Antihyperglycemic activity of Momordica cymbalaria in alloxan diabetic rats

Aqueous, ethanolic and hexane fractions of Momordica cymbalaria fruits were prepared and given individually at different doses 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 h after the treatment. The aqueous extract of Momordica cymbalaria at a dosage of 0.5 g/kg b.w. is showing maximal blood glucose lowering effect in diabetic rats. The same dosage did not produce any hypoglycemic activity in normal rats. The antihyperglycemic activity of Momordica cymbalaria fruit was compared with the treatment of Glibenclamide, an oral hypoglycemic agent.     

Antidiabetic effects of Tinospora crispa in rats

In Malaysia, an aqueous extract of Tinospora crispa stems is taken orally to treat diabetes mellitus. In the present study, normal and alloxan-diabetic rats were used to evaluate the hypoglycaemic properties of the extract. A hypoglycaemic effect was observed in moderately diabetic rats with concomitant improvement in insulinaemia. After a 2-week treatment with the extract (4 g/l in the drinking water), these rats also showed improvement in glucose tolerance. Moreover, acute intravenous treatment with the extract (50 mg/kg) caused an increase in plasma insulin levels. The data support the traditional belief that T. crispa extract could improve diabetic conditions by virtue of its action on the endocrine pancreas.     

Antidiabetic and hypolipidemic activity of Helicteres isora in animal models

Helicteres isora (Sterculiaceae) root juice has been used in the treatment of diabetes by several ethnic groups in different parts of India. A program was initiated to elucidate the scientific basis for the antidiabetic activity of H. isora. Ethanolic extract of H. isora root caused significant reduction in plasma glucose, triglyceride and insulin levels at 300 mg/kg dose after 9 days of administration to insulin resistant and diabetic C57BL/KsJdb/db mice. In normoglycemic and mildly hypertriglyceridemic Swiss albino mice, the extract also showed significant reduction in plasma triglyceride and insulin levels, without affecting plasma glucose level. An ethanolic extract showed activity distinctly different from glybenclamide and acarbose but similar to troglitazone in these models. In high fat fed hamster model, the extract showed significant reduction in plasma lipid levels. In order to identify the active pharmacophore, the ethanolic extract was further subjected to sequential partitioning with low, medium and high polarity solvents, which yielded a semipurified fraction having both euglycemic and lipid-lowering activity. Our study suggests that the extract of H. isora has insulin-sensitizing and hypolipidemic activity and has the potential for use in the treatment of type-2 diabetes.     

Extra-pancreatic effects of Momordica charantia in rats

The extra pancreatic effects of the oral hypoglycaemic plant Momordica charantia have been investigated in rats. It was found that the fruit juice of this plant caused an increased glucose uptake by tissues in vitro without concomitant increase of tissue respiration. Oral treatment with the juice prior to a glucose load was found to increase the glycogen content of liver and muscle while it had no effect on the triglyceride content of adipose tissue. Pretreatment of fasted rats with M. charantia fruit juice had no significant effect on the gluconeogenic capacity of kidney slices. Similar results were obtained with kidney slices pre-incubated with M. charantia fruit juice.     

Antidiabetic activity of Terminalia pallida fruit in alloxan induced diabetic rats

Different doses of ethanolic fraction of fruits of Terminalia pallida were evaluated for hypoglycemic and antihyperglycemic activity in normal and alloxan diabetic rats. The oral administration of ethanolic extract at a dosage of 0.5 g/kg body weight exhibited a significant antihyperglycemic activity in alloxan diabetic rats, whereas in normal rats no hypoglycemic activity was observed.     

