Preventive effects of Cassia auriculata L. flowers on brain lipid peroxidation in rats treated with streptozotocin

Evaluation of Antidiabetic, Antioxidant and Anti-Hyperlipidemic Effects of Solanum indicum Fruit Extract in Streptozotocin-Induced Diabetic Rats

BACKGROUND

Globally, diabetes mellitus is the most common cause of premature mortality after cardiovascular diseases and tobacco chewing. It is a heterogeneous metabolic disorder characterised by the faulty metabolism of carbohydrates, fats and proteins as a result of defects in insulin secretion or resistance. It was estimated that approximately 463 million of the adult population are suffering from diabetes mellitus, which may grow up to 700 million by 2045. Solanum indicum is distributed all over India and all of the tropical and subtropical regions of the world. The different parts of the plant such as the roots, leaves and fruits were used traditionally in the treatment of cough, asthma and rhinitis. However, the hypoglycaemic activity of the plant is not scientifically validated.

PURPOSE

The present study aimed to evaluate the antioxidant, antidiabetic and anti-hyperlipidaemic activity of methanolic fruit extract of Solanum indicum (SIE) in streptozotocin (STZ) induced diabetic rats.

METHOD

Experimentally, type II diabetes was induced in rats by an i.p. injection of STZ at a dose of 60 mg/kg. The effect of the fruit extract was evaluated at doses of 100 and 200 mg/kg body weight in STZ-induced diabetic rats for 30 days.

RESULT

The oral administration of fruit extract caused a significant (p < 0.05) reduction in the blood glucose level with a more prominent effect at 200 mg/kg. The fruit extract showed dose-dependent α-amylase and α-glycosidase inhibitory activity. It reduced the serum cholesterol and triglyceride levels remarkably in diabetic rats compared to normal. The extract showed the reduced activity of endogenous antioxidants, superoxide dismutase, glutathione peroxidase and catalase in the liver of STZ diabetic rats.

CONCLUSION

The result confirmed that the fruit extract of Solanum indicum showed a dose-dependent blood glucose lowering effect and significantly reduced elevated blood cholesterol and triglycerides. It prevented oxidative stress associated with type II diabetes in STZ rats.

Ethnopharmacological, Phytochemical, Pharmacological, and Toxicological Review on Senna auriculata (L.) Roxb.: A Special Insight to Antidiabetic Property

Avartaki (Senna auriculata (L.) Roxb. syn. Cassia auriculata L.; Family- Fabaceae ) is a traditional medicinal plant, widely used for the treatment of various ailments in Ayurveda and Siddha system of medicine in India. Almost all the parts of the plant, such as flowers, leaves, seeds, barks, and roots have been reported for their medicinal uses. Traditionally, it has been used in the treatment of diabetes, asthma, rheumatism, dysentery, skin disease, and metabolic disorders. The principle phytochemicals in Senna auriculata (L.) Roxb. are alkaloids, anthraquinone, flavone glycosides, sugar, saponins, phenols, terpenoids, flavonoids, tannins, steroids, palmitic acid, linoleic acid, benzoic acid 2-hydroxyl methyl ester, 1-methyl butyl ester, resorcinol, α-tocopherol-β-D-mannosidase, epicatechin, ferulic acid, quercetin-3-O-rutinoside, quercetin, proanthocyanidin B1. The extracts from its different parts and their isolated compounds possess a wide range of pharmacological activities such as antidiabetic, antioxidant, anti-inflammatory, antihyperlipidemic, hepatoprotective, nephroprotective, cardioprotective, anti-atherosclerotic, anticancer, antimutagenic, antimicrobial, antiulcer, antipyretic, anthelmintic, immunomodulatory, antifertility, anti-venom, and anti-melanogenesis. The toxicological findings from preclinical studies ensured the safety of the plant, but comprehensive clinical studies are required for the safety and efficacy of the plant in humans. The current review article aimed to provide up-to-date information about Senna auriculata (L.) Roxb. covering its ethnomedicinal, phytochemical, pharmacological, and toxicological aspects with special emphasis on its clinical implications in diabetes.

