基于特异质大鼠胆红素相关转运体功能抑制探讨首乌藤肝损伤机制

Study on mechanism of hepatotoxicity of Ploygoni Multiflori Caulis based on function inhibition of bilirubin-associated transporters in idiosyncratic rat

考察全粉及提取物对正常和特异质(LPS)大鼠胆红素相关转运体Oatp1a1,Oatp1b2和MRP2活性及mRNA表达的影响,探讨首乌藤致肝损伤的可能机制。正常及LPS大鼠分别连续灌胃首乌藤全粉及提取物7 d后,静脉注射转运体底物磺溴酞钠(BSP),测定其药动学参数,考察各转运体的活性,同时取肝组织检测转运体mRNA的表达。结果首乌藤全粉及提取物可使BSP的t_(1/2)和AUC显著升高,CL显著降低;AST和ALT显著性降低;Oatp1a1,Oatp1b2及MRP2的mRNA表达水平明显下降(P<0.05),但未见二者与LPS的协同作用。综上首乌藤及其提取物对胆红素相关转运体功能的抑制作用,可能是其是否造成肝损伤的原因之一。

To explore the possible mechanism of liver injury, the effects of Ploygoni Multiflori Caulis and its extractive on the function of bilirubin-associated transporters were investigated in normal （N） and idiosyncratic （LPS） rats （M）. The normal and LPS rats were respectively administrated powder of Ploygoni Multiflori Caulis, its extractive and same volume of 0.5% CMC-Na solution for 7 d. BSP, a substrate of the transporters of Oatp1a1 and Oatp1b2 was selected, and its pharmacokinetic parameters of intravenous injection were determined to examined the activity these transporters. Meanwhile the mRNA expressions of transporters were detected. Compared with N-blank control group, besides M-powder group, the Cmax has no significantly different from other groups, t1/2, AUC0-t and AUC0-∞ were significantly increased, and CL were significantly decreased. However, compared with N-blank control group, AST and ALT decreased significantly. The expression of Oatp1a1, Oatp1b2 and MRP2 mRNA was significantly decreased （P〈0.05）, but there was no act synergistically when Ploygoni Multiflori Caulis and extractive were combined with LPS. The function of Oatp1a1, Oatp1b2 and MRP2 in rats were significantly inhibited by Ploygoni Multiflori Caulis and extractive, which may be an important cause of hepatotoxicity.