茯茶水提物对Ⅱ型糖尿病小鼠糖代谢紊乱的干预作用

采用高脂高糖饲料联合链脲佐菌素诱导Ⅱ型糖尿病小鼠模型,研究茯砖茶水提物对Ⅱ型糖尿病小鼠的降糖功效。结果表明,茯茶水提取物干预能显著改善糖尿病小鼠多食、多饮、多尿、消瘦症状,降低空腹血糖浓度,提高机体对糖负荷的耐受性,提升胰岛素和胰岛素敏感水平,降低胰岛素抵抗水平。同时,q RT-PCR分析发现,茯茶水提物通过增强PPAR-α、GLUT2和GLUT4基因表达,促进了葡萄糖转运和肝脏内脂质代谢,从而改善糖尿病小鼠体内糖代谢紊乱。综上所述,茯茶能显著改善Ⅱ型糖尿病小鼠糖代谢紊乱症状,其中中、高剂量茯茶效果最为显著。     

Effect of N. sativa oil on impaired glucose tolerance and insulin insensitivity induced by high-fat-diet and turpentine-induced trauma

The aim of this study was to investigate the effect of N. sativa oil on impaired glucose tolerance and insulin insensitivity induced by high-fat diet and trauma. Three dietary groups were used in this study; Rat-Chow (RC), N. sativa oil diet (Combination 4% N. sativa oil and 16% butter oil) (NSOD) and 20% Butter Oil Diet (BOD). Each group was subdivided in two groups; control and trauma. Diets were supplemented for five consecutive weeks body weight increase per week was calculated. At end of the dietary treatments, single dose (2 mL kg(-1) body weight) of turpentine was injected in the dorso-lumber region. Intravenous glucose tolerance test (i.v. GTT) was performed, insulinogenic index and insulin sensitivity was measured. The results showed butter oil diet significantly increased the body weights and visceral fats compared other two groups, respectively. Fasting glucose levels did not change in trauma induced rats while insulin levels increased significantly and it found highest in butter oil diet fed animals. Impaired glucose tolerance was found sever in BOD fed traumatized rats. N. sativa oil diet protected impaired glucose tolerance and insulin insensitivity induced either via saturated fatty acids or injury. In conclusion, N. sativa oil may be used in post surgery diabetic patients to prevent the long going adverse effects from surgical trauma.     

Fucoxanthinol,Metabolite of Fucoxanthin,Improves Obesity-Induced Inflammation in Adipocyte Cells

Fucoxanthin (Fx) is a marine carotenoid found in edible brown seaweeds. We previously reported that dietary Fx metabolite into fucoxanthinol (FxOH), attenuates the weight gain of white adipose tissue of diabetic/obese KK-A^y mice. In this study, to evaluate anti-diabetic effects of Fx, we investigated improving the effect of insulin resistance on the diabetic model of KK-A^y mice. Furthermore, preventing the effect of FxOH on low-grade chronic inflammation related to oxidative stress was evaluated on 3T3-L1 adipocyte cells and a RAW264.7 macrophage cell co-culture system. A diet containing 0.1% Fx was fed to diabetic model KK-A^y mice for three weeks, then glucose tolerance was observed. Fx diet significantly improved glucose tolerance compared with the control diet group. In in vitro studies, FxOH showed suppressed tumor necrosis factor-α (TNF-α), and monocyte chemotactic protein-1 (MCP-1) mRNA expression and protein levels in a co-culture of adipocyte and macrophage cells. These findings suggest that Fx ameliorates glucose tolerance in the diabetic model mice. Furthermore, FxOH, a metabolite of Fx, suppresses low-grade chronic inflammation in adipocyte cells.     

