Comparison of antioxidative activities of fructus lycii with different commercial grades by bioassay detection

Objective: To establish a quality control method for fructus lycii based on its antioxidation scavenging 1,1-diphenyl-2-picrylhydrazyl(DPPH).Methods: Through orthogonal experiments,the extraction technology of fructus lycii was optimized,and the best reaction conditions were investigated with single-factor analysis.Results: The conditions included solid-liquid ratio 1∶10,and solvent of 50% ethanol,and extraction method of ultrasounding for 20 min were carried out for extracting fructus lycii samples.Then,the antioxidative activity of fructus lycii was detected.The optimal reaction system,0.05 mg·mL-1 DPPH plus 100 mg·mL-1 sample solution,was reacted for 90 min at room temperature.fructus lycii of different commercial grades exerted various scavenge rates of DPPH.The biological activity was higher in samples from high grade fructus lycii.Conclusion: The established bioassay method can objectively reflect the differences in antioxidative activities of samples from fructus lycii.This might be used for quality control of this medicine and other antioxidative TCMs,as well as for high-throughput activity screening.