Anti-obesity effect of a standardised ethanol extract from Curcuma longa L. fermented with Aspergillus oryzae in ob/ob mice and primary mouse adipocytes

BACKGROUND: We examined the anti‐obesity effect of fermented Curcuma longa L. (turmeric) standardised ethanol extract (FTE) in the C57BL/6J ob/ob mouse model. Mice were fed a chow diet containing FTE (0, 200, or 500 mg kg^?1 body weight) for 9 weeks. RESULTS: Supplementation with FTE significantly reduced body weight gain and retroperitoneal and epididymal adipose tissue weights compared to the ob/ob control group. Additionally, total cholesterol and triglyceride levels in serum and liver were significantly decreased in FTE‐200 and FTE‐500 groups when compared to those of the ob/ob control group, whereas the high‐density lipoprotein‐cholesterol level was significantly increased. The levels of serum adiponectin as well as mRNA expression of lipases, such as hormone sensitive lipase and adipose triglyceride lipase, were clearly increased. In primary adipocytes of C57BL/6J mice, FTE treatment caused a significant increase glycerol release and hormone sensitive lipase levels and decreased perilipin A levels. CONCLUSION: These results suggest that supplementation of FTE has potent anti‐obesity effects by controlling body weight, fat mass, serum lipids, and hepatic lipids. Moreover, FTE could be considered a potential resource for the treatment of obesity through its promotion of lipolysis via the protein kinase A pathway. Copyright © 2012 Society of Chemical Industry     

Facilitative effects of Eucommia ulmoides on fatty acid oxidation in hypertriglyceridaemic rats

BACKGROUND: Tea made from Eucommia ulmoides leaves is widely consumed as a health food, since recent studies have revealed various pharmacological effects of the tea, e.g. a hypotriglyceridaemic effect. This study was conducted to elucidate the mechanisms underlying the plasma triglyceride‐lowering effect of E. ulmoides leaves. RESULTS: Rats were divided into four groups: a normal group, a group fed a high‐fat/high‐fructose diet (untreated group) and two groups fed a high‐fat/high‐fructose diet and E. ulmoides tea (4 or 20 g L^?1 extract, treated groups). Plasma triglyceride concentrations were reduced in treated groups in a dose‐dependent manner compared with the untreated group. DNA microarray analysis revealed that genes involved in hepatic α‐, β‐ and ω‐oxidation, mainly related to the peroxisome proliferator‐activated receptor α and δ signalling pathway, were up‐regulated in the treated group. High‐performance liquid chromatography analysis showed that E. ulmoides leaves contain three phytochemicals that make up 60 mg g^?1 of the material and are likely to be the active components. CONCLUSION: This study indicates that the promotion of fatty acid oxidation, probably by the action of phytochemicals, participates in the ameliorative effect of E. ulmoides leaves on hypertriglyceridaemia. These findings provide the scientific evidence for the functionality of E. ulmoides. Copyright © 2011 Society of Chemical Industry     

Nepeta japonica Maximowicz extract from natural products inhibits lipid accumulation

BACKGROUND: To develop novel and crude anti‐obesity drugs from natural products is a promising field to approach the solution to a global health problem such as obesity. The aim of this study was to screen crude anti‐obesity drugs from 400 natural products on lipase inhibition activity in vitro. RESULTS: Among the natural products examined, 31 extracts showed significantly inhibition activity against porcine pancreatic lipase (triacylglycerol lipase, EC 3.1.1.3) by using spectrophotometry with 2,4‐dinitrophenylbutyrate as a substrate. Furthermore, 31 natural products were investigated with regard to their lipid inhibition in 3T3‐L1 cells. Among these, one of most promising was Nepeta japonica Maximowicz extract, which showed inhibition of triglyceride accumulation in 3T3‐L1 adipocytes, suggesting anti‐obesity activity. Also, the amount of glycerol released from cells into the medium was increased by treatment of Nepeta japonica Maximowicz extract at a concentration of 100 µg mL^?1. CONCLUSION: The present study suggests that a promising crude anti‐obesity drug screened from 400 natural products might be of therapeutic interest with respect to the treatment of obesity. Copyright © 2012 Society of Chemical Industry     