Growth,hormonal status and protein turnover in rats fed on a diet containing peas (Pisum sativum L.) as the source of protein

The inclusion of peas (Pisum sativum L.) as the source of protein in the diet of growing rats brings about a reduction in growth rate as well as the impairment in the liver, muscle and spleen weights as compared with casein fed controls. Also, a fall in plasma glucose, triglycerides and protein was observed in the legume fed animals, while no changes in cholesterol levels were found. Furthermore, the rats fed on the diet containing peas showed lower levels of plasma insulin, corticosterone, IGF-I and T₄ as compared with casein controls. Liver and muscle total protein (mg) and total DNA (mg) were markedly decreased in the legume fed animals, but DNA/g, protein/DNA and RNA/protein ratios were similar in both dietary groups. Likewise, liver and muscle fractional synthesis rates were similar in the casein and legume groups, while the whole body protein synthesis is assumed to be lower in the legume fed animals due to differences in body weights. It is concluded that animals fed on a diet containing peas (Pisum sativum L.) as the only source of protein showed less adverse effects than those found with other legumes such asVicia faba L. orPhaseolus vulgaris L., in which protein quality, antinutritional factors and nutrient availability could be involved.     

Chitosan Oligosaccharide Alleviates Abnormal Glucose Metabolism without Inhibition of Hepatic Lipid Accumulation in a High-Fat Diet/Streptozotocin-Induced Diabetic Rat Model

This study investigated the effects of chitosan oligosaccharide (COS) on glucose metabolism and hepatic steatosis in a high-fat (HF) diet/streptozotocin-induced diabetic rat model. Male Wistar rats were divided into: (1) normal control (NC group), (2) HF diet (HF group), (3) streptozotocin (STZ)-induced diabetes with HF diet (DF group), and DF group supplemented with (4) 0.5% COS (D0.5F group), (5) 1% COS (D1F group), and (6) 5% COS (D5F group) for 4 weeks. COS supplementation significantly decreased the plasma glucose, BUN, creatinine, uric acid, triglyceride (TG), and total cholesterol (TC) levels, and hepatic glucose-6-phosphatase activity, and significantly increased hepatic hexokinase activity and glycogen content in diabetic rats; but the increased hepatic TG and TC levels could not be significantly decreased by COS supplementation. Supplementation of COS increased superoxide dismutase activity and decreased lipid peroxidation products in the diabetic rat livers. COS supplementation significantly increased phosphorylated AMP-activated protein kinase (AMPK) protein expression, and attenuated protein expression of hepatic phosphoenolpyruvate carboxykinase (PEPCK) and phosphorylated p38 and renal sodium-glucose cotransporter-2 (SGLT2) in diabetic rats. These results suggest that COS may possess a potential for alleviating abnormal glucose metabolism in diabetic rats through the inhibition of hepatic gluconeogenesis and lipid peroxidation and renal SGLT2 expression.     

Effect of supplementation of blue green alga (Spirulina) on outcome of pregnancy in rats

To study the supplementary effect of Spirulina, pregnant rats were fed 5 different kinds of diets (casein, Spirulina, wheat gluten, Spirulina + wheat gluten, Spirulina-without additional vitamins and minerals), each providing 22% protein during the period of pregnancy. The outcome of pregnancy was assessed from litter and dams' weight and litter size. Maternal weight gain was found to be maximum with Spirulina + wheat gluten and least with the wheat gluten diet. Rats receiving Spirulina containing diets produced significantly (p<0.05) higher litter size than those receiving casein and wheat gluten. In spite of having higher litter size, Spirulina containing diet groups produced pups with birth weights comparable to those of casein. Spirulina appears to be a good dietary supplement during pregnancy.     

Iodine metabolism and tissue mineral levels in rats fed rapeseed protein concentrates supplemented with zinc

A 16-week feeding test of Tower (Brassica napus) and Span (Brassica campestris) rapeseed protein concentrates (RPC) was carried out on male and female Charles River CD (Sprague-Dawley) weanling rats. The diets contained 10% or 20% protein (N × 6.25) from each RPC and were supplemented with 150 mg zinc/kg. The control groups received a purified diet with casein or a laboratory chow diet. The results of the test diet groups did not reveal any adverse effect due to RPC on thyroid metabolism or the metabolism of zinc iron, copper, manganese, calcium, phosphorus, and magnesium. Nephrocalcinosis was observed in all female rats that were fed the test diets and the casein control diet, and therefore it could not be attributed to dietary RPC.Bureau of Nutritional Sciences, no. 120. Food Research Institute, no. 448.     

