New Curcumin Derivative Has Anti-Diabetic Effects
With more than 350 million people living with diabetes globally, it has become one of the most researched disorders of the time. Evidence also shows that complications of diabetes are associated with oxidative stress due to generation of free radicals in the body, especially the reactive oxygen species (ROS).
Heme-oxygenase-1 (HO-1) is an enzyme that catalyzes the degradation of heme (iron containing component of hemoglobin) to produce biliverdin, iron, and carbon monoxide. Earlier studies have shown that HO-1 helps in cellular defense against a number of tissue injuries, which means up-regulation of this enzyme helps to counteract the adverse change that would destabilize the equilibrium in the tissue. It is also well known for its antioxidant boosting properties and anti-apoptotic (anti cell-death) actions. Curcumin has been reported to induce HO-1 expression and protect the cell against oxidative stress.
Turmeric, a spice widely used in Indian cuisine, has curcumin as its active ingredient. Many studies have shown the efficacy of curcumin as an antioxidant and as a therapeutic agent for number of ailments including diabetes. However, because of poor absorption and rapid metabolism, curcumin can not be sufficiently used by the body.
So, Mohamed T Abdel Aziz and his colleagues used a new water soluble curcumin derivative (Patent pending PCT/EG2010/000008) called NCD to evaluate the anti-diabetic effects and effects on diabetes-induced ROS generation and oxidative degradation of lipids in type-1 diabetes.
They used this new derivative containing 3 percent curcumin on 50 female experimental animals for 45 days although only 46 animals remained after 45 days. The animals were grouped 10 each into -
• control group,
• control group receiving curcumin derivative,
• diabetic group,
• diabetic group receiving curcumin derivative, and
• diabetic group receiving curcumin derivative and HO inhibitor ZnPP.
The study results published in the journal Diabetology & Metabolic Syndrome, revealed that -
• Significant lowering of the plasma glucose and increase in the plasma insulin was observed in the diabetic group treated with NCD.
• NCD significantly decreased the mean plasma cholesterol, LDL cholesterol and triglycerides levels.
• NCD significantly increased the plasma HDL cholesterol level.
• Treatment with NCD significantly increased HO-1 expression and subsequent HO-activity.
To determine whether the action of curcumin is mediated by inducing HO-1, the researchers administered the HO inhibitor (ZnPP) to the group of diabetic rats receiving oral curcumin derivative. The group showed significant increase in the plasma glucose level and a significant decrease in insulin levels when compared to the other two diabetic groups, suggesting that the hypoglycemic action of curcumin may be, in part, due to HO-1 induction.
The researchers concluded that 'NCD appears to improve the lipid profile in diabetic rats by lowering total cholesterol, LDL, and triglycerides, while raising HDL levels. It is believed that curcumin exerts its cholesterol lowering actions by modulating cholesterol absorption, degradation, or elimination, rather than through an antioxidant mechanism. NCD also improves oxidative status, protects and enhances endogenous defenses directly proved by decreasing lipid peroxides (malondialdehyde) in pancreas & liver'.