Effect of Momordica charantia fruit juice on streptozotocin-induced diabetes in rats

The oral hypoglycaemic activity of Momordica charantia fruit juice was investigated in rats with streptozotocin-induced diabetes. Oral administration of the juice (10 ml/kg for 30 days) did not show a significant effect, either acute or cumulative, on the ability to tolerate an external glucose load. The glycosylated haemoglobin concentrations were significantly elevated in both juice-treated and untreated diabetic rats and there was no significant difference between the two groups. Viable beta-cells capable of secreting insulin upon stimulation appear to be required for M. charantia to exert its oral hypoglycaemic activity.     

Hypoglycemic and hypolipidemic effects of Coriandrum sativum L. in Meriones shawi rats

Ethnopharmacological relevance

The use of an aqueous extract of coriander (Coriandrum sativum L.; Apiaceae, Umbelliferae) seeds (CS-extract) in Moroccan traditional treatment of diabetes remains to be experimentally validated.

Aim of the study

The study aim was to investigate potential hypoglycemic (and hypolipidemic) activity of CS-extract after a single oral dose and after daily dosing for 30 days (sub-chronic study) in normal and obese-hyperglycemic-hyperlipidemic (OHH) Meriones shawi rats.

Materials and methods

After a single oral dose of CS-extract (20 mg/kg; predetermined as optimum), plasma glucose, insulin, total cholesterol (TC), and triglycerides (TG) were measured in normal and OHH rats (hypercaloric diet and forced limited physical activity); glibenclamide (GLB; 2.5 mg/kg) was used as reference. In the sub-chronic study, the effect of CS-extract and GLB (at the above doses) on body weight (BW), plasma glucose, insulin, TC, LDL-cholesterol, HDL-cholesterol, TG, urea and creatinine was determined in normal and OHH rats; insulin resistance (IR as HOMA-IR), atherosclerotic and cardioprotective indices were calculated.

Results

A single dose of CS-extract or GLB suppressed hyperglycemia in OHH rats, and normo-glycemia was achieved at 6-h post-dose; there was no effect on lipids, TG or insulin, but IR decreased significantly. The hypoglycemic effect was lower in normal rats. In the sub-chronic study in OHH rats, the test substances (CS-extract > GLB) reduced plasma glucose (normoglycemia on Day 21), insulin and IR, TC, LDL-cholesterol, and TG. Atherosclerotic index decreased while cardioprotective indices increased only by CS-extract, with no effect on BW, urea or creatinine.

Conclusion

Sub-chronic administration of CS-extract in OHH Meriones shawi rats normalized glycemia and decreased the elevated levels of insulin, IR, TC, LDL-cholesterol and TG. Since, the CS-extract decreased several components of the metabolic syndrome and decreased atherosclerotic and increased cardioprotective indices, CS-extract may have cardiovascular protective effect. The present study validates the traditional use of coriander in diabetes.     

Hypoglycemic and hypolipidemic effects of rutin on hyperglycemic rats

OBJECTIVE: To study the effects of rutin on serum glucose and lipid levels in hyperglycemic rats.METHODS: Male Wistar rats were subjected to intraperitoneal streptozotocin injections and a high-sugar, high-fat diet to establish a hyperglycemic and hyperlipidemic model. The model was considered to be successfully established in rats with fasting blood sugar(FBS) ≥ 11.1 mmol/L. The study included 6 groups with 10 rats each: a blank control group, a model group, a metformin group, and groups on large, medium and small doses of rutin.The groups received intraperitoneal streptozotocin or normal saline for 21 d. FBS, serum lipids, serum insulin, insulin sensitivity index(ISI), and levels of catalase(CAT), glutathione peroxidase(GSH-Px), superoxide dismutase(SOD) and malondialdehyde(MDA) levels were evaluated in all rats. Pancreatic tissue samples were harvested to observe structural changes in islet cells.RESULTS: Large, medium, and small doses of rutin were associated with significantly reduced FBS(P 0.05), and increased levels of ISI, CAT, GSH-Px and SOD, as well as decreased MDA(P 0.05). Rutin administration was also related with reduced total cholesterol, triglycerides and low density lipoprotein chesterol, as well as increased high density lipoprotein chesterol(P 0.05). Histologic evaluation revealed rutin induced repair of damaged islet cells.CONCLUSION: In diabetic rat models, rutin can significantly reduce FBS and blood lipids, improve anti-oxidant activity, increase insulin sensitivity, and induce repair of damaged islet cells.     

