Preliminary phytochemical and antimicrobial investigations of leaf extracts of Ochna schweinfurthiana (Ochnaceae).

Abstract

The antimicrobial activity of the acetone and methanol extracts of the leaves of Ochna schweinfurthiana F Hoffm (Ochnaceae) obtained through maceration was evaluated using disc diffusion and Nutrient broth dilution techniques. The microorganisms tested were: Staphylococcus aureus ATCC 021001, Bacillus subtilis NCTC 8236, Escherichia coli NCTC 10418, Salmonella typhi ATCC19430, Klebsiella pneumoniae ATCC 10031, Pseudomonas aeruginosa NCTC 6750, Candida albicans ATCC 10231; local hospital isolates: Streptococcus pyogenes, Corynebacterium ulcerans, Neisseria gonorrhoea and methicillin-resistant S. aureus. Susceptibility test results showed that both extracts (600 �g/disc) inhibited growth with a mean zone of inhibition range of 15 - 21 mm against Staphylococcus aureus, S. typhi, K. pneumoniae and P. aeruginosa; no activity was however observed against methicillin resistant S. aureus, N. gonorrhea, C. ulcerans, B. subtilis, E. coli and the only fungus, C. albicans. Sparfloxacin (100 �g/disc) a standard antibiotic inhibited the growth of all the organisms tested with the exception of C. albicans. Preliminary phytochemical screening revealed the presence of flavonoids, saponins and steroids/terpenes. The results suggest that the plant contains bioactive constituent(s) with modest antimicrobial activity and validates the ethno-medical use in wound dressing and other forms of bacterial infections.