OBJECTIVESTo study the effects of c9,t11-conjugated linoleic acid (c9,t11-CLA) on critical enzymes of linoleic acid metabolism in stomach granular cell (SGC-7901).

METHODSSGC-7901 was treated with c9,t11-CLA by 200, 100, 50 or 25 micromol/L for 24 hours. The effects of c9,t11-CLA on the cell proliferation was measured by monotetrazolium and the expression of Delta6-desaturase, Delta5-desaturase, COX-1, COX-2, 5-LOX mRNA were measured by reverse transcription polymerase chain reaction (RT-PCR).

RESULTSAt a concentration of 200, 100, 50, or 25 micromol/L, c9,t11-CLA suppressed the proliferation of SGC-7901 by 54.3%, 20.5%, 10.5% and 2.93%. The c9,t11-CLA might decrease the expression of COX-2 mRNA, and increase the expression of Delta6-desaturase and COX-1 in SGC-7901, but might not affect Delta5-desaturase and 5-LOX.

CONCLUSIONThe effects of c9,t11-CLA on the COX and Delta6-desaturase might play an important role in mediating the ability of c9,t11-CLA as to inhibiting the proliferation of tumor cells, and the anti-cancer activity by c9,t11-CLA might be associated with the linoleic acid metabolism.

Cell Line, Tumor ; Cyclooxygenase 1 ; genetics ; metabolism ; Cyclooxygenase 2 ; genetics ; metabolism ; Enzymes ; genetics ; metabolism ; Gene Expression Profiling ; Gene Expression Regulation, Enzymologic ; drug effects ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Linoleic Acids ; metabolism ; Linoleic Acids, Conjugated ; pharmacology ; Lipid Metabolism ; drug effects ; Lipoxygenase ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo study the effect of conjugated linoleic acid (CLA) on expression of adiponectin in white adipose tissue of obese rats.

METHODSMale Wistar rats were randomly divided into control group, high-fat group and high fat + CLA group (0.75 g, 1.50 g, 3.00 g per hundred gram diet weight), we observed the effect of CLA on serum insulin and glucose levels of obese rats, and the reverse transcription polymerase chain reaction (RT-PCR) technique was used to measure the expression level of adiponectin and peroxisome proliferator-activated receptor-gamma (PPARgamma) mRNA.

RESULTSThe serum insulin and glucose levels of obese rats were (11.11 +/- 2.73) microIU/ml, (5.09 +/- 0.66) mmol/L. The supplement of CLA decreased the hyperinsulinemia and hyperglycemia, the serum insulin in CLA group (0.75 g, 1.50 g, 3.00 g per hundred gram diet weight) were (6.99 +/- 1.77) microIU/ml, (7.36 +/- 1.48) microIU/ml, (7.85 +/- 1.60) microIU/ml (P < 0.05), and glucose were (4.28 +/- 0.72) mmol/L, (4.18 +/- 0.55) mmol/L (P < 0.05), (4.06 +/- 0.63) mmol/L (P < 0.05), CLA can increase the expression of adiponectin and PPARgamma in adipose tissue of obese rat.

CONCLUSIONThe CLA might improve the insulin resistance of the obese rat and increase the expression of adiponectin mRNA, which might possibly act through activating PPARgamma.

Adiponectin ; biosynthesis ; genetics ; Adipose Tissue ; metabolism ; Animals ; Insulin Resistance ; physiology ; Linoleic Acids, Conjugated ; pharmacology ; Male ; Obesity ; metabolism ; PPAR gamma ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Rats ; Rats, Wistar ; Reverse Transcriptase Polymerase Chain Reaction

This study was to investigate the anti-obesity effects of diglyceride (DG)-conjugated linoleic acid (CLA) containing 22% CLA as fatty acids in C57BL/6J ob/ob male mice. There were four experimental groups including vehicle control, DG, CLA, and DG-CLA. The test solutions of 750 mg/kg dose were orally administered to the mice everyday for 5 weeks. CLA treatments significantly decreased mean body weight in the obese mice throughout the experimental period compared to the control (p < 0.01). All test solutions significantly decreased the levels of triglyceride, glucose and free fatty acids in the serum compared with control (p < 0.05). The levels of total cholesterol were also significantly reduced in DG and DG-CLA groups compared with the control group (p < 0.05). CLA significantly decreased weights of renal and epididymal fats compared with the control (p < 0.05). DG and DG-CLA also significantly decreased the epididymal fat weights compared with the control (p < 0.05). A remarkable decrease in the number of lipid droplets and fat globules was observed in the livers of mice treated with DG, CLA, and DG-CLA compared to control. Treatments of DG and CLA actually increased the expression of peroxisome proliferator-activated receptor gamma. These results suggest that DG-CLA containing 22% CLA have a respectable anti-obesity effect by controlling serum lipids and fat metabolism.
Adipose Tissue/*drug effects ; Animals ; Anti-Obesity Agents/*pharmacology ; Blood Chemical Analysis ; Body Weight/*drug effects ; Diglycerides/*pharmacology ; Disease Models, Animal ; Eating/drug effects ; Gene Expression Regulation/drug effects ; Linoleic Acids, Conjugated/*pharmacology ; Lipids/blood ; Liver/drug effects/pathology ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Obese ; Obesity/*metabolism/pathology ; PPAR gamma/metabolism ; Time Factors

OBJECTIVETo study the gene expression of the resistin and the effects of conjugated linoleic acid on its expression in white adipose tissue of obese rats fed with high fat diet during the formation of insulin resistance.