Comparative in vivo antioxidant capacity of DL-2-hydroxy-4-methylthiobutanoic acid (HMTBA) and DL-methionine in male mice fed a high-fat diet

BACKGROUND: In animal diets, methionine (Met) is considered to be the first limiting amino acid, and the activity of synthetic Met is typically added either as DL ‐methionine (DLM) or as DL ‐2‐hydroxy‐4‐methylthiobutanoic acid (HMTBA). It has been demonstrated that HMTBA exhibits a higher antioxidant capability in vitro as compared to DLM. However, the difference in antioxidant capability between DLM and HMTBA in vivo is unknown. METHODS: In the present study, 60 male C57BL/6 mice were randomly divided into six groups and fed either a normal diet (NFD, 5.37% fat) or a high‐fat diet (HFD, 19.7% fat) in conjunction with 0.2% DLM, 0.2% HMTBA or 0.1% DLM and 0.1% HMTBA for 4 weeks. RESULTS: HFD supplemented with 2% DLM and NFD with 2% HMTBA both induced adverse affects in relation to serum lipid parameters and depressed antioxidant defense systems in the digestive system. However, these changes were restored in the 0.2% HMTBA‐treated HFD group. Furthermore, no significant differences were found in the lipid parameters and antioxidant status in the NFD and HFD group supplemented with 0.1% DLM and 0.1% HMTBA. CONCLUSION: HMTBA restored oxidative redox status under OS conditions and its antioxidant properties were positively correlated with the dosage included in diet. Copyright © 2011 Society of Chemical Industry     

Effects of the Polysaccharide from the Sporophyll of Brown Alga Undaria Pinnatifida on Serum Lipid Profile and Fat Tissue Accumulation in Rats Fed a High‐Fat Diet

We investigated the effects of the polysaccharide from the sporophyll of a selected brown alga Undaria pinnatifida on serum lipid profile, fat tissue accumulation, and gastrointestinal transit time in rats fed a high‐fat diet. The algal polysaccharide (AP) was prepared by the treatment of multiple cellulase‐producing fungi Trichoderma reesei and obtained from the sporophyll with a yield of 38.7% (dry basis). The AP was mostly composed of alginate and fucoidan (up to 89%) in a ratio of 3.75:1. The AP was added to the high‐fat diet in concentrations of 0.6% and 1.7% and was given to male Sprague–Dawley rats (5‐wk‐old) for 5 wk. The 1.7% AP addition notably reduced body weight gain and fat tissue accumulation, and it improved the serum lipid profile, including triglycerides, total cholesterol, and very low‐density lipoprotein‐cholesterol. The effects were associated with increased feces weight and shortened gastrointestinal transit time. In addition, the lipid peroxidation of the liver was decreased in both groups.     

The Beneficial Effect of Propolis on Fat Accumulation and Lipid Metabolism in Rats Fed a High-Fat Diet

ABSTRACT:  This study examined whether propolis, which had many biological activities, affected body fat and lipid metabolism. Four-week-old Wistar rats were fed a control or propolis diet for 8 wk. The control group was fed a high-fat diet, the low and the high group were fed a high-fat diet supplemented with 0.5% (w/w) and 0.05% (w/w) propolis, respectively. The weight of total white adipose tissue of the high group was lower than that of the control group. The level of PPARγ protein in the adipose tissues of the high group was significantly lower than that of the control group. In plasma and the liver, the high group showed a significantly reduced level of cholesterol and triglyceride compared to the control group. The liver PPARα protein level of the high group was significantly higher than that of the control group. The liver HMG-CoA reductase protein in the high group was also significantly lower than that in the control group. Results from rats on an olive oil loading test were used to investigate whether propolis inhibited triglyceride absorption. The serum triglyceride level of the group, which received propolis corresponding to the daily dose of the high group, was significantly lower than that of the control group. It is possible that the administration of propolis improves the accumulation of body fat and dyslipidemia via the change of the expression of proteins involved in adipose depot and lipid metabolism.     

