Phytochemical Screening and in vitro Antioxidant Properties of Methanol and Aqueous Leaf Extracts of Geophila obvallata

Abstract

Aim: This study investigated the phytochemical constituents and in vitro antioxidant properties of methanol and aqueous leaf extracts of Geophila obvallata using standard methods. Materials and Methods: The in vitro antioxidant assays carried out were 1, 1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging ability, Nitric oxide (NO•) radical scavenging activity assay, 2, 2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS•+) radical cation scavenging assay, ferric reducing properties and hydroxyl radical scavenging assays. Results: Phytochemical analysis revealed the presence of alkaloids, flavonoids, phenolic compounds, steroids, saponins, terpernoids and cardiac glycosides in both extracts. Relative to the aqueous extract, the methanol extract contained a higher amount of the secondary metabolites. However, both extracts exhibited appreciable and dose-dependent capacities for quenching DPPH, ABTS•+ and NO• free radicals, and potent ferric reducing ability to levels comparable to those of ascorbic acid. The crude methanol extract showed significantly increased (P<0.05) antioxidant activity than the aqueous extract. Conclusion: It was concluded that the extract possesses strong antioxidant properties due to its content of phytochemicals, and provides scientific basis for its ethno medicinal applications.