METHODSMale Wistar rats were randomly separated in control group, high-fat group and high fat + conjugated linoleic acid (CLA) group (0.75 g, 1.50 g, 3.00 g per 100 g diet weight), using reverse transcription polymerase chain reaction (RT-PCR) technique to measure the expression level of resistin and peroxisome proliferator-activated receptor-gamma (PPARgamma) mRNA expression.

RESULTSthe serum insulin and glucose levels of obese rats were (11.11 +/- 2.73) mIU/L, (5.09 +/- 0.66) mmol/L, and supplement of CLA might decrease hyperinsulinemia and hyperglycemia, in CLA group (0.75 g, 1.50 g, 3.00 g per 100 g diet weight) the serum insulin levels were (6.99 +/- 1.77) mIU/L, (7.36 +/- 1.48) mIU/L, (7.85 +/- 1.60) mIU/L, and glucose levels were (4.28 +/- 0.72) mmol/L, (4.18 +/- 0.55) mmol/L, (4.06 +/- 0.63) mmol/L. The expression of resistin in adipose tissue of obese rat fed with high fat diet was increased as compared with those fed with basic diet. CLA might increase the expression of resistin and PPARgamma in adipose tissue of obese rat.

CONCLUSIONThe expression of resistin mRNA of obese rat fed with high fat diet was higher than those fed with basic diet, and CLA might improve the insulin resistance in obese rats and possibly upregulate the expression of resistin through activing PPARgamma.

Adipose Tissue ; drug effects ; metabolism ; Animals ; Dietary Fats ; administration & dosage ; Gene Expression ; drug effects ; Insulin Resistance ; Linoleic Acids, Conjugated ; pharmacology ; Male ; Obesity ; etiology ; genetics ; PPAR gamma ; genetics ; RNA, Messenger ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Wistar ; Resistin ; genetics ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo study the effects of c9,t11-conjugated linoleic acid on the killing ability of macrophage to B16-MB cells in C57 mice and explore its possible mechanism.

METHODSThe five levels of CLA was designed as 0, 25, 50, 75, 100 micro mol/L. After macrophage was treated with CLA for 24 h, the killing ability of macrophage on B16-MB cells was evaluated by MTT, The expression of C57 mice macrophage cytokine IL-6, TNF-alpha and iNOS mRNA was detected by RT-PCR. The expression of Erk protein was examined by Western Blot assay.

RESULTSThe inhibitory effect of macrophage on tumor cell depend on the treatment of the increased c9,t11-CLA level, at the same time, the expression of IL-6, TNF-alpha and iNOS mRNA increased, the expression of Erk decreased with the elevating dose of CLA.

CONCLUSIONSc9,t11-CLA could increase the killing ability of macrophage in mice to B16-MB cells, and it was associated with induction of IL-6, TNF-alpha and iNOS mRNA expression. We speculate that antitumor ability of CLA may be associated with taking part in body immune regulation action, and the effects of CLA on the killing ability of murine macrophage to B16-MB cells was not associated with the MAPKErk pathway.

Animals ; Blotting, Western ; Cell Division ; Cell Line, Tumor ; Coculture Techniques ; Dose-Response Relationship, Drug ; Interleukin-6 ; genetics ; Linoleic Acids, Conjugated ; pharmacology ; Macrophages ; drug effects ; physiology ; Melanoma, Experimental ; pathology ; Mice ; Mice, Inbred C57BL ; Mitogen-Activated Protein Kinases ; metabolism ; Nitric Oxide Synthase ; genetics ; RNA, Messenger ; drug effects ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Tumor Necrosis Factor-alpha ; genetics

AIMTo study the effect of conjugated linoleic acid (CLA) on obese MSG mice with insulin resistance.

METHODSAbout four months old, obese MSG mice with insulin resistance were divided into control, CLA and rosiglitazone groups and drugs were administrated ig once a day. Body weights were recorded regularly, insulin and glucose tolerance were tested. In addition, serum insulin and TNF-alpha concentrations in serum and fat tissues were determined.

RESULTSCLA was shown to reduce the body weight and fat weight in MSG mice, but can not improve the abnormal insulin and glucose tolerance in these mice. Indeed, the serum insulin and TNF-alpha concentrations in the fat tissues of the group treated with CLA were higher than those in the models and the insulin sensitivity index was significantly lower than that in the model mice.

CONCLUSIONCLA can reduce the body weight of MSG mice, but can not improve the insulin resistance in these mice.

Adipose Tissue ; metabolism ; Animals ; Animals, Newborn ; Blood Glucose ; metabolism ; Body Weight ; drug effects ; Female ; Glucose Tolerance Test ; Insulin ; blood ; Insulin Resistance ; Linoleic Acids, Conjugated ; pharmacology ; Male ; Mice ; Mice, Inbred ICR ; Obesity ; chemically induced ; metabolism ; Sodium Glutamate ; Tumor Necrosis Factor-alpha ; metabolism