The present study reported the effects of Sclerocarya birrea stem-bark (SBSB) extracts on glucose uptake, insulin synthesis and the expression of glucose transporter 2 (GLUT2), glucokinase, pancreatic duodenal homeobox-1 (PDX-1), musculoaponeurotic fibrosarcoma oncogene homolog A (MafA) and pre-proinsulin genes in rat insulinoma (RIN)-m5F pancreatic beta cells. The amount of glucose taken-up by RIN-m5F cells was measured using a glucose oxidase-based assay kit. Intracellular and secreted insulin were measured using an enzyme linked immunoassay kit. Pre-proinsulin gene expression was determined using the conventional polymerase chain reaction (PCR) technique, while the expressions of GLUT2, glucokinase, PDX-1 and MafA genes were evaluated using quantitative real-time PCR technique. Of the four SBSB extracts investigated in the study, only the SBSB hexane extract positively affected all the study variables in RIN-m5F cells compared with the DMSO control. Thus, the SBSB hexane extract contains phytochemicals capable of enhancing insulin synthesis partly through up-regulation of the expression of GLUT2, glucokinase, PDX-1, MafA and pre-proinsulin genes.
- Gene expression
- Glucose uptake
- Insulin synthesis
- RIN-m5F pancreatic beta cells
- Sclerocarya birrea