1997; Tachibana et al., 2010). n Corresponding author at: Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, PR China. Tel.: þ 86 731 84805380; fax: þ 86 731 82354476. E-mail address: [email protected] (H.-H. Zhou).

Cytochrome P450s (CYPs) enzymes can metabolize various endogenous and exogenous compounds (Guengerich, 1997). Drug plasma levels increases by inhibition of CYP activity which can lead to toxicity and drugs withdrawal from the market (Kumar et al., 2012). Inula helenium was a common herb in East Asia, whose roots were traditionally used as a diaphoresis, diuretic, expectorant agent (Konishi et al., 2002). It was also used as agents of chronic enterogastritis, tuberculotic enterorrhea, bronchitis and preservative in China (Jiangsu New Medical College et al., 1986). Moreover, the roots were used to treat lung disorders and against tuberculosis in Native Americans (Moerman, 1986). Alantolactone (AL) (PubChem CID: 72724), as an active ingredient, has mainly been isolated from I. helenium L. plants (Blagojevic and Radulovic, 2012; Khan et al., 2012; Lim et al., 2007). AL shows various biological

http://dx.doi.org/10.1016/j.jep.2015.03.061 0378-8741/& 2015 Published by Elsevier Ireland Ltd.

Please cite this article as: Qin, C.-Z., et al., Mechanism-based inhibition of Alantolactone on human cytochrome P450 3A4 in vitro and activity of hepatic cytochrome P450 in mice. Journal of Ethnopharmacology (2015), http://dx.doi.org/10.1016/j.jep.2015.03.061i

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genes were chosen in Supplement 1. Real-time RT-PCR was conducted using the SYBRs Premix DimerEraser™ and on a LightCyclers 480 (Roche Diagnostics) detection system. The mRNA gene expression levels were normalized to β-actin gene expression.

2.4. Liver microsome prepare and determination of Cyps activities

Fig. 1. The inhibitory effect of AL (0, 0.01, 0.1, 1, 10, and 100 μM) on CYP3A4 and CYP2C19 enzyme activities in HLMs. The data were expressed as mean7 SD.

effects, including anthelmintic, antifungal (Tan et al., 1998; Tripathi et al., 1988), anti-inflammatory (Chun et al., 2012; Schmidt et al., 2002), antimicrobial (Stojanovic-Radic et al., 2012; Xin et al., 2008), and anti-proliferative effects on several cancer cell lines, such as prostate, ovary, colon, and leukemia (Konishi et al., 2002; Pal et al., 2010). However, most studies pay attention to pharmacological effects of AL and no study of its effects on CYPs has been conducted. In this study, we investigated the inhibitory effects of AL on CYP450 enzymes in human liver microsomes (HLMs) and also evaluated the mechanism of inhibition mode of AL. The inhibitory effect and mRNA of Cyps were also validated in mice. The study provides the evidence that herb drug may interact with other clinical drugs by inhibiting CYP450s.

2. Materials and methods 2.1. Chemicals The pooled human liver microsome (HLM) and cDNAexpressed recombinant enzyme CYP3A4 used in the incubation studies were purchased from BD Gentest Co. (Woburn, MA, USA). PrimeScripts RT reagent Kit With gDNA Eraser and SYBRs Premix DimerEraser™ were purchased from Takara Biotechnology Co., Ltd. (Dalian, China). Alantolactone (AL) was purchased from National Institute for the Control of Pharmaceutical and Biological Products (China). 2.2. Animals and treatments Eight weeks old male C57BL/6 mice were purchased and maintained at the Animal Experimental Center of Zhengzhou University. All animals were treated in accordance with the Institutional Animal Care Guidelines with the light, temperature, and humidity-controlled environment. AL (0, 25, 50 and 100 mg/ kg, once daily) was administered to mice (n¼ 5 for each dose) for 15 days. Livers were collected after experiment, frozen in liquid nitrogen, and stored at  80 1C. The study was approved by the ethical committee of the Zhengzhou University and complied with national laws relating to the conduct of animal experiments.

Microsomes were prepared from mice livers as described previously (Umegaki et al., 2002). Protein concentration was determined following manufacturer's instructions using Pierces BCA Protein Assay Kit (Thermo Scientific, Rockford, IL, USA). Enzyme activities were determined following a cocktail assay through liquid chromatography–tandem mass spectrometry (LC–MS/ MS). Incubation of liver microsome, NADPH regeneration, sample preparation, and HPLC-MS/MS analysis were performed as previously reported method (Qin et al., 2014).

