双环醇对大鼠黄曲霉毒素B1代谢和肝毒性的影响

目的:研究抗肝炎新药双环醇对大鼠黄曲霉毒素B_1(AFB_1)代谢和肝毒性的影响.方法:大鼠灌胃双环醇300 mg·kg~(-1)·d~(-1),连服三日后腹腔注射黄曲霉毒素B_1 1.5 mg·kg~(-1).给黄曲霉毒素B_1 16小时后观察双环醇对黄曲霉毒素B_1引起肝损伤的防护作用以及对体外代谢的影响.结果:双环醇(300 mg·kg~(-1)·d~(-1),连服三日)可明显降低黄曲霉毒素B_1引起的大鼠血清转氨酶和肝脏MDA的升高,增加低毒代谢产物AFQ_1的生成.双环醇还可增加大鼠肝脏细胞色素P450总量和胞浆谷胱甘肽含量,诱导P450 CYP2B1介导的7-戊氧基香豆素脱烃酶和谷胱甘肽疏基转移酶的活性.此外,双环醇对P450 CYP3A介导的红霉素脱甲基酶和 P450 CYP1A介导的7-乙氧基香豆素脱烃酶也有诱导作用.结论:双环醇可通过增加大鼠肝脏对AFB_1代谢的解毒功能起到肝保护作用.

Effects of bicyclol on aflatoxin B1 metabolism and hepatotoxicity in rats

AIM: To study the effect of new antihepatitis drug, bicyclol, on the metabolism and hepatotoxicity of aflatoxin B1 (AFB1) in rats. METHODS: Rats were given bicyclol 300 mg/kg/d ig for 3 d and then injected ip with AFB1 1.5 mg/kg. Liver damages were examined 16 h after ip AFB1. The in vitro metabolism of AFB1 by bicyclol-pretreated liver microsomes was investigated by HPLC assay. RESULTS: Bicyclol (300 mg/kg/d for 3 d) pretreatment provided protection against AFB1 hepatotoxicity as evidenced by the decrease of AFB1-elevated serum aminotransferase and hepatic malondialdehyde in rats. Bicyclol pretreatment slightly increased the production of the less toxic metabolite aflatoxin Q1. Bicyclol increased liver cytochrome P450 content, CYP 2B1-mediated 7-pentoxyresorufin O-dealkylase (PROD) activity, cytosolic glutathione (GSH) level, and GSH S-transferase (GST) activities. Moreover, bicyclol increased CYP 3A-mediated erythromycin-demethylase and CYP 1A-mediated 7-ethoxyresorufin O-deethylase (EROD) activities. CONCLUSION: Bicyclol protected rats against AFB1 hepatotoxicity by increasing the detoxifying metabolism of AFB1 in the liver.