In Vitro Antibacterial Activities of Methanol and Aqueous Extracts of Leaves of Carica papaya and Moringa oleifera Against Selected Human Pathogenic Bacteria

摘要

A medicinal plant is any plant which, in one or more of its organs, contains substances that can be used for therapeutic purposes. In developing countries all over the world, large numbers of people die daily of preventable or curable diseases because of the lack of even simple health care. So the study was interested entitled "In vitro antibacterial activities of methanol and aqueous extracts of leaves of Carica papaya and Moringa oleifera against selected human pathogenic bacteria". Moringa oleifera and Carica papaya is medicinal plants which have medicinal values for the treatment of various infectious illness were interested for investigation of their antibacterial activities against E. coli and H. pylore. Two solvent types (methanol and distilled water) were used for crude extraction. The vulnerability of the pathogen to the antibacterial substances was determined using the disc diffusion method. Minimum Inhibitory Concentration was determined by the broth dilution method. The results of the antibacterial activities revealed that both methanol and aqueous leaf extracts had inhibitory activities against the selected gram-positive and gram-negative test pathogens. Methanol extract of Carica papaya had the highest antibacterial activity (13.3 mm) against H. pylore, while Moringa oleifera indica exhibited the least zone of inhibition (8.2 mm) at a concentration of 150 mg/mL. The Antibacterial activities of heat treated crude extracts against the test pathogens were also determined at varying temperature (45-55) for a period of 30 and 60 minutes. The results revealed that at higher temperature and exposure time, there was a decrease in the zone of inhibitions. The Minimum Inhibitory Concentrations of the methanol extracts ranged from 1.25 mg/ml - 5 mg/mL; whereas, for aqueous extracts ranged from 2.5 mg/mL -10 mg/mL. In general, this study provides base line information for further work on the search for specific active compounds from the selected plant leaf extracts against human pathogenic bacteria.