Cardioprotective effects of resveratrol following myocardial ischemia and reperfusion

Resveratrol (RSV), a plant origin polyphenol, has shown beneficial cardiovascular effects. In this study, isolated hearts from male Wistar rats were studied using the Langendorff technique. Following 30 min stabilization, the hearts underwent 30 min global ischemia and 120 min reperfusion. The perfusion solution in the test group contained RSV (10 μM). Hemodynamics of the hearts, the markers of myocardial damage including creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), and troponin I were studied during the study. Furthermore, the infarct size and the markers of oxidative stress including catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GPX) were assayed in the homogenates of the hearts. The release of nitrite from the hearts and the occurrence of ventricular arrhythmias were also monitored throughout the experiment. Resveratrol caused a significant improvement in the restoration of the mechanical performance of the hearts following myocardial ischemia and reperfusion (MIR). Besides, the infarct size, CK-MB, LDH, and troponin I declined in the test group. Besides, the cardiac release of nitrite increased, and the redox status of the heart was improved as indicated by the levels of CAT, SOD, GPX, and MDA. Finally, the treatment caused significant decreases in the occurrences of single and salvo arrhythmias, ventricular tachycardia, and ventricular fibrillation. The current study suggests strong cardioprotective and antiarrhythmic effects for RSV following MIR.

Herbal beverages: Bioactive compounds and their role in disease risk reduction - A review

There is a renewed interest in non-nutritive bioactive compounds of foods and beverages as 'lifespan nutrients' in the risk reduction of non-communicable diseases. Herbal beverages, consumed as part of a balanced diet, may improve the antioxidant status and enhance the overall health status. Herbal teas/beverages are rich sources of natural bioactive compounds such as carotenoids, phenolic acids, flavonoids, coumarins, alkaloids, polyacetylenes, saponins and terpenoids, among others. A wealth of available scientific evidence demonstrates that natural bioactive compounds render a number of diversified biological effects, such as antioxidant, antibacterial, antiviral, antiinflammatory, antiallergic, antithrombotic and vasodilatory actions, as well as antimutagenicity, anticarcinogenicity and antiaging effects. A number of herbal beverages are consumed globally and some beverages have gained more popularity than others depending on their geographical origin. However, in the era of globalization, ethnic barriers have gradually been removed and such commodities although from different areas, are now universally available as international health-pro products.

A role of Ficus species in the management of diabetes mellitus: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetes mellitus is one of the most common global health concerns, with a rapidly increasing incidence. A variety of medicinal plants, particularly those belonging to the genus Ficus (Moraceae), and their active compounds have been used to treat diabetes and related chronic disorders since ancient times.

AIM OF THE STUDY

The aim of this review is to provide information regarding traditional and scientific knowledge of Ficus species with antidiabetic activity to researchers.

MATERIALS AND METHODS

A literature search was conducted to obtain information about the antidiabetic properties of Ficus from the electronic databases. Common and scientific names of various Ficus species were used as keywords for the search, along with the terms antidiabetic, hypoglycemic and diabetes.

RESULTS

Among the assorted species of Ficus that were included in our search, F. benghalensis, F. carica, F. glomerata, F. glumosa, F. racemosa, and F. religiosa exhibited remarkable antidiabetic properties with various mechanisms of action. Moreover, Ficus species are versatile sources of bioactive metabolites such as flavonoids, phenolic acids, tannins, alkaloids, glycosides, coumarins, triterpenoids, sterols and vitamin E. These extracts and isolated compounds significantly have enhanced insulin secretion and subsequently reduced blood glucose level in various in vivo studies.

CONCLUSION

This review summarizes the antidiabetic potentials of the genus Ficus, including pharmacological studies with mechanisms of action as well as ethnobotanical uses. This review can help inform future scientific research towards the development of novel antidiabetic drugs.