辣木提取物降脂作用的研究

目的探讨辣木提取物预防性降脂的作用。方法选用SD雄性大鼠为研究对象,通过喂养高脂膳食建立预防性肥胖高血脂模型,用辣木提取物进行辅助降脂试验,依据保健食品功能学评价规程进行。大鼠随机分为正常对照组、高脂模型对照组、辣木提取物高剂量组、中剂量组、低剂量组,实验后检测各组大鼠体重、血液生化指标(总胆固醇、甘油三酯、低密度脂蛋白、高密度脂蛋白)、脂肪重量和脂/体比、Lee′s指数。结果大鼠灌胃辣木提取物40 d后,各实验组血脂水平明显低于高脂模型对照组,其中高剂量组的血清总胆固醇、甘油三脂与高脂模型对照组相比分别有显著性差异(P0.05)和极显著性差异(P0.01)。辣木提取物各剂量组大鼠的肾周脂肪重量和附睾脂肪重量、脂/体比、Lee′s指数极显著低于高脂模型对照组(P0.01)。结论辣木提取物具有良好的辅助降血脂作用。     

Stevia rebaudiana Bertoni extract supplementation improves lipid and carnitine profiles in C57BL/6J mice fed a high‐fat diet

BACKGROUND: Stevia (Stevia rebaudiana Bertoni) is a non‐caloric natural‐source alternative to artificially produced sugar substitutes. This study investigated the effect of stevia extract on lipid profiles in C57BL/6J mice. Forty mice were divided into four groups: N‐C (normal diet and distilled water), H‐C (high‐fat diet and distilled water), H‐SC (high fat diet and sucrose, 1 mL kg^?1 per day), and H‐SV (high‐fat diet and stevia extract, 1 mL kg^?1 per day). RESULTS: Body weight gain was significantly higher in the H‐SC group than in the H‐SV group. Triglyceride concentrations in serum and liver were lower in the H‐SV group than in the H‐SC group. Serum total cholesterol concentrations were lower in the H‐SV and H‐C groups compared to the H‐SC group. The concentrations of acid‐insoluble acylcarnitine (AIAC) in serum were higher in the H‐SV group than in the H‐C and H‐SC groups and the acyl/free carnitine level in liver was significantly higher in the H‐SV group than in the N‐C group. These results were supported by mRNA expression of enzymes related to lipid metabolism (ACO, PPARα, ACS, CPT‐I, ACC) assessed by real‐time polymerase chain reaction. CONCLUSION: These results suggest that the supplementation of stevia extract might have an anti‐obesity effect on high‐fat diet induced obese mice. Copyright © 2010 Society of Chemical Industry     

Dietary Intake of Structured Lipids with Different Contents of Medium‐Chain Fatty Acids on Obesity Prevention in C57BL/6J Mice

Three medium‐ and long‐chain triacylglycerols (MLCT) with different contents of medium‐chain fatty acids (MCFA) (10% to 30%, w/w) were prepared and evaluated for their anti‐obesity potential in C57BL/6J mice. The group fed with a high fat diet of MLCT containing 30% (w/w) MCFA showed significantly decreased body weight and fat mass (P < 0.05) relative to the control mice fed an obesity‐inducing high fat rapeseed oil diet. In addition, serum parameters including triacylglycerols, total cholesterol, glucose, high‐density lipoprotein cholesterol, low‐density lipoprotein cholesterol, apolipoprotein A1 and apolipoprotein B in the treatment group fed with 30% (w/w) MCFA were close to those of mice fed with a low fat rapeseed oil diet, but significantly different (P < 0.05) from those of the obesity control group. Moreover, the intake of MLCT with high content of MCFA reduced the size of adipocytes. In addition, the visceral fat and liver weights, as well as the liver triacylglycerol for 3 treatment groups were lower than those of the obesity control group. These results demonstrate the great potential of MLCT with high content of MCFA in weight loss.     

Comparison of the Effects of Roasted and Boiled Red Kidney Beans (Phaseolus vulgaris L.) on Glucose/Lipid Metabolism and Intestinal Immunity in a High‐Fat Diet‐Induced Murine Obesity Model

