The Effect of Bitter Leaves (Vernonia amygdalina) Extract on Salmonella typhi and Salmonella paratyphi

Abstract

Research Background: Antibiotic-resistant strains of Salmonella spp have been a major foodborne pathogen threat to human and amplifysignificant food safety hazard. The emergence of multiple drug resistance salmonella in foods has necessitated a search for new antimicrobial substance from other sources, including plants. This research aimed to evaluate the phytochemicals and anti-salmonella activity of ethanol and coldwater extracts of bitter leaves (Vernonia amygdalina) extract against S. typhi and S. paratyphi. Experimental approach: Two species of Salmonella were collected from Dalhatu Araf Specialist Hospital, Lafia, Nasarawa State. The plant leaf extracts were screened for their phytochemical component to evaluate the availability of active bio-compounds in the leaves. The leaf extractswere subjected to antimicrobial analysis by disc diffusion method using different concentration of the leaf's extracts. Results and conclusion:The phytochemical evaluation showed that compounds such as Alkaloids, Cardiac glycosides, Flavonoids, Saponins, Steroids, Tannins, and Glycosides were present in different quantities. The extracts showed antibacterial effect against the bacteria with zone of inhibition ranging between8.1± 0.14 mm (9.257 mg/mL) to 22.5± 0.24 mm (75 mg/mL) on Salmonella typhi and 7.3± 0.11 mm (9.257 mg/mL) to 23.3± 0.31mm (75 mg/mL) on Salmonella paratyphi. Minimum Inhibitory Concentration was observed at 18.25 mg/mL and 37.5 mg/mL for ethanol and cold-water extracts of V. amygdalina,respectively, in both isolates.However, no significant difference in the extract's activity against the test isolates at p<0.05 was observed.V. amygdalina cold-water and ethanolic extracts possess phytochemical with inhibitory activities on Salmonella typhi and Salmonella paratyphi. Novelty and scientific contribution: This study showed that V. amygdalina possesses phytochemicals active against Salmonella and should be further explored to extract bioactive ingredient for use in Salmonella drug development and treatment regime.