Inhibitory activity of xanthine oxidase by fraction of Crateva andansonii.

Abstract

Objective: To study the inhibitory effect of various extracts from Crateva adansonii (C. adansonii) used traditionally against several inflammatory diseases such as rheumatism, arthritis, and gout, was investigated on purified bovine milk xanthine oxidase (XO) activity. Methods: Xanthine oxidase inhibitory activity was assayed spectrophotometrically and the degree of enzyme inhibition was determined by measuring the increase in absorbance at 295 nm associated with uric acid formation. Enzyme kinetics was carried out using Lineweaver-Burk plots using xanthine as the substrate. Results: Among the fractions tested, the chloroform fraction exhibited highest potency (IC50 20.2±1.6 µg/mL) followed by the petroleum ether (IC50 30.1±2.2 µg/mL), ethyl acetate (IC50 43.9±1.4 µg/mL) and residual (IC50 98.0±3.3 µg/mL) fractions. The IC50 value of allopurinol used, as the standard was 5.7±0.3 µg/mL. Conclusions: Enzyme inhibition mechanism indicated that the mode of inhibition was of a mixed type. Our findings suggest that the therapeutic use of these plants may be due to the observed Xanthine oxidase inhibition, thereby supporting their use in traditional folk medicine against inflammatory-related diseases, in particular, gout