Consumption of the common bean (Phaseolus vulgaris L.) is associated with beneficial effects on lipid and glucose metabolism; however, the influence of the bean processing method on these health benefits is not well understood. To investigate this, we processed red kidney beans (RKBs), a variety of the common bean, by roasting and boiling and compared the physiological effects of the two preparations in male C57BL/6N mice fed a high‐fat diet (HFD). The two RKB preparations differed mainly in their resistant starch content (roasted, 24.5%; boiled, 3.1%). Four groups of mice were fed for 12 weeks on a normal diet or a HFD (45 kcal% fat) supplemented with 10% control chow (HFD control group), 10% roasted RKB, or 10% freeze‐dried boiled RKB. We found that intake of roasted RKBs prevented hypercholesterolemia and increased fecal IgA and mucin content compared with the HFD control group, while intake of boiled RKBs improved glucose tolerance. Both RKB preparations suppressed the HFD‐associated increase in plasma aspartate aminotransferase and alanine aminotransferase levels, which are markers of liver injury. Mice fed roasted RKBs showed significantly increased hepatic expression of cholesterol 7‐alpha‐monooxygenase mRNA, suggesting that cholesterol suppression may be due to enhanced bile acid biosynthesis. In contrast, mice fed boiled RKBs showed significantly increased cecal content of n‐butyric acid, which may be related to the improved glucose tolerance in this group. These results indicate that the method by which RKBs are processed can profoundly affect their health benefits.     

Ethanol extracts of unroasted Coffea canephora robusta beans suppress adipogenesis in preadipocytes and fat accumulation in rats fed a high-fat diet

Anti-adipogenic and anti-obesity effects of a green coffee been extract (GCE) from unroasted Coffea canephora Robusta beans were investigated in vitro and in vivo. Insulin-induced adipogenesis in 3T3-L1 preadipocytes was inhibited by 25.6 and 87.9% following treatment with 100 and 500 μg/mL GCE, respectively. Expression of adipogenesis-specific genes was down-regulated. Body weight gains of C57BL/6 mice fed a high-fat diet (HFD) were suppressed in a concentration-dependent manner using GCE (0.3 or 1% in the diet), exhibiting a marked lower gain in 1% GCE-fed mice than in normal diet-fed animals. Decreases in body fat weights and the size of adipocytes were confirmed. GCE supplementation reduced concentrations of blood lipids and leptin, and attenuated hepatic steatosis. GCE inhibits adipogenesis by modulating cell signaling and improves dietary obesity by reducing lipid accumulation and the size of adipocytes.     

Ameliorative effect of saltwort (Salicornia herbacea) extract on hepatic dysfunction and hyperlipidemia in rats

To examine the effect of saltwort (Salicornia herbacea) on blood cholesterol and lipid metabolism, hyperlipidemia was induced in animal rats. Saltwort extract was then administered to the rats for 5 weeks, after which, blood biochemical changes were determined. Saltwort treatment resulted in a significant reduction of the levels of total cholesterol, blood triglyceride, and LDL-cholesterol. In contrast, the expression levels of HDL-cholesterol were increased at saltwort treatment group. The aspartate aminotransferase (AST: serum SGOT) value of the saltwort administration group was significantly reduced and the blood alanine aminotransferase (ALT: serum SGPT) levels decreased significantly in comparison to those in the negative control group. Degeneration of hepatic tissues due to the consumption of a high lipid diet for a long period of time was reported in the negative control group. On the other hand, in the saltwort administration group, a substantial reduction in the accumulation of lipid droplets in the cytoplasm was seen, and in addition, it was confirmed that the degeneration of hepatic tissues recovered almost to level of that of the normal control group. These data suggest that saltwort extract represents an excellent candidate for protection of rat hepatocytes from high fat diet-mediated damage.     

EFFECTS OF ORAL CHONDROITIN SULFATE ON LIPID AND ANTIOXIDANT METABOLISMS IN RATS FED A HIGH-FAT DIET

This study aimed at determining the effects of purified chondroitin sulfate (ChS) from pig laryngeal cartilage on the lipid and antioxidant metabolisms of male Sprague‐Dawley rats that are fed a high‐fat diet. Thirty‐two male rats were divided into four groups and fed for 5 weeks on a standard diet, a high‐fat diet or a high‐fat diet plus ChS. It was demonstrated that the high‐fat diet provoked lipid peroxidation and induced a severe depletion of lipoprotein lipase, hepatic lipidase, glutathione, catalase and superoxide dismutase levels. ChS was effective in reducing triglycerides, total cholesterol, low‐density‐lipid cholesterol and malondialdehyde levels elevated by the high‐fat diet. In addition, ChS might reduce the risk of atherosclerosis, as high‐density‐lipid cholesterol, lipoprotein lipase, hepatic lipidase and the ratio of high‐density‐lipoprotein cholesterol to total cholesterol were significantly higher than in the high‐fat‐diet rats. ChS restored the endogenous antioxidants glutathione, catalase and superoxide dismutase. These results showed that ChS was potent in lipid‐lowering and altering the antioxidative enzyme; however, excess ChS would disturb lipid profiles that went beyond the normal limits.     

