Food seasoning spices mixture improves glucose metabolism and lipid profile in fructose-fed hyperinsulinemic rats

Fructose feeding has been shown to induce insulin resistance in rats, associated with hyperinsulinemia, hyperglycemia, and hypertriglyceridemia. We have investigated the effect of administering food seasoning spices mixture (SM) on glucose, insulin, and lipids in circulation and carbohydrate enzymes in the erythrocytes of high fructose-fed rats. Additionally, we also measured the protein glycation status by assaying the levels of glycated hemoglobin, fructosamine, and plasma protein glycation. Male Wistar rats received a daily diet containing either 60% fructose or 60% starch (control). The rats were administered SM at three different doses (10, 30, or 50 mg/day per rat) orally 15 days later. At the end of the 45-day experimental period, fructose-fed rats showed significantly higher levels of plasma glucose and insulin, dyslipidemia, and alterations in enzyme activities. Treatment with SM significantly reduced plasma glucose and insulin levels and brought about a favorable lipid profile. In these rats, the activities of enzymes of glucose metabolism were normal. These effects were observed at all three doses of SM. High homeostasis model assessment (HOMA) values indicated insulin resistance in fructose-fed rats, while the HOMA values in SM-treated fructose-fed rats were comparable to those of control rats. We conclude that administration of SM improves glucose metabolism and plasma lipid profile in fructose-fed rats, possibly through improved insulin-sensitizing actions of the active constituents.     

Antidiabetic effect of probiotic dahi containing Lactobacillus acidophilus and Lactobacillus casei in high fructose fed rats

OBJECTIVE: We investigated the effect of low-fat (2.5%) dahi containing probiotic Lactobacillus acidophilus and Lactobacillus casei on progression of high fructose-induced type 2 diabetes in rats. METHODS: Diabetes was induced in male albino Wistar rats by feeding 21% fructose in water. The body weight, food and water intakes, fasting blood glucose, glycosylated hemoglobin, oral glucose tolerance test, plasma insulin, liver glycogen content, and blood lipid profile were recorded. The oxidative status in terms of thiobarbituric acid-reactive substances and reduced glutathione contents in liver and pancreatic tissues were also measured. RESULTS: Values for blood glucose, glycosylated hemoglobin, glucose intolerance, plasma insulin, liver glycogen, plasma total cholesterol, triacylglycerol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, and blood free fatty acids were increased significantly after 8 wk of high fructose feeding; however, the dahi-supplemented diet restricted the elevation of these parameters in comparison with the high fructose-fed control group. In contrast, high-density lipoprotein cholesterol decreased slightly and was retained in the dahi-fed group. The dahi-fed group also exhibited lower values of thiobarbituric acid-reactive substances and higher values of reduced glutathione in liver and pancreatic tissues compared with the high fructose-fed control group. CONCLUSION: The probiotic dahi-supplemented diet significantly delayed the onset of glucose intolerance, hyperglycemia, hyperinsulinemia, dyslipidemia, and oxidative stress in high fructose-induced diabetic rats, indicating a lower risk of diabetes and its complications.     

Effect of food seasoning spices mixture on biomarkers of oxidative stress in tissues of fructose-fed insulin-resistant rats

High fructose feeding in normal rats induces insulin resistance and also facilitates oxidative damage. The present study examines the effects of a spices mixture (SM) on oxidative stress markers and antioxidant potential in tissues of high fructose-fed insulin-resistant rats. Male Wistar rats received a semisynthetic diet containing either 60% fructose or 60% starch. SM administration at three different doses (10, 30, and 50 mg/day per rat) was initiated orally 15 days later and continued for the next 30 days. After the total experimental period of 45 days, peroxidation of lipids and antioxidant status in liver and kidney were quantified. Fructose-treated rats showed increased levels of peroxidation indices such as thiobarbituric acid-reactive substances and lipid hydroperoxides in tissues. The condition was associated with an inadequate antioxidant system. Administration of SM along with fructose diet reduced the levels of peroxidation markers in tissues and improved the antioxidant status. The positive effect of SM on the oxidant-antioxidant balance could be attributed to the active constituents of the different spices present in the mixture.     

