Cinnamaldehyde—A potential antidiabetic agent

Cinnamonum zeylanicum (cinnamon) is widely used in traditional system of medicine to treat diabetes in India. The present study was carried out to isolate and identify the putative antidiabetic compounds based on bioassay-guided fractionation; the compound identified decreased the plasma glucose levels. The active compound was purified by repeat column and structure of cinnamaldehyde was determined on the basis of chemical and physiochemical evidence. The LD(50) value of cinnamaldehyde was determined as 1850+/-37 mg/kg bw. Cinnamaldehyde was administered at different doses (5, 10 and 20 mg/kg bw) for 45 days to streptozotocin (STZ) (60 mg/kg bw)-induced male diabetic wistar rats. It was found that plasma glucose concentration was significantly (p<0.05) decreased in a dose-dependent manner (63.29%) compared to the control. In addition, oral administration of cinnamaldehyde (20 mg/kg bw) significantly decreased glycosylated hemoglobin (HbA(1C)), serum total cholesterol, triglyceride levels and at the same time markedly increased plasma insulin, hepatic glycogen and high-density lipoprotein-cholesterol levels. Also cinnamaldehyde restored the altered plasma enzyme (aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, alkaline phosphatase and acid phosphatase) levels to near normal. Administration of glibenclamide, a reference drug (0.6 mg/kg bw) also produced a significant (p<0.05) reduction in blood glucose concentration in STZ-induced diabetic rats. The results of this experimental study indicate that cinnamaldehyde possesses hypoglycemic and hypolipidemic effects in STZ-induced diabetic rats.     

Antihyperglycemic and antioxidant effects of a flavanone, naringenin, in streptozotocin–nicotinamide-induced experimental diabetic rats

In the present study, the putative antihyperglycemic and antioxidant effects of a flavanone, naringenin, were evaluated in comparison with those of glyclazide, a standard drug for therapy of diabetes mellitus. Diabetes was induced experimentally in 12-h-fasted rats by intraperitoneal injections of first streptozotocin (50 mg/kg b.w.) and then of nicotinamide (110 mg/kg b.w.) after a 15-min interval. Untreated diabetic rats revealed the following in comparison with normal rats: significantly higher mean levels of blood glucose and glycosylated hemoglobin, significantly lower mean levels of serum insulin, significantly lower mean activities of pancreatic antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase), significantly lower mean levels of plasma non-enzymatic antioxidants (reduced glutathione, vitamin C , vitamin E), significantly elevated mean levels of pancreatic malondialdehyde (MDA) and significantly elevated mean activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). Following oral administration of naringenin (50 mg/kg b.w./day) to diabetic rats for 21 days, the following observations were made in comparison with untreated diabetic rats: significantly lower mean levels of fasting blood glucose and glycosylated hemoglobin, significantly elevated serum insulin levels, significantly higher mean activities of pancreatic enzymatic antioxidants, significantly higher mean levels of plasma non-enzymatic antioxidants, lower mean pancreatic tissue levels of MDA and lower mean activities of ALT, AST, ALP and LDH in serum. The values obtained in the naringenin-treated animals approximated those observed in glyclazide-treated animals. Histopathological studies appeared to suggest a protective effect of naringenin on the pancreatic tissue in diabetic rats. These results suggest that naringenin exhibits antihyperglycemic and antioxidant effects in experimental diabetic rats.     

Effect of Coscinium fenestratum on hepatotoxicity in rats

Anti-hepatotoxic activity of methanol extract of Coscinium fenestratum stem (MEC) was investigated against carbon tetrachloride-induced hepatopathy in rats. Hepatotoxic rats were treated with MEC for a period of 90 days (60mg/kg body weight, daily, orally by intubation). Anti-hepatotoxic effect was studied by assaying the activities of serum marker enzymes like aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma glutamyl transpeptidase, lactate dehydrogenase etc. and glucose (6) phosphate dehydrogenase in liver. We also estimated the concentrations of total proteins, total lipids, triglycerides, phospholipids and cholesterol in serum, liver and kidney. The activities of all the marker enzymes registered a significant elevation in carbon tetrachloride-treated rats, which were significantly recovered towards an almost normal level in animals co-administered with MEC. Other biochemical changes induced by carbon tetrachloride too showed reliable signs of retrieving towards the normalcy. Histopathological analysis confirmed the biochemical investigations. This study unravels the anti-hepatotoxic activity of MEC.     