2.5. Inhibitory effects of AL on cytochrome P450s The inhibitory effects of AL on the activities of CYP2A6, CYP2C9, CYP2C19, CYP2D6 and CYP3A4 were investigated in triplicate using individual drug-probe substrates specific for each HLM– CYP or recombinant enzyme with HPLC-MS/MS detection. The range of concentrations of AL was set from 0.01 μM to 100 μM (5 points). The activities of CYPs were determined by using metabolites of respective probe substrates.

2.6. Dose-, and time-dependent inhibitory effects of AL on CYP3A4 HLMs were incubated with AL (0, 5, 10, 20 μM) in the absence or presence of an NADPH-generating system for 0, 10, 20, or 30 min at 37 1C. After inactivation incubation, aliquots were transferred to new incubation system containing an NADPHgenerating system and substrate cocktail set. The reaction system was incubated for 30 min at 37 1C in a shaking water bath. All incubations were performed in triplicate, and mean values were used for analysis.

2.7. Enzymatic kinetic study of inhibition To investigate the inhibition mode of AL, HLMs were preincubated with AL (0, 1, 2 μM) in potassium phosphate buffer (pH 7.4) for 30 min in the presence of NADPH. Midazolam was then added and incubated for 30 min at 37 1C. Midazolam was used as a probe substrate at 5, 10, or 20 μM. 2.8. cDNA-expressed CYP3A4 inactivation assay To confirm the selective inhibition of the CYP3A4 enzyme by AL, 10 pmol of human recombinant cDNA-expressed CYP3A4 was incubated with AL at 0.01 to 100 μM, with the NADPH system and midazolam as a selective CYP3A4 substrate for 30 min at 37 1C.

2.3. Total RNA extraction and real-time PCR quantification

2.9. Data analysis

RNA was extracted from prepared livers using the TRIzol reagent (Invitrogen, Carlsbad, CA). The concentration and purity of RNA were calculated by measuring the absorbance at 260 and 280 nm. RNA was reverse transcribed from 1 μg to generate cDNA using PrismPrimeScripts RT reagent Kit. The primers for related

A value of p o0.05 was considered statistically significant. The 50% inhibitory concentration (IC50) values were calculated by nonlinear regression using Graphpad Prism 5.0 (San Diego, CA, USA). Lineweaver–Burk plot and secondary plot were obtained from software SigmaPlot (version 10.0, Systat Software, Inc.)

Please cite this article as: Qin, C.-Z., et al., Mechanism-based inhibition of Alantolactone on human cytochrome P450 3A4 in vitro and activity of hepatic cytochrome P450 in mice. Journal of Ethnopharmacology (2015), http://dx.doi.org/10.1016/j.jep.2015.03.061i

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3. Results

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CYP2C19 activity was inhibited significantly in a dose-dependent manner (Supplement 4).

3.1. Inhibition of CYP450 activities by AL in HLMs The inhibitory effects of AL were examined on five typical reactions catalyzed by five human CYP enzymes in HLMs. AL showed a potent inhibition of CYP3A4 activity in HLMs with an IC50 value of 3.599 μM, and a moderate inhibition of CYP2C19 activity with IC50 value of 36.82 μM. However, AL caused no significant inhibition of CYP2A6, CYP2C9, and CYP2D6 activities (IC50 4100 μM). Fig. 1 illustrates the inhibitory effects of AL on CYP3A4 and CYP2C19 in HLMs.

3.6. Effects of AL on the mRNA expression levels of Cyps The mRNA expression levels of genes encoding Cyps are shown in Supplement 5. Cyp3a11 was most markedly and dose-dependently decreased than other Cyps after AL treatment. Cyp2c39 were decreased significantly when the mice treated with 50 or 100 mg/kg AL (p o0.05), while the lower dose of AL only showed slighter decrease tendency (p4 0.05). Moreover, AL showed no statistically significant effect on expression of Cyp2a4, Cyp2d22, and Cyp2c37 (p 40.05).

