The combined extracts of Monetes kerstingii flower, Mitragyna inermis root and Boswellia dalzielii bark were screened for their antimicrobial activity on Salmonella Typhi and Salmonella Paratyphi. These combined plants were also screened for their phytochemical properties as well as toxicity profile on Mice. The antimicrobial susceptibility pattern of the combined extracts together with the MIC, were determined using agar well diffusion and broth dilution method respectively. The susceptibility of the test organisms to the plants extracts was dose dependent. The ethanolic extract had stronger antimicrobial activity with zone of inhibition of 20mm against S. Paratyphi than the aqueous extract, which had 17mm. Meanwhile, the aqueous extract exhibited stronger antibacterial activity of 20mm against S. Typhi when compared with 18mm of the ethanolic extract. Both organisms had MICs of 12.5mg/ml for ethanolic extract. S. Typhi and S. Paratyphi had MICs of 12.5mg/ml and 25mg/ml respectively for aqueous extract. The MBC of S. Typhi was found to be 100mg/ml for ethanolic extract. S. Paratyphi had MBC of 200mg/ml for ethanolic extract. The MBC of the aqueous extract for S. Typhi and S. Paratyphi were 200mg/ml and 400mg/ml respectively. The phytochemical screening revealed the presence of tannins, flavonoids, saponins, cardiac glycosides, resins, alkaloids, carbohydrates, anthraquinones, steroids and terpenoids. The combined extract was non-toxic orally, but moderately toxic intraperitoneally with an LD₅₀ of 4472.14mg/kg body weight in Mice. Thus the traditional claims of the oral use of these combined plants extracts in the treatment of typhoid fever is therefore justified.

Anti-typhoidal, Toxicity, Extracts, Monetes kerstingii, Mitragyna inermis and Boswellia dalzielii