Preliminary phytochemical detection and in vitro antioxidant activity of Kigelia africana (Lam.) Benth leaves

Abstract

This study intended to evaluate free radical scavenging capacity to screen the presence of phytochemical compounds and quantitative estimation of total flavonoid and phenol contents of the Kigelia africana (Lam.) Benth Leaves. Preliminary phytochemical screening was performed by chemical testing of the components. The antioxidant activity was assessed through DPPH, ABTS, FRAP, and hydroxyl radical scavenging assays. Total flavonoid contents were determined by using quercetin as reference standard and total phenols determined by Folin Ciocalteu method with gallic acid as reference standard. Phytochemical screening indicates the presence of alkaloids, glycosides, sterols, tannins, flavonoids and saponins. The total flavonoid and phenolic content found to be higher in methanolic extract i.e. 5.8415 ± 0.0015 mg QE/gand 92.0809 ± 0.0045 mg GAE/g respectively. Antioxidant assays revealed that the methanolic extract exhibited the strongest activity among all tested extracts. The IC₅₀ values were recorded as 28.38 µg/mL for DPPH, 26.41 µg/mL for ABTS, 135.40 µg/mL for FRAP, and 156.70 µg/mL for hydroxyl radical scavenging. In comparison, the standard ascorbic acid showed IC₅₀ values of 23.55, 17.86, 82.29, and 92.52 µg/mL for the respective assays. The findings justified plants potential and Kigelia africana (Lam.) Benth could be represents as good candidate for further chemical and biological activity. These findings suggest that Kigelia africana leaves possess significant antioxidant potential, supporting their use as a promising candidate for further phytochemical isolation and biological investigations.