Antidiabetic activity of aqueous fruit extract of Cucumis trigonus Roxb. in streptozotocin-induced-diabetic rats

Ethnopharmacological relevance

Cucumis trigonus Roxb. (Cucurbitaceae) fruit is used in the Indian traditional medicine for the treatment of diabetes. Based on a number of reports on the blood glucose level reduction and the other complications of diabetes associated with some Cucurbitaceae plants, the antidiabetic effect of Cucumis trigonus fruit was investigated.

Aim of the study

To investigate the antidiabetic action of the aqueous extract of Cucumis trigonus fruits in the different models of rats.

Materials and methods

The antidiabetic activity of aqueous extract of Cucumis trigonus fruit was evaluated by using normal and streptozotocin-induced-diabetic rats. The acute effect of aqueous extract was evaluated by administering 500 mg/kg p.o. to normoglycemic rats. In the chronic model, the aqueous extract was administered to normal and STZ-induced-diabetic rats at dose of 500 mg/kg p.o. per day for 21 days. Blood glucose levels and body weights were monitored at specific intervals and different biochemical parameters were also carried out.

Results

The statistical data indicated the significant increase in the body weight, liver glycogen and serum insulin level and decrease in the blood glucose, glycosylated hemoglobin levels, total cholesterol and serum triglycerides. HDL cholesterol level was significantly increased when treated with the extract.

Conclusion

The aqueous fruit extract of Cucumis trigonus has had beneficial effects in reducing the elevated blood glucose level and lipid profile of STZ-induced-diabetic rats.     

Subchronic oral toxicity of evodia fruit powder in rats

Ethnopharmacological relevance

Evodia, a fruit from Evodia rutaecarpa, has been used in oriental medicine, and since its various pharmaceutical actions, including anti-cancer activity, have become known, evodia has been widely used as a dietary supplement. However, information regarding its toxicity is limited.

Materials and methods

Evodia fruit from Evodia rutaecarpa (Juss.) Benth. var. officinalis (Dode) Huang (0, 25, 74, 222, 667, and 2000 mg/kg) was administered orally five times per week for 13 weeks. Clinical signs, body weight, food consumption, hematology, serum chemistry, urinalysis, vaginal cytology, sperm morphology, organ weight, and gross and histopathological findings were evaluated.

Results

Urinary ketone body excretion was detected in males at 667 and 2000 mg/kg and in females at 2000 mg/kg. An increase in absolute/relative liver weight was observed in both sexes at 2000 mg/kg. Although levels of serum alanine aminotransferase, glucose, total cholesterol, and triglycerides were significantly reduced in males and/or females at 200 and/or 667 and 2000 mg/kg, all values were within normal ranges and were considered non-adverse. In addition, no treatment-related differences in body weight, food consumption, hematology, vaginal cytology, sperm morphology, or gross and histopathological examination were detected.

Conclusions

The subchronic no-observable-adverse-effect level for evodia fruit powder following oral administration in rats is greater than 2000 mg/kg.     

Antihyperglycemic and hypolipidemic effects of Costus speciosus in alloxan induced diabetic rats

