ABSTRACT
OBJECTIVE:To study the antioxidant activity of the different polar parts from Dictamnus dasycarpus and its ef-fects on tyrosinase activity. METHODS:Extract was extracted by 95% ethanol from D. dasycarpus,using petroleum ether,chloro-form,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 (IC50)],and tyrosinase method was used to investigate the related activity in different polar parts. RESULTS:The IC50 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 obvi-ously stronger than the other 2 parts,showing positive correlation with the concentration. Ethyl acetate and chloroform chave an ac-tivation 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.