黑米花色苷提取物对高脂膳食诱导大鼠肥胖形成的影响

研究黑米花色苷提取物对高脂膳食诱导大鼠肥胖的影响.将体重在180～220g左右的48只雄性SD大鼠根据体重随机分为四组,其中三个实验组分别在大鼠正常饲料中添加高脂饲料、黑米花色苷提取物以及高脂 黑米花色苷提取物混合物.喂饲大鼠12周后处死大鼠,收集血液、组织标本检测.结果表明,黑米花色苷提取物能够显著抑制高脂诱导的大鼠体重增加,同时也抑制了白色脂肪组织的生长,血脂中甘油三酯水平的升高及脂质在肝脏组织的堆积.研究结果显示:黑米花色苷提取物能够改善高脂膳食诱导的大鼠肥胖相关指标.     

Lipid metabolic effect of Korean red ginseng extract in mice fed on a high-fat diet

BACKGROUND: Ginseng saponin and ginsenosides exert anti‐obesity effects via the modulation of physiological lipid metabolism in vivo or intracellular signalling in cell culture systems. However, the complicated relationship between the anti‐obesity effects of ginseng and gene expression has yet to be defined under in vivo conditions. Therefore, we evaluated the relationship between the anti‐obesity effects of Korean red ginseng extract (KRGE) and hepatic gene expression profiles in mice fed long‐term on a high‐fat diet (HFD) in this study. RESULTS: KRGE reduces the levels of cholesterol, low‐density lipoprotein‐cholesterol (LDL‐C), serum triglycerides, and atherogenic indices. Levels of leptin, adiponectin and insulin, which regulate glucose and lipid metabolism, were impaired profoundly by HFD. However, KRGE treatment brought these levels back to normal. KRGE was found to down‐regulate genes associated with lipid metabolism or cholesterol metabolism (Lipa, Cyp7a1, Il1rn, Acot2, Mogat1, Osbpl3, Asah3l, Insig1, Anxa2, Vldlr, Hmgcs1, Sytl4, Plscr4, Pla2g4e, Slc27a3, Enpp6), all of which were up‐regulated by HFD. CONCLUSION: KRGE regulated the expression of genes associated with abnormal physiology via HFD. Leptin, insulin, and adiponectin, which carry out critical functions in energy and lipid metabolism, were shown to be modulated by KRGE. These results show that KRGE is effective in preventing obesity. Copyright © 2011 Society of Chemical Industry     

Modulation of lipid metabolism by polyphenol‐rich grape skin extract improves liver steatosis and adiposity in high fat fed mice

This study investigated the influence of polyphenol‐rich grape skin extract (GSE) on adiposity and hepatic steatosis in mice fed a high fat diet (HFD) and its underlying mechanisms based on adipose and hepatic lipid metabolism. C57BL/6J mice were fed a normal diet or a HFD (20% fat, w/w) with or without GSE (0.15%, w/w) for 10 weeks. The supplementation of GSE significantly lowered body weight, fat weight, plasma free fatty acid level, and hepatic lipid accumulation compared to the HFD group. Plasma leptin level was significantly lower, while the plasma adiponectin level was higher in the GSE group than in the HFD group. GSE supplementation significantly suppressed the activities of lipogenic enzymes in both adipose and liver tissues, which was concomitant with β‐oxidation activation. Furthermore, GSE reversed the HFD‐induced changes of the expression of genes involved in lipogenesis and β‐oxidation in the liver. These findings suggest that GSE may protect against diet‐induced adiposity and hepatic steatosis by regulating mRNA expression and/or activities of enzymes that regulate lipogenesis and fatty acid oxidation in the adipose tissue and liver.     

