Hypoglycemic effects of Cecropia pachystachya in normal and alloxan-induced diabetic rats

Ethnopharmacological relevance

Leaves of Cecropia pachystachya are described in the folk medicine as possessing antitusive, expectorant, antiasthmatic and hypoglycemic effects.

Aim of the study

To investigate the hypoglycemic and antioxidant effects of methanolic extract from the leaves of Cecropia pachystachya. The total amount of phenolic and flavonoids compounds was determined and the qualitative composition of the extract was analyzed.

Materials and methods

The hypoglycemic effect of the extract was tested in normal, glucose loading and alloxan-induced diabetic rats. The antioxidant activity was assessed by DPPH free radical scavenging and reduction power assays. The total amount of phenolic and flavonoids compounds was determined by Folin-Denis and AlCl₃ reagent method, respectively. The qualitative composition of the extract was analyzed using a HPLC-DAD system.

Results

The glucose tolerance test showed that in diabetic rats, the extract caused a significant hypoglycemic effect with a blood glucose reduction of 68% after 12 h. The administration of the extract in alloxan-induced diabetic rats also produced a significant reduction in the blood glucose levels at all points being more pronounced at 90 min (reduction of 60%). After 120 min, no significant difference was observed between the blood levels of the rats treated with the extract and those treated with the standard drugs (metformin and glibenclamide). The extract also presented relevant antioxidant activity with IC₅₀ = 3.1 μg/ml (DPPH assay) and EC₅₀ = 10.8 μg/ml (reduction power). Results were compared with the reference antioxidants quercetin, rutin, and ascorbic acid. The content of flavonoids was 83 mg/g plant and that of phenolics was 326 mg/g plant. Chlorogenic acid and the C-glycosylated flavones, orientin and isoorientin, were identified in the extract.

Conclusions

In conclusion, the findings showed that the folk medicinal plant Cecropia pachystachya possesses hypoglycemic and antioxidant effects which confirmed the traditional use of the plant in the treatment of diabetes. Chlorogenic acid and the C-glycosylated flavonoids may explain these activities.     

Hypoglycemic effect of a leaf extract of Pseuderanthemum palatiferum (Nees) Radlk. in normal and streptozotocin-induced diabetic rats

Ethnopharmacological relevance

Pseuderanthemum palatiferum (Nees) Radlk (Acanthaceae) was first found in Northern Vietnam and expanded throughout the country including the Mekong Delta region. The leaves of this plant are recommended in folk medicine of Vietnam and Thailand for promoting and treating various diseases including hypertension, diarrhea, arthritis, hemorrhoids, stomachache, tumors, colitis, bleeding, wounds, constipation, flu, colon cancer, nephritis, and diabetes.

Aim of the study

The hypoglycemic effect of an 80% ethanolic leaf extract from the leaves of Pseuderanthemum palatiferum (PPE) was investigated in normal and streptozotocin (STZ)-induced diabetic rats.

Materials and methods

The PPE was administered daily and orally to the rats at the doses of 250, 500, and 1000 mg/kg body weight (b.w.) for 14 days. The levels of fasting plasma glucose (FPG), serum insulin, and biochemical data such as blood urea nitrogen (BUN), triglycerides (TG), total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and alkaline phosphatase (ALP) were evaluated. The hypoglycemic effect of PPE was compared to that of the known anti-diabetic drug glibenclamide (0.25 mg/kg b.w.).

Results

FPG and serum insulin in normal rats were not significantly different from the control and test groups in all dosages. The treated diabetic rats which had received PPE and glibenclamide showed significantly (p < 0.05) decreased FPG and increased serum insulin levels at the end of the experiment. The hypoglycemic effect of PPE at the dose of 250 mg/kg b.w. was significantly (p < 0.05) more effective than that of glibenclamide. The serum insulin in PPE fed diabetic rats at the dose of 250 mg/kg b.w. was not different from those which had received glibenclamide, and this dose was significantly (p < 0.05) more effective than PPE at the doses of 500 and 1000 mg/kg b.w. while PPE increased HDL and decreased TC, TG, LDL, BUN and ALP in the diabetic rats.

