Antimicrobial effects of a crude plant lectin isolated from the stem of Tinospora tomentosa

Abstract

Crude plant lectins were isolated from the stem of Tinospora tomentosa and found its antibacterial and antifungal effects. Lectins were isolated by ammonium sulphate precipitation method. Presence of carbohydrate and proteins were investigated by thin layer chromatography and infrared spectroscopy techniques. Lectin was characterized by its binding affinity with carbohydrates and human erythrocytes by hemagglutination inhibition assay and SDS-page gel electrophoresis. The amount of proteins was quantitatively measured by Lowry method. Antibacterial and antifungal activities were investigated by disk diffusion assay. Minimum inhibitory concentrations of bacteria and fungus were determined from their dose-response curve. Salmonella induced hemagglutination activity was performed to investigate its binding affinity with bacterial cell surface. Isolated lectin contained carbohydrates and protein residues in its structure. Its molecular weight was about 32 kD and seemed as a monomeric. It showed binding affinities to lactose sugar and bacterial cell surfaces and inhibited hemagglutination. It showed a dose-response relationship in its antibacterial and antifungal activities. The stem of Tinospora tomentosa may be considered as an important medicinal plant for antimicrobial therapeutics.