Hypolipidaemic and hepatoprotective effects of ethanolic and aqueous extracts from Asparagus officinalis L. by‐products in mice fed a high‐fat diet

BACKGROUND: Asparagus (Asparagus officinalis L.) by‐products, i.e. the parts of the spears discarded during industrial processing, might have potential use as food supplements for their therapeutic effects. In this study the hypolipidaemic and hepatoprotective effects of ethanolic (EEA) and aqueous (AEA) extracts from asparagus by‐products were evaluated in mice fed a high‐fat diet (HFD). RESULTS: Continuous HFD feeding caused obvious hyperlipidaemia and liver damage in mice. However, both EEA and AEA significantly decreased the levels of body weight gain, serum total cholesterol and serum low‐density lipoprotein cholesterol in hyperlipidaemic mice when administered at a daily dose of 200 mg kg^?1 for 8 weeks. Also, serum high‐density lipoprotein cholesterol levels were evidently increased in the AEA‐treated group. Moreover, both EEA and AEA dramatically decreased the activities of alanine and aspartate transaminases in serum. Finally, superoxide dismutase activity and total antioxidant capacity were increased and malondialdehyde level and the distribution of lipid droplets decreased in liver cells of both EEA‐ and AEA‐treated mice. CONCLUSION: The findings of this study suggest that both EEA and AEA have strong hypolipidaemic and hepatoprotective properties and could be used as supplements in healthcare foods and drugs or in combination with other hypolipidaemic drugs. Copyright © 2010 Society of Chemical Industry     

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.     

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.     

The effect of chemically‐modified resistant starch,RS type‐4, on body weight and blood lipid profiles of high fat diet‐induced obese mice

This study was conducted to investigate the effects of feeding chemically‐modified resistant starch type‐4 (RS4) of normal (NCS) and high‐amylose corn starch (HACS) on weight gain and plasma and liver lipid profiles of mice fed a high‐fat diet (HFD). The experimental four groups were, respectively, fed following diets: A 40% HFD with NCS, HACS, NCS‐ and HACS‐RS4. A normal diet (ND) group of mice fed the standard diet was also used as control. In order to produce RS4 by chemical modification, corn starches were treated with STMP/STPP. Total RS (TRS) and total dietary fiber (TDF) levels of chemically‐modified NCS were 26.4 and 44.0%, respectively, while TRS and TDF levels in chemically‐modified HACS were 78.1 and 78.5%, respectively. Onset gelatinization temperatures of both modified corn starches clearly shifted to higher temperatures after STMP/STPP treatment. At the end of the diet trial, the mice on the HACS diet decreased body weight gain compared to the NCS‐fed mice. Adding NCS‐ and HACS‐RS4 to the diet significantly reduced the weight gain relative to NCS and HACS groups. Both RS4 diets were effective in improving the lipid profile compared to their respective controls. They significantly reduced the level of total lipid and total cholesterol.     

Effect of flavonol glycoside in mulberry (Morus alba L.) leaf on glucose metabolism and oxidative stress in liver in diet‐induced obese mice

BACKGROUND: Mulberry therapies on type 2 diabetic patients or streptozotocin‐induced diabetic rats have been reported to improve fasting blood glucose levels. We investigated the effects of dietary consumption of mulberry‐leaf powder and purified quercetin 3‐(6‐malonylglucoside), the quantitatively major flavonol glycoside in mulberry leaves, on glucose and lipid metabolism in high‐fat diet‐induced obese mice. Male C57BL/6J mice aged 8 weeks were assigned to three groups (control, mulberry leaf powder (MLP), and quercetin 3‐(6‐malonylglucoside) (Q3MG)) and treated with their respective diets for 8 weeks. RESULTS: We found that dietary supplementation of 10 g MLP kg^?1 or 1 g Q3MG kg^?1 in high‐fat diet effectively suppressed blood glucose levels. We also noted increased expression of glycolysis‐related genes and suppression of thiobarbituric acid reactive substances concentrations in the liver of Q3MG group compared to control mice. CONCLUSION: Dietary consumption of Q3MG, the quantitatively major flavonol glycoside in mulberry leaves, improved hyperglycemia in obese mice and reduced oxidative stress in the liver. Copyright © 2010 Society of Chemical Industry     

