Antioxidant and xanthine oxidase inhibitory activities of Kecapi (Sandoricum koetjape (Burm.f) Merr.) leaf extract

Sandoricum koetjape has been used as folk medicine for the treatment of several diseases. The study was undertaken to determine antioxidant property of S. koetjape extract. The xanthine oxidase inhibitory effect was also evaluated. The dried powder of S. koetjape leaves was extracted with methanol. The extract was then successively partitioned with different solvents: n-hexane, ethyl acetate, buthanol and water. Phytochemical, total phenolic contents (TPC) and total flavonoid compounds (TFC) were analysed. DPPH scavenging assay was conducted to evaluate antioxidant activity. Xanthine oxidase inhibitor were determined using spectrophotometer. The results showed that amongst of tested extract, methanol extract contained high amount of phenolic and flavonoid compounds. For antioxidant and XO inhibitor, ethyl acetate fraction revealed strong activity with IC50 values of 3.70 and 50.18 µg/mL, respectively. XO inhibition by ethyl acetate extract was found to be a competitive inhibition that mimics inhibition mechanism of allopuriol. LC-MS/MS chromatogram exhibited that the extract contains dehydrotumulosic acid, methyl ophiopogonanone A, quercetin-4′-glucoside, luteolin-7-β-D-glucopyranosid and neokurarinol. The result of this study indicated that the potency of S. koetjape extract as antioxidant and XO inhibitor.