Dioclea violacea lectin exerts pro-angiogenic effects by increasing VEGF and TNF-α levels via carbohydrate recognition domain

Abstract

Due to their interesting biological activities, a mannose-binding lectin isolated from Dioclea violacea seeds, known as DvL have attracted considerable attention. In this study, we performed macroscopic, histologic, and immunohistochemical analysis on chicken embryo chorioallantoic membranes (CAM) to investigate the effects of DvL on the angiogenic process. Data showed a potential angiogenic effect of DvL at the highest concentrations tested (50 and 100 μg/mL). This effect was confirmed through increased neovascularization, inflammatory cells, and fibroblasts in histological analysis of the CAM. In addition, the immunohistochemistry of CAM showed that DvL induced secretion of TNF-α and VEGF, important cytokines involved in angiogenesis. Therefore, increased neovascularization may result from a pro-inflammatory response through VEGF and TNF-α secretion. In contrast, the DvL effects on the angiogenic process and the TNF-α and VEGF secretion were significantly reduced by co-incubation with mannose. Thus, protein-carbohydrate interactions between DvL and cell membrane glycans are likely the main events involved in this effect. Therefore, our results demonstrated that DvL is a potent angiogenic agent, suggesting its potential application as a prototype molecule for developing new drugs with healing properties.