Antimicrobial properties and toxicity of Hagenia abyssinica (Bruce) J.F.Gmel, Fuerstia africana T.C.E. Fries, Asparagus racemosus (Willd.) and Ekebergia capensis Sparrm.

Abstract

Background: The world health organization (WHO) estimates that 80% of population in Africa relies on traditional remedies for their healthcare. However, very few studies have been carried out to establish the therapeutic effects of these remedies.

Objective: Four medicinal plants were investigated for antimicrobial activity and toxicity.

Materials and Methods: Plants were collected from their natural habitat, dried, and extracted with organic and aqueous solvents. Antimicrobial activity was determined by the disc diffusion assay technique. In vitro cytotoxicity studies were carried out on extracts using MTT assay on Vero cell lines while acute toxicity in Swiss mice.

Results: Extracts from H. abyssinica, F. africana and A. racemosus exhibited antibacterial activity with minimum inhibitory concentration of ≤ 6.25mg/ml against S. aureus, MRSA and P. aeruginosa. However, the plants studied had weak antifungal activity. H. abyssinica and F. africana extracts were found to be cytotoxic with CC₅₀ of ˂ 90 µg/ml. These extracts were tested for acute toxicity and found to be safe at 5000 mg/kg body weight per day.

Conclusion: The results of the study support the medicinal use of these plants and indicate that useful compounds from Hagenia abyssinica and Fuerstia africana can be isolated for further exploitation.

Keywords: Medicinal plants, Antimicrobial activity, Cytotoxicity, Acute toxicity