Evaluation of antioxidant and antibacterial activity of ethanolic leaf and stem extract of Ipomoea aquatica against skin infection

Bacterial skin infections are common ailment that are currently being treated with antibiotics. Developing resistance threaten the antibiotic's ability to treat infections. This can be overcome by discovering new plant source that exhibit antibacterial activity, such as Ipomoea aquatica.

To determine the antioxidant and antibacterial activity of ethanolic leaf and stem extracts of I.aquatica against the skin infection.

The extracts were obtained by soxhlet extraction method. Primary and secondary metabolites were determined in the phytochemical test. Total Phenolic Content (TPC) and Total Flavonoid Content (TFC) were evaluated by Folin-Ciocalteu method and aluminium chloride calorimetry method respectively. DPPH method was used to determine the antioxidant activity. Antibacterial activity was determined against Staphylococcus aureus, Streptococcus pyogenes and Escherichia coli by disc diffusion method using standard antibiotics as positive control and DMSO as negative control.

Phytochemical tests proves both extracts contain phenols and flavonoids. For TPC, stem extract (45.37 ± 0.02 mg GAE/g extract) was higher compared to leaf extract (25.22 ± 0.01 mg GAE/g extract). For TFC, leaf extract (26.59 ± 0.02 mg QCE/g extract) was higher compared to stem extract (22.29 ± 0.02 mg QCE/g dry extract). Antioxidant activity of stem extract is greater (1C50 = 5.18 mg/ml) than leaf extract (1C50 = 5.59 mg/ml). Antibacterial activity of leaf extract was more potent than stem which further proved with one-way ANOVA test (p < 0.05). All the tests were done in triplicate (n=3, mean ± SD)

Ethanolic stem extract possessed higher antioxidant activity than leaf extract which correlates with their TPC. Whereas ethanolic leaf extract possessed greater antibacterial properties than stem extract against bacteria responsible for skin infection that correlates with their TFC.