Conclusions

PPE has a beneficial effect in hyperglycemic rats and may prevent the complication of diabetes.     

Antidiabetic and antioxidant effect of various fractions of Phyllanthus simplex in alloxan diabetic rats

Aim of the study

To evaluate the antidiabetic and antioxidant effects of various fractions of Phyllanthus simplex on alloxan induced diabetes in rats.

Materials and methods

Hypoglycemic effect of Phyllanthus simplex fractions was evaluated in normal and diabetic rats. Diabetes was induced by intraperitoneal injection of alloxan monohydrate (120 mg/kg). Normal and diabetic rats were divided into different groups (six rats each group) and orally administered with petroleum ether (P.E.) (200 and 400 mg/kg), ethyl acetate (EtOAc) (100 and 200 mg/kg), methanol (125 and 250 mg/kg), water fraction (150 and 300 mg/kg) and glibenclamide (10 mg/kg) for 21 days. Blood samples were collected from overnight fasted normal rats on day 21, from overnight fasted diabetic rats at 7, 14 and 21 days of treatment and analyzed for blood glucose level. On day 22 blood samples were collected from diabetic rats to estimate biochemical parameters, rats were sacrificed by single stunning and tissues were excised to measure their antioxidant and glycogen status.

Results

In the normoglycemic rats, MeOH (125 and 250 mg/kg) and aqueous fractions (150 and 300 mg/kg) showed a significant (P < 0.05) hypoglycemic effect on day 21. In diabetic control rats, MeOH (125 and 250 mg/kg) and aqueous fractions (150 and 300 mg/kg) showed significant antihyperglycemic effect (P < 0.001). The active fractions (MeOH and aqueous) of Phyllanthus simplex also increased the body weight of diabetic rats significantly compared to the control group. The active fractions were able to normalize the marked alterations in antioxidant enzymes and antioxidant parameters levels in liver and kidney. Treatment with the active fractions also normalized the diabetic induced hyperlipidemia and liver glycogen.

Conclusions

These results demonstrate the antidiabetic and antioxidant potential of fractions of Phyllanthus simplex and suggests that the plant may have therapeutic value in diabetes and related complications.     

Hypoglycemic properties of some preparations and compounds from Artemisia ludoviciana Nutt

Ethnopharmacological relevance

Artemisia ludoviciana, commonly known as “estafiate”, plays an important role in contemporary Mexico for treating several diseases including diabetes. To establish the preclinical efficacy of Artemisia ludoviciana as hypoglycemic and/or antihyperglycemic agent using well-known animal models.

Materials and methods

Acute hypoglycemic as well as oral glucose (OGTT) and sucrose (OSTT) tolerance tests were used to demonstrate the value of the plant for treating diabetes. An essential oil (EO), an organic extract (OE) and an infusion (AE) were assayed in normal and NA-STZ-treated mice. The acute toxicity of the three preparations was analyzed by the Lorke method. The infusion was subjected to conventional phytochemical study using chromatographic conventional procedures. Some of the isolates were evaluated using the same pharmacological assays as well as an enzymatic test. The latter was employed to assess their potential inhibitory effect on yeast α-glucosidase.

Results

Oral administration of OE to normal mice significantly decreased blood glucose level only at the dose of 100 mg/kg; in NA-STZ-mice the hypoglycemic effect was observed at the three doses tested (31.6, 100, and 316 mg/kg). The infusion reduced significantly, blood sugar levels only in diabetic mice; the best effect was observed at the dose of 316 mg/kg. The EO was inactive when evaluated in normal mice. Regarding to the antihyperglycemic effect, the best effect was observed with the OE, during the OGTT and OSTT in diabetic mice. The infusion (AE) showed better effects during the OGTT in both normal and diabetic animals at the dose of 100 mg/kg. Finally, the EO was inactive during an OGTT at the three doses tested (31.6, 100, and 316 mg/kg) in diabetic mice. In addition, the results of AE on the enzymatic test using yeast α-glucosidase revealed an inhibition of 45%; this finding was consistent with the results obtained with the same preparation in vivo during an OSTT. Conventional phytochemical analysis of the active AE led to the isolation and characterization of eupatilin (1), jaceosidin (2), arglanin (3), salvinine (4), and 3,5-dicaffeoylquinic acid (5). Biological testing of 1 and 3 revealed their hypoglycemic effect. The hypoglycemic effect of arglanin (3) was attenuated in the presence of nicorandil, which suggested that the lactone behaved as an ATP-K⁺-channel blocker as glibenclamide. Salvinine (4) turned out to be a mixed α-glucosidase inhibitor, while 3 was inactive.