Prevention of high fructose-induced metabolic syndrome in male wistar rats by aqueous extract of Tamarindus indica seed

Tamarindus indica is used as a traditional treatment for diabetes. To elucidate whether Tamarindus indica seed aqueous extract (TSE) ameliorates metabolic syndrome in hyperinsulinemic rats, we evaluated serum insulin, dehydroepiandrosterone sulfate (DHEAS), triglyceride (TG), total cholesterol (TC), very low density lipoprotein (VLDL), low density lipoprotein (LDL), high density lipoprotein (HDL), and glucose levels in fructose-fed rats. Animals were divided into three groups; control (C) receiving tap water, fructose-fed (F) and TSE-treated fructose-fed rats (F-T) both receiving tap water supplemented with 10% (w/v) fructose. Water was prepared every day for a period of 8 weeks for all three groups. F-T rats were fed with TSE via gavage feeding at the dose of 20 mg/0.5 ml distilled water/100 g body weight per day. Fasting serum glucose levels of three groups were comparable. TSE treatment prevented the increase in fasting serum insulin, TG, TC, VLDL, and LDL in the F-T group (P<0.01) when comparing with the F group. Fructose feeding led to a decrease in fasting serum DHEAS, and HDL levels in the F group (P<0.01) compared with the control. TSE treatment prevented the decrease in fasting serum DHEAS, and HDL levels in the F-T group (P<0.01) while these results were not seen in control rats. It is indicated that the hyperinsulinemia in fructose-fed insulin resistant rats are associated with low levels of DHEAS, and HDL; and high levels of TC, VLDL, LDL, and TG. TSE supplementation probably ameliorates metabolic syndrome due to the improved insulin action.     

Effects of fructose feeding on lipid parameters in obese and lean, diabetic and nondiabetic Zucker rats

Effects of fructose feeding in moderate amounts on lipid metabolism of obese versus lean, and diabetic versus nondiabetic Zucker rats, were studied. Forty pairs of male lean and obese animals were assigned to two dietary groups, fructose and glucose. For each diet, one-half of lean and obese animals were injected with streptozotocin intraperitoneally (i.p.) to induce diabetes, and the other half were injected with buffer i.p. as a nondiabetic control group. After 9 wk of feeding, animals were fasted overnight, decapitated and exsanguinated. Organs were removed and weighed. Blood glucose, insulin, lactic acid, triglycerides, cholesterol, total liver lipids and urinary glucose were determined. Hyperphagia was observed in obese, non-diabetic and lean-diabetic animals. Streptozotocin injection drastically reduced insulin levels, and produced an impairment of growth, hyperglycemia, glucosuria, polydipsia and polyuria. Fructose feeding increased organ weights in kidney, liver and retroperitoneal adipose tissue, regardless of diabetic state. However, lactic acid levels were lower in fructose-fed groups than glucose-fed groups. In obese rats serum triglyceride levels were also lower in fructose-fed groups than in glucose-fed groups. Serum cholesterol was not affected by fructose feeding. The results indicated that fructose feeding did not produce hyperlipemia and lactic acidosis in the blood circulation in Zucker rats. However, fructose feeding did not improve glucose intolerance in diabetic animals, rather fructose feeding produced hyperinsulinemia in nondiabetic, obese animals.     

Fructose and sucrose feeding during pregnancy and lactation in rats changes maternal and pup fuel metabolism

