Antioxidant activities of Parquetina nigrescens
The antioxidant activities of different extracts (aqueous, methanol and flavonoid) of Parquetina nigrescens and butylated hydroxyl anisole, as reference compound, were evaluated in terms of scavenging effect, reducing power and inhibition of Fe2+/ascorbate-induced mitochondrial lipid peroxidation in rat liver. Extracts of P. nigrescens scavenged 2,2-diphenyl-1-picrylhydrazyl (DPPH) generated radicals in the increasing order of flavonoid > methanol > aqueous > BHA at 1000 g/ml. The reducing power followed a similar trend as observed with scavenging activities. Extracts of P. nigrescens, at 50 mg/ml, exhibited significant (P < 0.05) inhibitory effects on Fe2+/ascorbate-induced lipid peroxidation in rat liver mitochondria. These results showed that P. nigrescens contains antioxidants that could be useful in attenuating reactions which generate free radicals in the body.
Key words: Parquetina nigrescens, antioxidant activities, lipid peroxidation.