Optimization of the three natural products’ inhibitory effect on xanthine oxidase by response surface methodology

Quercetin,gallic acid and puerarin were selected as the objects of this study. Inhibitory rates and reaction types of the three natural products on xanthine oxidase were studied first. The method of response surface methodology was applied to study the three nature products’ inhibitory rate on xanthine oxidase based on single-factor tests. The results showed that the three nature products were reversible inhibitors against xanthine oxidase and the IC₅₀ of quercetin,gallic acid and puerarin were 44.86 μg/mL,183.61 μg/mL and 555.20 μg/mL,respectively. The inhibitory effect of quercetin was better than gallic acid and puerarin,and the inhibitory effect of puerarin was the worst. The results showed that the response surface methodology was reliable,and the optimal extraction conditions were 83.25 μg/mL for quercetin,166.50 μg/mL for gallic acid,and 650.00 μg/mL for puerarin. In this case,the inhibitory rate was 96.92%±0.17%,was very closed to the model predicts inhibition rate 96.97%.One side this study reduced the dosage and improved the efficiency of the inhibitors,on the other side,it laid foundation for natural products development and food research on anti-gout.