PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE

Azadirachta indica (Meliaceae; Neem tree) is a resourceful medicinal plant. Almost all parts of the plant are used in traditional and folklore medicine. This study was conducted to measure antioxidant activity, total phenolic content (TPC) and total flavonoid content (TFC) in a crude extract of different parts of the neem tree. 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging and Ferric-Reducing Antioxidant Power Assay (FRAP) were used to evaluate antioxidant activity, while total phenolic and total flavonoid compounds were measured using the Folin-Ciocalteu method and aluminium chloride (AlCl3) assay, respectively. Bark and leaf extract showed higher free radical scavenging activity, with IC50 value of 23.27 and 55.07 (µg/ml) respectively, while seed extract showed the lowest activity, with IC50 of 672.36 (µg/ml; (P<0.05). The bark extract revealed significantly higher antioxidant activity and phenolic content than the leaf and seed extract (P<0.05). Flavonoid content in leaf extract was found to be significantly higher (P<0.05) than in seed and bark extract; however, bark extract showed significantly lower flavonoid content than seed extract. These results suggest that the potency of Azadirachta indica makes it a good source of natural antioxidant compounds.