Document Type : Original paper
Department of Chemistry and Physics, Sokoine University of Agriculture, Morogoro, Tanzania.
Department of Veterinary and Animal Sciences, University of Copenhagen, Stigbøjlen 4, Frederiksberg C, Denmark.
Department of Biological and Pre-clinical Studies, Institute of Traditional Medicine, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.
Department of Clinical Pharmacology and Therapeutics, Hubert Kairuki Memorial University, 322 Regent Estate, Dar es Salaam, Tanzania.
Department of Biosciences, Sokoine University of Agriculture, Morogoro, Tanzania.
Tanzania Industrial Research and Development Organisation, Dar es Salaam, Tanzania.
Department of Microbiology and Parasitology, School of Medicine and Dentistry, University of Dodoma, Dodoma, Tanzania.
Department of Veterinary Medicine and Public Health, Sokoine University of Agriculture, Morogoro, Tanzania.
Background and objective: Commiphoraswynnertonii (Pax) is used in traditional medicine to treat infectious diseases. Previous studies have reported antimicrobial activity of this plant;however, the activity of compounds that are present in extracts of this plant has not been thoroughly documented. Likewise, the primary mode of action (bactericidal or bacteriostatic) and the possible toxicity on red blood cells have not been reported. Methods: Extracts of leaves, whole root, root bark, root wood, whole stem, stem bark and stem wood, were produced using hexane, dichloromethane, methanol and water. Cold and hot extraction methods were employed. Antibacterial activity of extracts was tested against selected medically important Gram-positive and Gram-negative bacteria by growth inhibition, minimum inhibitory concentrations and time kill assays. Moreover, haemolytic activity against sheep red blood cells was determined in vitro. Results: The hexane extracts of whole root and root bark, methanol extracts of root wood, and dichloromethane extracts from the leaves of C. swynnertonii inhibited the growth of S. aureus. MIC values for the extracts and compounds, indicated moderate activity against Gram-positive bacteria (Staphylococcus aureus, Streptococci species and Enterococci species) while the activity against Gram-negative bacteria (Escherichia coli, Klebsiella species, Pseudomonas aeruginosa, Salmonella species, Shigella sonnei and Yersinia enterocolitica) was weak. Time kill profiles showed the extracts have bacteriostatic activity against S. aureus, and low haemolytic effect, except for extracts of whole root and leaves at the concentration of 1000 µg/mL. Conclusion:Extracts of C. swynnertonii showed bacteriostatic activity against Gram-positive bacteria with low toxicity on red blood cells.