The in vitro antimicrobial activity of crude ethanolic, methanolic and water extracts of the stem bark ofJatropha curcas were investigated. The extracts exhibited antimicrobial activities with zones of inhibition ranging from 5 to 12, 8 to 20 and 0 to 8 mm for ethanol, methanol and water extracts respectively. The minimum inhibitory concentration (MIC) of the ethanol extract was between 0.5 and 6.25 mgml-1 while that of methanol extract ranged from 0.5 to 10 mgml-1. The minimum bactericidal concentration (MBC) for ethanol extract ranged between 2.0 and 12.50 mgml-1, while that of methanol ranged from 2.0 to 20 mgml-1. Again all the extracts exhibited appreciable activity against all the fungal species investigated. The zones of inhibition exhibited by the extracts against the test fungal species ranged between 15 and 18, 15 and 20 and 5 and 10 mm for ethanol, methanol and water extracts respectively. Phytochemical screening revealed the presence of saponin, steroids, tannin, glycosides, alkaloids and flavonoids in the extracts. The ability of the crude stem extracts of J. curcas to inhibit the growth of bacteria and fungi is an indication of its broad spectrum antimicrobial potential which may be employed in the management of microbial infections.
Key words: Jatropha curcas, antimicrobial activity, phytochemical screening, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC).
Historically, plants have provided a source of inspiration for novel drug compounds, as plant derived medicineshave made large contributions to human health and wellbeing. Their role is twofold in the development of newdrugs: (1) they may become the base for the development of a medicine, a natural blue print for the developmentof new drugs or; (2) a phytomedicine to be used forthe treatment of diseases (Iwu, 1993). Traditional medicineusing plant extracts continues to provide healthcoverage for over 80% of the world’s population, especially in the developing world (WHO, 2002). Jatropha species belong to the family Euphorbiaceae and are usedin traditional folklore medicine to cure various ailments inAfrica, Asia and Latin America (Burkill, 1994). Jatrophacurcas Linn is commonly called physic nut, purging nut orpig nut. Previous studies have reported that the plantexhibits bioactive activities for fever, mouth infections, jaundice, guinea worm sores and joint heumatism (Irvine,1961; Oliver-Bever, 1986). Fagbenro-Beyioku (1998) inv-estigated and reported the anti-parasitic activity of thesap and crushed leaves of J. curcas. The water extract ofthe branches also strongly inhibited HIV induced cytopathic effects with low cytotoxicity (Matsuse et al.1999). Previous works have shown that many Jatrophaspecies possess antimicrobial activity (Aiyela-agbe et al.,2000; Aiyelaagbe, 2001). Several studies have confirmedthe antimicrobial efficacy of different Jatropha species; however, there is insufficient informationregarding theantimicrobial activities of J. curcas Linn. Whatever limitedinformation available on the medicinal properties of J.curcas is mostly on the leaf extracts of the plant. In thispaper, the antimicrobial property of crude extracts of thestem bark of J. curcas has been studied as part of theexploration for new and novel bio-active compounds.
Antimicrobial activity and phytochemical screening of Stem bark extracts from Jatropha curcas (Linn)