Microbial Transformation of Gypenoside from Gynostemma pentaphyllum by Aspergullus glaucus and Its Biological Activities
- 生命科学－已发表论文 
以福建绞股蓝[Gynostemma pentaphyllum(Thunb)Makino]为材料,经乙醇提取和正丁醇萃取获得绞股蓝皂苷,利用灰绿曲霉(Aspergullus glaucus)微生物转化绞股蓝皂苷,通过测定绞股蓝皂苷和灰绿曲霉转化产物的抗癌、抗酪氨酸酶和抗氧化活性,比较绞股蓝皂苷经微生物转化修饰前后生物活性的差异.结果表明:灰绿曲霉转化产物对肝癌细胞SMMC7721有体外抑制作用,半抑制质量浓度(IC50)为91.66μg/m L,而绞股蓝皂苷抗癌效果不强;绞股蓝皂苷对蘑菇酪氨酸酶活力具有较强的抑制作用,IC50为0.14 mg/m L,其抑制作用属于可逆抑制,抑制类型为混合型抑制作用,而灰绿曲霉转化产物抗蘑菇酪氨酸酶活性较弱;绞股蓝皂苷和灰绿曲霉转化产物分别在0.2和2 mg/m L质量浓度下对DNA氧化损伤有保护作用.研究结果说明绞股蓝皂苷经微生物修饰后,抗癌效果增强,对蘑菇酪氨酸酶抑制作用和DNA氧化损伤保护作用减弱.该研究结果可为利用微生物转化法筛选抗癌绞股蓝皂苷奠定基础.Gynostemma pentaphyllum in Fujian Province was used as the material in this research.Gypenoside was extracted with ethanol and n-butyl alcohol. Gypenoside was microbially transformed by Aspergullus glaucus. The abilities of anticancer,anti-tyrosinase and anti-oxidation in gypenoside and transformation products were measured in our study.The difference of bioactivity between gypenoside and microbially transformed gypenoside was compared.The result showed that the products of transformation by A. glaucus affected the growth of hepatocellular carcinoma cells SMMC7721 with half maximal inhibitory concentration( IC50) values of 91. 66 μg/m L,but the anticancer activity of gypenoside was very weak.Gypenoside had strong inhibition to the mushroom tyrosinase. The value of IC50 was 0. 14 mg / m L. Moreover,the products of transformation by A. glaucus showed little anti-tyrosinase acti-vity.The kinesis study showed that the inhibition of gypenoside to mushroom tyrosinase was reversible and inhibition types were mixed. Gypenoside exhibited the active protective effect on H2O2-induced oxidative-stress damage at the concentration of 0. 2 mg / m L,and the products of transformation by A. glaucus were at 2 mg / m L. This research indicated that the anticancer effect of gypenoside modified by microorganisms was enhanced,but the activity of anti-tyrosinase and H2O2-induced oxidativestress damage became weakened.This study laid the foundation of screening anticancer gypenoside by means of microbial transformation.