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     

白藜芦醇对高脂诱导肥胖小鼠生长性能及肝脏糖脂代谢、能量代谢的影响

研究添加白藜芦醇对高脂日粮诱导肥胖小鼠的体重、采食量、脂质代谢、糖代谢及能量代谢的影响。选取40只C57BL/6J雄性小鼠,随机分成4组,分别采用低脂日粮(LFD)、低脂日粮+0.0276%白藜芦醇(LR)、高脂日粮(HFD)、高脂日粮+0.04%白藜芦醇(HR)饲喂12周。结果表明:与饲喂低脂日粮小鼠相比,高脂日粮组小鼠的体重显著增加(p<0.05),前4周的采食量显著减少(p<0.05),血清中谷草转氨酶(AST)和谷丙转氨酶(ALT)活性显著升高(p<0.05),肝脏中ALT和AST活性显著下降(p<0.05),脂质过氧化物(LPO)和丙二醛(MDA)含量均显著升高(p<0.05),己糖激酶(HK)、丙酮酸激酶(PK)和琥珀酸脱氢酶(SDH)活力显著下降(p<0.05);另外,饲喂高脂日粮小鼠肝脏MDH1、Sdha、PGC-1α mRNA的表达量显著下降(p<0.05)。饲喂添加了白藜芦醇的高脂日粮后,与高脂日粮组比,小鼠的体重显著降低(p<0.05),采食量显著增加(p<0.05),血清中AST和ALT活性显著降低(p<0.05),肝脏中AST活性显著升高(p<0.05),LPO和MDA含量显著降低(p<0.05),HK和PK活力显著升高(p<0.05)。另外,饲喂白藜芦醇对高脂日粮导致的肝脏中Hk2、Pkm、Cs、MDH1、Sdha mRNA表达量降低有显著的提高作用(p<0.05)。综上所述,日粮中添加0.04%的白藜芦醇能一定程度地缓解高脂日粮造成小鼠机体损伤,修复机体的脂质代谢、糖代谢和能量代谢。     

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.     

Okra polysaccharide improves metabolic disorders in high‐fat diet‐induced obese C57BL/6 mice

Okra is a tropical vegetable that is rich in polysaccharides. Here, we investigated the effects of okra polysaccharide (OP) on metabolic disorders in mice. We found that OP lowered body weight and glucose levels, improved glucose tolerance, and decreased serum total cholesterol levels in high‐fat diet‐fed C57BL/6 mice. OP regulated the gene expression of liver X receptors (LXRs) and peroxisome proliferator‐activated receptors (PPARs) and their target genes in the liver and the adipose tissue of the mice. These results suggest that OP may have therapeutic effects on metabolic diseases via the inhibition of LXR and PPAR signaling.     

大豆不溶性膳食纤维对高脂饮食诱导小鼠肥胖的预防作用

目的:研究大豆不溶性膳食纤维(Soybean insoluble dietary fiber,SIDF)对高脂饮食(High fat diet,HFD)诱导小鼠肥胖的预防作用及其机理。方法:将50只C57BL/6J小鼠随机分为正常饮食对照组(Normal diet,ND)、高脂饮食对照组(HFD)和大豆不溶性膳食纤维低(Low-dose soybean insoluble dietary fiber,LSIDF)(250 mg/kg BW/d)、中(Middle-dose soybean insoluble dietary fiber,MSIDF)(500 mg/kg BW/d)、高剂量组(High-dose soybean insoluble dietary fiber,HSIDF)(1 g/kg BW/d),ND组饲喂正常饲料,其余各组饲喂高脂饲料,连续喂养20周。实验结束后统计体质量、肝脏和脂肪湿质量,制作肝脏组织病理切片,测定血清及肝脏脂质水平,实时荧光定量聚合酶链式反应测定小鼠肝脏中脂代谢相关基因表达水平。结果:与HFD组比,SIDF各剂量组可显著减缓小鼠体重增加,降低其血清和肝脏中总胆固醇(Total cholesterol,TC)、甘油三酯(Triglyceride,TG)水平(P<0.05),并且HSIDF组效果优于LSIDF、MSIDF组;小鼠肝脏指数(P<0.05)和脂肪系数(P<0.001)显著降低,其中MSIDF和HSIDF组小鼠腹部脂肪(P<0.001)和肾周脂肪重量(P<0.001)显著减少;HSIDF组显著下调小鼠肝脏中脂肪酸合成酶(Fatty acid synthase,FAS)、二酰甘油酰基转移酶1(Diacylglycerol acyltransferase-1,DGAT1)、二酰甘油酰基转移酶2(Diacylglycerol acyltransferase-2,DGAT2)、硬脂酰辅酶A去饱和酶1(Stearyl-coenzyme A dehydrogenase-1,SCD1)基因表达水平(P<0.05),同时上调过氧化物酶体增殖物激活受体α(Peroxisome proliferators-activated receptor-α,PPARα)、肉毒碱棕榈酰基转移酶1a(Carnitine palmtoyl transferase-1a,CPT1a)基因表达水平(P<0.05)。结论:IDFS对HFD诱导小鼠肥胖具有预防作用,可能与减少脂质合成,加快脂肪酸氧化有关,其可作为一种潜在的膳食补充剂。     

