Abstract

The genus Gladiolus (Family: Iridaceae) has 260 species of a perennial herb. In West Africa the corms of Gladiolus species are used in food and Traditional Medicine, often in combination with other plant materials. This study aimed at verifying the basis for the use of these corms in both instances. Aqueous extracts of the corms obtained in Benue State, Nigeria, were tested for antimicrobial effects; and screened for key phytochemicals. Antimicrobial effects were evaluated by measuring the diameters of inhibition zones on agar plates, using clinical isolates of the bacteria: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus andListeria monocytogenes; and the fungi: Candida albicans, Aspergillus niger and Trichophyton mentagrophyte. The results showed that the extracts, at concentrations of 75 - 400 mg of the plant material per mL of water, were active against Pseudomonas aeruginosa and Aspergillus niger, but relatively inactive against the others. The extracts contained alkaloids, tannins, saponins, cardiac glycosides, flavonoids and carbohydrates, but attempts at TLC separation were only marginally successful. The somewhat selective antimicrobial effects of the extracts do however; suggest the basis for the use of these corms. But the presence of cardiac glycosides - a cardiotoxin, calls for caution in their use.

Key words: Gladiolus, corm, iridaceae, antimicrobial, food processing, traditional medicine, phytochemicals, Benue State.