Effects of Juniperus oxycedrus ssp. oxycedrus on tissue lipid peroxidation, trace elements (Cu, Zn, Fe) and blood glucose levels in experimental diabetes

Ethnopharmacological relevance

Juniperus oxycedrus L. (Cupressaceae) fruits and leaves are used internally and pounded fruits are eaten for diabetes in Turkey.

Aim of the study

To evaluate the interrelationships between the levels of chosen trace elements (copper, iron, and zinc) and hepatic, renal lipid peroxidation (TBARS) in streptozotocin-induced diabetic rats treated with Juniperus oxycedrus ssp. oxycedrus (J.o.s.o.) leaf and fruit extracts for 10 days.

Materials and methods

J.o.s.o. fruit and leaf extracts were administered in STZ-induced diabetic rats, at doses of 500 and 1000 mg/kg. The blood glucose levels were measured in the 1st, 4th, 7th and 10th day of experiment. Fe, Cu, and Zn contents and lipid peroxidation levels of liver and kidney tissues were determined by atomic absorption spectrophotometry and ultraviolet spectrophotometry, respectively.

Results

Treatment of diabetic rats with the J.o.s.o. fruit and leaf extracts decreased the blood glucose levels and both the levels of lipid peroxidation in liver and kidney tissues. J.o.s.o. extracts have augmented Zn concentrations in liver of STZ-induced diabetic rats.

Conclusions

Results indicated that J.o.s.o. fruit and leaf extracts might be beneficial for diabetes and its complications.     

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.     

Anti-hyperglycemic effect,inhibition of inflammatory cytokines expression,and histopathology profile in streptozotocin-induced diabetic rats treated with Arracacia tolucensis aerial-parts extracts

Ethopharmacological relevance

Arracacia tolucensis is a medicinal plant used in northeast of Mexico as a remedy to treat people with Diabetes mellitus (DM); however, there are no scientific studies that support this information. Thus, we evaluated the anti-hyperglycemic effect of the hexane, ethyl acetate and ethanol extracts from aerial parts in streptozotocin-induced diabetic rats.

Materials and methods

DM was induced in Wistar male rats by single intraperitoneal injection of streptozotocin (STZ 50 mg/kg). After STZ-induction, hyperglycemic rats were treated with all three extracts orally at a single dose (250 mg/kg) each 48 h for 21 days. Glibenclamide (1 mg/kg) was used as a reference drug. The fasting blood glucose levels, the hematic biometry and biochemical profiles, and the inhibition of inflammatory cytokines expression were estimated. Histopathology analysis of pancreas, liver, spleen, and kidney tissue was carried out.

Results

Ours results showed that ethyl acetate extract decreased blood glucose levels significantly (75%, p< 0.05) when compared to diabetic rats and controlled the body weight loss; the lipids level did not change, but the enzyme levels of aspartate aminotransferase and alanine aminotransferase decreased significantly (60.83% and 66.16%, respectively, p< 0.05) and inhibited the expression of inflammatory cytokines,with respect to diabetic rats. Histopathology injury was not observed; by contrast repair of islet of Langerhans was exhibited.

Conclusion

These results validate the use of Arracacia tolucensis as a treatment against DM and suggests it is suitable to continue studies for its safe therapeutic use.     

Antidiabetic effect of Symplocos cochinchinensis (Lour.) S. Moore. in type 2 diabetic rats

Aim

Symplocos cochinchinensis (Lour.) S. Moore. is used in Indian system of traditional medicine to treat diabetes mellitus. The present study aims to investigate the antidiabetic efficacy of the hexane extract of Symplocos cochinchinensis leaves in high fat diet-low streptozotocin (STZ) induced type 2 diabetic rats.

Materials and methods

The doses for the study were fixed based on Irwin test. The hypoglycemic effect of the hexane extract of Symplocos cochinchinensis leaves were studied in normal rats. Oral glucose and insulin tolerance tests were carried out. The antihyperglycemic effect of the hexane extract at 250 and 500 mg/kg was studied in high fat diet-low STZ induced type 2 diabetic rats for 28 days.

