Canadian Journal of Pure & Applied Sciences

Abstract: Medicinal plants present a promising option in the treatment of infectious diseases. Although literature is replete of the traditional utilization of Jatropha curcas for healing various ailments, scientific studies validating its phytochemotherapeutic properties are limited. In this study, both aqueous and methanol extracts of Jatropha curcas were tested against thirteen clinical staphylococcal isolates including Methicillin Resistant Staphylococcus aureus (MRSA) using agar diffusion and microdilution techniques. Nineteen commonly used antibiotics were employed as control drugs and to determine the resistance profiles of the organisms. Bactericidal activity was evaluated by the time-kill assay. The susceptibility patterns of all the staphylococcal isolates tested were similar in aqueous and methanol extracts. The methanol extract (100mg/ml) demonstrated inhibitory activity against Staphylococcus haemolyticus, which was resistant to ciprofloxacin, tetracycline and erythromycin. The MIC and MBC of the methanol extract ranged between 0.5 and 8mg/ml and between 4 and 128mg/ml respectively while that of aqueous extract ranged between 1 and 8mg/ml and between 4 and 128mg/ml respectively. The MRSA strain was sensitive to the methanol extract but resistant to twelve of the 20 antibiotics studied. Within the first 2.5h and 5h of incubation with the methanol extract, the MRSA isolate declined by 1.7log10 and 2.3log10 respectively while incubation with ciprofloxacin declined the growth by 3log10 and 4log10 respectively. The methanol extract exhibited the highest killing rates of 13.88 x 105cell/h against S. haemolyticus. The lowest killing rate, 1.86 x 105 cell/h, was against MRSA. 1 x 106 of the resistant staphylococcal cells was completely inhibited within 8hrs and there was no growth after 7 days. The methanol stem extract of Jatropha curcas exhibited enhanced bactericidal activity against staphylococcal strains and could be indicated for the empiric treatment of staphylococcal infections. Toxicity studies may need to be carried out to authenticate its use.