Abstract

Water Extractable Phytochemicals from Some Nigerian Spices Inhibit Fe2+- Induced Lipid Peroxidation in Rat's Brain - In Vitro

S.A. Adefegha and G. Oboh

This study sought to assess the ability of the aqueous extract of some Nigerian spices [ Monodora myristica (Africa nutmeg), Xylopia aethiopica (Ethiopian pepper), Syzygium aromaticum (Tropical Cloves), Piper guineense (Black pepper, Aframomum danielli (Bastered melegueta), Afromomum melegueta (Alligator pepper/ grains of paradise) and Clerodendrum volubile (Locally known as “Obenetete”)]; to inhibit Fe 2+ -induced lipid peroxidation in rat’s brain ( in vitro ) using Thiobarbituric acid reactive species (TBARS). The total phenol, total flavonoid and vitamin C contents, as well as ferric reducing antioxidant property, Fe 2+ - chelating ability, and the ability of the spice extracts to prevent Fe 2+ / H 2 O 2 - induced decomposition of deoxyribose were also determined. The results of the study revealed that incubation of the brain tissues in the presence of 25μM Fe 2+ caused a significant increase (p < 0.05) in malondialdehyde (MDA) production in the rat’s brain (173.4%) when compared with the basal (100%). However, the spice extracts caused a significant decrease (P< 0.05) in the MDA production in both the basal and the Fe 2+ - induced lipid peroxidation in the Rat’s brain, with Alligator pepper showing the highest inhibitory properties while Bastered melegueta had the least inhibition. Conclusively, the inhibitory effect of the spice extracts on lipid peroxidation (basal and Fe 2+ - induced) could be attributed to high total phenol, total flavonoid and vitamin C contents, as well as ferric reducing antioxidant property, Fe 2+ - chelating ability and inhibition of Fe 2+ /H 2 O 2 - induced decomposition of deoxyribose, with Alligator pepper showing the most promising potentials.