Assessment of Anti-Salmonella Activity of Aqueous and Ethanolic Extract of Senna siamae, Used in Traditional Management of Salmonellosis in Benin

Recent ethnopharmacological data cited Senna siamea as one of the most widely used medicinal plants in the management of salmonellosis in Benin. However, data related to its activity on non-typhoidal Salmonella spp are limited. This study aimed to assess the antibacterial activity of Senna siamea on multidrug-resistant Salmonella. Ethanolic and aqueous extracts of S. siamea were tested for their antibacterial activity on four multidrug-resistant Salmonella: Salmonella Typhimurium ATCC 14028 and three Salmonella spp. isolated from animals intended for human consumption in Benin. Well diffusion technique combined with the determination by microdilution of Minimum Bactericidal Concentration (MBC) and Minimum Inhibitory Concentration (MIC) were used for antibacterial testing. From antibacterial testing, inhibition diameters of the extracts ranged from 7 to 11 mm, for the susceptible strains. Colistin (reference antibiotic) was active on all Salmonella spp. with inhibition diameters between 18 and 19 mm. The MICs ranged from 3.125 to 25 mg/ml while MBCs of the extracts are greater than 100 mg/ml, so none of the extracts have antibacterial power (p.a). From these results, it appears that the use of Senna siamea in the traditional treatment of salmonellosis is justified. These results must be valued in the development of anti-salmonella phytomedicines.