Anti-free radical activities of kaempferol isolated from Acacia nilotica (L.) Willd. Ex. Del

In the present study the polyphenolic compound has been isolated from methanol extract of Acacia nilotica Willd. Ex. Del. which has been identified as kaempferol (AN-5) by NMR and mass spectroscopy. The antioxidant potential of the AN-5 was demonstrated in several in vitro assays: measuring the proton radical scavenging activity (DPPH scavenging assay), hydroxyl radical scavenging activity (deoxyribose degradation assay), metal chelating activity, reducing power and inhibition of lipid peroxidation. It was found that the effect of the compound AN-5 was strongly dose dependent up to the concentrations 1–50 μg/ml in DPPH assay and 1–100 μg/ml in deoxyribose degradation assay but did not show further change above the highest concentrations.