Corynaea crassa is a hemiparasitic plant native to America, used for the treatment of erectile dysfunction and has been shown to have antimicrobial properties. However, it lacks other biological studies to justify its use in traditional medicine. The objective was to examine the in vitro inhibitory activity of xanthine oxidase in hydroalcoholic extracts of the species from Ecuador and Peru. The extracts obtained by maceration and the Allopurinol used as the reference drug, at concentrations of 10, 30, 40, 50 and 60 µg/mL, were tested to measure the degree of in vitro inhibition of xanthine oxidase employing spectrophotometric determination at 295nm, which is associated with the formation of uric acid. The two extracts showed significant inhibitory activity on xanthine oxidase in a concentration-dependent manner, with the highest percentages being observed at the highest concentrations, being higher for the extract from the Ecuadorian species with enzyme inhibition percentages comparable to Allopurinol. Median inhibitory concentration (IC50) values of 15.35µg/mL and 17.42µg/mL were observed for the extracts from Ecuador and Peru, respectively, although the activity was more notable for the reference drug, which was shown to be an IC50 of 12.21 µg/mL. The results concluded the basis for the potential use of C. crassa in the treatment of hyperuricemia.
Keywords: xanthine oxidase, hydroalcoholic extracts, Allopurinol