Red Gedi Leaves Extract Increases Insulin Sensitivity Through IRS-1 and GLUT-4

The potential of red Gedi leaves (Abelmoschus manihot L. Medic), in controlling glucose homeostasis in conditions of insulin resistance are thought to work through molecular mechanisms on insulin target tissue receptors, including Glucose Transporter (GLUT) 4 and Insulin receptor substrate (IRS), but this has not been studied. Therefore, this study aims to prove the in vivo effect of ethanol extract of red Gedi leaves (EEGL) on insulin target tissue receptors, IRS-1, and GLUT-4 in diabetic rats. Rats model for Type 2 DM were prepared by High Fat Diet and High Fructose 25% also induced with low dose streptozotocin (STZ) 25 mg/kg BW. EEGL was given once a day for 4 weeks. At the end of the treatment blood glucose, insulin, IRS-1, and GLUT-4 levels by using ELISA. Pancreas and muscle histopathology was carried out using the HE-staining method. Results showed that EEGL reduced fasting blood glucose and plasma insulin (p<0.05, in parallel with increased levels of IRS-1, and GLUT-4. Post-treatment IRS 1 level in all groups higher than DM control rats (p<0.05) and reach the normal values. The histological profiles of muscle tissues and pancreas of EEGL treated animals were also improved compared to the diabetes and pioglitazone groups, their shape and number were similar to that of normal control groups. The results of this study show that ethanol extract of red Gedi leaves increase insulin sensitivity by increasing IRS-1 and GLUT-4 levels in DM type 2 rats. Further comprehensive pharmacodynamic effect on anti-diabetic molecular targets and toxicity studies need to be carried out to ensure the effect and safety of red Gedi leaves prior clinical trials of EEGM as one of herbal antidiabetics.