Xanthine oxidase inhibitory activity of methanolic extract of Alternanthera sessilis

Gout is caused by abnormal high level of uric acid in the body resulting from the deposition of urate crystals. Uric acid is the end product of purine metabolism in which xanthine oxidase (XO) catalyzes the oxidation of hypoxanthine and xanthine to uric acid. Allopurinol, an effective anti-hyperuricemic agent has limited clinical usage due to its adverse reactions. Therefore, it is very urgent to search for better phytochemicals, which possess ability as xanthine oxidase inhibitor. In the present study, hydromethanolic extract of red and green sessile joyweed, Alternanthera sessilis was evaluated for its in vitro XO inhibitory potential. Enzyme kinetic was determined using Lineweaver-Burk plot. Methanolic extract of green sessile joyweed showed higher XO inhibition compared to red sessile joyweed. The IC50 of XO inhibitory activity for green sessile joyweed was 557.77 ± 56.47 μg/mL. The mode of inhibition for red and green sessile joyweed was uncompetitive and non-competitive, respectively. The potential of green sessile joyweed as a source of natural XO inhibitor in the treatment of hyperuricemia or gout has been reported for the first time