We examined the effects of feeding a fructose, sucrose or reference diet during gestation and lactation on blood substrate levels and insulin sensitivity in rat adipose tissue. Female rats were fed either 50% fructose or 50% sucrose purified diets or a nonpurified diet ad libitum during gestation and lactation. Fasting blood samples were taken on d 10 of gestation and one oral glucose tolerance test was conducted on d 19 of gestation, with a second test performed on the day of weaning. All dams were killed 2 d after weaning. During gestation, fructose feeding induced hyperglycemia and hypertriglyceridemia in early pregnancy (d 10) relative to sucrose-fed rats, and hypotriglyceridemia in late pregnancy (d 19) as compared with the group fed the reference diet. Compared with the reference group, sucrose feeding also caused hypotriglyceridemia during late pregnancy. Pups delivered to fructose-fed dams were hyperglycemic at birth. In comparison with the reference group, fructose-fed dams were hypoglycemic, whereas sucrose-fed dams were hypertriglyceridemic at weaning. There was no difference in each of the two oral glucose tolerance test responses between the three groups after adjusting for the baseline difference in glucose levels. However, lipid synthesis in isolated fat cells in response to insulin stimulation was significantly lower in fructose-fed and sucrose-fed rats relative to the reference group.     

Effects of dehulled adlay on plasma glucose and lipid concentrations in streptozotocin-induced diabetic rats fed a diet enriched in cholesterol

Adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) is a cereal food for humans and has been also used as a superior medical herb substance and functional food for traditional treatment of diabetes in China. However, its scientific basis as a functional food is still unclear. The purpose of this study was to investigate the effect of dietary dehulled adlay on plasma lipid and glucose concentrations in diabetic rats. The diabetic male Sprague-Dawley (SD) rats, induced by injection of streptozotocin (60 mg/kg subcutaneously), were fed a cholesterol-rich diet (0.5% cholesterol) containing corn starch or dehulled adlay for four weeks. After completion of the experimental period, the abdominal adipose tissue and liver of rats were excised and weighed, and the plasma glucose, triglyceride, and lipoprotein cholesterol concentrations were assayed. The results showed that diabetic rats fed a dehulled adlay diet exhibited a greater adipose tissue weight (9.36 +/- 3.43 vs. 5.39 +/- 3.04 g, p < 0.05) and a reduced food intake (39.3 +/- 5.9 vs. 61.0 +/- 11.7 g/day, p < 0.05) when compared with animals fed a cornstarch diet. Significantly decreased plasma glucose (261.6 +/- 96.6 vs. 422.1 +/- 125.4 mg/dL, p < 0.05), total cholesterol (289.4 +/- 140.6 vs. 627.3 +/- 230.5 mg/dL, p < 0.05), and triglyceride (52.3 +/- 14.4 vs. 96.5 +/- 36.6 mg/dL, p < 0.05) levels were observed in rats fed the dehulled adlay diet. In addition, the ingestion of dehulled adlay appears to significantly decrease plasma low-density lipoprotein (LDL) plus very low-density lipoprotein (VLDL) cholesterol concentrations. Rats fed a dehulled adlay diet showed an increase in fecal weight and cholesterol contents of stools. Although a significantly decreased plasma thiobarbituric reactive substances (TBARS) value was observed in diabetic rats fed the dehulled adlay diet (6.2 +/- 3.4 vs. 11.0 +/- 3.8 nmol malondialdehyde (MDA)/mL, p < 0.05), no significant difference in the hepatic TBARS value was observed between the two dietary groups. Results from the present study suggest that dehulled adlay exhibited not only a hypolipidemic effect but also displayed a hypoglycemic ability in diabetic rats, indicating that dehulled adlay may play an important role in the regulation of plasma lipid and glucose metabolisms in diabetic rats induced by streptozotocin.     

Effect of skim milk and dahi (yogurt) on blood glucose, insulin, and lipid profile in rats fed with high fructose diet

