Antibacetial screening of leaves and stem of Carica papaya

Abstract

The purpose of the study was to investigate antibacterial activity of ethanolic extracts of leaves and stem of Carica papaya on selected microorganisms. Various Gram negative (Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella typhi, Salmonella paratyphi A, Shigella flexenert) and Gram positive bacteria (Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Micrococcus luteus) were used for the screening of antibacterial activities of the extracts of both parts that is leaves and stem. Antibacterial activity was expressed in terms of the radius of zone of inhibition. Both parts were tested in two doses (5 and 10 mgml-1) it was found that the antibacterial action was dose dependent and also a significant difference was observed in bacterial sensitivity to leaves and stem extracts, however the leaves extracts were found more active than the stem. The minimum inhibitory concentration (MIC) against test microorganism was studied by turbidity method. The range of MIC observed for leaves and stem was 1250 to 5000 μgml-1and 1250 to 10,000 μgml-1 respectively. C. papaya leaves and stem contains some valuable antibacterial compounds that inhibit the growth of wide variety of Gram-positive and Gram-negative organisms. Therefore the leaves and stem of C. papaya has antibacterial effects that could be useful in treating variety of bacterial infections. Key words: Carica papaya, ethanol extract, antibacterial activity, minimum inhibitory concentration.