Antimicrobial and phytochemical properties of aqueous extracts of <i>Gladiolus</i> corm (family Iridaceae) from Benue State of Nigeria

Abstract

The genus Gladiolus, embraces 260 species of a perennial herb belonging to the lily family: Iridaceae. In West Africa Gladiolus corm is used in food, and in ethnomedicines for treating gonorrhea and other infections. Often, the corm is used in combination with other plant materials, hence it is not known if the corm alone has antimicrobial effects. In this study aqueous extracts of the Gladiolus corms obtained in Benue State, Nigeria, were tested for their antimicrobial and phytochemicals properties. Antimicrobial effects were evaluated by measurement of inhibition zones using the bacteria, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes; and the fungi, Candida albicans, Aspergillus niger and Trichophyton mentagrophyte. The results showed that the extracts were active against Pseudomonas aeruginosa and Aspergillus niger, but relatively inactive against the others; and contain alkaloids, tannins, saponins, cardiac glycosides, flavonoids and carbohydrate. Separation of the constituents by thin layer chromatography was attempted. The results confirm the basis for the traditional use of Gladiolus corm, and are discussed within the context of their economic and medical relevance. The presence of cardiac glycosides in corm calls for caution in its use. It also shows good prospects for its use as preservative for food and herbal medicines. Keywords: Gladiolus, Corm, Antimicrobial, PhytochemicalJournal of Pharmacy and Bioresources, Vol. 6 no. 2, pp. 65-70 (September 2009)