金雀花碱在山豆根肝毒性中的作用

目的:通过金雀花碱(CYT)体内和体外的肝毒性研究,探讨山豆根的肝毒性是否与CYT相关。方法:小鼠肝AML12细胞用于体外肝毒性研究,细胞增殖及细胞毒性检测(CCK-8)试剂盒检测细胞活性。分别加入终浓度为6,10,14 mmol·L~(-1)的CYT,于加药后3,6,12,24 h,取细胞上清液,检测丙氨酸氨基转移酶(ALT),天门冬氨酸氨基转移酶(AST),总胆红素(TBIL)及乳酸脱氢酶(LDH)水平。急性毒性实验,小鼠分别单次口服灌胃24.8,33.1,44.2,58.9,78.5 mg·kg~(-1)CYT,设空白组。亚慢性毒性实验,小鼠随机分为3组,分别口服灌胃超纯水,11.2,14.0 mg·kg~(-1)CYT,连续90 d。第91天小鼠麻醉后取血清检测ALT,AST,TBIL,LDH等生化指标,并做肝脏病理切片。结果:CYT的半抑制浓度(IC50)为15.17 mmol·L~(-1)。14 mmol·L~(-1)CYT自6 h起,ALT,AST释放逐渐增加,于12 h达到峰值(P0.05,P0.01),之后有下降趋势(P0.01);14 mmol·L~(-1)CYT早在给药6 h,LDH释放就已经显著升高(P0.01),在12 h达到顶峰(P0.01),在24 h有下降趋势(P0.01);各浓度CYT在3,6,12,24 h时,较相应时间点空白组而言,TBIL释放均无显著性差异。在急性毒性实验,CYT的半数致死量(LD50)为48.16 mg·kg~(-1),属于全球化学品统一分类和标签制度(GSH)第2级。在亚慢性毒性实验,与空白组相比,CYT组小鼠血清ALT及LDH水平无明显差异;虽然CYT 14.0 mg·kg~(-1)组小鼠血清TBIL含量升高(P0.05),AST含量下降(P0.05),但是均在本实验室背景数据范围内,与空白组相比,肝组织病理学切片亦无明显差异,这一结果可能与CYT14.0 mg·kg~(-1)组小鼠一半死亡,导致血液生化及肝脏病理标本量减少相关。结论:CYT属于GSH分类的经口急性毒性2级毒性物质,其在体外培养条件下具有肝细胞毒性,但是其在体内的肝毒性以及是否为山豆根肝毒性的毒性成分需要进一步研究。

Effect of Cytisine on Hepatotoxicity of Sophorae Tonkinensis Radix et Rhizoma

Objective: To preliminarily investigate whether the hepatotoxicity of Sophorae Tonkinensis Radix et Rhizoma is associated with cytisine (CYT) by researching the hepatotoxicity of CYT in vivo and in vitro. Method: AML12 liver cells were cultured and employed as an in vitro model for hepatotoxicity. Cell viability of CYT was detected with a cell counting Kit-8 (CCK-8) assay. After various final concentrations of CYT (6, 10, 14 mmol·L^-1) were added and treated for 3, 6, 12 and 24 h, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL) and lactic dehydrogenase (LDH) in culture medium were measured. In the acute toxicity study, mice were administered with CYT by gavage at doses of 0, 24.8, 33.1, 44.2, 58.9, 78.5 mg·kg^-1, respectively. In the sub-chronic toxicity study, male mice were divided into three groups and orally treated with ultrapure water (11.2 mg·kg^-1 CYT and 14.0 mg·kg^-1 CYT) for 90 days. At the end of administration, the mice were anaesthetized for collecting serum and testing biochemical indicators, including ALT, AST, TBIL, LDH. Result: The half maximal inhibitory concentration (IC₅₀) value of CYT was the 15.17 mmol·L^-1. Since the treatment with 14 mmol·L^-1 for 6 h, LDH release robustly increased, peaked at 12 h (P<0.05, P<0.01), and declined at 24 h (P<0.01). Furthermore, in cells treated with 14 mmol·L^-1 CYT, the levels of LDH started to significantly increase at 6 h at the earliest (P<0.01), peaked at 12 h (P<0.01), and declined thereafter (P<0.01). However, 6, 10, 14 mmol·L^-1 CYT were found to have no effect on TBIL release. In the acute toxicity, median lethal dose (LD₅₀) of CYT was 48.16 mg·kg^-1 and belonged to grade 2 in the globally harmonized system of classification and labeling of chemicals (GSH). In the sub-chronic toxicity, compared with the blank control group, no significant change in ALT and LDH levels was observed in CYT treated mice. Although animals treated with 14.0 mg·kg^-1 CYT showed lower AST (P<0.05) and higher TBIL (P<0.05), these findings were unable to be correlated with the changes of enzyme activities induced by liver injury, since these parameters were within the background data range of our laboratory. There were no significant change in histopathological examination compared with control and CYT treated mice in the liver. This results may be related to the facts that half of the mice died in 14.0 mg·kg^-1 CYT treated group, which led to a decrease in the samples of biochemistry and hepatic histopathological examination. Conclusion: CYT belongs to the grade 2 toxic substance of GSH in oral acute toxicity. It has hepatocyte toxicity in vitro, but the hepatotoxicity in vivo and whether belonging to the hepatotoxic ingredient of radix Sophorae tonkinensis still needs to be further studied.