Study on the Hypouricemic Effect of Extracts from Dioscorea Nipponicae Rhizoma and Extracting Process of Its Ethanol Extract

OBJECTIVE To optimize the extracting process of ethanol extracts with hypouricemic effect from Dioscorea Nipponicae Rhizoma. METHODS The hyperuricemia model of rats was utilized to evaluate the hypouricemic effect of ethanol extracts from Dioscorea Nipponicae Rhizoma. Orthogonal design was utilized to optimize the preparing conditions including the concentration of ethanol, amount of ethanol, extraction times and extraction duration per time when dioscin was selected as the evaluation index. Both dioscin and serum uric acid levels were measured by HPLC. RESULTS The ethanol extracts of Dioscorea Nipponicae Rhizoma had hypouricemic action. Only extraction times had significant effect on the content of dioscin. CONCLUSION The optimum extraction process was to extract three times using six-fold 50% ethanol and 1 h per time.