Hypoglycemic and hepatoprotective activity of Rosmarinus officinalis extract in diabetic rats

The present study examined the effect of water extract (200 mg/kg body weight) of Rosmarinus officinalis L. in streptozotocin (STZ)-induced diabetic rats for 21 days. The hepatoprotective effects were investigated in the liver tissues sections. There was a significant increase in serum liver biochemical parameters (aspartate aminotransferase, alanine transaminase, and alkaline phosphatase), accompanied by a significant decrease in the level of total protein and albumin in the STZ-induced rats when compared with that of the normal group. The high-dose treatment group (200 mg/kg body wt) significantly restored the elevated liver function enzymes near to normal. This study revealed that rosemary extracts exerted a hepatoprotective effect. The results indicate that the extract exhibits the protective effect on tissues and prove its potentials as an antidiabetic agent.     

Metabolic alterations in skeletal muscle of chronically streptozotocin-diabetic rats

This study was accomplished to determine the effects of chronic streptozotocin diabetes and insulin treatment on selected enzymes and substrates used in energy transduction in muscles composed of different muscle fiber types. Triglyceride concentration in all the muscles of diabetic rats was significantly elevated. Glycogen and protein concentrations were unchanged. The enzyme activities of hexokinase and alanine aminotransferase were significantly reduced and 3-hydroxyacyl-CoA dehydrogenase increased in all the muscles. Declines in phosphofructokinase, lactate dehydrogenase, citrate synthase, and succinate dehydrogenase activities were found in the red gastrocnemius and plantaris. Glycerol-3-phosphate dehydrogenase activity was lower than normal in the red gastrocnemius. Insulin treatment to the diabetic rats returned the altered triglyceride content and enzyme activities to normal, with exception of the lower alanine aminotransferase activity in the red gastrocnemius and plantaris. However, this enzyme was significantly ameliorated when compared with the untreated diabetic rats. The findings show that hypoinsulinism has a differential effect on the enzymatic profile of the different skeletal muscle fiber types, with those of the red gastrocnemius being most severely affected. Insulin treatment returned the enzymatic profile of the fiber types in diabetic rats to essentially normal.     

Antihyperlipidemic and antidiabetic effects of umbelliferone in streptozotocin diabetic rats

The aim of the study was to evaluate blood glucose and lipid lowering effects of Umbelliferone (UMB) in streptozotocin (STZ) diabetic rats. Male albino Wistar rats (180 to 200 g) were induced diabetes by administration of STZ (40 mg/kg) intraperitonially. Normal and diabetic rats were treated with UMB in 10 percent dimethyl sulfoxide (DMSO) for 45 days. Diabetic rats had increased plasma glucose and decreased insulin, total proteins (TP), and albumin in addition to decreased food intake and body weight. Elevation in total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), very low density lipoprotein cholesterol (VLDL-C), triglycerides (TG), free fatty acids (FFA), and phospholipids (PL), and reduction in high density lipoprotein cholesterol (HDL-C) in the plasma were observed. Liver and kidney tissues of diabetic rats had elevation in the levels of TC, TG, FFA, and PL. Treatment with UMB decreased plasma glucose and increased insulin, TP, and albumin apart from food intake and body weight. In UMB-treated diabetic rats, plasma and tissue TC, TG, PL and FFA, and plasma LDL-C, VLDL-C, and HDL-C reversed to near normal. Thus, reduction of blood glucose and lipid profiles indicates that UMB has antidiabetic and antihyperlipidemic effects in diabetic rats.     