Conclusions

Artemisia ludoviciana preparations showed hypoglycemic and antihyperglycemic effects, which could explain its effectiveness for treating diabetes in contemporary Mexico. Some of the active principles of the plant included compounds 1–5. These compounds seem to be acting synergistically on different molecular targets which involved glucose absorption and insulin liberation.     

Hypoglycemic and antihyperglycemic effect of Begonia malabarica Lam. in normal and streptozotocin induced diabetic rats

Aim of the study

The stem of Begonia malabarica was used traditionally by the Malasar tribe to treat diabetes. To validate the hypoglycemic and antihyperglycemic effects of the hexane, ethylacetate and methanol extracts obtained from an ethnomedicinal plant, Begonia malabarica.

Materials and methods

The doses for the study were fixed based on Irwin test. The hypoglycemic effect of hexane, ethylacetate and methanol extracts of Begonia malabarica stems were studied in normal animals. The antihyperglycemic effect of the methanol extract was studied in streptozotocin induced diabetic rats.

Results

In normal rats the treatment with the methanol extract of Begonia malabarica had shown a highly significant reduction (16.54 and 34.47%) in plasma glucose levels from the 0 h values at the dose of 100 and 200 mg/kg respectively. In streptozotocin induced diabetic rats the body weight of the Begonia malabarica methanol extract treated animals had shown a significant increase (13.38% at 200 mg/kg) after 4 weeks treatment. The plasma glucose levels were reduced significantly by 46.57 and 50.20% after 4 weeks treatment at 100 and 200 mg/kg respectively. Likewise the absolute kidney weight was also reduced in a significant manner. After 25 days treatment the Begonia malabarica methanol extract treated animals had shown low fasting plasma glucose levels (54.29, 61.34% in 100 and 200 mg/kg) and reduced postprandial plasma glucose levels (54.23, 65.96% in 100 and 200 mg/kg) when compared with diabetic control values. Serum insulin levels and liver glycogen levels were increased to 40.04 and 42.18% in 200 mg/kg Begonia malabarica methanol extract treated animals respectively. The treatment with Begonia malabarica methanol extract did not change the triglycerides and total cholesterol levels. The urea and creatinine levels were also reduced significantly by this treatment. The reduction in SGPT levels indicated the absence of toxicity of Begonia malabarica extract at this dose level.

Conclusion

This study supports the use of Begonia malabarica by the Malasar tribe for the treatment of diabetes. Fractionation of this extract may yield novel prototypes to manage diabetes mellitus.     

Hypoglycemic activity and antioxidant potential of some medicinal plants traditionally used in Turkey for diabetes

Cydonia oblonga Mill. (Rosaceae) leaves, Helianthus tuberosus L. (Asteraceae) tubers, and Allium porrum L. (Liliaceae) bulbs are used as a folk remedy for the treatment of diabetes and they are also consumed as food in Turkey. In the present study, the antidiabetic and antioxidant activities of the ethanol extracts of these plants were studied in normal and streptozotocin-induced diabetic rats for 5 days. All extracts were administrated orally to rats at the doses of 250 and 500 mg/kg. Blood glucose level was measured according to glucose oxidase method. In order to determine antioxidant activity, thiobarbituric acid reactive substance (TBARS) and reduced glutathione (GSH) levels in liver, kidney, and heart tissues were measured by using spectrophotometric methods. Oral administration of Cydonia oblonga (500 mg/kg) and Allium porrum (500 mg/kg) extracts for 5 days in diabetic rats caused a decrease in blood glucose levels by 33.8% and 18.0%, respectively. Moreover, Allium porrum and Cydonia oblonga extracts induced significant alleviation on only heart tissue TBARS levels (44.6 and 45.7%), Helianthus tuberosus and Allium porrum extracts showed an inhibitory effect on kidney tissue TBARS levels (24.5 and 14.8%). None of the extracts restored GSH levels in kidney, liver, and heart tissues of diabetic rats.     

