Influence of curcuma (Curcuma xanthorrhiza Roxb) on lipid metabolism in rabbits

The efficacy of curcuma (Curcuma xanthorrhiza) in lowering blood plasma lipid was evaluated in rabbits. Forty male New Zealand white rabbits (2.3 kg) were divided into four equal groups and offered isoatherogenic diets with no curcuma, low curcuma (2 g kg^?1), medium curcuma (3 g kg^?1) and high curcuma (4 g kg^?1) for 120 days. Faeces and feed samples were collected. Body weight was measured weekly. Blood samples at 1, 2 and 4 months and liver samples at the last blood collection were taken. Curcuma did not influence feed, protein and fat consumption and protein excretion (P > 0.05) but significantly (P < 0.05) increased fat excretion. Cholesterol concentration was decreased by 46.6, 56.4 and 63.2% and HDL concentration was decreased by 9.9, 14.5 and 21.9% at 2, 3 and 4 g kg^?1 curcuma respectively. Curcuma significantly (P < 0.05) decreased LDL concentration and significantly (P < 0.01) decreased triglyceride concentration by 20.4, 28.5 and 29.5% at 2, 3 and 4 g kg^?1 respectively. HMG‐CoA reductase inhibitor was significantly (P < 0.05) increased by curcuma. Glucose was significantly (P < 0.05) reduced by 6.2, 7.6 and 18.0% at 2, 3 and 4 g kg^?1 curcuma respectively. Lipid peroxidation was prevented at 3 and 4 g kg^?1 curcuma. The enhanced fat excretion could have been mediated through an acceleration of lipid metabolism from extrahepatic tissues to the liver, which would increase the excretion of cholesterol via the bile and into the faeces. Since this is central to lipid metabolism, curcuma has potential as a phytotherapeutic agent under atherosclerosis and cardiovascular disease conditions. © 2002 Society of Chemical Industry     

Effect of orally administered phenethyl isothiocyanate on hepatic gene expression in rats

Scope: Phenethyl isothiocyanate (PEITC) is a constituent of cruciferous vegetables that has demonstrated cancer preventive activity in a number of cancer models including lung, prostate, and breast cancer. Our objective was to examine the effects of the oral administration of PEITC for 7 days on the hepatic expression of genes important in drug metabolism and toxicity in Sprague Dawley rats. The liver is the major site for the metabolism of various xenobiotics and carcinogens, and determining the effects of PEITC on the gene expression of hepatic enzymes may provide insight into mechanisms underlying the cancer preventive activity of PEITC. Methods and results: Using a microarray containing 282 genes, we observed that PEITC significantly up‐regulated UDP‐glucuronosyltransferase UGT1A6 and strongly down‐regulated nicotinamide N‐methyltransferase (NNMT). We also confirmed the down‐regulation of NNMT by real‐time quantitative RT‐PCR. Other genes that were significantly up‐regulated were the drug metabolizing enzyme cyp2b15, the anti‐apoptotic gene bcl2l2, and the stress regulators Gadd45b, Dnajb9, Dnajb5 and Hspb1. Conclusion: Our results indicate new targets that may be important in the mechanisms of the anticancer effects of PEITC. Of particular significance was the down‐regulation of NNMT which may represent a new target for the treatment of a variety of cancers.