3.2. Dose-dependent inhibitory effects of AL on CYP3A4 To investigate the mode inhibition of CYP3A4-catalyzed midazolam 10 -hydroxylation by AL, systems was determined with or without pre-incubating NADPH system for 0, 10, 20, or 30 min at 37 1C in HLMs. AL strongly and dose-dependently inhibited CYP3A4-catalyzed midazolam 10 -hydroxylation in HLMs, but not time-dependently (Supplement 2). 3.3. Mechanism-based inhibition of AL on CYP3A4 To investigate the mechanism-based inhibition of AL (0, 1, or 2 μM) on CYP3A4, different concentrations (5, 10, or 20 mM) of midazolam were tested. The Lineweaver–Burk plots (Fig. 2A) and secondary plots (Fig. 2B), both of which were linear, showed a noncompetitive inhibition type of AL on CYP3A4. Therefore, AL acts as a noncompetitive inhibitor on CYP3A4 with a Ki value of 1.09 μM in HLMs. 3.4. Inhibition of recombinant cDNA-expressed CYP3A4 by AL To evaluate the selectivity of the inhibitory effect of AL on CYP3A4, AL was incubated with human recombinant cDNAexpressed CYP3A4. AL showed a potent inhibition of CYP3A4 activity with IC50 values of 3.90 μM (Supplement 3). 3.5. Inhibition of CYPs by AL in mice After treatment with different concentrations of AL for 15 days, enzyme activities of different CYPs in mice liver were measured through metabolites of CYP isotype-specific probe drugs. Consistent with the results of the in vitro study in HLMs, CYP3A4 and

4. Discussion This study is the first to investigate the enzyme kinetics of the inhibitory effect of AL on CYP450 enzymes activities in HLMs, as well as to identify the inhibition in mice. AL significantly inhibits CYP3A4 and CYP2C19 enzyme activities in HLMs and mice. Moreover, AL significantly decreases mRNA expression of Cyps 2c and 3a family. Nowadays, multi-drug therapy has become common for patients with multiple diseases. However, alterations by CYP metabolism can lead to drug–drug interactions and adverse drug reactions (ADRs) (Lazarou et al., 1998). Moreover, the inhibitory effects of therapeutic drugs on CYP enzymes need to be studied to predict drug–drug interactions. With the development of herbal products, they should also be investigated to avoid ADRs due to the co-administration of herbal products and ethical drugs. CYP3A4 is the most important drug metabolizing enzyme, which metabolizes over 50% of all marketed drugs. (Omiecinski et al., 1999; Williams et al., 2004). CYP3A4 constitutes up to 60% liver CYP isoforms, expressed as most abundant in the human liver CYP enzyme system (Shimada et al., 1994). So, inhibition of CYP3A4 could cause plasma concentration alteration of other co-administration drugs. Alantolactone is a traditional Chinese medicinal herb officially listed in pharmacopeias (Stojakowska et al., 2006; Trendafilova et al., 2010). It belongs to a sesquiterpene lactone, and mainly extracted from the roots of I. helenium L. Alantolactone possesses an inhibitory activity for inflammation, microbial and cell growth in several cancer cell lines (Konishi et al., 2002; Lawrence et al., 2001) as reported before. According to our research, complications may occur when patients were treated with multiple drugs including AL. An alteration of CYP activity by AL may leads to serious or even fatal adverse drug

Fig. 2. Lineweaver–Burk plot (A) and secondary plot (B) obtained from a kinetic study of CYP3A4-catalyzed midazolam 10 -hydroxylation following a 30 min incubation with AL at 0 (●), 1 (○), or 2 (▼) μM. The results shown are the means of triplicate experiments.

Please cite this article as: Qin, C.-Z., et al., Mechanism-based inhibition of Alantolactone on human cytochrome P450 3A4 in vitro and activity of hepatic cytochrome P450 in mice. Journal of Ethnopharmacology (2015), http://dx.doi.org/10.1016/j.jep.2015.03.061i

