目的 研究隱丹參酮對脂多糖誘導(dǎo)肝硬化大鼠肝性腦病的改善作用,并探討其作用機制。方法 SD大鼠隨機分為對照組、模型組以及隱丹參酮5、15、45 mg/kg組,每組15只。模型組和隱丹參酮組背部sc 40% CCl₄橄欖油溶液0.3 mL/100 g(首次加倍),制備大鼠肝硬化模型;對照組背部sc等體積橄欖油溶液,2次/周。在實驗第10周結(jié)束時開始給藥。隱丹參酮組分別ig隱丹參酮5、15、45 mg/kg,對照組和模型組ig等體積生理鹽水,1次/d,共2周。在第12周結(jié)束時所有大鼠禁食過夜,模型組和隱丹參酮組大鼠iv脂多糖2 mg/kg誘導(dǎo)肝性腦病,對照組iv等劑量無菌生理鹽水。觀察各組大鼠的肝臟組織病理學(xué)形態(tài);采用血生化法檢測大鼠的肝功能指標(biāo)丙氨酸氨基轉(zhuǎn)移酶(ALT)、天冬氨酸氨基轉(zhuǎn)移酶(AST)水平和血氨水平,采用酶聯(lián)免疫吸附(ELISA)法測定血漿中內(nèi)毒素水平;考察大鼠肝性腦病分期和神經(jīng)行為;觀察神經(jīng)細胞5-溴-2′-脫氧尿嘧啶(BrdU)染色情況,計算BrdU陽性率;Western blotting試驗測定腦源性神經(jīng)營養(yǎng)因子(BDNF)的表達。結(jié)果 隱丹參酮組大鼠肝臟組織病理學(xué)形態(tài)發(fā)生明顯改善,血清中ALT、AST水平較模型組明顯降低(P<0.05、0.01),并呈現(xiàn)一定的劑量相關(guān)性。隱丹參酮組大鼠的血氨、內(nèi)毒素水平均比模型組顯著降低(P<0.05、0.01),并具有一定的劑量相關(guān)性。隱丹參酮組大鼠的肝性腦病分期評分明顯優(yōu)于模型組(P<0.01),并且反射評分也得到明顯改善,在隱丹參酮15、45 mg/kg組中尤為明顯。隱丹參酮組神經(jīng)細胞再生能力逐漸增強,在隱丹參酮45 mg/kg組中可以檢測到明顯的BrdU陽性細胞。隱丹參酮15、45 mg/kg組大鼠的BrdU陽性率均比模型組顯著升高(P<0.05、0.01),并具有一定的劑量相關(guān)性。隨著隱丹參酮劑量的增加,BNDF的表達與模型組比較出現(xiàn)明顯升高。結(jié)論 隱丹參酮對脂多糖誘導(dǎo)肝硬化大鼠肝性腦病具有明顯的改善作用,其作用機制與隱丹參酮對肝性腦病大鼠肝功能的改善,血清中血氨、內(nèi)毒素水平的降低,肝性腦病分期的改善,神經(jīng)行為能力的提高,BDNF表達的增強以及對神經(jīng)細胞再生的促進作用有關(guān)。

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.