Hypoglycemic and hypolipidemic effects of aqueous extract of Arachis hypogaea in normal and alloxan-induced diabetic rats.

The hypoglycemic and hypolipidemic effect of aqueous extract of Arachis hypogaea was investigated in normal and alloxan-induced diabetic rats. The extract caused a significant (P < 0.05) decrease of fasting blood glucose of both normal and alloxan-induced diabetic rats from 102.60 +/- 1.65 mg/dl to 88.79 +/- 0.94 mg/dl for normal and 189.0 +/- 30.79 mg/dl to 107.55 +/- 1.54 mg/dl for alloxan-induced diabetic rats. The extract also caused a significant (P < 0.05) decrease in serum triglyceride, total cholesterol, HDL-cholesterol and LDL-cholesterol in both normal and alloxan-induced diabetic rats.     

沙棘籽渣水提物对正常和糖尿病小鼠血糖的影响

本文研究了沙棘籽渣水提物(Aqueous extract of seabuckthorn seed residues,ASSR)对正常及糖尿病小鼠血糖、血脂代谢的影响。首先采用ASSR灌胃昆明种小鼠的急性毒性试验评价了ASSR的安全性;继而以250mg/kg和500 mg/kg剂量的ASSR连续灌胃正常小鼠3周;以250、500和800 mg/kg剂量的ASSR连续灌胃Al-loxan诱导的糖尿病小鼠3周,监测血糖,测定体重、血清胰岛素、总胆固醇和甘油三酯水平。结果显示:ASSR的LD50大于9.8 g/kg体重;连续给药3周,ASSR对正常小鼠的血糖和血脂代谢没有明显影响,但能明显降低糖尿病小鼠的血清葡萄糖和甘油三酯水平。上述结果表明:ASSR的LD50大于5 g/kg体重,按WHO急性毒性分级标准属于实际无毒级,其在实验性1型糖尿病小鼠模型上具有降血糖和降甘油三酯活性。     

Cytoprotective and anti-diabetic effects of Derris reticulata aqueous extract

The current study was aimed to investigate pancreatic protective and anti-diabetic activities of the aqueous extract of Derris reticulata stem. First, we evaluated a cytoprotective potential of D. reticulata extract on alloxan-induced damage in vitro. Treatment with D. reticulata extract at the doses of 250 and 500 μg/ml significantly increased cell viability of the pancreatic β-cell line RINm5F after exposure of alloxan. The anti-hyperglycemic activity of D. reticulata extract was further studied in alloxan-induced diabetic rats. A significant reduction in blood glucose level along with an increase in body weight was observed in diabetic rats treated with D. reticulata extract at 250 mg/kg body weight for 15 days. Serum aspartate transaminase and alanine transaminase levels were also significantly decreased compared to diabetic control rats. In accordance with in vitro cytoprotective effect, histopathological examination revealed that pancreatic islet cells of the extract-treated diabetic rat were less damage than those of the untreated diabetic group. In order to find another possible mechanism of action underling hypoglycemic activity, the effect on glucose absorption was examined using everted sac jejunum. The results showed that D. reticulata extract suppressed glucose absorption from small intestine. To corroborate safety use of D. reticulata extract, acute oral toxicity was also conducted in rats. Our results showed that none of the tested doses (250, 500, 1,000, and 2,000 mg/kg) induced signs of toxicity or mortality after administration of the extract. The results suggested that D. reticulata extract possess anti-diabetic activity, which resulting from its pancreatic cytoprotective effect and inhibition of intestinal glucose absorption.     

Inhibition of endogenous glucose production accounts for hypoglycemic effect of Spergularia purpurea in streptozotocin mice.

