Metabolic and nutritional aspects of the atherogenic atypical lipoproteins: Lipoprotein(a), remnant lipoproteins, and oxidized low-density lipoprotein

Coffee leaf extract exhibits anti-obesity property and improves lipid metabolism in high-fat diet-induced C57BL6 obese mice

In the present study, the effect of coffee leaf extract (CLE) on in vitro enzyme inhibition was studied. Furthermore, its impact on the high-fat diet (HFD)-induced obese mice (C57BL/6) at the levels of 100 and 200 mg/kg body weight along with positive control (orlistat) and the normal group maintained with starch-fed diet (SFD) was observed. CLE had significant α amylase and lipase enzyme inhibitory properties. In HFD-induced obese mice, treatment with CLE significantly reduced the body weight gain. The investigation demonstrated that CLE administration lowered blood glucose, total cholesterol, total triglycerides and LDL levels while increasing the HDL levels. It reduced the development of fatty liver by reducing hepatic fat accumulation and decreased the fat cell size in the adipose tissue. Further, CLE significantly increased the liver antioxidant enzyme activities and lowered the levels of hepatotoxicity markers in the serum when compared to the HFD-fed mice. The treatment also downregulated the mRNA expression of lipogenic transcription factors (SREBP-1c, CEBP-α) and enzymes (ACC, FAS) than HFD. Overall, the results indicate that coffee leaves have anti-obesity potential and can be used as functional ingredients in the development of innovative products for managing lifestyle disorders such as obesity.

Rice Bran Fermented with Kimchi-Derived Lactic Acid Bacteria Prevents Metabolic Complications in Mice on a High-Fat and -Cholesterol Diet

This aim of this study was to investigate the potential beneficial effects of rice bran powder, fermented by Weissella koreensis DB1 isolated from kimchi, to protect against obesity and dyslipidemia induced by a high-fat and high-cholesterol diet, in a mouse model. Male mice were fed a modified AIN-93M diet containing high fat/high-cholesterol (HFCD), or same diet supplemented with non-fermented rice bran powder (HFCD-RB) or fermented rice bran powder (HFCD-FRB) for 10 weeks. In the HFCD-FRB group, body weight, liver and white fat pads weights, triglyceride (TG), total cholesterol (TC), non-high-density lipopreotein cholesterol (non-HDL-C), insulin, glucose and leptine levels in serum, TG levels and the ratio of fat droplets in the liver, TG levels and fat cell size in adipose tissue were decreased, and (high-density lipopreotein cholesterol) HDL-C and adiponectin levels in serum were increased, compared with the HFCD group. The HFCD-FRB group had significantly lower CCAAT-enhancer-binding potein α (C/EBPα), sterol regulatory element-binding transcription protein-1c (SREBP-1c), fatty acid synthase (FAS), and acetyl CoA carboxylase (ACC) gene expression when compared to the HFCD group. The anti-obesity and hypolipidemic effects were marginally greater in the HFCD-FRB group than in the HFCD-RB group. These results suggest that fermented rice bran powder by Weissella koreensis DB1 may have potential beneficial effects on the obesity-related abnormalities and the dysfunction of lipid metabolism.

Hepatic gene expression related to lower plasma cholesterol in hamsters fed high-fat diets supplemented with blueberry peels and peel extract

This study analyzed plasma lipid profiles, genes related to cholesterol and bile acid metabolism, and inflammation in liver as well as adipose tissue from Syrian Golden hamsters fed high-fat diets supplemented with blueberry (BB) pomace byproducts including 8% dried whole blueberry peels (BBPWHL), 2% dried extract of peels (BBPX; 95% ethanol extract), and 6% residue from extracted peel (BBPEXT) compared to a diet containing 5% (w/w) microcrystalline cellulose (control). All BB diets significantly lowered plasma very low density lipoprotein cholesterol and total cholesterol concentrations. Interestingly, BB diets increased fecal lipid excretion. Hepatic CYP7A1 expression was up-regulated by all BB diets, and the expression of CYP51 was up-regulated by BBPX and BBPEXT diets, suggesting that both bile acid and cholesterol synthesis were increased. No significant changes in adipocyte gene expression related to inflammatory markers were observed with any BB diet. These data suggest that hepatic modulation of bile acid and cholesterol synthesis primarily contributes to the cholesterol-lowering effect of BB pomace byproducts.

Effect of blueberry feeding on plasma lipids in pigs

Two feeding trials were conducted with pigs to determine the effects of blueberry supplementation on plasma lipid levels and other indices of cardiovascular benefit. In the first trial, where basal diets contained a high level of plant-based components (70 % soya, oats and barley), supplementation with 1, 2 and 4 % blueberries resulted in a decrease in total, LDL- and HDL-cholesterol. The greatest reduction was observed in the 2 % blueberry-fed pigs, where total, LDL- and HDL-cholesterol were reduced 11.7, 15.1 and 8.3 %, respectively. In the second trial where basal diets contained only 20 % (w/w) of soya, oats and barley, the lipid-modulating effect of blueberries was attenuated, so that supplementation with 1.5 % blueberries reduced total cholesterol by 8 %, which occurred only in pigs whose diets had been supplemented with cholesterol (0.08 %), NaCl (0.11 %) and fructose (9 %). In the first feeding trial, blueberry supplementation had no effect on blood platelet activity. Blueberry supplementation also had no effect on the susceptibility of leucocyte DNA to oxidation in the first trial and no effect on the susceptibility of LDL to oxidation in the second trial. Results of these two feeding trials are discussed in relation to the effects of basal diet composition on lipid-modulating effects of blueberries.

Open tubular capillary electrochromatography: a new technique for in situ enzymatic modification of low density lipoprotein particles and their protein-free derivatives

Electrochromatography with open tubular capillaries coated with human low density lipoprotein (LDL) particles and their protein-free derivatives was studied as a method for their in situ enzymatic modification. LDL particles as monolayers or their protein-free derivatives (lipid microemulsions) were coated on 50 microm i.d. capillaries, which resemble tiny human blood vessels in size, the arterioles. The immobilized LDL particles were exposed to sphingomyelinase, phospholipase A2 or alpha-chymotrypsin at 25 and 37 degrees C. The mobility of the electro-osmotic flow was employed as a surface charge indicator, and the retention factors of steroids were used as hydrophobicity indicators. Moreover, the capillaries were, for the first time, coated with lipid microemulsions containing either LDL-derived or commercial lipids, and the immobilized microemulsions were treated with sphingomyelinase in capillary. The results demonstrate that open tubular capillaries provide a good microreactor for the in situ modification of LDL particles and lipid microemulsions. The technique only requires extremely low quantities of LDL particles, lipid microemulsions, and enzymes. It allows quick and easy alteration of the reaction conditions, and the enzymes can be collected and reused. Asymmetrical flow field flow fractionation provides useful information on the size of the enzymatically modified LDL particles.