Beneficial effect of yam on the amyloid β‐protein,monoamine oxidase B and cognitive deficit in mice with accelerated senescence

This study was designed to evaluate the effect of yam tuber material [Dioscorea alata L. var. purpurea (M.) Pouch.] on the amyloid β‐protein (Aβ) accumulation, monoamine oxidase (MAO) activity, cognitive ability and antioxidative defense system in senescence‐accelerated mice (SAMP8). Three‐month‐old male mice were fed with four different diets for 12 weeks: a casein diet (control group) and a casein diet supplemented with either 100, 200 or 400 g kg^?1 lyophilized yam. The results of the active shuttle avoidance test showed that the mice fed with the yam‐containing diets had significantly better learning and memory ability than the control group. All yam‐containing diet groups had lower Aβ levels and MAO B activities than the control, whereas the MAO A activity did not differ among the four diet groups. At the 400 g kg^?1 level, the yam‐containing diet group showed significantly lower concentration of thiobarbituric acid‐reactive substances (TBARS), higher total thiol level and superoxide dismutase (SOD) activity in the hippocampus than the control, but these values were not altered by the 100 and 200 g kg^?1 yam‐containing diet groups. The addition of 200 or 400 g kg^?1 yam also lowered the triglyceride levels but not the total cholesterol concentration. These results indicate that lyophilized yam could reduce brain Aβ accumulation, MAO B activity and cognitive deficits and promote the antioxidative defense system in SAMP8 mice. The improvements were in a dose‐dependent manner, possibly because the 400 g kg^?1 yam‐containing diet might contain more antioxidative phytochemicals. Copyright © 2006 Society of Chemical Industry     

High‐fat Diet‐induced Intestinal Hyperpermeability is Associated with Increased Bile Acids in the Large Intestine of Mice

Metabolic syndrome is characterized by low‐grade chronic systemic inflammation, which is associated with intestinal hyperpermeability. This study examined the effects of 3 high‐fat diets (HFDs) composed of different fat sources (soybean oil and lard) on the intestinal permeability, tight junction (TJ) protein expression, and cecal bile acid (BA) concentrations in mice, and then analyzed their interrelations. C57/BL6 mice were fed the control diet, HFD (soybean oil), HFD (lard), and HFD (mix; containing equal concentrations of soybean oil and lard) for 8 wk. Glucose tolerance, intestinal permeability, TJ protein expression, and cecal BA concentration were evaluated. Feeding with the 3 HDFs similarly increased body weight, liver weight, and fat pad weight, and induced glucose intolerance and intestinal hyperpermeability. The expression of TJ proteins, zonula occludens‐2 and junctional adhesion molecule‐A, were lower in the colons of the 3 HFD groups than in the control group (P < 0.05), and these changes appeared to be related to intestinal hyperpermeability. Feeding with HFDs increased total secondary BA (SBA) and total BA concentrations along with increases in some individual BAs in the cecum. Significant positive correlations between intestinal permeability and the concentrations of most SBAs, such as deoxycholic acid and ω‐muricholic acids, were detected (P < 0.05). These results suggest that the HFD‐induced intestinal hyperpermeability is associated with increased BA secretion. The abundance of SBAs in the large intestine may be responsible for the hyperpermeability.     