The purpose of this study was to determine the underlying mechanism of the hypoglycemic activity of the aqueous extract perfusion of Spergularia purpurea (SP) in diabetic mice and streptozotocin-induced diabetic rats. The aqueous extract was administered intravenously and the blood glucose levels were determined within 4 hours after starting the treatment. Plasma insulin concentrations and endogenous glucose production were also determined. The aqueous extract at a dose of 10 mg/kg produced a significant decrease in blood glucose levels in normal rats (P < 0.05), and even more in diabetic rats (P < 0.001). This hypoglycemic effect might be due to an extra-pancreatic action of the aqueous extract of SP, since the basal plasma insulin concentrations were unchanged after SP treatment. In diabetic mice, a similar effect was observed and the results showed that aqueous extract of SP caused a potent inhibitor effect on basal endogenous glucose production (p < 0.001). We conclude that aqueous extract perfusion of SP inhibits endogenous glucose production in mice. This inhibition is at least one mechanism explaining the observed hypoglycemic activity of this plant in diabetic animals.     

Alpha-glucosidase inhibition from a Chinese medical herb (Ramulus mori) in normal and diabetic rats and mice

Alpha-glucosidase inhibitors are oral antidiabetic drugs. A traditional Chinese medical herb, Sangzhi (Ramulus mori), appears to have properties similar to those of alpha-glucosidase inhibitors. The effects of an aqueous extract of Shangzhi (SZ) were studied in normal and alloxan diabetic rats and mice, and these results compared with those for acarbose, an alpha-glucosidase inhibitor. In our grade-dose studies, SZ was found to lower and prolong the zenith of blood glucose concentration (ZBG) after sucrose or starch loading and stabilize blood glucose levels in fasting normal and alloxan diabetic mice. After 2 weeks of SZ administration with high-calorie chow or a normal diet, the fasting and non-fasting blood glucose concentrations in alloxan diabetic mice and rats were decreased. In alloxan rats, the blood fructosamine concentration was lowered. Results for acarbose and SZ were similar. These indicate that SZ has alpha-glucosidase inhibitory effects.     

Hypoglycemic and antihyperglycemic activity of Syzygium alternifolium (Wt.) Walp. seed extracts in normal and diabetic rats

Aqueous, ethanolic and hexane fractions of Syzygium alternifolium seeds were prepared and given different doses of these extracts individually to different batches of rats (both normal and alloxan diabetic rats) after an overnight fast. The blood glucose levels were measured at 0, 1, 3, 5 and 7 hours after the treatment. The aqueous extract of Syzygium alternifolium at a dosage of 0.75 g/kg b.w. is showing maximum blood glucose lowering effect in both normal and alloxan diabetic rats. The ethanol and hexane fractions are also showing hypoglycemic and antihyperglycemic activity, but the effect is significantly less than that of aqueous extract. The antihyperglycemic activity of Syzygium alternifolium seed was compared with the treatment of Glibenclamide.     

Insulin secretagogue effect of Ichnocarpus frutescence leaf extract in experimental diabetes: a dose-dependent study

Ichnocarpus frutescence (L.) R.Br. is an evergreen plant and many preparations have been used in traditional Indian medicine for centuries to treat several illnesses including diabetes. However, scientific evidence supporting these actions is lacking. In the present study we prepared various extracts of I. frutescence (IF) leaves which were tested against streptozotocin-induced diabetic rats. IF leaf methanolic extract (IFLMExt) showed significant plasma glucose lowering effect. Therefore, we prepared IFLMExt, which was tested against different types of glycemia (normal, glucose-fed hyperglycemic and streptozotocin-induced diabetic rats) for their potential to induce insulin secretion and cellular insulin responses. Fasting plasma glucose (FPG) levels were determined at different doses and times following treatment with IFLMExt or with vehicle in normal, glucose fed-hyperglycemic and diabetic rats. Oral administration of IFLMExt led to a significant blood glucose-lowering effect in glucose-fed hyperglycemic and diabetic rats. The hypoglycemic effect was observed at doses of 100 and 200 mg/(kg bw) after 6 and 2 h administration, respectively, in glucose-fed hyperglycemic rats. The maximum effect of IFLMExt was detected at 2 h with 200 mg/(kg bw) in diabetic animals and this profile was maintained for the next 6 h (37.23%) but increased after that at 24 h. Oral administration of IFLMExt daily for 45 days to diabetic rats significantly reduced the FPG (54.5%) to near normal. After 7 days of streptozotocin administration plasma insulin decreased in diabetic controls compared to normal controls. Treatment with IFLMExt significantly prevented the decrease in plasma insulin levels from day 0 to 45 in comparison to diabetic controls. Oral administration of n-hexane fraction led to a significant glucose-lowering effect in diabetic rats (54.50%). Histopathological examination showed that IFLMExt extract protected the pancreatic tissue from streptozotocin-induced damage enormously. Oral administration of IFLMExt extract and n-hexane fraction to normal and streptozotocin-induced diabetic rats decreased plasma glucose levels without hypoglycemic effect. The results suggest that methanolic extract and n-hexane fraction of IF may provide new therapeutic avenues against diabetes.     

