猪苓及猪苓多糖对BBN联合糖精作用Fisher-344大鼠肝脏代谢酶的影响

Effects of Aqueous Extract of Sclerotia of Polyporus umbellatus and Polyporus Polysaccharide on Liver Metabolic Enzyme of Fisher-344 Rats Induced by BBN Combined Saccharin

以BBN联合糖精作用Fisher-344大鼠,分别使用ELISA及RT-PCR方法测定样本中CYP450、GST和NQO1酶活性及Gstpi和NQO1 mRNA相对表达含量。结果表明,猪苓及猪苓多糖均可使样本中CYP450酶活性显著降低,其中猪苓对CYP450酶活性抑制呈剂量依赖性;猪苓及猪苓多糖对样本中GST无明显影响,猪苓可显著升高样本中NQO1酶活性;猪苓高剂量及猪苓多糖可上调GSTPi mRNA表达,猪苓及猪苓多糖对NQO1 mRNA表达无明显作用。研究表明猪苓及猪苓多糖抗癌作用与降低CYP450与升高NQO1酶活性有关,但机制有待进一步研究。

The present aimed to evaluate effects of sclerotia of P. umbellatus FRIES aqueous extract （SPUE） and Polyporus polysaccharide （PPS） on liver metabolic enzyme of Fisher-344 rat induced by N-butyl-N-（4-hydroxybutyl） nitrosamine （BBN） combined saccharin. The rat liver enzyme activities of CYP450, glutathione S-transferase （ GST）, and NAD（P） H：quinone oxidoreductase 1 （NQO1） were determined by ELISA. The relative expressions of liver glutathione S-transferase π （GSTPi） and NQO1 mRNA were measured with RT-PCR. The present report showed the SPUE and PPS decreased the activity of rat liver CYP450 enzyme, the effect had dose-effect relationship;they had no significant effect on the activity of rat liver GST enzyme, and they could increase the activity of rat liver NQO1 enzyme;the high dose SPUE could up-regulate the GSTPi mRNA relative expression in rat liver,they had no effect on the NQO1 mRNA relative expression in rat liver. In conclusion, the inhibition of bladder carcinogenesis by SPUE and PPS associate with the decreasing of rat liver CYP450 enzyme activity and increasing of NQO1 enzyme activity, but the mechanism needs further research.