Antidiabetic and antilipidemic effect of eremanthin from Costus speciosus (Koen.)Sm., in STZ-induced diabetic rats

The increasing prevalence of diabetes mellitus worldwide is an issue of major socio-economic concern. Diabetes mellitus is a complex and a multifarious group of disorders that disturbs the metabolism of carbohydrates, fat and protein. Medicinal plants play an important role in the management of diabetes mellitus especially in developing countries. Costus speciosus is widely used in Indian medicine to treat various diseases. Eremanthin was isolated from C. speciosus. The structure was identified using gas chromatography–mass spectrometry (GC–MS) analysis. Eremanthin was administered to streptozotocin (STZ) (50 mg/kg bw) induced diabetic male Wistar rats at different doses (5, 10, 20 mg/kg bw) for 60 days. Plasma glucose level was significantly (p < 0.05) reduced in a dose dependent manner when compared to the control. In addition, oral administration of eremanthin (20 mg/kg bw) significantly decreased glycosylated hemoglobin (HbA_1c), serum total cholesterol, triglyceride, LDL-cholesterol and at the same time markedly increased plasma insulin, tissue glycogen, HDL-cholesterol and serum protein. Eremanthin also restored the altered plasma enzyme (aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, alkaline phosphatase and acid phosphatase) levels to near normal. Results of this experimental study indicated that eremanthin possessed hypoglycemic and hypolipidemic activities and hence it could be used as a drug for treating diabetes.     

Effects of pycnogenol treatment on oxidative stress in streptozotocin-induced diabetic rats

Free radicals and oxidative stress have been implicated in the etiology of diabetes and its complications. This in vivo study has examined whether subacute administration of pycnogenol, a French pine bark extract containing procyanidins that have strong antioxidant potential, alters biomarkers of oxidative stress in normal and diabetic rats. Diabetes was induced in female Sprague-Dawley rats by a single injection of streptozotocin (90 mg/kg body weight, ip), resulting (after 30 days) in subnormal body weight, increased serum glucose concentrations, and an increase in liver weight, liver/body weight ratios, total and glycated hemoglobin, and serum aspartate aminotransferase activity. Normal and diabetic rats were treated with pycnogenol (10 mg/kg body weight/day, ip) for 14 days. Pycnogenol treatment significantly reduced blood glucose concentrations in diabetic rats. Biochemical markers for oxidative stress were assessed in the liver, kidney, and heart. Elevated hepatic catalase activity in diabetic rats was restored to normal levels after pycnogenol treatment. Additionally, diabetic rats treated with pycnogenol had significantly elevated levels of reduced glutathione and glutathione redox enzyme activities. The results demonstrate that pycnogenol alters intracellular antioxidant defense mechanisms in streptozotocin-induced diabetic rats.     

Ameliorating effect of eugenol on hyperglycemia by attenuating the key enzymes of glucose metabolism in streptozotocin-induced diabetic rats

Epidemiological studies have demonstrated that diabetes mellitus is a serious health burden for both governments and healthcare providers. This study was hypothesized to evaluate the antihyperglycemic potential of eugenol by determine the activities of key enzymes of glucose metabolism in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced into male albino Wistar rats by intraperitoneal administration of STZ (40 mg/kg body weight (b.w.)). Eugenol was administered to diabetic rats intragastrically at 2.5, 5, and 10 mg/kg b.w. for 30 days. The dose 10 mg/kg b.w. significantly reduced the levels of blood glucose and glycosylated hemoglobin (HbA1c) and increased plasma insulin level. The altered activities of the key enzymes of carbohydrate metabolism such as hexokinase, pyruvate kinase, glucose-6-phosphate dehydrogenase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, and liver marker enzymes (AST, ALT, and ALP), creatine kinase and blood urea nitrogen in serum and blood of diabetic rats were significantly reverted to near normal levels by the administration of eugenol. Further, eugenol administration to diabetic rats improved body weight and hepatic glycogen content demonstrated the antihyperglycemic potential of eugenol in diabetic rats. The present findings suggest that eugenol can potentially ameliorate key enzymes of glucose metabolism in experimental diabetes, and it is sensible to broaden the scale of use of eugenol in a trial to alleviate the adverse effects of diabetes.     