Auraptene regulates gene expression involved in lipid metabolism through PPARα activation in diabetic obese mice

Scope: Peroxisome proliferator‐activated receptor‐α (PPARα) is a key regulator of circulating lipid level. Thus, various food‐derived compounds that activate PPARα as agonists have been screened and characterized. Methods and results: We investigated the effects of auraptene, a citrus‐derived compound serving as a PPARα agonist in vitro, on abnormalities in lipid and glucose metabolisms. In high‐fat‐diet (HFD)‐fed KK‐Ay diabetic obese mice, auraptene treatment suppressed hyperlipidemia and triglyceride accumulation in the liver and skeletal muscle, and increased the mRNA expression levels of the PPARα target genes involved in fatty acid oxidation in the liver and skeletal muscle. Moreover, the adipocyte size in the auraptene‐treated mice was significantly smaller than that in the control HFD‐fed mice resulting in the improvement of HFD‐induced hyperglycemia and abnormalities in glucose tolerance. Conclusions: These findings indicate that auraptene activates PPARα also in vivo and its treatment may improve abnormalities in lipid and glucose metabolisms, suggesting that auraptene is a valuable food‐derived compound for managing metabolic disorders.     

Hypolipidaemic and antioxidant capacities of polysaccharides obtained from Laminaria japonica by different extraction media in diet‐induced mouse model

This study shows the industrial feasibility of using aqueous methods to produce antioxidative and hypolipidaemic polysaccharides from Laminaria japonica (LJP). Comparison was firstly made among the polysaccharides prepared using different extraction media, that is water alone (LJPW) and citric acid (LJPC), sulphuric acid, hydrochloric acid and phosphoric acid. LJPC enabled the highest extract yield (~11% dry weight), bile salt adsorption rate (~59% dry weight), ABTS radical scavenging activity (IC₅₀ value 1.06 mg mL^?1) and ORAC antioxidant activity (341.87 μmol Trolox g^?1). In animal trial using diet‐induced high‐fat mice, oral administration of LJP produced with citric acid (LJPC) at a high dose (200 mg kg^?1 body mass per day) enabled significantly higher serum HDL‐C, lower LDL‐C/HDL‐C and unaltered LDL‐C, whilst a medium dose (100 mg kg^?1 body mass per day) significantly decreased LDL‐C. Administration of LJP produced with water (200 mg kg^?1 body mass per day) significantly lowered serum LDL‐C. Therefore, LJP may provide dose‐dependent pharmacological and therapeutic effects to combat atherosclerosis through their hyperlipidaemic and antioxidant properties.     

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     

Effects of dietary fibre‐ and polyphenol‐rich grape products on lipidaemia and nutritional parameters in rats

The aim of this work was to evaluate the effects of three dietary fibre‐ and polyphenol‐rich materials obtained from grapes on serum cholesterol, lipoprotein and triglyceride concentrations as well as on body weight, fat and protein digestibility in adult Wistar rats fed on cholesterol‐free and 10 g kg⁻¹ cholesterol‐added diets. Dietary fibre content of materials ranged from 540 to 590 g kg⁻¹. Intake of grape products increased stool weight and the amount of fat and protein excreted in faeces, but did not affect negatively animal growth or protein efficiency of the diet in Wistar rats. Studied grape fractions lower serum total cholesterol and LDL cholesterol concentrations in hypercholesterolemic rats. These results could be taken into account in potential applications of these products as a food ingredient. © 2000 Society of Chemical Industry     

Cornus officinalis vinegar reduces body weight and attenuates hepatic steatosis in mouse model of nonalcoholic fatty liver disease

This study aimed to determine the main bioactive components of Cornus officinalis vinegar (COV) and assess the effects of COV on the body weight (BW) and hepatic steatosis in a nonalcoholic fatty liver disease (NAFLD) mouse model. Seven-week-old KM female mice were divided into five treatment groups: (1) Normal control (NC) group, (2) high fat diet (HFD) group, (3) low concentration treatment group (3.5% COV), (4) medium concentration treatment group (5.0% COV), and (5) high concentration treatment group (6.5% COV). Mice in the NC group were fed with a normal chow diet, and those in the other four groups were fed with a HFD known for causing obesity for 10 weeks. Then, mice in the three COV treatment groups were orally administered with COV once a day for 6 weeks. Results showed that the contents of loganin and morroniside in COV reached 16.82 and 51.17 µg/ml, respectively, and COV also contained multiple organic acids. COV significantly reduced BW, abdominal fat weight, liver weight, and the levels of glucose, triglyceride, and low-density lipoprotein cholesterol of serum and increased the levels of high-density lipoprotein cholesterol of serum (p < 0.05). COV also improved the liver function and anti-oxidant activity of liver (p < 0.05). COV treatments increased the interleukin-10 expression and reduced the tumor necrosis factor-α expression in the liver tissue of NAFLD mice (p < 0.05). Histopathological observation revealed that COV suppressed hepatic lipid accumulation and steatosis. The results suggest that COV may contribute to the alleviation of NAFLD and obesity.     

