Interaction of Apigenin and Hesperetin on Xanthine Oxidase Inhibition and Their Inhibitory Mechanism

Lim, Ser Lyi (2019) Interaction of Apigenin and Hesperetin on Xanthine Oxidase Inhibition and Their Inhibitory Mechanism. Final Year Project (Bachelor), Tunku Abdul Rahman University College.

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Abstract

Xanthine oxidase (XO) catalyzes the oxidation of xanthine and hypoxanthine to uric acid. Hyperuricemia caused by the over-production or under-excretion of uric acid are often associate with various diseases. The present study was carried out to investigate the interaction of apigenin and hesperetin on xanthine oxidase inhibition and their inhibitory mechanism. Ethyl acetate extract (EtOAc) of Chrysanthemum morifolium were screened for flavonoids contents, and xanthine oxidase inhibitory activity. The mode of inhibition between apigenin and hesperetin on xanthine oxidase was determined by enzyme kinetics using Lineweaver-Burk plot and varying concentrations of xanthine as substrate. The EtOAc demonstrated 63.5 ± 1.93% of XO inhibition, and presence of apigenin and hesperetin were confirmed by using high-performance liquid chromatography (HPLC) at retention time of 15.999 minute and 25.68 minute respectively. Inhibition kinetics assay showed that apigenin and hesperetin inhibited XO activity reversibly in a competitive manner and interaction assay of apigenin and hesperetin showed additive effect on XO inhibition. Keywords: Xanthine oxidase, apigenin, hesperetin, additive, competitive inhibition.