Investigation of the effect of addition of Momordica charantia to glibenclamide on amelioration of endothelial dysfunction in diabetic rats by activating Takeda G protein-coupled receptor 5

Endothelial dysfunction (ED) is a significant risk factor of blood vessel related diseases of diabetes and this study evaluate the effect of adding Momordica charantia (Mc) to glibenclamide (GLB) on ED markers in diabetic rats. Streptozotocin (STZ-40mg/kg b. w.) induced diabetic rats were randomly put into 3 groups with 10 rats/group; diabetic control [DC] group, glibenclamide treated group (GLB -2.5mg/kg) and GLB-Mc treated group (2.5mg/kg + 400mg/kg). Serum glucose was measured weekly for eight weeks whereas insulin, sVCAM-1, vWF-Ag and interleukin-6 [IL-6] were measured at week0 and week8. Luciferase assay was performed to determine luminescence. At week8, GLB and GLB-Mc groups revealed improvements in blood glucose and insulin concentrations (P [less than or equal to] 0.05) when compared to corresponding baseline values with GLB-Mc group showing slightly greater improvements. GLB-M c group also revealed improvement (P [less than or equal to] 0.05) in vWF-Ag, sVCAM-1 and IL-6 concentrations but was non- significant in GLB group when compared to corresponding baseline values. Comparison between GLB and GLB-Mc group showed significantly high concentration of sVCAM-1 in GLB group (P [less than or equal to] 0.05) due to its minimal effect on TGR5 activation. We conclude that adding M. charantia to GLB may be a useful choice for modulating diabetes induced ED due to its stimulatory effect on TGR5 receptors. Keywords: Diabetes mellitus, endothelial dysfunction, TGR5, Momordica charantia, glibenclamide.