The Antimicrobial Potential and Phytochemical Composition of Aristolochia Ringens VAHL

Abstract

Aristolochia ringens, a plant called Ako-igun in Yoruba, is widely distributed in southwestern Nigeria. Traditionally, it is used for the treatment of cancerous sore, lung inflammation, dysentery and dermatitis. The antimicrobial activity of A. ringens was tested on six pathogenic bacteria viz., Shigella sonnei, Salmonella typhii, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Proteus mirabilis and five fungi viz., Fusarium sp, Sporotrichum sp, Pichia sp, Penicillium camemberti and Aspergillus niger.Extracts from powdered stem and root barks of A. ringens were prepared using sterile water, ethanol, petroleum ether and acetone. The extracts were tested on each of the pathogens for their antimicrobial properties. The stem and the root barks were also screened for presence of secondary metabolites following standard procedures.The aqueous extracts of the stem and the root barks were not effective against all the bacteria and fungi tested except Shigella sonnei with Minimum Inhibitory Concentration (MIC) of 40mg/ml. Petroleum ether extracts of the stem and root barks were equally not active against all the bacteria isolates used but the root bark extracts reacted effectively against the fungal isolates, showing good potency at 40mg/ml. Ethanol extract of the stem bark was very potent against all the bacteria isolates at MIC of 33.3mg/ml except Shigella sonnei while the root bark ethanol extract only showed little effectiveness against the fungi. A similar result was obtained when acetone was used as solvent of extraction. Comparatively, ethanol and acetone stem and root bark extracts were less potent on the fungi isolates than the petroleum ether extract. The plant parts studied showed the presence of alkaloids, flavonoids, tannins, terpenoids and cardiac glycosides.Thus, the root and stem bark extracts from Aristolochia ringens may be broad based in their antimicrobial activities. The extracts, if purified and crystallized, may serve as alternatives to antimicrobial drugs.

Keywords: Aristolochia ringens, Microorganisms, Ethnomedicine, Phytochemicals, Plant extracts