Starchy legumes in human nutrition,health and culture

Starchy legumes have been consumed by humans since the earliest practice of agriculture and have been ascribed medicinal and cultural as well as nutritional roles. They are an important component of the diet in the developing countries in Africa, Latin America, and Asia where they are especially valuable as a source of dietary protein to complement cereals, starchy roots and tubers. Legumes contain 20–30% protein which is generally rich in lysine and limiting in sulfur amino acids. The nutritional quality of legume protein is limited by the presence of both heat labile and heat stable antinutrients as well as an inherent resistance to digestion of the major globulins. In addition to its nutritional impact, legume protein has been shown to reduce plasma low density lipoprotein when consumed. Legume starch is more slowly digested than starch from cereals and tubers and produces less abrupt changes in plasma glucose and insulin upon ingestion. Starchy legumes are also valuable sources of dietary fiber as well as thiamin and riboflavin. Starchy legumes are a valuable component of a prudent diet, but their consumption is constrained by low yields, the lack of convenient food applications, and flatulence.     

Nutrient composition and biological evaluation of mesta (Hibiscus sabdariffa) seeds

Two varieties of mesta (Hibiscus sabdariffa) seeds were analysed for their proximate composition. Their protein (18.8–22.3%), fat (19.1–22.8%) and dietary fiber (39.5–42.6%) contents were found to be high. The seeds were found to be a good source of minerals like phosphorus, magnesium and calcium. Their lysine and tryptophan contents were also high. Sulphur containing amino acids were limiting in this seed protein and the chemical score of mesta seed protein was 40 and 57 for AMV-2 and Bhimili-1 varieties respectively. Mesta seed oil is rich in unsaturated fatty acids (70%), of which linoleic acid constituted 44%. Weanling rats were fed with 10% mesta seed protein before and after cooking for 4 weeks. Food intake of animals receiving raw mesta seed diets was significantly lower than those receiving cooked mesta seed diets as well as the casein control diet. Protein and dry matter digestibilities of raw and cooked mesta seed diets were lower than that of casein control diet. Cooking improved the food intake, gain in body weight, dry matter and protein digestibility of mesta seed diets. PER and NPU of cooked mesta seed diets were significantly higher than the corresponding raw diets. These results indicate that cooked mesta seed protein is of relatively good quality.     

β-Carotene from the Alga Dunaliella bardawil Decreases Gene Expression of Adipose Tissue Macrophage Recruitment Markers and Plasma Lipid Concentrations in Mice Fed a High-Fat Diet

Vitamin A and provitamin A carotenoids are involved in the regulation of adipose tissue metabolism and inflammation. We examined the effect of dietary supplementation using all-trans and 9-cis β-carotene-rich Dunaliella bardawil alga as the sole source of vitamin A on obesity-associated comorbidities and adipose tissue dysfunction in a diet-induced obesity mouse model. Three-week-old male mice (C57BL/6) were randomly allocated into two groups and fed a high-fat, vitamin A-deficient diet supplemented with either vitamin A (HFD) or β-carotene (BC) (HFD-BC). Vitamin A levels in the liver, WATs, and BAT of the HFD-BC group were 1.5–2.4-fold higher than of the HFD group. BC concentrations were 5–6-fold greater in BAT compared to WAT in the HFD-BC group. The eWAT mRNA levels of the Mcp-1 and Cd68 were 1.6- and 2.1-fold lower, respectively, and the plasma cholesterol and triglyceride concentrations were 30% and 28% lower in the HFD-BC group compared with the HFD group. Dietary BC can be the exclusive vitamin A source in mice fed a high-fat diet, as shown by the vitamin A concentration in the plasma and tissues. Feeding BC rather than vitamin A reduces adipose tissue macrophage recruitment markers and plasma lipid concentrations.     

