水飞蓟素对建鲤肝细胞DNA损伤的保护作用及相关细胞因子的影响

Effects of silymarin on hepatic DNA damage and expression of related cytokines in Cyprinus carpio var. jian

为了评价水飞蓟素对建鲤肝组织损伤的保护作用,探索其可能的保肝机制,本研究用含水飞蓟素(0.1、0.5和1.0 g/kg)的饲料饲喂建鲤60 d,再腹腔注射30%四氯化碳(CCl4)植物油混合液,损伤72 h后采集肝组织,分别研究肝指数、肝细胞DNA损伤、肝组织病理切片、核转录因子NF-κB/C-Rel及细胞因子i NOS和IL-1β的mRNA表达量的变化。结果显示,0.5和1.0 g/kg的水飞蓟素能显著抑制CCl4导致的建鲤肝指数增大,同时能有效减少肝细胞DNA断片的产生,对肝细胞彗星的慧尾长、尾部DNA百分含量、尾矩及Olive尾矩等损伤指标均有显著改善作用;水飞蓟素能明显减轻CCl4作用导致的肝组织广泛性空泡变性、细胞轮廓不清、核固缩和核溶解等组织学病变;0.5和1.0 g/kg的水飞蓟素能显著抑制CCl4诱导的NF-κB/C-Rel和i NOS表达量的增加,而低、中、高浓度的药物均能显著下调IL-1β的表达量;随着水飞蓟素浓度的增大,对肝指数、肝细胞DNA损伤、病理切片及细胞因子的mRNA表达的影响均表现出剂量效应。结果表明,水飞蓟素能有效改善肝细胞DNA的损伤程度,其保肝作用可能与抑制NF-κB活化及下调其下游细胞因子i NOS和IL-1β的表达有关。

The present study aimed to evaluate the hepatoprotective effects of silymarin against carbon tetrachloride（CCl4 ）-induced hepatotoxicity in Cyprinus carpio var. jian. Fish were fed diets containing four doses of silymarin（0,0.1,0.5 ,and 1.0 g/kg）for 60 d,and then given an intraperitoneal injection of 30% CCl4 in olive oil at a volume of 0.05 mL/10 g body weight. At 72 h post injection, liver samples were collected for the liver index, comet assay, histopathological examination and cytokines mRNA detection. Results showed that the increase of the liver index induced by COl4 was significantly inhibited by pre-treating the fish with 0.5 and 1.0 g/kg silymarin in the diets. Comet assay showed silymarin could effectively reduce DNA fragment generation of hepatic cells;tail moment, olive tail moment, tail length and tail DNA% were positively changed in fish pretreated with 0.5 and 1.0 g/kg silymarin. In the liver tissue, silymarin had a protective effect on Jian carps with the alleviation of histological changes such as cell swelling, extensive vacuoles degeneration, karyopyknosis and karyolysis. At the same time, the elevation of nuclear factor-KB （NF-KB/C-Rel） and iNOS mRNA expressions induced by CCl4 were also inhibited by the pre-treatments with 0. 5 and 1. 0 g/kg silymarin, and the IL-1β mRNA expression was significantly inhibited by pretreatment with 0.1,0.5 and 1.0 g/kg slymarin. The positive effects of silymarin on the liver index, comet assay, histopathological examination and gene expressions were observed in a dose-dependent manner. Overall results prove that silymarin can improve the degree of hepatic cell DNA damage, and the hepatoprotective functions may be related to inhibition of the NF-κB activation and down-regulation of the downstream genes expression such as iNOS and IL-1β.