Time-Dependent Evaluation Of The Antibacterial And Phytochemical Properties Of Vernonia Amygdalina And Gongronema Latifolium

Background: Many plants in Africa are medicinal including domesticated edible vegetables. The time-dependent antibacterial efficacy of two popular Nigerian vegetables (Vernonia amygdalina and Gongronema latifolium) on clinical isolates of Staphylococcus aureus and Escherichia coli was evaluated. Phytochemical compositions were also evaluated using direct chemical estimation and thin layer chromatography respectively. Methods : Leaves were extracted with aqueous and alcoholic solvents at 2 hours and 72 hours at various concentrations and tested against bacteria using the agar well diffusion method. Minimum inhibitory/bactericidal concentrations were also determined. Results: Ethanol extracts of fresh leaves were more active than methanol extracts when were decocted in 98% alcoholic concentrations. The highest zone size obtained was 18mm at 125mg/ml concentration of ethanol extract against S. aureus. Activity was most prominent at 2 hours of decoction. Both plants had inhibition values of 2500 μg/ml each on E. coli as MIC and MBC while G. latifolium showed 5000 μg/ml each as MIC and MBC and V. amygdalina showed 625μg/ml each as MIC and MBC values respectively on S. aureus. The plants were shown to have ample quantities of saponins, flavonoids and alkaloids. Conclusions: This result has shown the relative potency of edible vegetables against bacteria. The level of phytochemical compounds bitter vegetable plants contain points to the usefulness of G. latifolium and Vernonia amydalina as credible supplements for antibiotics when used fresh or used as fresh solvent decoctions.