Antibacterial activity of Calotropis procera and Ficus sycomorus extracts on some pathogenic microorganisms

Abstract

In vitro antibacterial potential of chloroform, absolute ethanol, methanol, ethanol (70%) and aqueous extracts of Calotropis procera and Ficus sycomorus leaves and latex were evaluated against five Gram-negative bacteria (Neisseria lactamica ATCC 23970, Salmonella typhi ATCC 19430, Shigella flexenri ATCC 12022, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922) and two Gram-positive bacteria (methicillin-resistant Staphylococcus aureus MRSA ATCC 43300, S. aureus CONS ATCC 29213). The antibacterial activities were expressed as zone of inhibition; minimum inhibitory concentrations (MIC) and also the survival curve was determined as kinetic studies. Interestingly, among all the tested extracts, aqueous and ethanol (either absolute or 70%) of C. procera and F. sycomorus leaves and latex were the best solvents for elute polar antibacterial substances and showed bacteriocidal effect against most Gram-positive and negative bacteria. Also, latex extracts were more pronounced than leaf extracts on human pathogenic bacteria. The most resistant bacterium was E. feacalis against both plant extracts. On the other hand, S. areus MRSA was the most sensitive bacteria especially with ethanol 70% extract of leaves and latex for both plants. The results of MIC for these extracts show more or less values higher than the chloramephnicol. Our conclusion confirms that, susceptibility of Gram-positive bacteria to the aqueous or ethanolic extracts of leaves for both plants was more than those of Gram-negative bacteria. The activities of 70% ethanol extracts recorded highest activity against Gram-negative bacteria than those of other extracts. The results therefore established a good support for the use of C. procera and/or F. sycomorus in traditional medicine against Gram-positive and negative pathogenic bacteria.

Keywords: Caltropis procera, Ficus sycomorus, plant latex, leaf extract, pathogenic bacteria

African Journal of Biotechnology, Vol 13(31) 3271-3280