Effects of a Leucaena leucocephala leaf extract on xanthine oxidase activity and serum oxypurine levels in mice

Abstract

There is a need for novel alternatives to the medical use of allopurinol. In this sense, the present study obtained a leaf extract of L. leucocephala, and its chemical composition, inhibitory action against xanthine oxidase (XO) in vitro, inhibitory interaction between the extract and allopurinol, and the inhibitory action on XO in vivo using mice treated with potassium oxonate and hypoxanthine were determined. Polyphenol and flavonoid compounds were found in the leaf extract. For the leaf extract, the IC50 and maximal values were 334.60 µg/mL and 46.4 % for the inhibition of XO. The 3:1 ratio combination of allopurinol and extract showed IC50 and waDRI values of 1.35 µg/mL, 1.13 (allopurinol) and 1015.72 (extract) to inhibit XO, resulting in a synergistic interaction against XO in vitro. This combination also enhanced the therapeutic success in the mouse model compared with allopurinol administered alone. The present study presents the first evidence for the use of an allopurinol and L. leucocephala extract combination at a 3:1 ratio as a substitute for the administration of allopurinol alone.