Studies on the effects of plant lectins on hematopoietic stem cells

Abstract

Epidemiological studies have shown that the diets rich in fruits, herbs and spices are associated with good health and low risk of cardiovascular disease and these foods are rich in lectins. After ingestion, most lectins bind to the absorptive microvilli of the small intestine, and from there they may gain access into the circulation through endocytosis, ultimately reaching various tissues. The resistance of the lectins towards the proteolytic activities of digestive enzymes and their ability to enter systemic circulation and tissues, taken together with their ability to bind to cell surface molecules containing specific carbohydrate moieties, indicate that they may affect the functions of various tissues. Accordingly, it is of considerable importance to establish whether a given lectin has deleterious or beneficial effects for mammals. In the present study, we have made a systematic attempt to examine the effects of two mannose-specific plant lectins namely, banana lectin (BL) and garlic lectin (GL), on the hematopoietic stem/progenitor cells. Since both BL and GL are the constituents of commonly consumed food items – banana and Garlic – it was imperative to study the effect of an oral administration of these lectins on the hematopoiesis of mice. The mice were fed with the lectins on weekly basis for various time periods and their marrow cells were subjected to stem cell-specific functional and phenotypic assays. The output of these various assays clearly indicated that an oral administration of both BL and GL leads to an increase in the hematopoietic stem/progenitor (HSPC) pool of the mice.