Hypoglycemic effect of Sclerocarya birrea {(A. Rich.) Hochst.} [Anacardiaceae] stem-bark aqueous extract in rats

This study was undertaken to evaluate the hypoglycemic effect of Sclerocarya birrea [(A. Rich.) Hochst.] subspecies caffra (Sond.) Kokwaro [family: Anacardiaceae] stem-bark aqueous extract in normal (normoglycemic) and in streptozotocin (STZ)-treated, diabetic Wistar rats. In one set of experiments, graded doses of S. birrea stem-bark aqueous extract (SB, 100-800 mg/kg p.o.) were separately administered to groups of fasted normal and fasted diabetic rats. In another set of experiments, a single dose of the plant aqueous extract (SB, 800 mg/kg p.o.) was used. The hypoglycemic effect of this single dose (SB, 800 mg/kg p.o.) of S. birrea stem-bark aqueous extract was compared with that of chlorpropamide (250 mg/kg p.o.) in both fasted normal and fasted diabetic rats. Following acute treatment, relatively moderate to high doses of S. birrea stem-bark extract (SB, 100-800 mg/kg p.o.) produced dose-dependent, significant reductions (P < 0.05-0.001) in the blood glucose concentrations of both fasted normal and fasted diabetic rats. Chlorpropamide (250 mg/kg p.o.) also produced significant reductions (P < 0.05-0.001) in the blood glucose concentrations of the fasted normal and fasted diabetic rats. Administrations of the single dose of S. birrea stem-bark aqueous extract (SB, 800 mg/kg p.o.) significantly reduced (P 0.01 < 0.001) the blood glucose levels of both fasted normal (normoglycemic) and fasted STZ-treated, diabetic rats. The results of this experimental animal study indicate that aqueous extract of Sclerocarya birrea possesses hypoglycemic activity, and thus lend credence to the suggested folkloric use of the plant in the management and/or control of adult-onset, type-2 diabetes mellitus in some African communities.     

Antidiabetic effect of Cogent db,a herbal drug in alloxan-induced diabetes mellitus

Cogent db, a compound herbal drug, was investigated for its possible antidiabetic effect in alloxan-induced diabetic rats. Oral administration of 0.15, 0.30 and 0.45 g/kg body wt. of the aqueous solution of Cogent db for 40 days exhibited a significant reduction in blood glucose, glycosylated haemoglobin and increased plasma insulin, total haemoglobin along with antihyperlipidemic effects in diabetic rats. The effective dose was found to be 0.45 g/kg body wt. It also prevents body weight loss in diabetic rats. An oral glucose tolerance test (OGTT) was also performed in experimental diabetic rats in which there was a significant improvement in glucose tolerance in rats treated with Cogent db. A comparison was made between the action of Cogent db and a known antidiabetic drug — glibenclamide (600 μg/kg body wt.). The antidiabetic effect of Cogent db was more effective than that observed with glibenclamide.     

