Antibacterial activity and toxicological evaluation of Anogeissusleiocarpus and Psidium guajava on Escherichia coli and Staphylococcus aureus

Abstract

The study was carried out to determine the antibacterial activities and toxicological evaluation of Anogeissusleiocarpus and Psidiumguajava on Escherichia coli and Staphylococcus aureus isolated from clinical samples. The plants leaves were extracted using Hexane, Methanol, Ethanol and Water. Various concentrations (50, 25, 12.5 and 6.25mg/ml) of the crude extract of the plants were prepared and their antibacterial activity against Staphylococcus aureus and E. coli was determined using Agar well (Diffusion) method. Toxicity of the plants was evaluated, acute toxicity test, kidney and liver function tests. The result revealed that at 50mg/ml concentration, the leaf extract of Psidiumguajava was active against Staphylococcus aureus and E. coli exhibiting the highest zones of inhibition of 19mm and 9mm respectively. Whereas The leaf extract of Anogeissusleiocarpus only inhibited the growth of Staphylococcus aureus recording highest zone of inhibition of 15mm at a concentration of 50mg/ml. The plant extracts were found to be non-toxic as the LD⁵⁰  was above 5000mg/kg and the biochemical parameters evaluated for both liver and kidney function tests revealed values that are within normal range. Hence the study established that consumption of the leaves of P.guajava for medicinal purpose can be said to be innocuous, as such the plant could be regarded as a potential candidate in the search of potent and harmless plants of therapeutic value.