Corrective role of chickpea intake on a dietary-induced model of hypercholesterolemia

A feeding trial was conducted in order to evaluate the potential effect on the lipid profile in a experimentally induced situation of hypercholesterolemia of a previously uninvestigated legume (Cicer aretinum L.) widely included in Mediterranean and Latinamerican human diets. Rats fed on a hypercholesterolemic diet containing saturated fat, cholesterol and cholic acid (H) had 123 percent higher serum cholesterol and 62 percent greater triacylglycerols levels than the animals receiving casein (C) protein. The LDL and VLDL cholesterol levels were 1330 percent and 35 percent higher, respectively, and HDL cholesterol 34 percent lower in the group of animals given the H diet as compared to controls. Further feeding of the hypercholesterolemic rats with animal protein (HC) resulted in a significant decrease of triacylglycerols (–70 percent), which reflected the decrease in the VLDL fraction. These effects on the lipid metabolism were more marked when the legumeCicer aretinum L. was present in the diet (HL). Significantly decreased concentrations of total cholesterol (–54 percent) and triacylglycerols (–70 percent) as well as the levels of LDL (–54 percent) and VLDL (–70 percent) were seen in rats fed chickpeas. In conclusion, a differential hypocholesterolemic effect between dietary casein and chickpea intake in a model of hypercholesterolemia induced by the diet was found, with beneficial effects on the lipid metabolism when legume was included in the diet as compared to casein. This suggests, for apparently the first time, that chickpea consumption may have a corrective effect in some alterations of the lipid profile.Abbreviations ANF Antinutritional factors - CD Cardiovascular disease - C Casein diet (Control diet) - H Hypercholesterolemic diet - L Legume diet - SD standard deviation     

Effect of Anthocyanin-Rich Extract from Black Rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L. <Emphasis Type="Italic">indica</Emphasis>) on Hyperlipidemia and Insulin Resistance in Fructose-Fed Rats

This study was designed to evaluate the effect of an anthocyanin-rich extract from black rice on hyperlipidemia and insulin resistance in fructose-fed rats. Rats fed fructose diet for 4 weeks exhibited significantly higher plasma insulin levels and lower insulin sensitivity than the control rats fed AIN-93G diet. Dietary supplementation with the anthocyanin-rich extract (5 g/kg of high-fructose diet) prevented the development of fructose-induced insulin resistance. After fructose-induced insulin resistance had been established, 4-week treatment with the anthocyanin-rich extract (5 g/kg of high-fructose diet) or pioglitazone (270 mg/kg of high-fructose diet) ameliorated the glucose intolerance and hyperlipidemia, but the extract failed to reverse the fructose-induced hyperinsulinemia as pioglitazone did. In addition, rats supplemented by the extract exhibited lower oxidative stress than the fructose-fed controls, as indicated by the lower concentrations of plasma thiobarbituric acid reactive substances and blood oxidized glutathione. Overall, these results suggest that the anthocyanin-rich extract from black rice improves certain metabolic abnormalities associated with diets high in fructose.     

Growth,blood chemistry and histology of rats fed zincsupplemented rapeseed protein concentrates

Two rapeseed protein concentrates (RPC) supplemented with zinc oxide were fed to male and female rats at two levels providing approximately half or all of the protein in a purified basal diet containing 20% protein (N×6.25). Control groups were given either a purified basal diet with casein or a laboratory chow diet. After 16 weeks, there were no significant (P<0.05) differences in body weight except the male rats fed the casein control diet had higher body weights than did other male rats. No significant differences were observed in organ weights including thyroids, hematology, bone marrow differential counts, serum glucose, urea nitrogen, total protein, albumin/globulin ratio, cholesterol, transaminases or alkaline phosphatase. The levels of serum vitamins A and E of females fed some of the RPC diets were less than in those fed the caseincontrol diet, but equal to those in females fed laboratory chow diet. Females fed either RPC or casein in the semi-purified diets, which contained zinc oxide, exhibited kidney calcification.Bureau of Nutritional Sciences, No. 112; Food Research Institute, No. 420.     

