Total Phenolic and Flavonoid Contents, Antioxidant Activity and Phytochemical Screening of Calotropis Procera Stem Bark Extracts

Abstract

In continuation of the need to search for phytochemicals in parts of some rare and native plants of Nigeria origin. This study was designed to carry out phytochemical screening, antioxidant properties and determination of total phenolics and flavonoid contents in Calotropis procera Stem. The phytochemical screening of stem bark of C. procera using aqueous and methanol extracts revealed the presence of tannins, phenols and flavonoid. The aqueous extract was also found to contain saponins while methanol extract also has steroids. Steroids was the only metabolite present in hexane extract. The anti-oxidant activity, total phenolic and flavonoid contents of aqueous and methanolic extracts of stem bark of C. procera were evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, Folin-Ciocalteau and aluminium chloride colorimetric assays. From the results obtained, the methanolic extract was observed to have demonstrated a significant concentration of phenolic (81.65±0.92 mg GAE/g), and flavonoid (46.08±0.71 mg RE/g) than the aqueous extract (66.07±0.43 mg GAE/g, 31.34±0.39 mg RE/g). The aqueous and methanol extracts showed maximum activities of 28.16±0.64% and 81.65±0.71% at 1 mg/ml respectively. However, the ascorbic acid exhibited 83.12±1.02% in the DPPH assay. The results of the present study, shows that both aqueous and methanolic extracts could serve as a valuable source of natural antioxidants.