Results

The extracts showed no adverse effects up to 5 g/kg concentration. In hypoglycemic study, after treatment with hexane extract at 250 and 500 mg/kg the blood glucose was mildly reduced. In oral glucose tolerance test, the treatment with the hexane extract at 250 and 500 mg/kg showed a highly significant reduction of 12.07% and 23.58% in plasma glucose levels, respectively 30 min after glucose load. The insulin tolerance test also showed improved insulin sensitivity after 60 min of insulin treatment. In high fat diet-low STZ induced type 2 diabetic rats, after 28 days treatment with the hexane extract at 250 and 500 mg/kg reduced the plasma glucose level by 17.04% and 42.10%, respectively. A significant reduction in plasma insulin, plasma and hepatic total cholesterol (TC), triglycerides (TG) and free fatty acids (FFA) and a significant increase in liver glycogen were observed in treated diabetic rats.

Conclusion

This study demonstrated the potential antidiabetic property of hexane extract of Symplocos cochinchinensis leaves on type 2 diabetes mellitus, thus justifying its traditional usage.     

Evaluation of antidiabetic and antihyperlipidemic activity of Artemisia indica linn (aeriel parts) in Streptozotocin induced diabetic rats

Ethnopharmacological relevance

Diabetes mellitus is a major metabolic disorder affecting a huge population all over the world. Artemisia species have been extensively used for the management of diabetes in folkloric medicine. The present study is designed to investigate the antidiabetic and antihyperlipidemic effects of aeriel parts of Artemisia indica.

Materials and methods

Hydromethanolic crude extracts, chloroform, ethyl acetate and n-butanol fractions of aerial parts of Artemisia indica were tested for their antidiabetic potential in Streptozotocin (STZ) (50 mg/kg, i.p.) induced diabetic Sprague-Dawley rats. Blood glucose level, body weight, serum lipid profile and activities of liver enzymes were determined. The extracts were further subjected to preliminary phytochemical analysis.

Results

A daily oral dose of hydromethanolic crude extracts (200 and 400 mg/kg b.w.) and chloroform fraction (200 mg/kg b.w.) of Artemisia indica for 15 days showed a significant reduction in blood glucose level which was comparable to that of the standard antidiabetic drug, glibenclamide (500 μg/kg, p.o.). Artemisia indica extracts also showed reduction in total cholesterol, triglycerides and low density lipoproteins as well as serum creatinine level, serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT) and alkaline phosphatase (ALP) in diabetic rats.

Conclusion

According to the results Artemisia indica possesses hypoglycemic, antihyperlipidemic and valuable effects on liver and renal functions in diabetic rats, which seems to validate its traditional usage.     

In vivo and in vitro antidiabetic effect of Cistus laurifolius L. and detection of major phenolic compounds by UPLC–TOF-MS analysis

Ethnopharmacological relevance

In Turkish folk medicine, various parts of Cistus laurifolius L. are used to treat gastric ulcer and various types of pains. Additionally the tea prepared from the leaves is used to decrease symptoms of diabetes.

Materials and methods

In the present study, the hypoglycemic effects of aqueous and ethanol extracts of Cistus laurifolius were investigated in normal, glucose loaded hyperglycemic and streptozocin (STZ)-induced diabetic rats. α-Glucosidase and α-amylase enzyme inhibitory effects were determined to evaluate the mechanism of action. Total phenolic content of the extracts were determined by using Folin–Ciocalteu reagent and Ultra Performance Liquid Chromatography–Time of Flight Mass Spectrometer (UPLC–TOF-MS) was used to detect the major phenolic compounds in the extract.

Results

Results indicated that blood glucose levels of the STZ-induced diabetic rats were decreased by ethanol extract at of 250 and 500 mg/kg doses as compared to control group (16%–34%). In glucose loaded animals, extracts have shown a weak hypoglycemic effect (11%–20%). Additionally, the ethanol extract of Cistus laurifolius is found to be a potent inhibitor of α-glucosidase and α-amylase, possibly due to several polyphenolic compounds present within the extract. Twelve major flavonoids (apigenin, quercetin, kaempferol, naringenin, quercitrin and their derivatives), gallic, ellagic and chlorogenic acid in chromatographic fingerprint were analyzed by the on-line UPLC–TOF-MS system.

Conclusions

Due to having inhibitory effect on blood glucose level and carbohydrate digesting enzymes (α-glucosidase and α-amylase), Cistus laurifolius leaves might be beneficial for diabetic patients.     

Antioxidant and anti-inflammatory effects of Urtica pilulifera extracts in type2 diabetic rats

Ethnopharmacological relevance

"Urtica pilulifera has been traditionally used in Egyptian system as an herbal remedy to be a diuretic, antiasthmatic, anti-inflammatory, hypoglycemic, hemostatic, antidandruff and astringent"

Aim of the study

To evaluate the potential effects of ethyl acetate (EA), chloroform (CHLOR) and hexane (HEXA) extracts of Urtica piluliferaas oral anti-diabetic agents as well as to evaluate their possible anti-oxidant and anti-inflammatory effects in type2 diabetic rat model.

