Interaction of Lectins Isolated from Four Selected Local Vegetables on Gastrointestinal Pathogenic Bacteria

Abstract Lectins are carbohydrate recognizing proteins that bind mono-and oligosaccharide specifically and reversibly but are devoid of catalytic activity. In contrast to antibodies, they are not products of immune response. This study explores the isolation and partial characterization of lectin from leaves of Vernonia amygdalina, Talinum triangulare, Telfairia occidentalis and the kernels of Irvingia gabonensis focusing on their degree of antibacterial activities against some selected gastrointestinal pathogenic bacteria. Out of the different leaf materials, only lectin isolated from Vernonia amygdalina leaves exhibited the highest antibacterial activity against all tested bacteria. Agglutination of red blood cells by lectin from Talinum triangulare were significantly enhanced by D-lactose, D-maltose and D-glucose compared to lectin from other plant materials. Stability study showed that all the lectins were stable at temperature ranging from 20℃ to 30℃ and their activities were reduced with a corresponding increase in temperature. With the exception of lectin from Vernonia amygdalina, there were two different pH ranges for optimum activity of the respective isolated lectin. The study showed that the lectins from the different plant materials were capable of inhibiting the growth of the bacterial isolates. Thus, they may be suitable candidates for the prevention and treatment of gastrointestinal infections