Inhibitory Effects of Phenolics and Saponins From Commonly Consumed Food Legumes in China Against Digestive Enzymes Pancreatic Lipase and α-Glycosidase

Total phenolic and saponin components were extracted from 13 commonly consumed food legumes produced in China, and then a systematic comparative study was conducted to investigate their inhibitory effects against digestive enzymes, pancreatic lipase, and α-glycosidase, respectively. Saponin extract (1 mg/mL) from black bean exhibited the highest (41.8%) pancreatic lipase inhibitory effect, followed by phenolic extract from adzuki bean with 36.3%, saponin extract from yellow soybean with 34.1%, saponin extract from pinto bean with 32.6%. It is worth mentioning that both phenolic and saponin extracts from the mung bean, adzuki bean, lima bean, and pinto bean exhibited inhibitory effects against pancreatic lipase. Among four beans, the adzuki bean had the highest inhibitory effects against pancreatic lipase activity. In the α-glycosidase assays, phenolic extracts exhibited stronger α-glycosidase inhibitory activity than that of saponins in general. Phenolic extracts of the adzuki bean, black bean, fava bean, lentil, rock bean, and red kidney bean inhibited over 80% of α-glycosidase activity at the concentration of 1 mg/mL. Both phenolic and saponin extracts from the adzuki bean and rock bean exhibited inhibitory effects against α-glycosidase. The results indicate that adzuki bean is one of the best target beans for further study on their anti-obesity and anti-diabetes effects via cell and animal models.     

Effects of Theabrownin from Pu-erh Tea on the Metabolism of Serum Lipids in Rats: Mechanism of Action

Abstract: Theabrownin (TB), one of the main bioactive components in pu-erh tea, has a significant blood lipid-lowering effect in hyperlipidemic rats. Therefore, it was hypothesized that TB would regulate the activity of key enzymes involved in lipid metabolism and accelerate the catabolism of exogenous cholesterol in rats fed a high fat diet. A total of 90 Sprague–Dawley rats were randomly divided into a normal control group (Group I), a high fat diet group (Group II), and high-fat diet plus TB group (Group III). A total of 10 rats were selected from each group and killed at 15, 30, or 45 d after starting the study for analysis. After feeding 45 d, the contents of TC, TG, and LDL-C levels in Group II were increased by 54.9%, 93.1%, and 134.3% compared with those in Group III, respectively, and the content of HDL-C in Group II was decreased by 55.7%. These effects were inhibited in the rats in Group III, which exhibited no significant differences in these levels compared with Group I, indicating that TB can prevent hyperlipidemia in rats fed a high fat diet. TB enhanced the activity of hepatic lipase and hormone-sensitive triglyceride lipase (HSL) and increased the HSL mRNA expression in liver tissue and epididymis tissue. The HL activity in serum of Group III was increased by 147.6% compared with that in Group II. The content of cholesterol and bile acid in the feces of rats was increased by 21.11- and 4.08-fold by TB. It suggested that TB could promote the transformation and excretion of dietary cholesterol of rats in vivo.     

Hypolipidaemic and hypoglycaemic effects of total flavonoids from seed residues of Hippophae rhamnoides L. in mice fed a high-fat diet

BACKGROUND: The present study was designed to investigate the hypolipidaemic and hypoglycaemic effects of total flavonoids from seed residues of Hippophae rhamnoides L. (FSH) in a high‐fat diet fed mouse model. Consumption of a high‐fat diet (HFD) for 4 weeks caused a significant rise of serum total cholesterol in mice. These hypercholesterolaemic mice then were orally administrated with different doses of FSH (50, 100 and 150 mg kg^?1 body weight) and simvastatin (20 mg kg^?1 body weight) for another 12 weeks under continuous HFD feeding. RESULTS: FSH administration markedly reduced total mouse body, liver, and epididymal fat pad weights. Serum total cholesterol and low density of lipoprotein‐cholesterol levels were also significantly decreased by FSH treatment. Additionally, FSH significantly lowered total cholesterol and triglyceride concentrations in liver, and the results were corroborated by transmission electron microscope findings. The rise in serum glucose was significantly suppressed by FSH treatment while improving impaired glucose tolerance. CONCLUSION: These results suggest that FSH possesses hypolipidaemic and hypoglycaemic properties in mice fed a high‐fat diet and could be developed as a supplement in healthcare foods and drugs. Copyright © 2011 Society of Chemical Industry