Material and methods

Type2 diabetes was induced by a high fat diet and low dose streptozotocin (STZ). Diabetic adult male albino rats were allocated into groups and treated according to the following schedule; Pioglitazone HCL (PIO), EA, CHLOR and HEXA extracts of Urtica pilulifera at two doses of 250 and 500 mg/kg were used. In addition, a normal control group and a diabetic control one were used for comparison. Blood glucose, insulin resistance, antioxidant enzymes, 8-hydroxy-2-deoxyguanosine (8-OHdG) as well as C-reactive protein and tumor necrosis factor-α levels were evaluated.

Results

EA and CHLOR extracts of Urtica pilulifera exhibited a significant hypoglycemia associated with antioxidant and anti-inflammatory effects in diabetic rats; however, HEXA extract showed no beneficial effect. These activities are responsible, at least partly, for improvements that have been seen in hyperglycemia and insulin resistance of diabetic rats.

Conclusion

Our results encourage the traditional use of Urtica pilulifera extract as an antioxidant and anti-inflammatory agent as an additional therapy of diabetes.     

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.     

Antidiabetic and antioxidant effects of Annona muricata (Annonaceae), aqueous extract on streptozotocin-induced diabetic rats

Ethnopharmacological relevance

The leaves of Annona muricata are used in Cameroon to manage diabetes and its complications. The aim of this study was to evaluate the antidiabetic, antioxidant activities and the potential toxicity of aqueous extract of Annona muricata in streptozotocin-induced diabetic rats.

Material and methods

Oral administration of Annona muricata aqueous extract (100 mg/kg or 200 mg/kg) was studied in normal and streptozotocin-induced diabetic rats. In long term treatment, 2 weeks after streptozotocin-induced diabetic rats, animals received plant extract during 28 consecutive days. For a protective effect, extract was administered 3 days prior to streptozotocin exposure and animals were observed 2 weeks without treatment.

Results

The plant extract was not effective in normal rats. In diabetic rats, single administration of the extract significantly reduced blood glucose levels by 75% and 58.22% respectively at the dose of 100 mg/kg and 200 mg/kg as compared to the initial value. Treatment of normal rats 3 days prior to diabetes induction showed that, Annona muricata extract has no effect within 72 h following STZ injection. However, after 14 days post-treatment, the extract at the dose of 100 mg/kg significantly reduced blood glucose levels as compared with initial value and diabetic control rats. Immunohistochemical staining of pancreatic β-cells of diabetic rats treated with the dose of 100 mg/kg expressed strong staining for β-cell compared to diabetic control. In a long-term study daily administration of Annona muricata aqueous extract for 28 days to diabetic rats, reduced blood glucose levels, serum creatinine, MDA, AST, ALT activity, and nitrite levels LDL-cholesterol. Total cholesterol, triglycerides, SOD, and CAT activity contents were restored.

Conclusion

These different results show that the antidiabetic activity of Annona muricata aqueous extract can be explained by its hypolipidaemic effect, its antioxidant and protective action on pancreatic β-cells, which in turn improve glucose metabolism.     

Effect of Cydonia oblonga Mill. leaf extracts or captopril on blood pressure and related biomarkers in renal hypertensive rats

Ethnopharmacological relevance

Cydonia oblonga Mill. (COM) is used in traditional Uyghur medicine to treat or prevent cardiovascular disease. In a previous study COM leaf extracts were found to be active in renal hypertensive rats (RHR). The present study tests the dose-dependence of the effect of ethanol leaf extracts on hypertension and on biomarkers associated with blood pressure control, such as angiotensin-II (AII), plasma renin activity (PRA), apelin-12 (A), endothelin (ET) and nitric oxide (NO), compared to captopril.

Methods

Two-kidney one-clip (2K1C) Goldblatt model rats were divided randomly into six groups: sham, model, captopril 25 mg/kg, COM leaf extract 80, 160 and 320 mg/kg (n=10 each). Drugs were administered orally daily for eight weeks. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured before treatment and every 2 weeks. Blood and kidney samples were collected after the last treatment to measure AII, PRA, A, ET and NO.

Results

RHR had increased blood pressure, AII, A, PRA, ET and decreased NO. Treatment with captopril reduced blood pressure, AII, A, PRA, and ET, though not quite to normal values. COM leaf extracts significantly and dose-dependently reduced blood pressure, AII, A, RA and ET, whereas NO was increased. The highest dose of COM had the same effects as captopril.

