Assessment on antioxidant activity of the aqueous leaf extracts of Combretum microphyllum and the effect of Co(II)-leaf extract complex on antibacterial activity of leaf extracts of the plant material

Abstract

BackgroundIn the present study, different aqueous leaf extracts of C.microphyllum prepared by maceration were investigated for their antioxidant potential, antibacterial activity, and polyphenolic and flavonoid contents. MethodLeaf samples of C. microphyllum were collected, milled, air-dried, pulverized, and subjected to maceration extraction with water as a solvent. The total phenolic, flavonoid contents, and antioxidant activity of the aqueous extract were evaluated using the Folin-Ciocalteu reagent (FCR), aluminum chloride colorimetric assay, ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays, respectively. ResultThe total phenolic content and the total flavonoid content of the plant extract were found to be 540.28 and 40.81 mg/100 g dry weight, respectively. The results from DPPH radical scavenging and FRAP assays revealed that the C. microphyllum extract exhibited strong antioxidant activity. The antibacterial property of the aqueous leaf extract was found to be biologically inactive against the selected bacterial strains. However, its complex with Cobalt(II) demonstrated significant antibacterial activity against all the tested strains. ConclusionThis medicinal plant has been found to contain antioxidant components that can be utilized in the treatment and prevention of infectious diseases after proper standardization. In addition, this work showed the possibility to develop antibiotics from biologically inactive naturally occurring substances by coordination with metal ions.