In the present study, the effect of skim milk and the fermented milk product named dahi (yogurt) on plasma glucose, insulin, and lipid levels as well as on liver glycogen and lipid contents in rats fed with high fructose diet has been investigated. Rats were fed with high fructose diet (21%) supplemented with skim milk, dahi (10 g/day each), or no milk product (control group) for 6 weeks. After 6 weeks of high fructose diet administration, the plasma glucose became significantly higher in control animals (246 mg/dL), whereas it was lower in skim milk (178 mg/dL)- and dahi (143 mg/dL)-fed rats. The glucose tolerance became impaired at the third week of feeding of high fructose diet in control animals, whereas in skim milk- and dahi-fed animals achievement of glucose intolerance was delayed until the fourth and fifth week, respectively. Blood glycosylated hemoglobin and plasma insulin were significantly lower in skim milk (10% and 34%, respectively)- and dahi (17%, and 48%, respectively)-fed animals than those of the control group. Plasma total cholesterol, triglycerides, low-density lipoprotein-cholesterol, and very-low-density lipoprotein-cholesterol and blood free fatty acids were significantly lower in skim milk (13%, 14%, 14%, 19%, and 14%, respectively)- and dahi (22%, 33%, 30%, 33%, and 29%, respectively)-fed animals as compared with control animals. Moreover, the total cholesterol, triglyceride, and glycogen contents in liver tissues were also lower in skim milk (55%, 50%, and 36%, respectively)- and dahi (64%, 27%, and 4%, respectively)-fed animals as compared with control animals. In contrast, high-density lipoprotein-cholesterol in plasma was higher in skim milk (14%)- and dahi (29%)-fed animals as compared with control animals. These results indicate that skim milk and its fermented milk product, dahi, delay the progression of fructose-induced diabetes and dyslipidemia in rats and that these may be useful as antidiabetic food supplements that can be included in daily meals of the diabetic as well as normal population.     

Effects of fructose, levamisole and vanadate on insulin action in rat adipose tissue

The effects of dietary fructose, levamisole and vanadate on insulin-stimulated conversion of D-[U-14C]glucose to 14CO2 and to 14C-labeled lipid were examined in rat epididymal adipose tissue. Male weanling rats were fed isoenergetic diets containing either 27% (wt/wt) fructose or glucose for 11 wk. During the final 4 wk, rats in each group were either untreated (control) or treated orally with 20 mg/kg body wt levamisole or 0.5 ppm vanadate via their drinking water. Basal glucose oxidation to CO2 was 45% higher in the fructose-control than in the glucose-control group. Insulin-stimulated glucose oxidation in both control groups was not higher than the basal rate in fructose-fed rats. Basal lipogenesis was 31% lower in the fructose-control than in the glucose-control group. Insulin-stimulated lipogenesis was much higher than basal, but was not different between fructose- and glucose-control groups. Levamisole increased basal lipogenesis in fructose-fed rats. Vanadate acted synergistically with fructose in greatly diminishing insulin-stimulated glucose oxidation. Fasting plasma insulin levels were lower and fasting plasma glucose and triglycerides were higher in fructose- than in glucose-fed rats, irrespective of treatment. Results suggest that adaptation to dietary fructose enhances basal oxidative capacity in an insulin-like fashion and reduces the basal lipogenic capacity of adipose tissue. Treatment with levamisole and vanadate lowers the overall rate of glucose metabolism and alters the effects of fructose.     

Substituting honey for refined carbohydrates protects rats from hypertriglyceridemic and prooxidative effects of fructose

Recent findings indicate that a high fructose diet has a prooxidant effect in rats compared with a starch diet. Because honey is rich in fructose, the aim of this study was to assess the effect of substituting honey for refined carbohydrates on lipid metabolism and oxidative stress. Rats were fed for 2 wk purified diets containing 65 g/100 g carbohydrates as wheat starch or a combination of fructose and glucose or a honey-based diet prepared by substituting honey for refined carbohydrates (n = 9/group). The same amount of fructose was provided by the honey and fructose diets. The hypertriglyceridemic effect of fructose was not observed when fructose was provided by honey. Compared with those fed starch, fructose-fed rats had a lower plasma alpha-tocopherol level, higher plasma nitrite and nitrate (NOx) levels and were less protected from lipid peroxidation as indicated by heart homogenate TBARS concentration. Compared with those fed fructose, honey-fed rats had a higher plasma alpha-tocopherol level, a higher alpha-tocopherol/triacylglycerol ratio, lower plasma NOx concentrations and a lower susceptibility of heart to lipid peroxidation. Further studies are required to identify the mechanism underlying the antioxidant effect of honey but the data suggest a potential nutritional benefit of substituting honey for fructose in the diet.     