虾青素对肝脂代谢与昼夜节律的调节作用

研究虾青素对非酒精性脂肪性肝病（non-alcoholic fatty liver disease,NAFLD）的干预作用及与代谢相关的昼夜节律紊乱的缓解作用。采用高脂/高胆固醇饲喂建立NAFLD小鼠模型和添加虾青素的干预模型。动物实验选用SPF级C57BL/6小鼠,随机分成正常组、高脂模型组和高脂添加虾青素组。采用常规酶联免疫吸附测定法测定血清中甘油三酯、总胆固醇（total cholesterol,TC）、高密度脂蛋白胆固醇（high density lipoprotein cholesterol,HDL-C）、低密度脂蛋白胆固醇（low density lipoprotein cholesterol,LDL-C）浓度及谷丙转氨酶（alanine aminotransferase,ALT）、谷草转氨酶（aspartate transaminase,AST）活力等肝损伤指标,苏木精-伊红染色法观察肝组织形态学变化,荧光定量聚合酶链式反应（real-time quantitative polymerase chain reaction,qPCR）检测与肝脂代谢、胆固醇代谢、昼夜节律相关的基因表达及昼夜节律变化。结果显示：与正常组相比,高脂模型组小鼠体质量、肝脏指数、肥胖指数均高度显著增加（P＜0.001）,虾青素干预后肝脏指数、肥胖指数均极显著降低（P＜0.01）。高脂饲喂导致小鼠血脂水平升高（HDL-C除外）,尤其是LDL-C浓度升高明显,而虾青素干预可以有效降低TC和LDL-C浓度,并升高HDL-C浓度,改善脂质的代谢。高脂/高胆固醇饲喂会高度显著升高小鼠血清ALT、AST活力（P＜0.001）,造成肝损伤。与高脂模型组相比,虾青素干预可极显著降低小鼠ALT、AST活力（P＜0.01）,缓解肝脏损伤,并明显改善肝脏脂质代谢关键酶的基因表达,包括脂肪酸合成酶和胆固醇合成关键酶羟甲基戊二酸单酰辅酶A还原酶。同时,虾青素干预也增加了胆固醇7α-羟化酶的表达量,促进胆固醇氧化。虾青素调节上述基因的表达具有昼夜节律性,能够缓解或修正由高脂导致的生物钟节律相关因子时钟昼夜节律调节器及脑和肌肉芳香烃受体核转运体样蛋白1以及肝脏脂质代谢关键基因昼夜节律表达的紊乱。本研究表明虾青素具有改善高脂所致肝代谢紊乱的节律性调节作用。     

Vitamin D3 regulation of body fat,cytokines, and calpain gene expression

BACKGROUND: We conducted an in vivo experiment to determine whether vitamin D₃ acts as a fat synthesizer and/or meat tenderizer in mice. At 6 weeks of age, 20 male C57BL/6 wild‐type mice were randomly divided into two groups (10 mice per group) and fed a modified AIN93G diet with (vitamin D₃ diet) or without (basal diet) 10 IU 25‐OH‐cholecalciferol kg^?3 for 3 weeks. RESULTS: When vitamin D₃ was fed to mice for 3 weeks, body fat was significantly increased compared to mice fed a basal diet. There was, however, no difference in body weight between the two groups. Vitamin D₃ increased the gene expressions of pro‐inflammatory cytokines and peroxisome proliferator‐activated receptor gamma, but decreased interleukin‐15 in adipose tissue through nuclear vitamin D receptor and uncoupling protein‐2 signals. The muscle inducible nitrate oxide synthase content of mice fed vitamin D₃ was higher than those fed a basal diet, while muscle arginase l showed a reverse phenomenon. longissimuss dorsi muscle of vitamin D₃‐fed mice showed more severe fat deposition than those fed a basal diet. Vitamin D₃ amplified muscle u‐ and m‐calpain protein content and suppressed muscle calpastatin protein content. CONCLUSION: These findings suggest that vitamin D₃ can be used as a fat synthesizer and meat tenderizer in meat‐producing animals. Copyright © 2011 Society of Chemical Industry