Isolation of antioxidant principle from Azadirachta seed kernels: determination of its role on plant lipoxygenases.

An antioxidant principle was isolated from Azadirachta indica seed using high pressure liquid chromatography with a hydrophobic reverse-phase chromatography column. The eluted molecule had lambdamax at 224 and 272 nm and was a potent inhibitor of plant lipoxygenases. In in vivo studies of horsegram during germination, low levels of lipoxygenase activity and lipid peroxides were found upon treatment with the Azadirachta extract. The antioxidant property of Azadirachta indica has not been previously reported.