Effects of Ballota nigra on blood biochemical parameters and insulin in albino rats

Ingestion of aqueous 70% ethanol extract of Ballota nigra (400 mg/kg body weight for 7 days) by albino rats (n=10) was investigated to study its effects on glucose, total cholesterol, triglycerides, aspartate aminotransferase (AST), alanine aminotransferase (ALT), troponin I (TnI), serum creatine kinase (CK), total protein, total bilirubin and blood urea. Ballota nigra extract caused a significant decrease in blood glucose, total serum cholesterol and CK levels. Blood levels of TnI, AST, ALT, triglycerides, total bilirubin, total protein and blood urea were unchanged. The hypoglycemic effect of Ballota nigra extract on albino rats was further investigated by conducting a glucose tolerance test intraperitoneally (IPGTT). Healthy rats that were fasting for 18 hours followed by administration of a dose of 400 mg/kg body weight of the crude extract of Ballota nigra, orally. A significant decrease in blood glucose levels (after 15, 30, and 45 minutes) with a significant increase in serum insulin level (after 15 and 30 minute) was noted. These results suggest that, the crude extract of Ballota nigra have hypoglycemic, insulin-releasing and cholesterol lowering effects in rats.     

Red potato extract protects from D-galactosamine-induced liver injury in rats

The protective effects of red potato extract (RPE) as to liver damage were determined in D-galactosamine (GalN)-intoxicated rats. Increases in serum aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase activities, all of which were induced by GalN injection, decreased in RPE administered rats, suggesting that RPE acts as a functional food showing anti-hepatotoxicity.     

葛根素对2型糖尿病大鼠的治疗作用*

目的:观察葛根素对2型糖尿病(T2DM)大鼠的治疗作用。方法:采用高糖高脂饲料喂养加一次性腹腔注射60 mg/kg链脲佐菌素的方法建立T2DM 大鼠模型,随机分为正常组,模型组,二甲双胍(40 mg/kg)组,葛根素低、中、高剂量(40,80,160 mg/kg)组,每组10只大鼠;造模成功后,灌胃给药4周,每周测量大鼠体重和空腹血糖(FBG),末次给药24 h后取血,收集血清,检测各组大鼠的血糖、血清甘油三酯(TG)、总胆固醇(TC) 、低密度脂蛋白-胆固醇(LDL-C)水平、高密度脂蛋白-胆固醇(HDL-C),血清天门冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)活性,血清尿素氮(BUN)、肌酐(SCr)、尿酸(UA)水平。结果:干预4周后,与正常组比较,模型组大鼠体重显著降低(P＜0.01),FBG,TC,TG,LDL-C,ALT,AST,BUN,SCr,UA均显著升高(P＜0.01),而HDL-C 显著降低(P＜0.01);与模型组比较,二甲双胍组和葛根素各剂量组大鼠体重均显著增加(P＜0.01),FBG,TC,TG,LDL-C,ALT,AST,BUN,SCr,UA均显著降低(P＜0.01),而HDL-C显著升高(P＜0.01)。结论:葛根素能够减少T2DM大鼠体重降低幅度,降低血脂、血糖水平,可用于T2DM的治疗。     

Effect of a novel insulinotropic agent, succinic acid monoethyl ester, on lipids and lipoproteins levels in rats with streptozotocin-nicotinamide-induced type 2 diabetes