Effect of Gymnema montanum Leaves on Serum and Tissue Lipids in Alloxan Diabetic Rats

The effect of Gymnema montanum leaves on alloxaninduced hyperlipidemia was studied in male Wistar rats. Ethanolic extract of G. montanum leaves was administered orally and different doses of the extract on blood glucose, serum and tissue lipids, hexokinase, glucose-6-phosphatase, thiobarbituric acid–reactive substances (TBARS), hydroperoxides, and glutathione in alloxan-induced diabetic rats were studied. G. montanum leaf extract (GLEt) at doses of 50, 100, 200 mg/kg body weight for 3 weeks suppressed the elevated blood glucose and lipid levels in diabetic rats. GLEt at 200 mg/kg body weight was found to be comparable to glibenclamide, a reference drug. These data indicate that G. montanum represents an effective antihyperglycemic and antihyperlipidemic adjunct for the treatment of diabetes and a potential source of discovery of new orally active agent for future therapy.     

Effect of sodium molybdate on carbohydrate metabolizing enzymes in alloxan-induced diabetic rats

We evaluated the effect of sodium molybdate on carbohydrate metabolizing enzymes and mitochondrial enzymes in diabetic rats. Diabetic rats showed a significant reduction in the activities of glucose metabolising enzymes like hexokinase, glucose-6-phosphate dehydrogenase, glycogen synthase and in the level of glycogen. An elevation in the activities of aldolase, glucose-6-phosphatase, fructose 1,6- bisphosphatase, glycogen phosphorylase and in the level of blood glucose were also observed in diabetic rats when compared to control rats. The activities of mitochondrial enzymes isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, NADH-dehydrogenase and cytochrome-C-oxidase were also significantly lowered in diabetic rats. Molybdate administration to diabetic rats reversed the above changes in a significant manner. From our observations, we conclude that administration of sodium molybdate regulated the blood sugar levels in alloxan-induced diabetic rats. Sodium molybdate therapy not only maintained the blood glucose homeostasis but also altered the activities of carbohydrate metabolising enzymes. Molybdate therapy also considerably improved the activities of mitochondrial enzymes, thereby suggesting its role in mitochondrial energy production.     

老头草半仿生提取物的降血糖作用研究

本文利用尾静脉注射四氧嘧啶90mg/kg致糖尿病小鼠模型,研究了老头草半仿生提取物(LSBE)的降血糖作用,测定了LSBE对正常和糖尿病模型小鼠的血糖(Glu)、胆固醇(Chol)、甘油三酯(TG)、血清胰岛素(Ins)和胰淀粉酶(Amy)的影响。结果显示LSBE可使正常及模型小鼠血糖明显降低,并发现治疗8d后四氧嘧啶模型小鼠Ins、TG升高,Amy降低。     

Anti-diabetic activities of Acanthopanax senticosus polysaccharide (ASP) in combination with metformin

Combination therapy had become very popular currently for the diabetes mellitus and its complications, because of long term unreasonable drug use and adverse reaction to human body. In this study, a polysaccharide (ASP) from the roots of Acanthopanax senticosus was evaluated as an adjuvant with metformin for antidiabetic therapy in alloxan-induced diabetic rats. The result identified ASP plus metformin had a more beneficial promotion for relieving the symptoms of diabetes and reversing liver and kidney damage to normal level than only metfomin administration to diabetic rats. The blood glucose, blood lipid (TC and TG), thiobarbituric acid reactive substances (TBARS), AST, ALT, ALP, total bilirubin, creatinine and urea levels in diabetic rats were decreased by combination of ASP and metformin. Furthermore, the body weight, liver glycogen formation, antioxidant substance (GSH) and antioxidant enzyme (SOD and GPX) levels increased evidently in diabetic mice treated with both ASP and metformin. In particular, sometimes ASP plus metformin could significantly reverse the pathophysiologic parameters of diabetic rats to normal level than only metformin administration. Therefore ASP could be developed to a new adjuvant combined with metformin for diabetes mellitus therapy in the future.     

