10E12Z CLA alters adipocyte differentiation and adipocyte cytokine expression and induces macrophage proliferation

Dietary supplementation with conjugated linoleic acid induces anemia with combined features of megaloblastic and hemolytic anemia

This study investigates whether dietary supplementation with conjugated linoleic acids (CLA) induces anemia in mice. Male Kunming White mice were randomly assigned to two groups: one fed a CLA-supplemented diet and the other a linoleic acid (LA)-supplemented diet as control. Compared with those in LA group, periodic manual erythrocyte counts revealed red blood cells (RBCs) in CLA group significantly reduced on days 47 (p < 0.05), 61 (p < 0.01), and 86 (p < 0.001). Complete blood count (CBC) analysis demonstrated that CLA group exhibited 48.96 % lower RBCs (p < 0.01) and 46.49 % reduced hematocrit (HCT, p < 0.01), but displayed 7.82 % higher mean corpuscular volume (MCV, p < 0.01) and a 41.77-fold increase in monocyte proportion (MONO %, p < 0.001). Brilliant cresyl blue (BCB)-stained blood smears showed reticulocyte counts in CLA group exceeding twice those of controls (p < 0.01). The levels of plasma vitamin B12 and folate in CLA-fed mice decreased by 24.72 % (p < 0.05) and 23.15 % (p < 0.01), respectively, while direct bilirubin levels increased significantly (p < 0.05). Electron microscopic images of the liver showed an enhanced phagocytic effect of Kupffer cells on RBCs. No intergroup differences were observed in RBC osmotic fragility, plasma iron levels, or renal erythropoietin (EPO) mRNA expression. These findings suggest CLA-induced anemia may result from nutritional deficiencies and/or enhanced phagocytic activity of the monocyte-macrophage system. We conclude that dietary CLA supplementation triggers anemia with mixed characteristics of both megaloblastic and hemolytic anemia.

Tissue-dependent effects of cis-9,trans-11- and trans-10,cis-12-CLA isomers on glucose and lipid metabolism in adult male mice

Mixtures of the two major conjugated linoleic acid (CLA) isomers trans-10,cis-12-CLA and cis-9,trans-11-CLA are used as over the counter supplements for weight loss. Because of the reported adverse effects of CLA on insulin sensitivity in some mouse studies, we sought to compare the impact of dietary t10c12-CLA and c9t11-CLA on liver, adipose tissue, and systemic metabolism of adult lean mice. We fed 8 week-old C57Bl/6J male mice with low fat diets (10.5% Kcal from fat) containing 0.8% t10c12-CLA or c9t11-CLA for 9 or 38 days. Diets containing c9t11-CLA had minimal impact on the endpoints studied. However, 7 days after starting the t10c12-CLA diet, we observed a dramatic reduction in fat mass measured by NMR spectroscopy, which interestingly rebounded by 38 days. This rebound was apparently due to a massive accumulation of lipids in the liver, because adipose tissue depots were visually undetectable. Hepatic steatosis and the disappearance of adipose tissue after t10c12-CLA feeding was associated with elevated plasma insulin levels and insulin resistance, compared to mice fed a control diet or c9t11-CLA diet. Unexpectedly, despite being insulin resistant, mice fed t10c12-CLA had normal levels of blood glucose, without signs of impaired glucose clearance. Hepatic gene expression and fatty acid composition suggested enhanced hepatic de novo lipogenesis without an increase in expression of gluconeogenic genes. These data indicate that dietary t10c12-CLA may alter hepatic glucose and lipid metabolism indirectly, in response to the loss of adipose tissue in mice fed a low fat diet.

Effects of Phytosterol Supplementation on Serum Levels of Lipid Profiles, Liver Enzymes, Inflammatory Markers, Adiponectin, and Leptin in Patients Affected by Nonalcoholic Fatty Liver Disease: A Double-Blind, Placebo-Controlled, Randomized Clinical Trial

OBJECTIVE

Considering the high prevalence of nonalcoholic fatty liver disease and based on the evidence about the role of dietary cholesterol in liver inflammation, and also with regard to the effect of phytosterols on the metabolism of cholesterol, we aimed at exploring the therapeutic potential of phytosterol supplementation against nonalcoholic fatty liver disease.

METHOD

Thirty-eight patients with nonalcoholic fatty liver disease were randomly divided into two groups: The phytosterol group (n = 19) received a 1.6-g phytosterol supplement daily and the control group (n = 19) received 1.6 g starch daily as placebo for an 8-week period. Blood samples of all patients were taken at baseline (week 0) and at the end of the study (week 8) for measurement of lipid profiles, liver enzymes, inflammatory markers, adiponectin, and leptin.

RESULTS

Phytosterol supplementation significantly improved the levels of low-density lipoprotein cholesterol, aspartate aminotransferase, alanine aminotransferase, and tumor necrosis factor alpha compared to the placebo group. On the other hand, there were no significant differences between the two groups in total cholesterol, triglycerides, high-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol, ratios of low-density lipoprotein cholesterol/high-density lipoprotein cholesterol and total cholesterol/high-density lipoprotein cholesterol, gamma-glutamyl transferase, interleukin 6, high-sensitivity C-reactive protein, adiponectin, and leptin.

CONCLUSIONS

The present study suggested that daily consumption of 1.6 g phytosterols efficiently lowers low-density lipoprotein cholesterol, aspartate aminotransferase, alanine aminotransferase, and tumor necrosis factor alpha in patients with nonalcoholic fatty liver disease.

The dietary fatty acid 10E12Z-CLA induces epiregulin expression through COX-2 dependent PGF(2α) synthesis in adipocytes

Conjugated linoleic acids (CLAs) are a group of dietary fatty acids that are widely marketed as weight loss supplements. The isomer responsible for this effect is the trans-10, cis-12 CLA (10E12Z-CLA) isomer. 10E12Z-CLA treatment during differentiation of 3T3-L1 adipocytes induces expression of prostaglandin-endoperoxide synthase-2 (Cyclooxygenase-2; COX-2). This work demonstrates that COX-2 is also induced in fully differentiated 3T3-L1 adipocytes after a single treatment of 10E12Z-CLA at both the mRNA (20-40 fold) and protein level (7 fold). Furthermore, prostaglandin (PG)F(2α), but not PGE(2), is significantly increased 10 fold. In female BALB/c mice fed 0.5% 10E12Z-CLA for 10 days, COX-2 was induced in uterine adipose (2 fold). In vitro, pharmacological COX-2 inhibition did not block the effect of 10E12Z-CLA on adipocyte-specific gene expression although PGF(2α) was dose-dependently decreased. These studies demonstrate that PGF(2α) was not by itself responsible for the reduction in adipocyte character due to 10E12Z-CLA treatment. However, PGF(2α), either exogenously or endogenously in response to 10E12Z-CLA, increased the expression of the potent mitogen and epidermal growth factor (EGF) receptor (EGFR) ligand epiregulin in 3T3-L1 adipocytes. Blocking PGF(2α) signaling with the PGF(2α) receptor (FP) antagonist AL-8810 returned epiregulin mRNA levels back to baseline. Although this pathway is not directly responsible for adipocyte dependent gene expression, these results suggest that this signaling pathway may still have broad effect on the adipocyte and surrounding cells.