ANTIBACTERIAL ACTIVITIES OF SELECTED MEDICINAL PLANTS AGAINST DIARRHOEA CAUSING PATHOGENS

Abstract

Traditional preparations of medicinal plants with antimicrobial activities have been extensively used in the West African regions. This study was carried out to identify the antimicrobial properties and synergistic effects of the bioactive compounds of selected medicinal plants against diarrhea causing pathogens.Using cold maceration methods, extracts from Vernonia amygdalina (22.86g),  Acacia nilotica (22.80g),, Anogeissus leiocarpus (22.87g), Carica papaya (19.05g),, Piliostigma thoningi (22.80g),  and Khaya senegalensis (13.94g) .The highest extract yield was obtained in A. leiocarpus The plant crude extracts exhibited varying degree of antibacterial activities at various concentrations against Vibrio cholerae, Klebsiella pneumoniae and Salmonella enterica serovar, with A. leiocarpus (32.33±0.73, 34.00±1.15f, 36.33±1.17) and K. senegalensis (36.00±0.81f, 19.00±0.98, 22.00±0.69) having the highest antibacterial activity as they showed significantly higher zones of inhibition at all concentrations against all the test organisms. The minimum inhibitory concentration (MIC) and minimum bacteriacidal concentration (MBC) was observed and recorded at 1.02±0.12, 1.04±0.29 and 1.92±0.23 mg/mL concentrations. The most active extracts were fractioned by column chromatography and, n-Hexane fraction of the most active crude extracts A. leiocarpus (0.64g) and K. senegalensis (0.46g) produced the highest yields followed by the aqueous and ethyl acetate fractions. Significant difference was observed in the antibacterial activity of A. leiocarpus and K. senegalensis fractions. All fractions of A. leiocarpus (aquous, and n-Heaxane) fractions had higher activity against all test organisms (36.67±1.00, 32.00±0.23 and 31.00±1.56) while Ethylacetate fraction of K. senegalensis showed activity against K. pneumoniaee and V. cholarae while no activity against S. enterica serovar Kentucky. The synergistic effect of column chromatography fractions of A. leiocarpus and K. senegalensis was concentration dependent as one of inhibition increase with increasing concentration of the fractions. However, there was no significant difference between all experimental animals from all groups when compared to the control. Significant difference was observed in some liver parameters including a decrease in Alanine aminotransferasae (ALT) and aspartate aminotransferasease (AST) and increase in Total protein and albumin values. Significant differences were also observed in lipid parameters, kidney function and haematological parameters. Histological analysis of the liver and kidney of infected mice administered with A. leiocarpus and K. senegalensis fractions showed largely preserved architecture signifying that the plant extracts did not cause any detrimental changes and had no toxic effect. Therefore, the plant crude and fractions are recommended for the treatment of diseases caused by the test organism based on traditional medicine rules and regulations.