Lectins from Vigna radiata - A potential health supplement

There has been growing interest in use of nutraceuticals of plant origin, because of their impact on the status of human health and disease prevention. Plant lectins, a unique group of proteins and glycoproteins with potent biological activity, occur in commonly consumed foods such as legumes. The lectins can be used as dietary supplements due to their potential benefits of enzyme inhibition. The present research work discusses lectins from Vigna radiata (L.) R.Wilczek as an effective and economical source of natural antioxidants and α-amylase inhibitors which can prove to be a potential dietary and health supplement.

Lectins from Vigna radiata were extracted by macerating the seed meal in 50 mM phosphate buffer saline (pH 5.2) containing D-(+)-Galactose at 40^oC. The lectin rich extract was prepared by salt precipitation. The precipitate was dialysed against distilled water for 48 hours. The lectins were purified by Size exclusion Chromatography by using Sephadex G75. The presence of lectins was confirmed by hemmagglutination assay. The fractions showing agglutination were pooled together and lyophilized. The yield of relatively purified lectins was found to be 0.044%w/w.

Lectin rich extract was evaluated for anti-oxidant property by TBARS assay. The IC₅₀ value of the lectin rich extract was found to be 598.32±3.2µg/ml. The extract was also subjected to the evaluation of α-amylase inhibitory activity. The IC₅₀ value was found to be 552±6.09µg/ml. This study provides evidence on the potential health benefits of lectins from Vigna radiata, thus confirming the traditional claim.

References: 1. Heller VG (1927) JBC 435–442.