目的 研究隐丹参酮对脂多糖诱导肝硬化大鼠肝性脑病的改善作用,并探讨其作用机制。方法 SD大鼠随机分为对照组、模型组以及隐丹参酮5、15、45 mg/kg组,每组15只。模型组和隐丹参酮组背部sc 40% CCl₄橄榄油溶液0.3 mL/100 g(首次加倍),制备大鼠肝硬化模型;对照组背部sc等体积橄榄油溶液,2次/周。在实验第10周结束时开始给药。隐丹参酮组分别ig隐丹参酮5、15、45 mg/kg,对照组和模型组ig等体积生理盐水,1次/d,共2周。在第12周结束时所有大鼠禁食过夜,模型组和隐丹参酮组大鼠iv脂多糖2 mg/kg诱导肝性脑病,对照组iv等剂量无菌生理盐水。观察各组大鼠的肝脏组织病理学形态;采用血生化法检测大鼠的肝功能指标丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)水平和血氨水平,采用酶联免疫吸附(ELISA)法测定血浆中内毒素水平;考察大鼠肝性脑病分期和神经行为;观察神经细胞5-溴-2′-脱氧尿嘧啶(BrdU)染色情况,计算BrdU阳性率;Western blotting试验测定脑源性神经营养因子(BDNF)的表达。结果 隐丹参酮组大鼠肝脏组织病理学形态发生明显改善,血清中ALT、AST水平较模型组明显降低(P<0.05、0.01),并呈现一定的剂量相关性。隐丹参酮组大鼠的血氨、内毒素水平均比模型组显著降低(P<0.05、0.01),并具有一定的剂量相关性。隐丹参酮组大鼠的肝性脑病分期评分明显优于模型组(P<0.01),并且反射评分也得到明显改善,在隐丹参酮15、45 mg/kg组中尤为明显。隐丹参酮组神经细胞再生能力逐渐增强,在隐丹参酮45 mg/kg组中可以检测到明显的BrdU阳性细胞。隐丹参酮15、45 mg/kg组大鼠的BrdU阳性率均比模型组显著升高(P<0.05、0.01),并具有一定的剂量相关性。随着隐丹参酮剂量的增加,BNDF的表达与模型组比较出现明显升高。结论 隐丹参酮对脂多糖诱导肝硬化大鼠肝性脑病具有明显的改善作用,其作用机制与隐丹参酮对肝性脑病大鼠肝功能的改善,血清中血氨、内毒素水平的降低,肝性脑病分期的改善,神经行为能力的提高,BDNF表达的增强以及对神经细胞再生的促进作用有关。

Objective To study the improvement of cryptotanshinone on hepatic encephalopathy in rats with cirrhosis induced by lipopolysaccharide (LPS) and to explore its mechanism. Methods SD rats were randomly divided into control, model, and cryptotanshinone (5, 15, and 45 mg/kg) groups, and each group had 15 rats. Rats in model and cryptotanshinone groups were sc administered with 40% CCl₄ olive oil solution 0.3 mL/100 g (double dosage in first time), and were established liver cirrhosis models. And rats in control group were sc administered with the same volumes of 40% CCl₄ olive oil solution, twice per week. The drugs were administered at the end of the 10th week of the experiment. Rats in cryptotanshinone groups were ig administered with cryptotanshinone 5, 15, and 45 mg/kg, and those in control and model groups were ig administered with the same volume of normal saline. The treatment were carried out once daily, and lasted for 2 weeks. Rats in model and cryptotanshinone groups were iv administered with LPS 2 mg/kg to induce hepatic encephalopathy models. And rats in control group were iv administered with the same volumes of stroke-physiological saline solution. Histopathology of liver in rats was observed. Levels of liver index alanine aminotranferease (ALT),aspartate aminotransferase (AST), and blood ammonia were determined by blood biochemical method. Levels of endotoxin in serum were determined by ELISA method. Hepatic encephalopathy stage and nervous behavior were studied. BrdU staining of hippocampal nerve cell was observed, and positive rates were calculated. Brain-derived neurotrophic factor (BNDF) express was determined by Western blotting method. Results Histopathology of liver in rats from cryptotanshinone groups were obviously improved, and levels of ALT and AST in serum were significantly decreased (P < 0.05, 0.01) compared with model group which presented a certain dose-related. Compared with model group, levels of blood ammonia and endotoxin in rats from cryptotanshinone groups were significantly decreased (P < 0.05, 0.01) with dose-dependent manner. Hepatic encephalopathy stage scores and reflection score of rats in cryptotanshinone groups (especially 15 and 45 mg/kg groups) were better than those of model group (P < 0.01). Regeneration ability of hippocampal neural cell in rats from cryptotanshinone groups were promoted, and BrdU positive cells were obvious in cryptotanshinone 45 mg/kg group. Compared with model group, BrdU positive rate of hippocampal nerve cell in rats from cryptotanshinone 15 and 45 mg/kg groups were significantly increased (P < 0.05, 0.01) with a certain dose-related. Compared with model group, BNDF express was significantly increased with the increase of cryptotanshinone dose. Conclusion Cryptotanshinone has significant improvement on hepatic encephalopathy in rats with cirrhosis induced by endotoxin, whose mechanism may be related to improvement of liver index, decrease of levels of blood ammonia and endotoxin, improvement of hepatic encephalopathy stage and nervous behavior, promotion of BNDF expression, and enhancement of regeneration ability of hippocampal neural cells.