白鲜皮不同极性部位的抗氧化活性及对酪氨酸酶活性的影响

Antioxidant Activity of the Different Polar Parts from Dictamnus dasycarpus and Its Effects on Tyrosinase Activity

目的:研究白鲜皮不同极性部位的抗氧化活性及对酪氨酸酶活性的影响。方法:白鲜皮通过95%乙醇提取得醇提物,用水溶解后分别用石油醚、三氯甲烷、乙酸乙酯萃取,得到不同极性部位。采用1,1-二苯基-2-三硝基苯肼(DPPH)法考察其抗氧化活性[以半数抑制浓度(IC_(50))表示],酪氨酸酶法考察不同极性部位活性。结果:白鲜皮石油醚、三氯甲烷和乙酸乙酯部位清除DPPH自由基的IC_(50)分别为0.875、0.824、0.407 mg/mL。当各极性部位质量浓度分别为25.0、50.0、100、200、300、400、500μg/mL时,石油醚部位对酪氨酸酶的抑制率依次为-3.18%、-4.98%、0.160%、0.044%、2.31%、3.89%、4.29%,三氯甲烷部位对酪氨酸酶的抑制率依次为-33.39%、-31.48%、-10.14%、-5.42%、-9.70%、-4.06%、-0.42%,乙酸乙酯部位对酪氨酸酶的抑制率依次为-17.63%、-17.89%、-18.42%、-21.84%、-20.26%、-22.13%、-32.36%。结论:白鲜皮乙酸乙酯部位清除DPPH自由基的能力明显强于其他两个萃取部位,且与浓度呈正相关;乙酸乙酯、三氯甲烷部位对酪氨酸酶有激活作用,三氯甲烷部位对酪氨酸酶的激活作用与浓度呈负相关;石油醚部位对酪氨酸酶的活性具有双向调节作用。

OBJECTIVE：To study the antioxidant activity of the different polar parts from Dictamnus dasycarpus and its effects on tyrosinase activity. METHODS：Extract was extracted by 95% ethanol from D. dasycarpus,using petroleum ether,chloroform,ethyl acetate to obtain different polar parts after dissolved in water. 1,1-diphenyl-2-trinitrophenylhydrazine（DPPH）method was used to investigate its antioxidant activity [expressed as half inhibitory concentration（IC（50））],and tyrosinase method was used to investigate the related activity in different polar parts. RESULTS：The IC（50） of petroleum ether,chloroform,ethyl acetate parts for scavenging DPPH free radicals were 0.875,0.824,0.407 mg/mL,respectively. When the mass concentration of each polar part were 25.0,50.0,100,200,300,400,500 μg/mL,the inhibition rate of petroleum ether part to tyrosinase were -3.18%,-4.98%,0.160%,0.044%,2.31%,3.89%,4.29%;that of trichloromethane part were -33.39%,-31.48%,-10.14%,-5.42%,-9.70%,-4.06%,-0.42%;and that of ethyl acetate part were -17.63%,-17.89%,-18.42%,-21.84%,-20.26%,-22.13%,-32.36%. CONCLUSIONS：The capacity in scavenging DPPH free radicals in ethyl acetate part is obviously stronger than the other 2 parts,showing positive correlation with the concentration. Ethyl acetate and chloroform chave an activation effect on tyrosinase,the activation effect of chloroform part on tyrosinase was negatively correlated with the concentration and petroleum ether part has a two-way regulatory effect on the activity of tyrosinase.