Antihyperglycemic effects of total flavonoids from Polygonatum odoratum in STZ and alloxan-induced diabetic rats

Aim of the study

Total flavonids of Polygonatum(P) odoratum (TFP) were tested for anti-diabetic activity in streptozotocin (STZ)-induced diabetic mice and alloxan-induced diabetic rats.

Materials and methods

Rhizoma Polygonati Odorati, well-known Chinese traditional medicine, is widely used for treatment of diverse diseases for example diabetes. In our study, TFP was extracted by 70% ethanol and purified by macroreticular resin. The experiments were designed to detect the anti-diabetic activity of TFP by determination of blood glucose (BG) using one touch gluco-meter and insulin levels by using a radioimmunoassay kit in streptozotocin (STZ)-induced diabetic mice and alloxan-induced diabetic rats and alpha-amylase inhibitory activity by alpha-amylase inhibition assay in vitro.

Results

TFP had beneficial effects on regulation of blood glucose. Daily administration with 50–200 mg/kg body weight of TFP for 9 days can reduce significantly hyperglycemia in STZ-induced diabetic mice. Thirtieth day administration with TFP (50–200 mg/kg body weight) also decreased significantly fasting blood glucose in alloxan-induced diabetic rats. The hypoglycemic effect of TFP at 50 and 100 mg/kg is less than that of acarbose 20 mg/kg and gliclazide 15 mg/kg. The hypoglycemic effects of TFP at 200 mg/kg is similar to that of acarbose 20 mg/kg and gliclazide 15 mg/kg. TFP also could increase significantly the insulin level in alloxan-induced type 2 diabetic rats (P < 0.05) compared with control. Alpha-amylase inhibition assay in vitro showed that TFP inhibited significantly alpha-amylase activity in a dose-dependent manner.

Conclusions

TFP possess significant dose-dependent anti-diabetic activity. TFP is one of the primary hypoglycemic active compounds of Polygonatum odoratum which would worth further study and development.     

Evaluation of antihyperglycemic activity of Cocos nucifera Linn. on streptozotocin induced type 2 diabetic rats

Ethnopharmacological relevance

The plant Cocos nucifera Linn. (Arecaceae) is commonly known as coconut. Traditionally the juice of the young spadix when fresh is used in diarrhea and diabetes.The objective of the present study was to investigate the effect of antidiabetic activity and effect on lipid profile as well as cardioprotective effect of hydro-methanol extract of Cocos nucifera (HECN) on streptozotocin (STZ)-induced diabetic rats.

Materials and methods

After 72 h of STZ (50 mg/kg, b.w. i.p.) administration, animals showing plasma sugar level more than 250 mg/dl were considered as diabetic rat. Fasting blood glucose (FBG) levels were measured on 0th (after 72 h of STZ), 5th, 10th, and 15th day. On the 15th day all the animals were sacrificed and the serum biochemical parameters and antioxidant enzyme status were measured.

Results

HECN treated animals showed a significant reduction in FBG level as compared with diabetic control group. Serum enzyme level (SGOT, SGPT, SALP), lipid peroxidation and antioxidant enzyme level such as CAT, GSH, SOD and cholesterol and triglycerides in the HECN treated groups were restored towards normal level as compared to diabetic control groups and the values were comparable with the standard groups (glibenclamide).

Conclusion

Improvement in the FBG and the restoration of all other biomarker as well as enzymes indicates that HECN has very good antidiabetic activity with very low side effects and provides a scientific rationale for the use as an antidiabetic agent.     

Antidiabetic activity of Paspalum scrobiculatum Linn. in alloxan induced diabetic rats

Ethnopharmacological relevance

Paspalum scrobiculatum Linn. (Poaceae) is traditionally used to treat diabetes mellitus. The grains of Paspalum scrobiculatum are having potential in the development of drug for diabetes due to their antidiabetic activity.

