Inhibitory effect of Physalis alkekengi extracts in different phenological stages on xanthine oxidase activity

Introduction: Physalis alkekengi (Solanaceae) is a rich source of various antioxidants. There are some reports that show P. alkekengi has been used for treatment of a wide range of diseases including gout and inflammation. Xanthine oxidase plays a crucial role in gout. Many natural compounds such as various flavonoids have been reported to have inhibitory effect on xanthine oxidase. Methods: Different parts of P. alkekengi including leave, calyx, green and orange fruits at different stages of plant growth were gathered from around the Tonekabon, Iran. Then, they were dried in the dark and powdered. Inhibitory effect of various plant extracts on xanthine oxidase activity was measured. Soluble sugar and ascorbic acid contents of plant samples, and their correlation with xanthine oxidase inhibitory effect were also determined. Results: All extracts from different parts of P. alkekengi at the concentration of 0.3 mg/ml had inhibitory effect on xanthine oxidase activity with different degrees from 45% (leaves in the vegetative stage) up to 86.86% (leaves in the green fruit stage and calyxs). The leaves, fruits and calyx stage of maturity contained the highest amount of soluble sugar. Also, maximum amount of total ascorbic acid was displayed in an orange calyx, 12.65 mg.fw-1. Conclusion: These results suggest that extracts of P. alkekengi at different phonological stages have high inhibitory effects on xanthine oxidase activity and they are valuable sources of antioxidant compounds. The green fruit, green calyx and orange calyx had the highest inhibitory effects on the xanthine oxidase activity. Therefore, they are recommended as the most appropriate tissues for the next pharmacological studies.