普洱茶中没食子酸及其改善饮食诱导的糖脂代谢紊乱研究进展

糖脂代谢紊乱是引发心血管疾病、糖尿病和脂肪肝的重要原因之一。普洱茶中的没食子酸能够通过调节能量代谢和脂肪细胞分化、促进葡萄糖吸收与利用、提高胰岛素敏感性,进而改善饮食诱导引起的葡萄糖和脂质代谢紊乱。没食子酸通过AMPK途径、IR-Akt途径以及PPAR-γ受体调节线粒体能量代谢、胰岛素敏感性和葡萄糖吸收,从而维持糖脂代谢稳态。本文综述了普洱茶中的没食子酸及其改善饮食诱导的糖脂代谢紊乱作用和作用机制的研究进展。     

The USDA trypsin inhibitor study. IV. The chronic effects of soy flour and soy protein isolate on the pancreas in rats after two years

In two year feeding trials, histologic changes in the pancreas of the Wistar rat were evaluated after chronic dietary exposure to raw and heated, dehulled, defatted soy flour and soy protein isolates which provided a range of trypsin inhibitor (TI) concentrations from 93 to 1271 mg/100 g diet. Also investigated was the nutritional interaction of level of dietary protein with the development of pancreatic pathology. Graded levels of TI were achieved from mixtures of raw and heated soy flour or protein isolate. Dietary protein levels were 10%, 20%, and 30%; the two higher levels obtained in some diets through casein supplementation. A total of 26 diets, including casein controls, were fed to groups of 40 male rats. Growth rates with these diets were commensurate with protein quality and level. Mortality rates tended to be slightly greater in the higher protein diets, and rats fed only raw soy as a source of protein survived well.Two lesions, nodular hyperplasia (NH) and acinar adenoma (AA) constituted the major pathological findings in the pancreas, and the incidence rates of both were positively associated with the concentration of dietary TI. The incidences of pancreatic NH and AA compared to those of the corresponding casein control were significantly elevated in rats fed heated soy flour supplying 10% protein and the lowest level of TI investigated (93 mg/100 g diet). At low levels of TI (215 mg/100 g diet), supplementation by casein to raise the concentration of protein from 10% to 20% and 30% reduced the frequency of NH and AA. When the dose-response data for NH and AA was linearized by plotting the probit of percent incidence against log of TI concentration per gram of dietary protein, the response to soy flour and soy protein isolate was not significantly different. Numerous lesions commonly found in the aging rat were diagnosed, and modulation of their rate of occurrence by nutritional factors associated with the diets was apparent in some instances.Reference to a company and/or product named by the Department is only for purposes of information and does not imply approval or recommendation of the product to the exclusion of others which may also be suitable.     

Study on the Mechanism of the Blood-Glucose-Lowering Effect of Collagen Peptides from Sturgeon By-Products

In a previous study, we found that the collagen peptides prepared from the by-products of Bester sturgeon had an inhibitory effect on elevated blood glucose levels in a glucose tolerance test with ICR mice. In the present study, we examine the mechanism of the effect of sturgeon collagen peptides (SCPs) in detail. When glucose was orally administered to mice along with the SCPs, it was found that the glucose remained in the stomach for a longer time. In the above tests, the amount of glucose excreted in the feces of mice also increased. On the contrary, it was revealed that the SCPs have a dipeptidyl-peptidase-IV (DPP-IV) inhibitory ability in an in vitro test. In subsequent oral and intravenous glucose administration tests, glucagon-like peptide-1 (GLP-1) and insulin levels in the blood of mice were maintained at high levels. These results suggested the following three mechanisms: SCPs slow the rate of transportation of glucose from the stomach into the small intestine, resulting in delayed glucose absorption; SCPs suppress the absorption of glucose in the small intestine and excrete it from the body; SCPs inhibit DPP-IV in the blood and maintain a high GLP-1 level in blood, which in turn stimulates insulin secretion.     

Differential roles of breakfast only (one meal per day) and a bigger breakfast with a small dinner (two meals per day) in mice fed a high-fat diet with regard to induced obesity and lipid metabolism

Background

Recent studies on humans and rodents have suggested that the timing of food intake plays an important role in circadian regulation and metabolic health. Consumption of high-fat foods during the inactive period or at the end of the awake period results in weight gain and metabolic syndrome in rodents. However, the distinct effects of breakfast size and the breakfast/dinner size ratio on metabolic health have not yet been fully examined in mice.