Protective effect of Morus rubra L. leaf extract on diet-induced atherosclerosis in diabetic rats

The antiatherosclerotic effect of aqueous leaves extract of Morus rubra was studied in streptozotocin-induced diabetic rats fed with atherosclerotic (Ath) diet [1.5 ml olive oil containing 8 mg (3, 20,000 IU) vitamin D2 and 40 mg cholesterol] for 5 consecutive days. A short-term toxicity assessment was also conducted in healthy rats to examine toxic effects of the extract. Oral administration of extract to diabetic rats (100, 200 and 400 mg/kg body weight per day for a period of 30 days) produced significant (p<0.001) fall in fasting blood glucose (FBG) in a dose-dependent manner. Treatment with the extract (400 mg/kg) showed significant (p<0.001) improvement in body weight and serum lipid profile i.e., total cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol and VLDL-cholesterol, when compared with diabetic control. Endothelial dysfunction parameters (sVCAM-1, Fibrinogen, total NO levels and oxidized LDL), apolipoprotein A and apolipoprotein B were significantly (p<0.001) reversed to near normal, following treatment with the extract. Thus, our study shows that aqueous leaf extract of Morus rubra (400 mg/kg) significantly improves the homeostasis of glucose and fat and possesses significant anti-atherosclerotic activity.     

Antihyperglycaemic activity of aqueous extract of Embelia ribes Burm in streptozotocin-induced diabetic rats

Forty days of orally feeding the aqueous E. ribes extract (100 and 200 mg/kg) to streptozotocin (40 mg/kg, iv, single dose) induced diabetic rats produced significant decrease in heart rate, systolic blood pressure, blood glucose, blood glycosylated hemoglobin, serum lactate dehydrogenase, creatine kinase and increase in blood glutathione levels as compared to pathogenic diabetic rats. Further, the extract significantly decreased the levels of pancreatic lipid peroxides and increased the levels of pancreatic superoxide dismutase, catalase and glutathione. The results suggest that aqueous E. ribes extract exhibits a significant blood glucose and blood pressure lowering potential. Further, it enhances endogenous antioxidant defense against free radicals produced under hyperglycaemic conditions, thereby, seemingly protects the pancreatic beta-cells against loss in streptozotocin induced diabetic rats.     

The Protective Effect of Vanadium Against Diabetic Cataracts in Diabetic Rat Model

The present study was designed to investigate the effect of vanadium in alloxan-induced diabetes and cataract in rats. Different doses of vanadium was administered once daily for 8 weeks to alloxan-induced diabetic rats. To know the mechanism of action of vanadium, lens malondialdehyde (MDA), protein carbonyl content, activity of superoxide dismutase (SOD), activities of aldose reductase (AR), and sorbitol levels were assayed, respectively. Supplementation of vanadium to alloxan-induced diabetic rats decreased the blood glucose levels due to hyperglycemia, inhibited the AR activity, and delayed cataract progression in a dose-dependent manner. The observed beneficial effects may be attributed to polyol pathway activation but not decreased oxidative stress. Overall, the results of this study demonstrate that vanadium could effectively reduce the alloxan-induced hyperglycemia and diabetic cataracts in rats.     