In the present study, the effect of succinic acid monoethyl ester (EMS) on the pattern of lipids and lipoproteins in streptozotocin-nicotinamide induced type 2 diabetes was investigated. Type 2 diabetes was induced in male Wistar rats by single intraperitoneal injection (i.p.) of 45 mg/kg streptozotocin, 15 min after the i.p administration of 110 mg/kg body weight of nicotinamide. The carboxylic nutrient EMS was administered intraperitonially at a dose of 8 Μmol/g body weight for 30 days. At the end of experimental period, the effect of EMS on plasma glucose, insulin, thiobarbituric acid reactive substances (TBARS) and hydroperoxide (HP) and serum triglycerides (TG), phospholipids (PL), free fatty acids (FFA), total cholesterol (TC), very low density lipoprotein-cholesterol (VLDL-C) and low density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C) and the percentage of antiatherogenic index (AAI) (ratio of HDL-C to total cholesterol) were studied. Administration of EMS to diabetic rats resulted in a signi. cant reduction in the elevated levels of plasma glucose, TBARS and hydroperoxides as well as TG, PL, FFA, TC, VLDL-C and LDC-C levels. The decreased plasma insulin and serum HDL-C and percentage of AAI in diabetic rats were also reversed towards near normal. The effect produced by EMS was compared with metformin, a reference drug. The results indicates that the administration of EMS and metformin to nicotinamide-streptozotocin diabetic rats normalized plasma glucose, insulin concentrations and caused marked improvement in altered lipids, lipoprotein and lipid peroxidation markers during diabetes. Our results show the antihyperlipidemic properties of EMS and metformin in addition to its antidiabetic action. Moreover, the antihyperlipidemic effect could represent a protective mechanism against the development of atherosclerosis.     

The Effect of Boron on Some Biochemical Parameters in Experimental Diabetic Rats

In this study, we evaluated the effect of boron (B) as boric acid (BA) on body weight (b.w.); blood glucose; plasma insulin; lipase and paraoxonase (PON1) activities; and serum triglyceride, total cholesterol, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, lipid peroxidation (MDA), and total antioxidant capacity (TAC) in streptozotocin (STZ)-induced experimental diabetes in rats. Sixty Wistar albino rats (200–250 g) were divided into six groups of ten. The groups received the following treatment: group 1, control group; group 2, 50 mg/kg (b.w.) i.p. STZ-induced diabetes; group 3, 5 mg/kg (b.w.) B; group 4, 10 mg/kg (b.w.) B; group 5, diabetes + 5 mg/kg (b.w.) B; and group 6, diabetes + 10 mg/kg (b.w.) B. The experiment lasted 4 weeks. Increased serum MDA levels with diabetes were significantly reduced and although it is not statistically significant, serum TAC levels approached to values of control group; also, insignificant increases were observed in HDL cholesterol levels in experimental diabetic rats with treatment 5 and 10 mg/kg B. Furthermore, body weight, plasma insulin, and lipase activities increased insignificantly, blood glucose and serum LDL cholesterol decreased significantly, and total cholesterol levels decreased insignificantly in the diabetes + 10 mg/kg B group. There was no difference between the groups in terms of plasma PON1 activities and serum triglyceride levels. In conclusion, B may have beneficial effects on some biochemical parameters changes in experimental diabetes, and in order to determine the full effect of this element on the metabolism, further studies are required which use various dosages and compounds of B.     

Antihypercholesterolemic and antioxidative effects of an extract of the oyster mushroom, Pleurotus ostreatus, and its major constituent, chrysin, in Triton WR-1339-induced hypercholesterolemic rats