Antihyperglycemic and hypolipidemic effects of alpha, beta-amyrin, a triterpenoid mixture from Protium heptaphyllum in mice

ABSTRACT: BACKGROUND: Pentacyclic triterpenes in general exert beneficial effects in metabolic disorders. This study investigated the effects of alpha, beta-amyrin, a pentacyclic triterpene mixture from the resin of Protium heptaphyllum on blood sugar level and lipid profile in normal and streptozotocin (STZ)-induced diabetic mice, and in mice fed on a high-fat diet (HFD). FINDINGS: Mice treated with alpha, beta-amyrin (10, 30 and 100 mg/kg, p.o.) or glibenclamide (10 mg/kg, p.o.) had significantly reduced STZ-induced increases in blood glucose (BG), total cholesterol (TC) and serum triglycerides (TGs). Unlike glibenclamide that showed significant reductions in BG, TC and TGs in normoglycemic mice, alpha, beta-amyrin did not lower normal blood sugar levels but at 100 mg/kg, manifested a hypolipidemic effect. Also, alpha, beta-amyrin effectively reduced the elevated plasma glucose levels during the oral glucose tolerance test. Moreover, the plasma insulin level and histopathological analysis of pancreas revealed the beneficial effect of alpha, beta-amyrin in the preservation of beta cell integrity. In mice treated orally with alpha, beta-amyrin (10, 30 and 100 mg/kg) or fenofibrate (200 mg/kg), the HFD-associated rise in serum TC and TGs were significantly less. The hypocholesterolemic effect of alpha, beta-amyrin appeared more prominent at 100 mg/kg with significant decreases in VLDL and LDL cholesterol and an elevation of HDL cholesterol. Besides, the atherogenic index was significantly reduced by alpha, beta-amyrin CONCLUSIONS: These findings reflect the potential antihyperglycemic and hypolipidemic effects of alpha, beta-amyrin mixture and suggest that it could be a lead compound for drug development effective in diabetes and atherosclerosis.     

Quercetin ameliorates hyperglycemia and dyslipidemia and improves antioxidant status in type 2 diabetic db/db mice

This study investigated the hypoglycemic, hypolipidemic, and antioxidant effects of dietary quercetin in an animal model of type 2 diabetes mellitus. Four-week-old C57BL/KsJ-db/db mice (n = 18) were offered an AIN-93G diet or a diet containing quercetin at 0.04% (low quercetin, LQE) or 0.08% of the diet (high quercetin, HQE) for 6 weeks after 1 week of adaptation. Plasma glucose, insulin, adiponectin, and lipid profiles, and lipid peroxidation of the liver were determined. Plasma glucose levels were significantly lower in the LQE group than in the control group, and those in the HQE group were even further reduced compared with the LQE group. The homeostasis model assessment for insulin resistance (HOMA-IR) showed lower values for LQE and HQE than for the control group without significant influence on insulin levels. High quercetin increased plasma adiponectin compared with the control group. Plasma triglycerides in the LQE and HQE groups were lower than those in the control group. Supplementation with high quercetin decreased plasma total cholesterol and increased HDL-cholesterol compared with the control group. Consumption of low and high quercetin reduced thiobarbituric acid reactive substances (TBARS) levels and elevated activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in the liver. Thus, quercetin could be effective in improving hyperglycemia, dyslipidemia, and antioxidant status in type 2 diabetes.     