Aim of the study

To evaluate the antidiabetic activity of aqueous and ethanolic extracts of grains of Paspalum scrobiculatum Linn. (Poaceae) in alloxan induced diabetic rats.

Materials and methods

Aqueous and ethanolic extracts (250 and 500 mg/kg body weight), were administered orally to male Wistar albino rats. Alloxan monohydrate was used to induce diabetes mellitus. Total phenolic content was estimated in the extracts. The parameters studied included oral glucose tolerance test, fasting blood glucose, serum insulin and glycated haemoglobin levels, liver glycogen content, serum lipid profile, and changes in body weights.

Results

In oral glucose tolerance test, reduction of fasting blood glucose levels took place from 60 min of extract administration. The extracts produced a dose-dependent fall in fasting blood glucose (FBG). After 15 days of treatment with extracts the maximum reduction in FBG (35.14%) was observed in diabetic rats treated with ethanolic extract 500 mg/kg dose. A significant increase in serum insulin level was observed in the treated rats. Serum lipid levels were reversed towards near normal and a control in the loss of body weight was observed in treated rats as compared to diabetic control. The extract treatment also showed a significant increase in the liver glycogen and a significant decrease in glycated haemoglobin levels. The results demonstrate that Paspalum scrobiculatum possesses significant antidiabetic activity in diabetic rats.

Conclusion

The results suggest that Paspalum scrobiculatum has antidiabetic activity, thereby justifying its traditional claim and augmenting it into the present day systems of medicine.     

Preliminary study of antidiabetic activity of the methanolic leaf extract of Axonopus compressus (P. Beauv) in alloxan-induced diabetic rats

Ethnopharmacological relevance

Axonopus Compressus is commonly used by the people of Southern Nigeria to treat different ailment such as common cold and diabetes. This study therefore, evaluated the anti-diabetic effect of the methanolic leaf extract of the plant.

Materials and methods

Diabetes was induced in the rats by intraperitoneal (i.p.) injection of alloxan monohydrate at the dose of 180 mg/kg. Three test doses of the extract (250, 500 and 1000 mg/kg) administered per os through gastric gavage to the rats were used in the study. The activity was compared to a standard reference drug (glibenclamide, 2 mg/kg) and a negative control. Blood from the tail snip was used to measure the effects of the extract and drug at 0, 1, 3 and 6 h using autoanalyzer (AccuCheck Active^®) glucose kit.

Results

Methanolic leaf extract of Axonopus compressus at all the doses (250, 500 and 1000 mg/kg) used caused a respective time dependent and significant (p < 0.0001) reduction (by 31.5%, 19.8% and 24.5%) of the blood glucose levels in the diabetic rats when compared to the negative control group at the 6th hour. However, the reference drug (glibenclamide, 2 mg/kg) decreased the blood glucose levels by 69.9% and the tween 20 solution (negative control) increased the blood glucose level by 15.2% at the 6th hour. Moreso, the extract at the different test doses caused various degrees of reduction of the blood glucose levels of the test rats at 1st, 3rd and 6th hours when compared to the negative control rats.

Conclusion

The findings suggest that Axonopus compressus may possess antidiabetic property.     

Hypoglycemic effect of bitter melon compared with metformin in newly diagnosed type 2 diabetes patients

Ethnopharmacological relevance

Bitter melon (Momordica charantia L.) has been widely used as an traditional medicine treatment for diabetic patients in Asia. In vitro and animal studies suggested its hypoglycemic activity, but limited human studies are available to support its use.

Aim of study

This study was conducted to assess the efficacy and safety of three doses of bitter melon compared with metformin.

Materials and methods

This is a 4-week, multicenter, randomized, double-blind, active-control trial. Patients were randomized into 4 groups to receive bitter melon 500 mg/day, 1000 mg/day, and 2000 mg/day or metformin 1000 mg/day. All patients were followed for 4 weeks.

