虫草多糖逆转DMN诱导大鼠肝纤维化的作用及机制研究

目的：研究虫草多糖抗肝纤维化作用的机制。方法： 将SD大鼠随机分为正常组、模型组、虫草多糖组。采用二甲基亚硝胺诱导的大鼠肝纤维化模型。经过虫草多糖治疗4周后,大鼠肝脏用丽春红胶原染色观察大鼠胶原纤维沉积的变化,观察大鼠血清肝功能的变化,盐酸水解法检测肝组织羟脯氨酸含量,Envision 两步法测定肝组织Ⅳ型胶原含量和金属蛋白酶组织抑制因子2（TIMP-2）含量；酶图法检测肝组织金属蛋白酶2（MMP-2）活性,同时检测肝组织超氧化物歧化酶（SOD）活性和丙二醛（MDA）含量的改变。结果：镜下检查可见模型组大鼠肝脏胶原纤维间隔形成；血清肝功能指标异常,MMP-2含量降低；组织Hyp含量,Ⅳ型胶原含量,I型胶原蛋白表达,TIMP-2,MDA含量,均较正常组均显著增加,SOD活性下降,而虫草多糖组的上述指标较模型组均有不同程度的显著下降,使SOD活性升高,MMP-2含量升高。结论：虫草多糖有显著的抗肝纤维化作用,其机制与促进胶原降解和抗脂质过氧化作用有关。

Effects of corydyceps polysaccharide on liver fibrosis induced by DMN in rats

OBJECTIVE: To study the mechanism of Corydyceps polysaccharide (CP) actions against liver fibrosis. METHOD: SD rats were randomly divided into normal control group, DMN-induced liver fibrosis model group and CP treated group. Model group and CP group were injected intraperitonealy with 0. 5% dimethylnitrosamine (DMN) at dose of 2 mL x kg(-1) for 4 weeks to induce liver fibrosis. Then the later group was orally taken CP for 4 weeks. Liver tissue hydroxyproline (Hyp) content was determined by Jamall's method. The liver serum of ALT and AST activities, level of albumin and total bilirubin were analyzed The liver collagen deposition and were observed with Masson' collagen stains. In addition,the tissue inhibitor of metallprteinase-2 (TIMMP-2) level, metalloproteinade-2 (MMP-2) activity, type IV collagen content were observed. Liver samples were also analyzed malondiadehyde (MDA)level and superoxide dismutase (SOD) activity. RESULT:Compare with model group, CP improved the hepatic function (ALT, AST, Alb and Tbil). There were significant decreased of MDA content in CP group, SOD of CP group were markedly increased. Compared to those of normal control group, Hyp content, IV collagen content, TIMMP-2 level in liver tissue of model group increase significantly, and MMP-2 activity decreased, while CP decrees these pathological increase at different degrees. CONCLUSION: CP exerts rather good action against liver fibrosis, and with the mechanism relating to improve degradation of the deposited collagens and anti-lipid peroxiation.