Hyperglycemia, abnormal lipid and antioxidant profiles are the most usual complications in diabetes mellitus. In the present study, the antihyperglycemic, antihyperlipemic and antioxidant potency of an ethanol extract of Costus speciosus root was investigated in alloxan-induced diabetic male (Charles Foster) rats. Four groups of alloxan diabetic rats (n = 6) were administered orally with different doses of Costus speciosus root extract (150, 300 and 450 mg/kg BW) and a standard drug, glibenclamide (600 microg/kg BW), for 4 weeks. Two groups of rats (n = 6) served as normal and diabetic controls. While the diabetic controls showed significant abnormal carbohydrate, lipid and antioxidant profiles, administration of 150 mg/kg BW dose neither improved glucose nor lipid metabolism and antioxidant levels. Administration of 300 and 450 mg/kg BW doses, however, resulted in a reversal of diabetes and its complications. Both doses significantly brought down blood glucose concentration (26.76%, 34.68%), increased glycogenesis and decreased glyconeogenesis bringing the glucose metabolism toward normalcy. These doses also reversed the hyperlipidemia by reducing plasma total lipid (12.87%, 178.24%), cholesterol (21.92%, 30.77%) and triglyceride (25.32%, 33.99%) and improved hepatic antioxidant enzyme activities. The high dose (450 mg/kg BW) was found to have more potential antioxidant activities compared with glibenclamide. It is concluded that Costus speciosus root extract possesses anti-hyperglycemic, antihyperlipemic and antioxidative effects, which may prove to be of clinical importance in the management of diabetes and its complications.     

Hypoglycemic and hypolipidemic effects of fresh leaf aqueous extract of Cymbopogon citratus Stapf. in rats

The present study was designed to investigate the hypoglycemic and hypolipidemic effects of the single, daily oral dosing of 125-500 mg/kg of fresh leaf aqueous extract of Cymbopogon citratus Stapf. (CCi) in normal, male Wistar rats for 42 days. The average weights of rats per group were taken at 2 weeks interval for 42 days. On day 43, blood samples from the rats were collected for fasting plasma glucose (FPG), total cholesterol, triglycerides, low-density lipoproteins (LDL-c), very low-density lipoprotein (VLDL-c) and high-density lipoprotein (HDL-c) assays through cardiac puncture under halothane anesthesia. Acute oral dose toxicity study of CCi was also conducted using limit dose test of the Up and Down Procedure statistical program (AOT425StatPgm, Version 1.0) at a dose of 5000 mg/kg body weight/oral route. Our results showed CCi to lower FPG and lipid parameters dose dependently (p<0.05) while raising the plasma HDL-c level (p<0.05) in same dose-related fashion but with no effect on plasma triglycerides level (p>0.05). Results of acute oral toxicity showed CCi to be of low toxicity and as such could be considered relatively safe on acute exposure. Thus, confirming its folkloric use and safety in suspected Type 2 diabetic patients.     

Antidiabetic potential of unripe Carissa carandas Linn. fruit extract

Ethnopharmacological relevance

Carissa carandas commonly known as Karanda have a long history of use in traditional system of medicine. It is used by tribal healers of Western Ghat region of Karnataka as hepatoprotective and antihyperglycemic. However, no scientific data is available to validate the folklore claim. The present study has been designed to evaluate its unripe fruit for the antidiabetic activity.

Aim

In the present study, methanol extract of unripe fruits and its fractions were studied for its antidiabetic potential.

Materials and methods

The methanol extract and its fractions were screened for antidiabetic activity in alloxan induced diabetic rats. The polyphenolic, flavonoid and flavanone contents of methanolic extract and its fractions were also determined and correlated with its antidiabetic activity.

Results

The experimental data indicated that the methanol extract and its ethyl acetate soluble fraction has significantly lowered the elevated blood glucose levels by 48% (p < 0.001) and 64.5% (p < 0.001) respectively at dose level of 400 mg/kg per oral after 24 h as compared to diabetic control. In order to assess the role of polyphenolic components in the relevant activity, polyphenolic and flavonoid contents were determined. The polyphenolic and flavonoid content of methanol extract and its ethyl acetate soluble fraction were found to be 15.8 ± 1.2 mg and 18.55 ± 0.34 mg (gallic acid equivalent/g extract) and flavonoid content 2.92 ± 0.03 mg and 1.534 ± 0.30 mg (rutin equivalent/g extract) respectively.