Conclusion

The effects of COM extracts on blood pressure and biomarkers were dose-dependent and at the highest dose similar to those of captopril. This suggests an action of COM on the renin–angiotensin system, which could explain its antihypertensive effect.     

Hypoglycemic and antihyperglycemic effect of Witheringia solanacea in normal and alloxan-induced hyperglycemic rats

Aim of the study

Witheringia solanacea is a small shrub that belongs to the Solanaceae family. The plant is used as an antidiabetic in Costa Rican herbal medicine. The aim of this study was to evaluate the hypoglycemic and antihyperglycemic activity of the aqueous extract of W. solanacea leaves in rodent models.

Materials and methods

A crude extract of W. solanacea leaves was prepared in boiling water and the aqueous filtrate was lyophilized. A single oral dose of 250, 500 and 1000 mg/kg of the extract was evaluated for hypoglycemic activity in a glucose tolerance test in normal rats and for antihyperglycemic activity in alloxan-induced (140 mg/kg) diabetic rats. The blood glucose level was determined at different times by the glucose oxidase method.

Results

Dosage of 500 and 1000 mg/kg of the extract significantly decreased (p < 0.05) blood glucose levels in the glucose tolerance test in normal rats after 1 h, there was no significant difference observed at 250 mg/kg. Dose of 500 mg/kg of the extract significantly reduced (p < 0.05) blood glucose levels in alloxan induced hyperglycemic rats at 4 and 5 h.

Conclusions

In the present study, the hypoglycemic and antihyperglycemic potential of the W. solanacea was demonstrated in rats. These results give support to the traditional use of W. solanacea as antidiabetic herbal medicine.     

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 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.     

Anti-hyperglycemic activity of the leaves of Tetracera scandens Linn. Merr. (Dilleniaceae) in alloxan induced diabetic rats

Aim of the study

The present study was aimed to investigate the anti-diabetic potential of the leaves of Tetracera scandens Linn. Merr. (Dilleniaceae) in vivo with regard to prove its efficacy by local herbalists in the treatment of diabetes frailties.

Materials and methods

Crude aqueous (AQ) and methanol (MEOH) extracts of the leaves of T. scandens L. were administered to both normal and alloxan induced diabetic male albino rats (Wistar strain). The blood glucose levels were measured at 0, 2, 4, 6 and 8 h after oral administration of AQ and MEOH extracts.

Results

Significant reduction in glucose was observed in fasting blood glucose levels in the treated diabetic rats without causing any hypoglycemic effect compared to normal rats. Both polar extracts of the leaves of T. scandens L. exhibited significant anti-hyperglycemic activity at different doses and intervals. The highest anti-hyperglycemic effect (62.5%) was observed by the AQ extract at 0.25 g/kg body weight (b.w.) and MEOH extract (36.5%) at 0.5 g/kg b.w. after 8 h. The significant anti-hyperglycemic activity was found to be comparable with a known oral synthetic hypoglycemic drug, glibenclamide 0.25 mg/kg b.w.

Conclusion

This study provides scientific evidence that the leaves of T. scandens L. have anti-diabetic efficacy and justifies its utility by local herbalists. However, more experiments at the clinical levels are required to confirm the utility of this plant by traditional practitioners in the management of diabetes mellitus.     

Renoprotection of Danshen Injection on streptozotocin-induced diabetic rats,associated with tubular function and structure

Ethnopharmacological relevance

Danshen Injection, the aqueous extracts of Radix Salvia miltiorrhiza (S. miltiorrhiza), is one of the most commonly used traditional Chinese herbs in chronic renal failure treatment. In present study, the mechanism of the renoprotective effect of Danshen Injection was analyzed on streptozocin (STZ)-induced diabetic rats.

Materials and methods

Diabetic experimental model was established in male Sprague-Dawley (SD) rats by intraperitoneal injection of STZ. Rats with blood glucose concentration of higher than 300 mg/dl were intraperitoneally administered with Danshen Injection at a dose of 0.78 ml/kg day. The blood glucose, 24 h urinary protein excretion, serum creatinine (sCr), blood urea nitrogen (BUN), advanced glycation end products (AGEs), lipid peroxide (LPO), antioxidant enzyme of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), transforming growth factor-β1 (TGF-β1), and histomorphological changes in kidney of diabetic rats were analyzed during the course of Danshen Injection administration, as well as the tubular function index of albumin reabsorption of fluorescein isothiocyanate labeled bovine serum albumin (FITC-BSA).

