Inhibitory effects of isolated compounds from black coloured rice bran on the complement classical pathway

The present study evaluated the anticomplement effects of isolated compounds from black coloured rice bran in the classical pathway of the complement system. Using column chromatography, three compounds: oryzafuran, quercetin and protocatechuic acid, were isolated and evaluated for in vitro anticomplement activity. Oryzafuran showed the most potent inhibitory activity against the complement system, with 50% inhibitory concentration (IC50) values of 126.2 µg/mL. This is the first report of anticomplement activity of isolated compounds from black coloured rice bran.