蛹虫草MF27高抗氧化活性提取物筛选及保肝作用研究

本研究对一株优质蛹虫草菌株MF27不同提取物进行体外抗氧化活性比较,筛选得到高抗氧化活性提取物,并进一步探究该提取物对CCl₄诱导的小鼠肝损伤的修复作用。以DPPH自由基和羟自由基的清除率为抗氧化评价指标,从菌丝体发酵液、菌丝体水提物/醇提物、以及子实体水提物/醇提物中筛选菌株MF27的高抗氧化活性提取物;以CCl₄致小鼠急性肝损伤为模型,通过检测血清生化指标、肝功指标的变化,来评价该高活性提取物的体内抗氧化保肝效果。体外抗氧化实验结果表明,MF27的不同提取物均具有较好的体外抗氧化活性,但对清除DPPH和OH自由基能力最好的提取物是子实体水提物,其对DPPH自由基的半数有效浓度（EC₅₀）为0.096mg/mL,对羟自由基的半数有效浓度（EC₅₀）为0.196mg/mL,当在1mg/mL 时对DPPH自由基的清除率为94.94%,对羟自由基的清除率为70.17%;体内抗氧化保肝结果显示,给药组（子实体水提物）相比模型组而言,小鼠血清中ALT、AST以及肝脏中MDA水平极显著降低（P<0.01）、SOD水平极显著升高（P<0.01）,表明子实体水提物能有效改善氧化性肝损伤,同时与阳性对照（联苯双酯）对比,给药组在肝脏指数上表现出相当的作用（P>0.05）。本研究表明菌株MF27的最有效抗氧化活性提取物是子实体水提物,它对体内氧化性肝损伤有一定的修复能力,揭示MF27子实体水提物具有成为抗氧化性肝损伤功能产品的潜力。

Screening and hepatoprotective effects of high antioxidant extract from Cordyceps militaris MF27

A comparison of antioxidant activity in vitro between different extract of Cordyceps militaris MF27 was made, and an extract with high antioxidant activity was obtained. The repair function of the extract to liver injury induced by CCl₄ in mice was further studied. Using extracorporeal scavenging rate of DPPH free radical and hydroxyl free radical as antioxidant evaluation index, the extract with high antioxidant activity was selected from fermentation broth, aqueous extract and alcohol extract of mycelia, and aqueous extract and alcohol extract of fruiting body. An acute liver injury model in mice by using CCl₄ was established, and evaluation of internal antioxidant and liver protection effect of the extract with high antioxidant activity was made by testing the change of serum biochemical indices and liver function index. The result showed that all the extracts had good antioxidant activity in vitro, but the aqueous extract of fruiting body was possessed of the best ability of scavenging free radicals. The half effective concentration (EC₅₀) of the aqueous extract of fruiting body is 0.096mg/mL for DPPH free radicals and 0.196mg/mL for hydroxyl free radical. At concentration of 1mg/mL, the clearance rate is 94.94% to DPPH free radicals and 70.17% to hydroxyl free radical. In comparison with the model experimental group, the levels of ALT and AST in serum and MDA in liver of the mice in the administration group treated with aqueous extract of fruiting body significantly decreased (P<0.01) as a result of in vivo antioxidation and improvement of liver function. The level of SOD in liver significantly increased (P<0.01), indicating that aqueous extract of the fruiting body can improve oxidative liver damage effectively. Compared with positive control group treated with biphenyl diester, the administration group manifested a great drug efficacy (P>0.05) in the liver index. It is proved that the aqueous extract of fruiting body of C. militaris MF27 has a certain repairing ability in vivo to oxidative liver injury, and possesses potential becoming of antioxidant damage functional product.