Effect of Tetrahydrocurcumin (THC) on lipid peroxidation and lipids in streptozotocin (STZ)-nicotinamide-induced diabetic rats
The main objective of the study was to investigate the effect of THC on lipid profile and lipid peroxidation in STZ- and -nicotinamide-induced diabetic rats. A total of 24 adult male albino rats (18 diabetic surviving rats, 6 normal rats) were orally administered with THC (80 mg/kg body weight) in aqueous suspension for 45 days. It was found that there was significant reduction in blood glucose level and improvement of plasma insulin in diabetic rats, and significantly restored total hemoglobin and glycosylated hemoglobin levels. The study report concludes that THC alleviated levels of serum and tissue lipids and lipid peroxidation marker, and showed beneficial effect on plasma insulin and blood glucose level (Murugan and Pari, 2006).
Influence of THC on hepatic and renal functional markers and protein levels in experimental type 2 diabetic rats
The study investigated the effect of THC on hepatic and renal functional markers and protein levels in rats with STZ and nicotinamide-induced diabetes. A total of 24 adult diabetic male albino wistar rats weighing 180 – 220 g were orally administered with THC (80 mg/kg body weight) or curcumin (80 mg/kg body weight) for 45 days. After treatment with THC and curcumin, total protein, albumin, globulin and albumin/globulin ratio were brought back to near normal. The decreased levels of urea, uric acid and creatinine with increased levels of albumin and urine volume in the diabetic rats were brought to near normal when treated with THC and curcumin. The protective effect observed with THC was more prominent than with curcumin (Murugan and Pari, 2007b).
Changes in glycoprotein components in STZ-nicotinamide Induced Type 2 diabetes: Influence of THC from Curcuma longa
The purpose of this study was to investigate the effect of THC on plasma and tissue glycoproteins in rats with STZ and nicotinamide induced diabetes. A total of 24 adult male albino wistar rats were rendered with STZ induced diabetes. The diabetic rats were orally administered with THC (80 mg/kg body weight) or curcumin (80 mg/kg body weight) for 45 days. Glucose, plasma insulin and glycoprotein components in plasma and tissues (hexose, hexosamine, fucose and sialic acid) were determined. It was observed that levels of plasma insulin and tissue sialic acid were increased whereas the levels of tissue hexose, hexosamine and fucose were near normal in diabetic rats treated with THC. The study results conclude that THC reverses abnormalities in the levels of glycoprotein components, increased level of insulin in diabetic rats, which may be responsible for the reversal of glycoprotein changes (Pari and Murugan, 2007).
Curcumin activates AMPK and suppresses gluconeogenic gene expression in hepatoma cells
In this study the effects of curcumin, Curcumin C3 complex® and Tetrahydrocurcuminoids (THCs) on metabolic targets that modulate insulin action were examined at concentrations comparable to their bioavailability. Curcuminoids did not exert a direct effect on receptor tyrosine kinase activity and 2-deoxy glucose uptake in L6-GLUT4myc cells, or intestinal glucose metabolism measured by DPP4/α-glucosidase inhibitory activity. The study demonstrates that curcuminoids effectively suppressed dexamethasone-induced phosphoenol pyruvate carboxy kinase (PEPCK) and glucose-6-phosphatase (G6Pase) in H4IIE rat hepatoma and Hep3B human hepatoma cells. The study concludes that curcuminoids increase phosphorylation of AMP-activated protein kinase (AMPK) and its downstream target acetyl-CoA carboxylase (ACC) in H4IIE and Hep3B cells with 400 times (curcumin) to 100,000 times (THC) the potency of metformin (kim et al., 2009).