Effects of dietary saturated,monounsaturated and polyunsaturated fats on plasma lipids and lipoproteins in diabetic rats*

The effects of altering the type of dietary fat on plasma lipid and lipoprotein levels were investigated in streptozotocin‐diabetic rats fed non‐purified diets containing corn oil, olive oil, cod‐liver oil, sheep tallow and lard. After 32 days of experimental feeding, plasma levels of glucose, triglycerides, total cholesterol, low density and high density lipoprotein cholesterol were determined. Body weights and food intake were also measured. In neither animal group did the type of fat in the diet affect significantly the plasma levels of lipids and lipoproteins and their calculated ratios, and plasma glucose, body weight change or accumulative food intakes. In all studied diabetic rats, significant correlations were observed between body weight change and the following plasma variables: total cholesterol level (r = —0.37, P < 0.03), low density lipoprotein cholesterol level (r = —0.38, P<0.03) and triglycéride concentration (r = —0.36, P < 0.04). A significant positive correlation (r = 0.60, P < 0.0003) was also found between plasma levels of glucose and triglycérides. No significant correlations were noticed between accumulative food intakes and any of the studied variables. It is concluded that, in uncontrolled hyperglycemia in diabetes, the type of fat in the diet exerts little or no influence on plasma lipid and lipoprotein concentrations.     

Neither dietary fructose, dextrose nor starch modifies in vitro glycerol release by adipocytes from streptozotocin-diabetic rats.

Because we found previously that fructose feeding could alter lipolytic responses to isoproterenol and insulin in normal rats, we studied the effects of the same diet in neonatal, streptozotocin-diabetic rats. Twenty-seven 5-wk-old diabetic Sprague-Dawley rats were fed a diet containing 57% carbohydrate as either fructose, dextrose or starch for 6 wk. At the end of the nutritional period, plasma glucose and insulin concentrations in fed rats were similar in the three diabetic groups. Plasma triacylglycerol concentrations were higher in the fructose-fed group than in the other two groups (P < 0.05). Neither the maximal adipocyte lipolytic response (fructose = 1147 +/- 165%, starch = 1823 +/- 329% and dextrose = 1287 +/- 239% of basal values) nor the sensitivity to isoproterenol (ED50) was changed by the dietary carbohydrate exchange. The maximal antilipolytic action of insulin (starch = 68 +/- 10%, dextrose = 41 +/- 13%, fructose = 95 +/- 29% of stimulated lipolysis values) was comparable in the three diet groups. Thus, 6 wk of fructose feeding in diabetic rats increased plasma triacylglycerol concentrations, but had no detectable effect on plasma glucose or insulin concentrations, isoproterenol-induced lipolysis or the antilipolytic action of insulin.     

Green tea supplementation ameliorates insulin resistance and increases glucose transporter IV content in a fructose-fed rat model

Summary.Background: Sprague-Dawley rats fed a fructose-rich diet exhibit insulin resistance and hypertension, a pathologic status resembling human type II diabetes mellitus, and are an excellent laboratory animal model for research on insulin action and the development of hypertension. Since green tea has numerous beneficial effects, we tested its effect on fructose-fed rats. Aim: The present study was therefore designed to further evaluate the effects of green tea supplementation on insulin resistance, hypertension, and the glucose transporters I and IV contents in adipose tissue in the fructose-fed rat model.Methods: The animals were divided into three groups and fed for 12 weeks with standard chow and water (control group), a high fructose diet and water (fructose group), or the same high fructose diet, but with green tea (0.5 g of lyophilized green tea powder dissolved in 100 mL of deionized distilled water) instead of water (fructose/green tea group). During the 12 weeks study period, fresh water or green tea was provided daily at 6:00 PM. Blood pressure was measured twice a week, and an oral glucose tolerance test performed after 12 weeks of diet supplementation.At the end of the experiment, plasma triglyceride (TG), free fatty acid (FFA), glucose, and insulin were assayed. The epididymal fat pads from all rats in the same group were pooled and adipocytes isolated and tested for insulin binding, glucose uptake, and their content of glucose transporters I (GLUT I) and IV (GLUT IV).Result: Compared to the control group, the fructose group developed fasting hyperglycemia, hyperinsulinemia, and elevated blood pressure. Insulin-stimulated glucose uptake and insulin binding of adipocytes were significantly reduced, and the glucose transporter IV content of adipocytes also decreased. The fructose/green tea group showed improvement in all of these metabolic defects and in insulin resistance and blood pressure.Conclusion: Based on these results, we suggest that the amelioration of insulin resistance by green tea is associated with the increased expression of GLUT IV.     