Hypoglycemic activity of a polyphenolic oligomer-rich extract of Cinnamomum parthenoxylon bark in normal and streptozotocin-induced diabetic rats

Cinnamon bark has been reported to be effective in the alleviation of diabetes through its antioxidant and insulin-potentiating activities. The water-soluble polyphenolic oligomers found in cinnamon are thought to be responsible for this biological activity. In this study, the hypoglycemic activity of a polyphenolic oligomer-rich extract from the barks of Cinnamomum parthenoxylon (Jack) Nees was studied in normal, transiently hyperglycemic, and streptozotocin (STZ)-induced diabetic rats. Oral administration of the extract at doses of 100, 200, and 300 mg/kg body wt. caused significant changes in body weight loss and fasting blood glucose levels of normal rats. In STZ-induced diabetic rats, after administration of the extract at doses of 100, 200, and 300 mg/kg body wt. over 14 days, the blood glucose levels were decreased by 11.1%, 22.5%, and 38.7%, respectively, and the plasma insulin levels were significantly increased over pre-treatment levels. In an oral glucose tolerance test, the extract produced a significant decrease in glycemia 90 min after the glucose pulse. These results suggest that Cinnamomum parthenoxylon polyphenolic oligomer-rich extract could be potentially useful for post-prandial hyperglycemia treatment.     

Antidiabetic activity of aqueous extract and non polysaccharide fraction of Cynodon dactylon Pers

Petroleum ether (60 degrees-80 degrees C), chloroform, acetone, ethanol, aqueous and crude hot water extracts of the whole plant of C. dactylon and the two fractions of aqueous extract were tested for antihyperglycaemic activity in glucose overloaded hyperglycemic rats and in alloxan induced diabetic model at two-dose levels, 200 and 400 mg/kg (po) respectively. The aqueous extract of C. dactylon and the non polysaccharide fraction of aqueous extract were found to exhibit significant antihyperglycaemic activity and only the non polysaccharide fraction was found to produce hypoglycemia in fasted normal rats. Treatment of diabetic rats with aqueous extract and non polysaccharide fraction of the plant decreased the elevated biochemical parameters, glucose, urea, creatinine, serum cholesterol, serum triglyceride, high density lipoprotein, low density lipoprotein, haemoglobin and glycosylated haemoglobin significantly. Comparatively, the non polysaccharide fraction of aqueous extract was found to be more effective than the aqueous extract.     

Hypoglycemic effect of cotton seed aqueous extract in alloxan-induced diabetes mellitus in rats

The aqueous extract of cotton seed is able to reduce blood sugar in alloxan-induced diabetes mellitus in rats. A dose of 1000 mg/kg was found to be an effective dose. Cotton seed extract was able to enhance the liver glycogen, like glibenclamid, and was also able to reduce blood cholesterol which was found raised in the diabetic state. Further it was able to normalize the altered level in the liver lipid peroxide content. The role of cotton seed aqueous extract is suggested in the lipid metabolism which is altered during diabetes mellitus.     

Angiogenic strategy for human ischemic heart disease: Brief overview

Diabetes mellitus is one of the most common endocrine diseases. In UAE many traditional plants such as the Citrullus colocynthis (Handal) are used as antidiabetic remedies. The aim of this study was to examine the effect of the aqueous extract of the seed of C. colocynthis on the biochemical parameters of normal and streptozotocin (STZ)-induced diabetic rats. Diabetes mellitus was induced by a single intraperitoneal (60 mg/kg body wt1) injection of STZ. Normal and diabetic rats were fed with the plant extract daily by oral intubation for 2 weeks. Blood sample were collected at the beginning and end of the experiment for the measurement of biochemical parameters. The plasma level of alanine aminotranferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), lactic dehydrogenase (LDH) increased significantly after the onset of diabetes. Oral administration of the plant extract reduced the plasma level of AST and LDH significantly. However, the plant extract failed to reduce the increased blood level of GGT and ALP in diabetic rats. Blood urea nitrogen (BUN) increased significantly after the onset of diabetes. No significant difference was observed in the blood creatinine, K+, Na+, Ca2+ and P levels of normal and diabetic rats. The plant extract did not have any effect on BUN level, however, it caused an increase in the level of K+, Na+ in diabetic rats. In conclusion, oral administration of the aqueous extract of the C. colocynthis can ameliorate some of the toxic effects of streptozotocin.