Hypercholesterolemia and oxidative stress are known to accelerate coronary artery disease and progression of atherosclerotic lesions. In the present study, an attempt was made to evaluate the putative antihypercholesterolemic and antioxidative effects of an ethanolic extract of the oyster mushroom (Pleurotus ostreatus) and chrysin, one of its major components, in hypercholesterolemic rats. Hypercholesterolemia was induced in rats by a single intraperitoneal injection of Triton WR-1339 (300 mg/kg body weight (b.wt.)), which resulted in persistently elevated blood/serum levels of glucose, lipid profile parameters (total cholesterol, triglycerides, low-density lipoprotein-, and very low-density lipoprotein-cholesterol), and of hepatic marker enzymes (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase). In addition, lowered mean activities of hepatic antioxidant enzymes (catalase, superoxide dismutase, and glutathione peroxidase) and lowered mean levels of nonenzymatic antioxidants (reduced glutathione, vitamin C, and vitamin E) were observed. Oral administration of the mushroom extract (500 mg/kg b.wt.) and chrysin (200 mg/kg b.wt.) to hypercholesterolemic rats for 7 days resulted in a significant decrease in mean blood/serum levels of glucose, lipid profile parameters, and hepatic marker enzymes and a concomitant increase in enzymatic and nonenzymatic antioxidant parameters. The hypercholesterolemia-ameliorating effect was more pronounced in chrysin-treated rats than in extract-treated rats, being almost as effective as that of the standard lipid-lowering drug, lovastatin (10 mg/kg b.wt.). These results suggest that chrysin, a major component of the oyster mushroom extract, may protect against the hypercholesterolemia and elevated serum hepatic marker enzyme levels induced in rats injected with Triton WR-1339.     

The effect of thyroid hormones on blood insulin level and metabolic parameters in diabetic rats

The effect of exogenous thyroid hormones on blood insulin and metabolic parameters in diabetic rats was investigated. Three groups of rats were treated with streptozotocin (STZ; 50 mg/kg b.w., intravenously) and one group receiving only saline served as control. Beginning with the third day after STZ treatment, until the last day before decapitation, i.e. for 11 days, two groups of diabetic rats were treated with T3 (50 microg/kg b.w., i.p.) or T4 (250 microg/kg b.w., i.p.). After two weeks, STZ injected rats had lower body weight, hyperglycemia with a simultaneous drop in blood insulin and decrease of T3 and T4 concentrations in comparison to control animals. Liver glycogen content was also reduced, whereas serum lactate, free fatty acids, triglycerides and cholesterol were elevated. Exogenous thyroid hormones given to diabetic rats substantially attenuated hyperglycemia without any significant changes in blood insulin concentration. An additional reduction of body weight gain and depletion in liver glycogen stores were also observed. Thyroid hormones augmented serum lactate and cholesterol and had no beneficial effect on elevated free fatty acids and triglycerides. It can be concluded that in spite of partial restriction of hyperglycemia, thyroid hormones evoked several unfavourable changes strongly limiting their potential use in diabetes.     

Effect of D,L-carnitine, acetyl-D,L-beta-methylcholine chloride and glycine betaine on some processes of carbohydrate metabolism of humans and goats.

Oral administration of carnitine in normal and diabetic subjects showed a marked decrease in the level of blood glucose during the oral glucose tolerance test (OGTT) except for the three hour samples in diabetic subjects, while a decrease in the level of subsequent blood pyruvate samples was observed during the OGTT in normal and diabetic subjects after the administration of carnitine. During the OGTT, the peak of blood glucose and blood pyruvate level was generally delayed in the diabetic subjects. Furthermore, the mean blood pyruvate levels were elevated above those of normal subjects during the late stages of the test. The mean levels of blood glucose and blood pyruvate of all samples after the administration of carnitine were significantly higher in diabetics than the corresponding values in noramls. Carnitine administration decreased the total blood amino acid nitrogen level only in diabetic subjects. Carnitine caused a highly significant increase in the activity of serum alanine aminotransferase in normal and diabetic subjects, while it had no effect on the activity of serum aspartate aminotransferase. In goats, the level of blood glucose during the intravenous glucose tolerance test (IVGTT) was not affected by carnitine (1,3 or 6 mg/kg body weight). Carnitine in all doses used had no effect on the total blood amino acid nitrogen during the IVGTT, or on the activity of serum alanine aminotransferase and serum aspartate aminotransferase in the fasting samples. Acetyl-D,L-beta-methylcholine had no effect on the level of blood glucose, total blood amino acid nitrogen, the activity of serum alanine aminotransferase or serum aspartate aminotransferase in normal and diabetic subjects. The level of blood pyruvate decreased both in normal and diabetic subjects, in the samples that represented the peak of the curve. Glycine betaine had no effect on blood glucose, pyruvate, total blood amino acid nitrogen and the activity of serum alanine aminotransferase or serum aspartate amino transferase in normal and diabetic subjects or in goats.     