Lotus leaf alleviates hyperglycemia and dyslipidemia in animal model of diabetes mellitus

The purpose of this study was to investigate the effects of lotus leaf on hyperglycemia and dyslipidemia in animal model of diabetes. Inhibitory activity of ethanol extract of lotus leaf against yeast α-glucosidase was measured in vitro. The effect of lotus leaf on the postprandial increase in blood glucose levels was assessed in streptozotocin-induced diabetic rats. A starch solution (1 g/kg) with and without lotus leaf extract (500 mg/kg) was administered to the rats after an overnight fast, and postprandial plasma glucose levels were monitored. Four-week-old db/db mice were fed a basal diet or a diet containing 1% lotus leaf extract for 7 weeks after 1 week of acclimation to study the chronic effect of lotus leaf. After sacrifice, plasma glucose, insulin, triglycerides (TG), total cholesterol (CHOL), high-density lipoprotein (HDL)-CHOL, and blood glycated hemoglobin levels were measured. Lotus leaf extract inhibited α-glucosidase activity by 37.9%, which was 1.3 times stronger than inhibition by acarbose at a concentration of 0.5 mg/mL in vitro. Oral administration of lotus leaf extract significantly decreased the area under the glucose response curve by 35.1% compared with that in the control group (P < 0.01). Chronic feeding of lotus leaf extract significantly lowered plasma glucose and blood glycated hemoglobin compared with those in the control group. Lotus leaf extract significantly reduced plasma TG and total CHOL and elevated HDL-CHOL levels compared with those in the control group. Therefore, we conclude that lotus leaf is effective for controlling hyperglycemia and dyslipidemia in an animal model of diabetes mellitus.     

Hypoglycemic and hypocholesterolemic potential of Persea americana leaf extracts

The effect of aqueous and methanolic leaf extracts of Persea americana on plasma glucose, total cholesterol, low-density lipoprotein cholesterol (LDL-CHOL), and high-density lipoprotein cholesterol (HDL-CHOL) in rats was investigated. Albino rats were fed a diet containing 20% groundnut oil, 0.5% cholesterol, and 0.25% cholic acid to induce hypercholesterolemia. They were then treated daily with aqueous or methanolic extract of P. americana leaf (10 mg/kg of body weight) for 8 weeks. There were no significant (P > .05) differences in the overall body weight gain of the hypercholesterolemic rats compared to normal control. Liver to body weight ratio, plasma glucose, total cholesterol (T-CHOL), and LDL-CHOL levels were significantly (P < .05) elevated in rats fed hypercholesterolemic diet compared to normal controls. The administration of aqueous and methanolic leaf extracts of P. americana induced reductions in plasma glucose (16% and 11%,respectively), T-CHOL (8% and 5%, respectively), and LDL-CHOL (19% and 20%, respectively) in the treated rats compared to the hypercholesterolemic controls. Also, plasma HDL-CHOL concentrations increased by 85% and 68%, respectively, in the aqueous and methanolic extract-treated rats compared to the hypercholesterolemic controls. These results suggest that aqueous and methanolic leaf extracts of P. americana lower plasma glucose and influence lipid metabolism in hypercholesterolemic rats with consequent lowering of T-CHOL and LDL-CHOL and a restoration of HDL-CHOL levels. This could represent a protective mechanism against the development of atherosclerosis.     

Bone quality and strength are greater in growing male rats fed fructose compared with glucose