Methods

We examined whether the parameters of metabolic syndrome were differentially affected in mice that consumed a large meal at the beginning of the awake period (breakfast; one meal group) and a relatively smaller meal at end of the awake period (dinner; two meals group). The mice of each group were provided equal food volume per day.

Results

Mice on one meal exhibited an increase in body weight gain, hyperinsulinemia, hyperleptinemia, and a decrease of gene expression associated with ??-oxidation in adipose tissue and liver compared with those on two meals. The circadian expression pattern of the Clock gene in mice on one meal was disturbed compared with those on two meals.

Conclusions

In conclusion, a bigger breakfast with a smaller dinner (two meals per day) but not breakfast only (one meal per day) helps control body weight and fat accumulation in mice on a high-fat meals schedule. The findings of this study suggest that dietary recommendations for weight reduction and/or maintenance should include information on the timing and quantity of dietary intake.     

Anti-Obese Effect of Glucosamine and Chitosan Oligosaccharide in High-Fat Diet-Induced Obese Rats

Objective: This study is to evaluate the anti-obese effects of glucosamine (GLC) and chitosan oligosaccharide (COS) on high-fat diet-induced obese rats. Methods: The rats were randomly divided into twelve groups: a normal diet group (NF), a high-fat diet group (HF), Orlistat group, GLC high-, middle-, and low-dose groups (GLC-H, GLC-M, GLC-L), COS1 (COS, number-average molecular weight ≤1000) high-, middle-, and low-dose groups (COS1-H, COS1-M, COS1-L), and COS2 (COS, number-average molecular weight ≤3000) high-, middle-, and low-dose groups (COS2-H, COS2-M, COS2-L). All groups received oral treatment by gavage once daily for a period of six weeks. Results: Rats fed with COS1 gained the least weight among all the groups (P < 0.01), and these rats lost more weight than those treated with Orlistat. In addition to the COS2-H and Orlistat groups, the serum total cholesterol (CHO) and low-density lipoprotein cholesterol (LDL-C) levels were significantly reduced in all treatment groups compared to the HF group (P < 0.01). The various doses of GLC, COS1 and COS2 reduced the expression levels of PPARγ and LXRα mRNA in the white adipose tissue. Conclusions: The results above demonstrated that GLC, COS1, and COS2 improved dyslipidemia and prevented body weight gains by inhibiting the adipocyte differentiation in obese rats induced by a high-fat diet. Thus, these agents may potentially be used to treat obesity.     

Partial replacement of dietary casein with soy protein isolate can reduce the severity of retinoid-induced hypertriglyceridemia

Previous research carried out in an animal model of retinoid-induced hypertriglyceridemia – rats fet a 13-cis retinoic acid (13cRA)-containing diet having casein as the protein source – has demonstrated that the complete replacement of dietary casein with soy protein isolate (SPI) can decrease the severity of this condition. In this study, the effect of partially replacing dietary casein with SPI was investigated. Five groups of male Fischer 344 rats were used in a 14-day study, with two groups being fed diets having casein as the protein source, without or with 13cRA (groups A and B, respectively), and three groups being fed 13cRA-containing diets in which SPI was used to bring about the isonitrogenous replacement of 25, 50, or 100% of the casein in the formula for the diet used for group B (groups C-E, respectively). Serum triglyceride concentration for group B was significantly different ( p < 0.05) from that of groups A, D, and E (5.41 vs 2.62, 4.04, and 2.66 mmol/l, respectively). Serum cholesterol concentrations for groups D and E were significantly lower ( p < 0.05) than for groups A and B (1.63 and 1.60 vs 2.00 and 2.14 mmol/l, respectively). Thus, the isonitrogenous replacement of 50% of dietary casein with SPI can reduce the severity of retinoid-induced hypertriglyceridemia while decreasing the serum concentration of cholesterol.