Results

There was a significant decline in fructosamine at week 4 of the metformin group (−16.8; 95% CI, −31.2, −2.4 μmol/L) and the bitter melon 2000 mg/day group (−10.2; 95% CI, −19.1, −1.3 μmol/L). Bitter melon 500 and 1000 mg/day did not significantly decrease fructosamine levels (−3.5; 95% CI −11.7, 4.6 and −10.3; 95% CI −22.7, 2.2 μmol/L, respectively).

Conclusions

Bitter melon had a modest hypoglycemic effect and significantly reduced fructosamine levels from baseline among patients with type 2 diabetes who received 2000 mg/day. However, the hypoglycemic effect of bitter melon was less than metformin 1000 mg/day.     

Hypoglycemic effect of Rehmannia glutinosa oligosaccharide in hyperglycemic and alloxan-induced diabetic rats and its mechanism

The hypoglycemic and anti-diabetic effect of Rehmannia glutinosa oligosaccharide (ROS) in glucose-induced hyperglycemic and alloxan-induced diabetic rats and its mechanism was investigated in this paper. It was found that pretreatment of ROS in normal rats with 100 mg/kg for 3 days, i.p., induced a partial prevention of hyperglycemia caused by glucose (2g/kg, i.p.), while when hyperglycemia was induced in adrenalectomized (ADX) rats, the preventive effect of ROS on hyperglycemia was lost. In alloxan-induced diabetic rats, ROS (100 mg/kg for 15 days, i.p.) showed a significant decrease in blood glucose level and hepatic glucose-6-phosphatase activity with an increase in hepatic glycogen content. Furthermore, ROS raised plasma insulin level and lowered plasma corticosterone level in alloxan-induced diabetic rats. The results indicated that oligosaccharide of Rehmannia glutinosa Libosch. exerted a significant hypoglycemic effect in normal and alloxan-induced diabetic rats. The regulatory mechanism of ROS on glucose metabolism was adrenal dependent and had a close relation with the neuroendocrine system.     

Antihyperglycemic and antioxidant effect of Berberis aristata root extract and its role in regulating carbohydrate metabolism in diabetic rats

Ethnopharmacological relevance

Berberis aristata DC root is used in traditional medicine for a number of ailments including metabolic disorders.

Aim of the study

The aim of the present study was to explore the antihyperglycemic and antioxidant potential of 50% aqueous ethanolic root extract of Berberis aristata (BA) in alloxan induced diabetic rats.

Materials and methods

BA root extract (250 mg/kg) was administered to diabetic rats and standard drug glybenclamide (0.6 mg/kg) to group serving as positive control. Effect of extract on antioxidant and carbohydrate metabolism regulating enzymes of liver was studied in diabetic rats along with its safety parameters.

Results

The main constituents of root were identified as berberine, berbamine and palmatine through HPTLC. The extract besides being safe, lowered the blood glucose significantly without any hypoglycemic effect on their control counterparts. It increased CAT, SOD, GPx, GR activity significantly and reduced lipid peroxidation (41.6%) and protein carbonylation (30.15%). It also increased the glucokinase and glucose-6-phosphate dehydrogenase activities and decreased glucose-6-phosphatase activity in diabetic rats which play a critical role in glucose homeostasis.

Conclusion

Thus, the extract of Berberis sristata (root) has strong potential to regulate glucose homeostasis through decreased gluconeogenesis and oxidative stress.     

Effect of Moringa oleifera Lam. leaves aqueous extract therapy on hyperglycemic rats

Ethnopharmacological relevance

In Indian traditional system of medicine, Moringa oleifera Lam. Syn. Moringa pterygosperma Gaerth (Moringaceae) is commonly used as healing herb to treat diabetes.

Aim of the study

The purpose of the present study was to assess the effect of M. oleifera leaves aqueous extract therapy on glycemic control, haemoglobin, total protein, urine sugar, urine protein and body weight.

Materials and methods

Variable doses of 100, 200 and 300 mg kg⁻¹ of aqueous extract were administered orally by gavage for evaluating their hypoglycemic and antidiabetic effects on fasting blood glucose (FBG), oral glucose tolerance test (OGTT) and post prandial glucose (PPG) of normal and streptozotocin (STZ) induced sub, mild and severely diabetic rats.