Conclusion

The increased antidiabetic potential of ethyl acetate fraction over methanol extract is due to its partial purification achieved by fractionation which resulted in increase in degree of polymerization and segregation of secondary metabolites.     

Antidiabetic effects of Swertia macrosperma extracts in diabetic rats

Ethnopharmacological relevance

Swertia macrosperma is a traditional folk medicine used for its anti-hepatitis, antipyretic and antidotal effects as “Dida” or “Zangyinchen” in Tibet, Yunnan and Guizhou province for a long time, and it has been reported for its anti-diabetic effects in a Chinese patent. Swertia macrosperma was reported rich in xanthones, iridoids, seco-iridoids and their glycosides, several of which had been documented as potential antidiabetic agents. The objective of this study was to investigate the antidiabetic effect of Swertia macrosperma in diabetic rats.

Materials and methods

This study was designed firstly to evaluate the effect of Swertia macrosperma on glucose consumption in HepG2 cells. Based on the result in HepG2 cells, the antidiabetic effect of ethanol extract (EE) and n-butanol extract (BE) were investigated in diabetic rats induced by high fat fed and streptozotocin. The effects of EE and BE on fasting blood glucose, oral glucose tolerance test, serum insulin, glycosylated hemoglobin, serum lipid level, serum antioxidant parameters, glucokinase, glucose-6-phosphatase activities and glycogen content in liver tissue were measured, histology examination of pancreatic tissue was also carried out.

Results

After 4 weeks treatment with EE and BE, apparently decreased fasting blood glucose concentrations were observed in these treated groups, compared with the diabetic control groups. Additionally, improvement in serum antioxidant parameters and lipid profile were evidenced clearly. Moreover, EE and BE had effects of protecting the pancreatic β-cells and stimulating insulin secretion from the remaining pancreatic β-cells, evidenced by pancreatic histology examination. Increased glucokinase activity and decreased glucose-6-phosphatase activity were observed in liver.

Conclusion

The results of in vivo and in vitro experiment suggested that EE and BE of Swertia macrosperma had excellent effects on controlling the hyperglycemia and hyperlipidemia in diabetic rats.     

Study of hypoglycaemic and hypolipidemic effects of Inula viscosa L. aqueous extract in normal and diabetic rats

The present study was designed to examine the hypoglycaemic and hypolipidemic activity of Inula viscsa aqueous extract on normal and diabetic rats. In normal rats, a significant reduction in blood glucose levels 2 h was observed after a single oral administration (p<0.001). Repeated daily oral administration significantly reduced blood glucose levels after 4 days of treatment (p<0.01). In diabetic rats, a significant reduction in blood glucose levels was observed 1 h after a single oral administration (p<0.001). Repeated oral administration reduced blood glucose levels at the 4th day (p<0.001). No change in total plasma cholesterol and triglyceride levels was observed after both a single and repeated oral administration in both normal and diabetic rats. In addition, plasma insulin levels and body weight remained unchanged after 15 days of repeated oral administration in normal and diabetic rats. We conclude that Inula viscosa possess a hypoglycaemic but not hypolipidemic activity in normal and diabetic rats. The observed hypoglycaemic activity seems to be independent of insulin secretion.     