Hypoglycemic effect of crude exopolysaccharides produced by a medicinal mushroom Phellinus baumii in streptozotocin-induced diabetic rats

The antidiabetic effect of the crude exopolysaccharides (EPS) produced from submerged mycelial culture of Phellinus baumii in streptozotocin (STZ)-induced diabetic rats was investigated. The produced EPS consisted of two different heteropolysaccharides and two proteoglycans. The food intake of the diabetic control rats (STZ) was increased by 28.1%, whereas body weight gain was reduced by 44.1% as compared to the nondiabetic animals (NC). The plasma glucose level in the EPS-fed rats (EPS) was substantially reduced by 52.3% as compared to the diabetic rats (STZ), which is the highest hypoglycemic effect among mushroom-derived materials documented in literature. The activities of alanine aminotransferase (ALT) and asparate aminotransferase (AST) were significantly decreased by administration of P. baumii EPS, thereby exhibiting a remedial role in liver function. The significant increase in weights of liver, spleen, and kidney was observed in diabetic groups (both STZ and EPS) compared to NC. The results suggest that orally administrated P. baumii EPS exhibited considerable hypoglycemic effect in STZ-induced diabetic rats and that these EPS may be useful for the management of diabetes mellitus.     

Antihyperglycemic effect of fraxetin on hepatic key enzymes of carbohydrate metabolism in streptozotocin-induced diabetic rats

Epidemiological studies have demonstrated that the diabetes mellitus is a serious health burden for both governments and healthcare providers. The present study was hypothesized to evaluate the antihyperglycemic potential of fraxetin by determining the activities of key enzymes of carbohydrate metabolism in streptozotocin (STZ) – induced diabetic rats. Diabetes was induced in male albino Wistar rats by intraperitoneal administration of STZ (40 mg/kg b.w). Fraxetin was administered to diabetic rats intra gastrically at 20, 40, 80 mg/kg b.w for 30 days. The dose 80 mg/kg b.w, significantly reduced the levels of blood glucose and glycosylated hemoglobin (HbA1c) and increased plasma insulin level. The altered activities of the key enzymes of carbohydrate metabolism such as glucokinase, glucose-6-phosphate dehydrogenase, glucose-6-phosphatase, fructose-1,6-bisphosphatase and hepatic enzymes (aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP)) in the liver tissues of diabetic rats were significantly reverted to near normal levels by the administration of fraxetin. Further, fraxetin administration to diabetic rats improved body weight and hepatic glycogen content demonstrated its antihyperglycemic potential. The present findings suggest that fraxetin may be useful in the treatment of diabetes even though clinical studies to evaluate this possibility may be warranted.     

金耳菌丝体多糖对实验性2型糖尿病大鼠的降血糖作用研究

本文研究了金耳菌丝体多糖(TMP)对实验性2型糖尿病大鼠血糖、血脂、胰岛素敏感性和抗氧化能力的影响。采用烟酰胺,链脲佐菌素和高脂饲料诱导2型糖尿病大鼠模型,以50和100mg/(kg.d)剂量的TMP连续灌胃48d,监测血糖,测定血清胰岛素、体重、脂代谢及抗氧化系统部分相关指标,并进行口服糖耐量实验。结果显示,TMP可明显降低2型糖尿病大鼠的血清葡萄糖、总胆固醇、甘油三酯和丙二醛水平,并极显著提高受试模型鼠的胰岛素敏感指数,血清超氧化物歧化酶活性和肝脏过氧化氢酶活性。此外,TMP能显著降低糖耐量实验中糖负荷后120min时糖尿病大鼠的血糖含量。上述结果表明TMP可有效降低实验性2型糖尿病大鼠的血糖水平,纠正脂代谢紊乱,改善胰岛素抵抗,增强抗氧化能力。