Oral administration of a turmeric extract inhibits LDL oxidation and has hypocholesterolemic effects in rabbits with experimental atherosclerosis

The oxidation of low-density lipoproteins (LDL) plays an important role in. the development of atherosclerosis. Curcumin is a yellow pigment obtained from rhizomes of Curcuma longa and is commonly used as a spice and food col ouring. Curcumin and turmeric extracts have several pharmacological effects including antitumour, anti-inflammatory, antioxidant and antiinfectious ac tivities although the precise mechanisms involved remain to be elicited. We evaluated the effect of an ethanol-aqueous extract obtained from rhizomes of C. longa on LDL oxidation susceptibility and plasma lipids in atheroscle rotic rabbits. A total of 18 rabbits were fed for 7 weeks on a diet contain ing 95.7% standard chow, 3% lard and 1.3% cholesterol, to induce atheroscle rosis. The rabbits were divided into groups, two of which were also orally treated with turmeric extract at doses of 1.66 (group A) and 3.2 (group B) mg/kg body weight, respectively. A third group (group C) acted as a control . Plasma and LDL lipid composition, plasma alpha-tocopherol, plasma retinol , LDL TEARS, LDL lipid hydroperoxides and analysis of aortic atheroscleroti c lesions were assayed. The low but not the high dosage decreased the susce ptibility of LDL to lipid peroxidation. Both doses had lower levels of tota l plasma cholesterol than the control group. Moreover, the lower dosage had lower levels of cholesterol, phospholipids and triglycerides in LDL than t he 3.2-mg dosage. In conclusion, the use of this extract could be useful in the management of cardiovascular disease in which atherosclerosis is impor tant. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.