雅安藏茶对脂质代谢紊乱大鼠减肥降脂作用研究

目的:研究雅安藏茶对脂质代谢紊乱大鼠的减肥降血脂作用。方法:建立SD大鼠脂质代谢紊乱模型,给药6周后,通过对大鼠的体重、Lee's指数、腹腔脂肪湿重、脂体比、肝体比,血清甘油三脂(TG)、总胆固醇(TC)、低密度脂蛋白胆固醇(LDLC)、高密度脂蛋白胆固醇(HDL-C)等血脂水平进行检测,并取脂肪组织和肝脏进行HE染色分析,观察雅安藏茶对其作用的影响。结果:与模型组比较,雅安藏茶(1.5 g/kg、3.0 g/kg)剂量组以及血脂康组(0.125 g/kg)对脂质代谢紊乱大鼠体重、Lee's指数、腹腔脂肪湿重、脂体比、肝体比及血脂水平,均表现为显著性下降;脂肪和肝脏组织HE观察显示,藏茶各剂量组(0.75 g/kg、1.5 g/kg和3.0 g/kg)大鼠脂肪和肝脏细胞表现为不同程度的脂肪细胞缩小和肝脏脂肪变性减轻改变。结论:雅安藏茶对脂质代谢紊乱大鼠具有减肥降血脂作用。     

Antidiabetic and adaptogenic properties of Momordica charantia extract: An experimental and clinical evaluation

The hypoglycaemic properties of Mormodica charantia (bitter gourd) water extract was tested on alloxan diabetic rats experimentally. A fall of blood sugar after 3 week's treatment with aqueous extract of fruits of the herb was found to be significant (p<0.01). The aqueous extract of fruit was more effective in diabetes (fall of blood sugar 54% after 3 week's therapy) than the powder of the dried fruit (fall 25% nonsignificant). Hypoglycaemic effects in diabetic patients were found to be highly significant (p<0.01) at the end of the trial but were cumulative and gradual, unlike that produced by insulin. Adaptogenic properties are indicated by the delay in the appearance of cataracts, the secondary complications of diabetes and relief in neurological and other common symptoms even before the hypoglycaemia occurred.     

Antidiabetic and hypocholesterolaemic effects of fenugreek

The seeds of Trigonella foenum graecum (fenugreek) have been reported to have antidiabetic and hypocholesterolaemic properties in both animal models and humans. Activity has been attributed largely to fenugreek's saponin and high fibre content, and is probably not related to its major alkaloid trigonelline. Antihyperglycaemic effects have been linked to delayed gastric emptying caused by the fibre content, and to (unidentified) components that inhibit carbohydrate digestive enzymes. Fenugreek administration may increase plasma insulin levels in vivo. Its major free amino acid, 4-hydroxyisoleucine, stimulates insulin secretion from perfused pancreas in vitro. The hypocholesterolaemic effect has been attributed to increased conversion of hepatic cholesterol to bile salts due to loss, in the faeces, of complexes of these substances with fenugreek fibre and saponins. Fenugreek treatment selectively reduces the LDL and VLDL fractions of total cholesterol, and HDL-cholesterol has also been reported to increase in alloxan-induced diabetic rats and type II diabetic individuals following treatment with fenugreek. Fenugreek administration has not been reported to cause any toxicological effects. Its regular consumption may therefore be beneficial in the management of diabetes and the prevention of atherosclerosis and coronary heart disease. © 1998 John Wiley & Sons, Ltd.     

南瓜和苦瓜的生药鉴定

目的 为南瓜和苦瓜的鉴定和开发利用提供科学依据。方法 显微鉴定和理化鉴定。结果 南瓜和苦瓜均有明显的显微和理化鉴别特征。结论 这些特征可作为南瓜和苦瓜鉴别的根据。     

Antidiabetic effect of Olea europaea L. in normal and diabetic rats

The antidiabetic effect of an alcohol extract of olive (Olea europaea L.) leaves was investigated in normal and streptozotocin-induced diabetic rats. The oral administration of the olive leaves extract (0.1, 0.25 and 0.5 g/kg body wt) for 14 days significantly decreased the serum glucose, total cholesterol, triglycerides, urea, uric acid, creatinine, aspartate amino transferase (AST) and alanine amino transferase (ALT) while it increased the serum insulin in diabetic rats but not in normal rats (p < 0.05). A comparison was made between the action of olive leaves extract and glibenclamide (600 microg/kg), a known antidiabetic drug. The antidiabetic effect of the extract was more effective than that observed with glibenclamide.