Inhibition of GLUT2 transporter by geraniol from Cymbopogon martinii: a novel treatment for diabetes mellitus in streptozotocin-induced diabetic rats

Objective To isolate and identify the bioactive component from Cymbopogon martinii having GLUT2 transporter inhibitory activity - towards development of a novel strategy for treatment of diabetes mellitus. Method Isolation of bioactive component was carried out using differential solvent extraction, HPTLC and HPLC, and identification was done by GC-MS. In-vitro studies on intestine, liver, kidney and in-vivo assessment by OGTT and long-term treatment on diabetic rats were carried out. Key findings Geraniol was isolated and identified as bioactive component. Intestinal glucose absorption demonstrated 60.28% inhibition of transport at 648.34 mu m of geraniol. It was found to inhibit glucose release from liver on adrenaline challenge by 89.82% at 324.17 mu m/ml. Kidney glycogen content doubled using 648.34 mu m of geraniol as compared to control. Geraniol demonstrated 2.14 times higher renal glucose output than diabetic control. OGTT demonstrated prevention of postprandial spikes. Prolonged treatment for 60 days with 29.37 mm/kg B.W. twice a day of geraniol improved the lipid profile, HbA1C levels and renal parameters. In mRNA studies for 10 days, over expression of GLUT2 was prevented by geraniol. Conclusions Inhibition of GLUT2 by geraniol has the potential to reduce hyperglycaemia and prevent secondary complications in diabetes.