Plant Lectins: Bioactivities and Bioapplications

Abstract Lectins are proteins that possess at least one noncatalytic domain that allows them to selectively recognize and reversibly bind specifically free sugars (monosaccharides) or oligosaccharides, present in the cell without altering the structure of carbohydrate which make possible their use as decoders of cellular carbohydrates. They have a largest distribution in nature in all kingdoms of life with a higher distribution in plants and also in animals and microorganisms. The plant lectins represent a unique group of proteins with potent biological activity, where legumes lectins represent the largest thoroughly studied family. Based on their mechanism of action, the plant lectins can exert action in diverse biological process as plant protection and in medicine as lectin-based delivery systems, biomedical research, as diagnostic and in disease treatment. In animal cells lectins can have action in various of biological process included the cellular adhesion, invasion, metastasis inhibition, action on angiogenesis and in cellular death by autophagy, necrose, and or apoptosis. The best-known legume lectins are phytohemagglutinin from red kidney beans ( Phaseolus vulgaris L.), soybean agglutinin from Glycine max , concanavalin A from jack bean ( Canavalia ensiformis ), peanut lectin from Arachis hypogaea , and pea lectin from Pisum sativum . Others important plant lectins with recognized antitumor activity (where ConA is included) are Ulex europaeus agglutinin, Viscum album coloratum agglutinin, mistletoe lectin, and Viscum album agglutinin from Viscum album L. and Galanthus nivalis agglutinin, among others. This review aims to give the state of art of lectins as potential candidates for the development of more efficient anticancer or cancer preventive drugs.