Results

The dose of 200 mg kg⁻¹ decreases blood glucose level (BGL) of normal animals by 26.7 and 29.9% during FBG and OGTT studies respectively. In sub and mild diabetic animals the same dose produced a maximum fall of 31.1 and 32.8% respectively, during OGTT. In case of severely diabetic animals FBG and PPG levels were reduced by 69.2 and 51.2% whereas, total protein, body weight and haemoglobin were increased by 11.3, 10.5 and 10.9% respectively after 21 days of treatment. Significant reduction was found in urine sugar and urine protein levels from +4 and +2 to nil and trace, respectively.

Conclusion

The study validates scientifically the widely claimed use of M. oleifera as an ethnomedicine to treat diabetes mellitus.     

In vivo assessment of antidiabetic and antioxidant activities of rosemary (Rosmarinus officinalis) in alloxan-diabetic rabbits

Rosemary (Rosmarinus officinalis), used in traditional Turkish folk medicine for the treatment of hyperglycaemia, is widely accepted as one of the medicinal herb with the highest antioxidant activity. Accordingly, the present study was designed to investigate the possible actions of ethanolic extract of the leaves of Rosmarinus officinalis on glucose homeostasis and antioxidant defense in rabbits. In the first set of experiments, hypoglycaemic effects of oral administration of various doses (50, 100 and 200 mg/kg) of the extract were examined in normoglycaemic and glucose-hyperglycaemic rabbits. Optimal effect was observed in both of the animal groups with a dose of 200 mg/kg of the extract and this activity was independent from the effects of insulin. In another part of experiments, acute effect of various doses of the Rosmarinus officinalis extract on blood glucose and serum insulin levels was studied in alloxan-induced diabetic rabbits. Of the three doses of extract, the highest dose (200 mg/kg) significantly lowered blood glucose level and increased serum insulin concentration in alloxan-diabetic rabbits. The last set of experiments designed to investigate the subacute effect of the Rosmarinus officinalis extract on repeated administration in alloxan-diabetic rabbits. At the doses of 100 and 200 mg/kg, antihyperglycaemic effect of extract was accompanied by a significant increase in serum insulin levels in diabetic rabbits. Furthermore, during 1 week of treatment of diabetic rabbits with a dose of 200 mg/kg of the extract showed that the extract possessed a capability to inhibit the lipid peroxidation and activate the antioxidant enzymes. It was concluded that probably, due to its potent antioxidant properties, the Rosmarinus officinalis extract exerts remarkable antidiabetogenic effect.     

Antidiabetic effect of Ficus religiosa extract in streptozotocin-induced diabetic rats

Aims of study

In Indian traditional system of medicine, Ficus religiosa (Family Moraceae) is prescribed for the treatment of diabetes mellitus. In the present study, the antidiabetic effect of aqueous extract of Ficus religiosa bark (FRAE) was investigated in normal, glucose-loaded hyperglycemic and streptozotocin (STZ)-induced diabetic rats.

Materials and methods

Oral administration of FRAE at the doses of 25, 50 and 100 mg/kg was studied in normal, glucose-loaded and STZ-diabetic rats.

Results

The three doses caused significant reduction in blood glucose levels in all the models. The effect was more pronounced in 50 and 100 mg/kg than 25 mg/kg. FRAE also showed significant increase in serum insulin, body weight and glycogen content in liver and skeletal muscle of STZ-induced diabetic rats while there was significant reduction in the levels of serum triglyceride and total cholesterol. FRAE also showed significant antilipidperoxidative effect in the pancreas of STZ-induced diabetic rats. The antidiabetic effect of Ficus religiosa was compared with glibenclamide, a well-known hypoglycemic drug.

Conclusion

The results indicate that aqueous extract of Ficus religiosa bark possesses significant antidiabetic activity.     