Results

The intraperitoneal administration of Danshen Injection could ameliorate the physiological dysfunctions of increased 24 h urinary protein excretion((48.21±8.04)%), sCr((39.4±3.7)%), and BUN((43.37±6.74)%), alleviate the ultrastructural abnormalities of hypertrophy, matrix expansion, and fibrosis in glomerulus, decrease the TGF-β1 expression, AGEs and LPO accumulation, and increase the activity of SOD and GSH-Px in kidney of diabetic rats, but did not significantly influence the blood glucose. Besides these, the Danshen Injection administration also partly restored the decrease of megalin expression in tubules and reabsorptive function of FITC-BSA, in diabetic rats.

Conclusion

The renoprotection of Danshen Injection on diabetic rats was associated with the preservation of tubular function and structure from the hyperglycemia induced toxicities of inappropriate cytokines secretion, oxidative stress, advanced glycation stress, and megalin expression deletion.     

Antidiabetic activity of alcoholic stem extract of Nervilia plicata in streptozotocin-nicotinamide induced type 2 diabetic rats

Ethnopharmacological relevance

Nervilia plicata (Orchidaceae) has long been used in the antidiabetic medicinal preparations of traditional healers of Wayanad (Kerala), but recuperative potential of the plant was remained undefined. We demonstrated the regenerative potential of the plant extract on kidney affected by type 2 diabetes besides lowering blood glucose.

Aim of the study

The aim of the current study was to investigate the recuperative and regenerative potential of alcoholic stem extract of Nervilia plicata on streptozotocin-nicotinamide induced type 2 diabetic models.

Materials and methods

Non insulin dependent diabetes mellitus (NIDDM) was induced in overnight fasted rats by intramuscular injection (IMI) of 60 mg/kg STZ and 120 mg/kg of nicotinamide after 5 min interval. Blood glucose was assessed by a glucometer, serum urea and creatinine levels were determined by diacetylmonooxime method and Jaffe reaction respectively. Kidney sections were taken and stained with Masson's tri-dye and Periodic Acid Schiff (PAS) and examined for structural changes. Also lipid peroxidation product (LPP) levels were determined as thio barbituric acid reactive substance levels (TBARS) method.

Results

On administration of 5 mg/kg of plant extract, blood glucose levels of the NIDDM rats showed 62.00 and 76.29% decrease in the blood glucose levels on day 0 and day 30 respectively. Damages caused to the kidney tissue were negligible or not seen. Serum urea and creatinine levels showed 61.49 and 70.96% decrease on day 30. LPP levels of kidney and pancreas showed 70.58 and 77.41% decrease respectively.

Conclusion

These results demonstrate significant antidiabetic and regenerative potential of the Nervilia plicata, justifying the use of plant in the indigenous system of medicine. Isolation and characterisation of the compound(s) playing pivotal role in the cure would open new vistas in the therapy of type 2 diabetes.     

The efficacy of Prosopis glandulosa as antidiabetic treatment in rat models of diabetes and insulin resistance

Ethnopharmacological relevance

Diabetes mellitus is rampantly increasing and the need for therapeutics is crucial. In recognition of this, untested antidiabetic agents are flooding the market. Diavite™ which is a product consisting solely of the dried and ground pods of Prosopis glandulosa (Torr.) [Fabaceae] is currently marketed as a food supplement with glucose stabilizing properties. However, these are anecdotal claims lacking scientific evidence. The aim of this study was to determine the efficacy of Prosopis glandulosa as an antidiabetic agent.

Materials and methods

Male Wistar rats were rendered (a) type 1 diabetic after an intraperitoneal injection of STZ (40 mg/kg) and (b) insulin resistant after a 16-week high caloric diet (DIO). Zucker fa/fa ZDF rats were used in a pilot study. Half of each group of animals was placed on Prosopis glandulosa treatment (100 mg/kg/day) for 8 weeks and the remaining animals served as age-matched controls. At the time of sacrifice, blood was collected for glucose and insulin level determination, the pancreata of the STZ rats were harvested for histological analysis and cardiomyocytes prepared from the DIO and Zucker fa/fa hearts for determination of insulin sensitivity.