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reactions (ADRs). Drug–drug interaction between AL and other drugs especially those known to be metabolized by CYP3A4 should be cautious. Animal model, especially mouse model, is frequently used to study human genes to provide primary in vivo evidence and identify results in vitro. In view of similarity of expression and function of most orthologous genes between the two species (Muruganandan and Sinal, 2008), we choose mice to identify the inhibitory effects by AL. The orthologous gene of human Cyp3a4 is similar to Cyp3a11 in mice. The decrease of Cyp3a11 mRNA mediated by AL suggests potential herb–drug interactions by those drugs co-administered with AL. Meanwhile, AL may result in herb–drug interactions mediated by Cyp2c. The results provide in vitro and in vivo evidence of potential drug interaction by AL. Nevertheless, there are several limitations in the study. Further clinical trials are needed to determine whether AL exerts adverse effect when co-administered with other drugs. Moreover, there are usually many components of traditional Chinese medicine, and these constituents in the plant may interact with each other. Thus, the inhibitory effect on CYP450 only by AL may be neutralized by other constituents. Whether it exerts a favorably influence on other medical treatments also deserve further investigation. In conclusion, this study demonstrates an inhibitory effect of AL on CYP3A4-catalyzed midazolam 10 -hydroxylation in HLMs dosedependently in a noncompetitive manner. Moreover, AL could inhibit CYP2C19 activity. The inhibition was also validated by in vivo study of mice. AL could also significantly decreased mRNA expression of Cyps 2c and 3a family. The result indicated that AL might cause herb–drug interactions when co-administrated with those involving CYP3A4 and CYP2C19 substrates. The clinical studies of drugs co-administered with AL inhibition needs further investigation. Conflict of interest No conflict to disclose. Appendix A. Supporting information Supplementary data associated with this article can be found in the online version at http://dx.doi.org/10.1016/j.jep.2015.03.061. Reference Blagojevic, P.D., Radulovic, N.S., 2012. Conformational analysis of antistaphylococcal sesquiterpene lactones from Inula helenium essential oil. Nat. Prod. Commun. 7, 1407–1410. Chun, J., Choi, R.J., Khan, S., Lee, D.S., Kim, Y.C., Nam, Y.J., Lee, D.U., Kim, Y.S., 2012. Alantolactone suppresses inducible nitric oxide synthase and cyclooxygenase-2 expression by down-regulating NF-kappaB, MAPK and AP-1 via the MyD88 signaling pathway in LPS-activated RAW 264.7 cells. Int. Immunopharmacol. 14, 375–383. Guengerich, F.P., 1997. Role of cytochrome P450 enzymes in drug-drug interactions. Adv. Pharmacol. 43, 7–35.

