Trans-11 Vaccenic Acid Reduces Hepatic Lipogenesis and Chylomicron Secretion in JCR:LA-cp Rats

Abstract

Trans-11 vaccenic acid (VA) is the predominant trans isomer in ruminant fat and a major precursor to the endogenous synthesis of cis9,trans11-conjugated linoleic acid in humans and animals. We have previously shown that 3-wk VA supplementation has a triglyceride (TG)-lowering effect in a rat model of dyslipidemia, obesity, and metabolic syndrome (JCR:LA-cp rats). The objective of this study was to assess the chronic effect (16 wk) of VA on lipid homeostasis in both the liver and intestine in obese JCR:LA-cp rats. Plasma TG (P < 0.001), total cholesterol (P < 0.001), LDL cholesterol (P < 0.01), and nonesterified fatty acid concentrations, as well as the serum haptoglobin concentration, were all lower in obese rats fed the VA diet compared with obese controls (P < 0.05). In addition, there was a decrease in the postprandial plasma apolipoprotein (apo)B48 area under the curve (P < 0.05) for VA-treated obese rats compared with obese controls. The hepatic TG concentration and the relative abundance of fatty acid synthase and acetyl-CoA carboxylase proteins were all lower (P < 0.05) in the VA-treated group compared with obese controls. Following acute gastrointestinal infusion of a VA-triolein emulsion in obese rats that had been fed the control diet for 3 wk, the TG concentration was reduced by 40% (P < 0.05) and the number of chylomicron (CM) particles (apoB48) in nascent mesenteric lymph was reduced by 30% (P < 0.01) relative to rats infused with a triolein emulsion alone. In conclusion, chronic VA supplementation significantly improved dyslipidemia in both the food-deprived and postprandial state in JCR:LA-cp rats. The appreciable hypolipidemic benefits of VA may be attributed to a reduction in both intestinal CM and hepatic de novo lipogenesis pathways.

Vaccenic and Elaidic Acid Equally Esterify into Triacylglycerols, but Differently into Phospholipids of Fed Rat Liver Cells

“…1a) allowed more cholesterol molecules to be shifted from their unsteady positions into the surrounding medium for lipoprotein formation. This would not be the case for trans-11 that, contrary to trans-9, was associated with lower blood total and LDL-cholesterol in rats [62].…”

Assessment of hepatoprotective potential of N. indicum leaf on haloalkane xenobiotic induced hepatic injury in Swiss albino mice

“…The predominant food component tetradecanoic acid (myristic acid) showed free radical scavenging activity [55] and cholesterol modulating activity in vivo [56]. Vaccenic acid demonstrated convincing hypolipidemic activity by decreasing hepatic lipogenesis in experimental rats [57]. The natural antioxidant phytol inhibits lipid peroxidation and scavenge NO and hydroxyl radical in vitro [58].…”

Trans fatty acids and weight gain

“…The animals receiving the TFA diet gained an additional 7.20 ± 2.70% body weight compared with 1.78±1.95% for those fed the cis FA diet (P ¼ 0.049). Assuming a linear relationship between weight gain and consumption of TFA, this would correspond to an increase of 0.42 or 0.55 kg over 6 years for a 1% increase in TFA in an Total body weight and weight of intra-abdominal tissue were slightly higher in animals fed either the R-TFA or I-TFA diets compared with the control diet, but none of these differences were statistically significant Wang et al 26,27 Male JCR:LA-cp rats, either obese or lean Fed diets with and without 1.5% (wt/wt) vaccenic acid for 3 25 Male Sprague-Dawley rats Fed diets containing 10 or 45% total fat for 8 weeks 10% SFA diet (LF-SFA) and 45% SFA diet (HF-SFA) used a combination of soyabean oil and lard. LF-Trans diet was identical to the LF-SFA diet, but with the lard replaced by elaidic acid, giving 4.6% TFA After 6 weeks, in vivo 1H-MR showed more adipose tissue in LF-Trans rats than those on LF-SFA diet (0.07±0.01 vs 0.04±0.01 g, Po0.05).…”

“…24 There were also no differences in food intake or weight gain in groups of lean and obese JCR:LA-cp rats fed diets with and without 1.5% (wt wt À1 ) vaccenic acid (the predominant TFA in ruminant sources 25 ) for 3 26 or 16 weeks. 27 Diets containing partially hydrogenated vegetable oil (1.05% of E from TFA), palm, canola or soy oil were fed to lactating female rats and then to their weaned male offspring until the males were 45 days old. 28 Animals on the partially hydrogenated vegetable oil and palm oil diets had higher total body weight and carcass fat content than their counterparts on the soy or canola diets, even though food intake was significantly lower in the partially hydrogenated vegetable oil group than in the other three groups.…”