ORIGINAL ARTICLE |
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Year : 2011 | Volume
: 3
| Issue : 4 | Page : 250-255 |
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Protective effects of goldenseal (Hydrastis canadensis L.) on acetaminophen-induced hepatotoxicity through inhibition of CYP2E1 in rats
Katsunori Yamaura1, Maki Shimada1, Noriyuki Nakayama1, Koichi Ueno2
1 Department of Geriatric Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Chiba University, Japan 2 Department of Geriatric Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Chiba University; Center for Preventive Medical Science, Chiba University, Japan
Correspondence Address:
Katsunori Yamaura 1-8-1 Inohana, Chuo-ku, Chiba 260-8675 Japan
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/0974-8490.89745
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Background: Goldenseal (Hydrastis canadensis L.) inhibits various cytochrome P450 (CYP) isoforms such as CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A in vitro. High doses of acetaminophen (APAP) generate the highly reactive intermediate, N-acetyl-p-benzoquinone imine (NAPQI), catalyzed mainly by CYP2E1. The aim of this study was to investigate the hepatoprotective effects of orally administrated goldenseal against APAP-induced acute liver failure (ALF) via inhibition of CYP2E1. Materials and Methods: Male Wistar rats were treated orally with goldenseal (300 and 1000 mg/kg) 2, 18, and 26 h before and 6 h after oral APAP (400 mg/kg) administration. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities as well as serum APAP concentration were evaluated. Results: Goldenseal extract inhibited CYP1A2, CYP2D6, CYP2E1, and CYP3A activity, and the inhibitory effect on CYP2E1 was the strongest (IC 50 4.32 μg/mL). Treatment with goldenseal (300 mg/kg) significantly attenuated the APAP-induced increase in serum AST and ALT, and the hepatoprotective effect of goldenseal was stronger than that of silymarin (200 mg/kg). Moreover, serum APAP concentration was increased by goldenseal treatment, presumably as a result of the inhibitory effect of goldenseal on the metabolism of APAP to NAPQI. Conclusion: These results suggest that goldenseal ameliorates APAP-induced ALF and that this protection can likely be attributed to the inhibition of CYP2E1 activity, which generates the highly reactive intermediate of APAP. |
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