Results

Type 1 diabetic model: Prosopis glandulosa treatment resulted in significant increased insulin levels (p < 0.001), which was accompanied by a significant decrease in blood glucose levels (p < 0.05). Additionally, Prosopis glandulosa treatment resulted in increased small β-cells (p < 0.001) in the pancreata. The body weight of the STZ animals decreased significantly after STZ injection, with Prosopis glandulosa treatment partially preventing this. Zucker fa/fa rats: Prosopis glandulosa treatment significantly reduced fasting glucose levels (p < 0.01) and improved IPGTT, when comparing treated to untreated animals. DIO insulin resistant model: Prosopis glandulosa treatment resulted in an increased basal (p < 0.01) and insulin-stimulated (p < 0.05) glucose uptake by cardiomyocytes prepared from this group.

Conclusions

The present study showed that Prosopis glandulosa treatment moderately lowers glucose levels in different animal models of diabetes, stimulates insulin secretion, leads to the formation of small β-cells and improves insulin sensitivity of isolated cardiomyocytes.     

Effect of Cydonia oblonga Mill. leaf extract on serum lipids and liver function in a rat model of hyperlipidaemia

Ethnopharmacological relevance

Cydonia oblonga Mill. leaves are traditionally used in Uyghur medicine to treat or prevent cardiovascular disease. Beyond a demonstrated effect on thrombosis, we tested it for an effect on dyslipidemia, in a rat model of hyperlipidemia.

Methods

Seventy healthy Sprague Dawley rats were randomly divided into 6 groups: normal controls, model controls, simvastatin, and low-, medium- and high-dose Cydonia oblonga Mill. leaf extracts (COM), orally for 56 days. The normal controls were fed a normal diet, all other groups a high fat diet. Rat weights were recorded over time. Total cholesterol (TC), triglycerides (TG), low and high-density lipoproteins (LDL, HDL), as well as AST, ALT and total protein (TP) were measured in serum at the end of the study. The antioxidant capacity of glutathione peroxidase (GSH-PX), superoxide dismutase (SOD), malondialdehyde (MDA) was measured in liver samples, along with lipoprotein lipase (LPL), and hepatic lipase (HL). Liver pathology was described.

Results

COM dose-dependently reduced TC, TG, LDL-C and MDA, inhibited the activity of ALT, AST and LPS, increased HDL-C content, increased the activity of SOD, GSH-PX, LPL and HL, and reduced liver steatosis in hyperlipidaemia rats, which was significant at medium and high doses. The effect of COM was similar to that of simvastatin except for increased LPL and HL which were reduced by COM but not by simvastatin.

Conclusion

Cydonia oblonga Mill. leaf extracts have hypolipidaemic and hepatoprotective effects, probably related to increasing antioxidant capacity and lipoprotein metabolism in the liver, and inhibition of lipogenesis.     

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.     

Effect of Cydonia oblonga Mill. fruit and leaf extracts on blood pressure and blood rheology in renal hypertensive rats

Ethnopharmacological relevance

Quince, Cydonia oblonga Mill. (COM), is used in traditional Uyghur medicine to treat or prevent cardiovascular diseases. Uyghur people have greater longevity and lower blood pressure than other central Asian populations. We therefore tested COM fruit and leaf extracts on blood pressure and rheology in renal hypertensive rats (RHR).

Materials and methods

Two-kidney, one-clip (2K1C) renal hypertensive rats were divided randomly into eleven groups: sham, model, and model treated with daily doses of 80 and 160 mg/kg aqueous or ethanol extracts of COM fruit or leaves, or 25 mg/kg captopril (n=10 per group), given orally once daily for 8 weeks. Blood pressure was measured before treatment and every 2 weeks thereafter. Blood rheology was tested after 8 weeks.

Results

Model rats had higher blood pressure than sham 8 weeks after the procedure (systolic blood pressure 193±7 vs. 138±8 mmHg, p<0.05). Those treated with captopril had decreased blood pressure within 2 weeks but that did not return to the level found in the sham group at 8 weeks (167±7, p<0.05 vs. model). With the COM extracts, the effect on blood pressure was notable after 4 weeks. At 8 weeks blood pressure was similar with captopril and with 160 mg ethanol leaf extract (166±4, p<0.05 vs. model), the most effective of the extracts. Model rats had higher blood viscosity and lower erythrocyte deformability than sham. Captopril had little effect on blood rheology; whereas COM extracts reduced whole blood viscosity and improved erythrocyte deformability to levels approaching those found in sham.

Conclusions

COM extracts have antihypertensive activity in renal hypertensive rats. The additional effect on rheology, compared to captopril, may convey added interest. Further studies of these effects in man appear warranted.