Jiangsu New Medical College, 1986. Dictionary of Traditional Chinese Medicines. Q6 57 Smaller-size edition. Shanghai Scientific and Technological Publishing House, 58 Shanghai, China80 (ed.). 59 Khan, M., Yi, F., Rasul, A., Li, T., Wang, N., Gao, H., Gao, R., Ma, T., 2012. Alantolactone 60 induces apoptosis in glioblastoma cells via GSH depletion, ROS generation, and mitochondrial dysfunction. IUBMB life 64, 783–794. 61 Konishi, T., Shimada, Y., Nagao, T., Okabe, H., Konoshima, T., 2002. Antiproliferative 62 sesquiterpene lactones from the roots of Inula helenium. Biol. Pharm. Bull. 25, 63 1370–1372. 64 Kumar, S., Sharma, R., Roychowdhury, A., 2012. Modulation of cytochrome-P450 inhibition (CYP) in drug discovery: a medicinal chemistry perspective. Curr. 65 Med. Chem. 19, 3605–3621. 66 Lau, C., Mooiman, K.D., Maas-Bakker, R.F., Beijnen, J.H., Schellens, J.H., Meijerman, I., 67 2013. Effect of Chinese herbs on CYP3A4 activity and expression in vitro. 68 J. Ethnopharmacol. 149, 543–549. Lawrence, N.J., McGown, A.T., Nduka, J., Hadfield, J.A., Pritchard, R.G., 2001. 69 Cytotoxic Michael-type amine adducts of alpha-methylene lactones alantolac70 tone and isoalantolactone. Bioorg. Med. Chem. Lett. 11, 429–431. 71 Lazarou, J., Pomeranz, B.H., Corey, P.N., 1998. Incidence of adverse drug reactions in hospitalized patients: a meta-analysis of prospective studies. J. Am. Med. Assoc. 72 279, 1200–1205. 73 Lim, S.S., Kim, J.R., Lim, H.A., Jang, C.H., Kim, Y.K., Konishi, T., Kim, E.J., Park, J.H., Kim, 74 J.S., 2007. Induction of detoxifying enzyme by sesquiterpenes present in Inula 75 helenium. J. Med. Food 10, 503–510. Moerman, D.E. (Ed.), 1986. Medicinal Plants of Native America, Ann Arbor, 76 Michigan, U.S.A. 2, p. 642. 77 Muruganandan, S., Sinal, C.J., 2008. Mice as clinically relevant models for the study 78 of cytochrome P450-dependent metabolism. Clin. Pharmacol. Ther. 83, 818–828. 79 Pal, D., Mitra, A.K., 2006. MDR- and CYP3A4-mediated drug-herbal interactions. Life 80 Sci. 78, 2131–2145. 81 Pal, H.C., Sehar, I., Bhushan, S., Gupta, B.D., Saxena, A.K., 2010. Activation of caspases 82 and poly (ADP-ribose) polymerase cleavage to induce apoptosis in leukemia HL-60 cells by Inula racemosa. Toxicol. in Vitro 24, 1599–1609. 83 Qin, C.Z., Ren, X., Tan, Z.R., Chen, Y., Yin, J.Y., Yu, J., Qu, J., Zhou, H.H., Liu, Z.Q., 2014. A 84 high-throughput inhibition screening of major human cytochrome P450 85 enzymes using an in vitro cocktail and liquid chromatography-tandem mass 86 spectrometry. Biomed. Chromatogr. 28, 197–203. Schmidt, T.J., Brun, R., Willuhn, G., Khalid, S.A., 2002. Anti-trypanosomal activity of 87 helenalin and some structurally related sesquiterpene lactones. Planta Med. 68, 88 750–751. 89 Shimada, T., Yamazaki, H., Mimura, M., Inui, Y., Guengerich, F.P., 1994. Interindividual variations in human liver cytochrome P-450 enzymes involved in the 90 oxidation of drugs, carcinogens and toxic chemicals: studies with liver micro91 somes of 30 Japanese and 30 Caucasians. J. Pharmacol. Exp. Ther. 270, 414–423. 92 Stojakowska, A., Michalska, K., Malarz, J., 2006. Simultaneous quantification of 93 eudesmanolides and thymol derivatives from tissues of Inula helenium and I. royleana by reversed-phase high-performance liquid chromatography. Phyto94 chem. Anal. 17, 157–161. 95 Stojanovic-Radic, Z., Comic, L., Radulovic, N., Blagojevic, P., Denic, M., Miltojevic, A., 96 Rajkovic, J., Mihajilov-Krstev, T., 2012. Antistaphylococcal activity of Inula 97 helenium L. root essential oil: eudesmane sesquiterpene lactones induce cell membrane damage. Eur. J. Clin. Microbiol. Infect. Dis. 31, 1015–1025. 98 Tachibana, T., Kato, M., Takano, J., Sugiyama, Y., 2010. Predicting drug-drug 99 interactions involving the inhibition of intestinal CYP3A4 and P-glycoprotein. 100 Curr. Drug Metab. 11, 762–777. Tan, R.X., Tang, H.Q., Hu, J., Shuai, B., 1998. Lignans and sesquiterpene lactones from 101 Artemisia sieversiana and Inula racemosa. Phytochemistry 49, 157–161. 102 Trendafilova, A., Chanev, C., Todorova, M., 2010. Ultrasound-assisted extraction of 103 alantolactone and isoalantolactone from Inula helenium roots. Pharmacogn. 104 Mag. 6, 234–237. Tripathi, Y.B., Tripathi, P., Upadhyay, B.N., 1988. Assessment of the adrenergic beta105 blocking activity of Inula racemosa. J. Ethnopharmacol. 23, 3–9. 106 Umegaki, K., Saito, K., Kubota, Y., Sanada, H., Yamada, K., Shinozuka, K., 2002. 107 Ginkgo biloba extract markedly induces pentoxyresorufin O-dealkylase activity in rats. Jap. J. Pharmacology 90, 345–351. 108 Xin, X.L., Ma, X.C., Liu, K.X., Han, J., Wang, B.R., Guo, D.A., 2008. Microbial 109 transformation of alantolactone by Mucor polymorphosporus. J. Asian Nat. 110 Prod. Res. 10, 933–937.

Please cite this article as: Qin, C.-Z., et al., Mechanism-based inhibition of Alantolactone on human cytochrome P450 3A4 in vitro and activity of hepatic cytochrome P450 in mice. Journal of Ethnopharmacology (2015), http://dx.doi.org/10.1016/j.jep.2015.03.061i

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Mechanism-based inhibition of Alantolactone on human cytochrome P450 3A4 in vitro and activity of hepatic cytochrome P450 in mice.

Alantolactone (AL), one of the main active ingredients in Inula helenium L., has been included in various prescriptions of traditional Chinese medicin...
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