Phytochemical Screening And In Vitro Antioxidant Activities Of Methanol Extracts Of Vitex Doniana Leaves And Stem Bark

Background: Vitex doniana is a deciduous tree commonly consumed as a delicacy, medicine or spice. It is considered as a safe spice with several medicinal properties. The aim of this study was to evaluate the phytochemical composition and in-vitro antioxidants of the leaf and stem back of Nigerian Vitex doniana. Methods: Methanol extract of leaf and stem of Vitex doniana was evaluated for total flavonoids, total phenols and other secondary metabolites contents using standard procedures. The antioxidants activities were evaluated using 2, 2-diphenyl-1-picryl-hydrazyl (DPPH) Radical Scavenging Activity, Inhibition of Lipid Peroxidation and ferric reducing antioxidant properties (FRAP) assays. Results: The leaves extract of Vitex doniana contains 273.04±6.35 mg/100g of total phenol, 65.88±2.67 mg/100 g of total flavonoids, 205.30±7.43 mg/100g of tannins, 9.39±0.43 mg/100g of alkaloids and 31.66±1.38 mg/100g of saponins, while the stem extract contains 667.15±7.92 mg/100g of total phenol, 165.00±0.56 mg/100g of total flavonoids, 97.54±11.79 mg/100g of tannins, 194.75±8.01 mg/100g of alkaloids and 39.00±0.20 mg/100g of saponins. The leaf and stem extract promoted an inhibition of free radicals with IC50 values of 144.90 µg/mL and 143.26 µg/mL respectively in DPPH, 736.15 µg/mL and 659.55 µg/mL respectively in lipid peroxidation activity and the extracts show considerable ferric reducing antioxidant properties in a concentration dependent manner. These shows low reducing properties compare to ascorbic acid aside the lipid peroxidation inhibitory activity. Conclusion: Methanol leaf extract of Vitex doniana contains some useful potential antioxidant compounds that could serve as candidate for the development of drug for therapeutic purposes.