Antioxidant Potential and Xanthine Oxidase Inhibitory Activity of Croton sparsiflorus

Abstract

Croton sparsiflorus (traditional treatment for cuts, ulcer, fever, inflammation,

hypertension, analgesic and as antivenom) extracts were examined

for xanthine oxidase inhibitory (XOI) potential, antioxidant activity

(DPPH^• and phosphomolybdenum assays) and total phenolics. Dichloromethane

(CSD), chloroform (CSC), ethyl acetate (CSEA), acetone

(CSA), ethanol (CSE) and n-butanol (CSB) extracts inhibited xanthine

oxidase > 50 % at 100 μg/mL concentration with IC₅₀ values of 23.82,

17.34, 9.31, 11.35, 43.25 and 87.50 μg/mL, respectively. CSEA, CSM

(methanolic extracts) and CSE extract exhibited significant DPPH^• free

radical scavenging potential. Total phenolics; estimated as gallic acid

equivalents (mg/g of the extract); ranged from 28 to 483 (CSC, CSEA

and CSA > 400 mg/g). A weak correlation of total phenolics with XOI

and phosphomolybdenum assays (R² = 0.5413 and 0.4975, respectively)

proved phenolics are not the only bioactive compounds responsible for

these activities. Strong correlation between total phenolics and DPPH^•

free radical scavenging (R² = 0.8485) marked phenolics as the major

free radical scavengers.