Antihyperglycemic activity of kinsenoside, a high yielding constituent from Anoectochilus roxburghii in streptozotocin diabetic rats

Different doses of kinsenoside, a high yielding constituent from Anoectochilus roxburghii, was orally administered to further investigate its biological activity and pharmacological mechanisms that involve in the hypoglycemic effect on streptozotocin (STZ) diabetic rats. Our study showed that this compound exhibited significantly antihyperglycemic activity at the dose of 15mg/kg body weight, which is speculated to be partially attributed to modulating the activity of enzymatic antioxidants, scavenging free radicals, and reducing the content of factor NO. Much more intact beta cells in the islets of Langerhans with denser insulin in kinsenoside-treated groups than the negative control were observed, which greatly supported the morphological and functional elucidation. These results displayed that kinsenoside could be useful for repairing beta cells in pancreatic islet injury as well as improving its function. The OGTT evidenced that this compound could promote the glucose tolerance of acute glucose increase in both diabetic and normal healthy rats.     

Effect of Punica granatum Linn. (flowers) on blood glucose level in normal and alloxan-induced diabetic rats

‘Gulnar farsi’, male abortive flowers of Punica granatum L., are used for the treatment of diabetes mellitus in Unani medicine. Oral administration of its aqueous-ethanolic (50%, v/v) extract led to significant blood glucose lowering effect in normal, glucose-fed hyperglycaemic and alloxan-induced diabetic rats. This effect of the extract was maximum at 400 mg/kg, b.w.     

日本毛连菜降血糖作用的实验研究

目的:研究日本毛连菜对正常小鼠及糖尿病模型小鼠血糖的影响.方法:尾静脉注射四氧嘧啶50 mg·kg-1,72 h后血糖高于11.1 mmo1·L-1为糖尿病模型.小鼠随机分为6组:正常组、模型组、消渴丸组(0.75 g·kg-1·d-1)、日本毛连菜低、中、高剂量组(1.5,3,6 g·kg-·d-1),ig给予药物14 d,测定空腹血糖,并进行了日本毛连菜急性毒性实验.结果:给药14 d后,日本毛连菜水提物低、中、高剂量组的血糖值分别达到(7.52±1.47),(7.33±2.99),(7.79±1.84) mmo1·L-1,与模型组比较有显著性差异(P＜0.05).急性毒性实验表明最大给药量为120 g·kg-1.结论:日本毛连菜对实验性高血糖小鼠有明显降糖作用,且毒性较小.     

In-vitro and in-vivo antiadipogenic,hypolipidemic and antidiabetic activity of Diospyros melanoxylon (Roxb)

Ethnopharmacological relevance

The plant Diospyros melanoxylon (Roxb) belongs to the family Ebenaceae that is native to India and Sri-lanka. This is a medium-sized tree, reaching a height of 15 m and is well known for its beedi making leaves throughout the world. The purpose of the present study is to assess the effect of Diospyros melanoxylon leaves petroleum ether extract on blood glucose level, lipid level, insulin level, body weight, water and food intake in Streptozotocin (STZ) induced diabetic rats.

Materials and methods

Two different doses of extract AK001 (250 mg/kg) and AK002 (500 mg/kg) of Diospyros melanoxylon leaves were taken to evaluate different activities. The animals were divided into five groups namely normal control, diabetic control, reference group, AK001 and AK002 each containing six animals for in-vivo study. In-vitro study for antiadipogen activity was performed on 3T3-L1 cell line.

Results

The extract showed dose dependent fall in Fasting Glucose Level (FSG) in experimental diabetic animals with significant reduction in food and water intake and increase in body weight. The extract exhibited hypocholesterolemic and hypotriglyceridemic effects while increased level of HDL in diabetes induced rats. In-vitro activity showed more than 75% viability of cells and significant inhibition in differentiated cells as compared to non-differentiate cells in 3T3-L1 cell line. The extract exhibited the concentration-dependent inhibitory effect with an IC₅₀ value of 689.22 μg/ml.

Conclusions

The extract exhibited significant results for antiadipogenic, antidiabetic and hypolipidemic activity both in-vivo and in-vitro and it may prove to be effective for the treatment of both types of diabetes, i.e. Insulin Dependent Diabetes Mellitus (IDDM) and Noninsulin Dependent Diabetes Mellitus (NIDDM).