Optimization of peak bone mass during adolescence is important for osteoporosis prevention. Studies in rodents and humans have demonstrated the harmful effects of sugar intake on bone health. With the high levels of sucrose in the diets of adolescents, it is necessary to understand the influence of glucose and fructose on growing bones. This study compared the effects of dietary glucose and fructose on bone formation, microarchitecture, and strength. Because of the different metabolic effects of glucose and fructose, we hypothesized that their individual effects on bone would be different. Eighteen male Sprague-Dawley rats (age, 60 days) were randomly assigned to high-fructose (n = 9; 40% fructose, 10% glucose) or high-glucose diet (n = 9; 50% glucose) for 12 weeks. Bone measurements included histology and histomorphometry of trabecular bone in the distal femur and a 3-point bending test of the whole tibia. Whole liver mass and postprandial serum glucose, insulin, and triglycerides were used to assess differences in energy metabolism between the diets. There were no differences in food intake, body weight, or visceral adiposity between groups, but fructose consumption led to heavier livers (P = .001) and elevated serum triglycerides (P = .00). The distal femurs of fructose-fed rats had greater bone volume (bone volume/total volume; P = .03), lower bone surface (bone surface/bone volume; P = .02), and thicker trabeculae (trabecular thickness; P = .01). The tibias of the fructose-fed rats also withstood a greater maximum flexure load (P = .032). These results indicate that consumption of the high-fructose diet resulted in stronger bones with enhanced microarchitecture than consumption of the high-glucose diet.     

抗氧化维生素对大鼠脂代谢及清道夫受体表达的影响

目的 :　观察不同水平的 VE、VC对 SD大鼠血脂代谢、脂质过氧化和清道夫受体( SR) m RNA表达的作用。方法 :　将诱导成高脂模型的 SD雄性大鼠分为 5个组 ,分别饲以含不同剂量的 VE( 1 5 0 mg/kg diet、35 0 mg/kg diet)、VC( 1 0 0 0 mg/kg diet、2 0 0 0 mg/kg diet)高脂饲料和阳性对照组 8w。结果 :　 VE组和 VC组低剂量均可降低血清中 TC、LDL- C、致动脉粥样硬化指数 ( AI)和 Apo- B及脂质过氧化物水平 ,并可升高 HDL- C、HDL - C/LDL- C,同时能抑制肺组织SR- m RNA的表达 ;而增高 VC剂量对上述指标无显著性作用。结论 :　VE、VC能降低血清 TC与 LDL- C、抑制 LDL氧化和 SR- m RNA表达。     

Comparison of enzymatically synthesized inulin, resistant maltodextrin and clofibrate effects on biomarkers of metabolic disease in rats fed a high-fat and high-sucrose (cafeteria) diet

BACKGROUND: While naturally occurring inulin has anti-hyperlipidemic effects in animals and humans, health effects of synthetic inulin with different degrees of fructose polymerization remain poorly understood. AIM OF THE STUDY: Our study aimed at distinguishing health effects of synthetic inulin with different degrees of fructose polymerization (DP) from those of resistant maltodextrin and clofibrate. METHODS: We examined effects of synthetic inulin on serum and liver lipid profiles and blood biochemical parameters in rats fed a high-fat and high-sucrose (HF, cafeteria) diet when compared to resistant maltodextrin and clofibrate. RESULTS: Treatment with inulin (average DP = 6-8, 16-17 and 23) and resistant maltodextrin for 3 weeks reduced the elevation in liver levels of triacylglycerol and total cholesterol of rats fed the cafeteria diet but not the standard diet. In these groups, inulin (average DP = 16-17) significantly reduced the portal plasma glucose level. Moreover, the levels of portal plasma propionate and circulating serum adiponectin, which were decreased in cafeteria rats, recovered to nearly normal levels after administration of inulin (average DP = 16-17). In addition, the dietary inulin suppressed elevation in levels of portal plasma insulin and circulating serum leptin and induction of acetyl-CoA carboxylase and fatty acid synthase mRNAs in the liver of cafeteria rats, consistent with the reduction of liver lipids. The dietary inulin and clofibrate markedly reduced triacylglycerol levels in serum very low density lipoprotein (VLDL) and liver and epididymal adipose tissue weights of cafeteria rats; the extent of suppression by the dietary inulin was higher than that by clofibrate. No additive or synergistic effect of the dietary inulin and clofibrate was found in decrease in circulating serum VLDL and liver lipid levels. CONCLUSION: These observations indicate that the dietary inulin may prevent the development of metabolic disease such as hyperlipidemia and hyperinsulinemia caused by intake of cafeteria diet, in association with suppression of liver lipogenesis.