Effect of natural products on diabetes associated neurological disorders

Diabetes mellitus, a metabolic disorder, is associated with neurological complications such as depression, anxiety, hypolocomotion, cognitive dysfunction, phobias, anorexia, stroke, pain, etc. Traditional system of medicine is long known for its efficient management of diabetes. The current review discusses the scope of some common medicinal herbs as well as secondary metabolites with a special focus on diabetes-mediated central nervous system complications. Literatures suggest that natural products reduce diabetes-mediated neurological complications partly by reducing oxidative stress and/or inflammation or apoptosis in certain brain regions. Natural products are known to modulate diabetes-mediated alterations in the level of acetylcholinesterase, choline acetyltransferase, monoamine oxidase, serotonin receptors, muscarinic receptors, insulin receptor, nerve growth factor, brain-derived neurotrophic factor, and neuropeptide in brain. Further, there are several natural products reported to manage diabetic complications with unknown mechanism. In conclusion, medicinal plants or their secondary metabolites have a wide scope and possess therapeutic potential to effectively manage neurological complications associated with chronic diabetes.

Antihyperlipidemic activity of Cassia auriculata flower extract in oleic acid induced hyperlipidemia in Saccharomyces cerevisiae

The Cassia auriculata herb has been traditionally used in India for medicinal purposes to treat hyperglycemia, diabetes, rheumatism, asthma, and skin diseases. In the present study, ethanolic extract of Cassia auriculata flower (Et-CAF) depicted anti-hyperlipidemic effect in the budding yeast cells. The hyperlipidemic conditions were induced in the yeast cells with oleic acid which showed an increase in triacylglycerol (TAG) and sterol esters (SE), and was supported by the mRNA expression of LRO1 and DGA1 (involved in TAG formation); as well as ARE1 and ARE2 (involved in SE formation). The anti-hyperlipidemic effect by the Et-CAF was compared with the commercial drug Atorvastatin. The lipid droplets were increased in the hyperlipidemic yeast cell that was observed under the confocal microscope with BODIPY staining; Atorvastatin and Et-CAF reduced the lipid droplets. This study revealed that the anti-hyperlipidemic effect in Et-CAF has gained importance and might be used to fill the gap created by the allopathic drugs.

In vitro alpha-amylase inhibition and in vivo antioxidant potential of Momordica dioica seeds in streptozotocin-induced oxidative stress in diabetic rats

Momordica dioica Roxb. Commonly known as "Kakora" in Telugu, is used in the Indian traditional system of medicine for the treatment of diabetes. The aim of this study was to investigate the antidiabetic activity of methanolic extract of M. dioica seeds (MEMD) in streptozotocin (STZ) induced diabetic rats. The in vitro α-amylase inhibitory activity of the MEMD was done by spectrophotometric method. Diabetes was induced by STZ (45 mg/kg; i.p), MEMD (100 & 200 mg/kg; b.wt) and standard drug metformin (50 mg/kg; b.wt) were administered to the diabetic rats. Blood glucose was estimated on the 11th day and the level of MDA, SOD and CAT was estimated in the liver tissue homogenate after the 15 days of experimental period. MEMD showed significant inhibition of alpha amylase activity and the IC₅₀ was found to be 48 μg/ml. Oral administration of MEMD significantly reduced blood glucose level (P < 0.05), diminished the MDA level and refurbished depleted antioxidant enzymes and Insulin level to normalcy. These findings revealed that M. dioica seeds possess antihyperglycemic, antioxidant and anti lipid peroxidative activity and thus mitigate STZ-induced oxidative damage.

In vivo anti-diabetic, antioxidant and molecular docking studies of 1, 2, 8-trihydroxy-6-methoxy xanthone and 1, 2-dihydroxy-6-methoxyxanthone-8-O-β-D-xylopyranosyl isolated from Swertia corymbosa

1, 2, 8-trihydroxy-6-methoxy xanthone (1) and 1, 2- dihydroxy-6-methoxyxanthone-8-O-β-d-xylopyranosyl (2) are the main constituents of petroleum ether and ethyl acetate extracts from Swertia corymbosa (Gentinaceae), a medicinal plant used in Indian traditional system for the treatment of diabetes. The present study was designed to examine the antihypoglycemic, antihyperlipidemic and antioxidant effect of compounds 1 and 2 in streptozotocin (STZ) induced diabetic rats. Diabetes was induced in male Wistar rats by a single intraperitoneal injection of STZ (60 mg/kg b.w.). The isolated compounds 1 and 2 at a dose of 50 mg/kg b.w., produced the maximum fall of 83% in the blood glucose level in the diabetic rats after 3h of the treatment. The administration of 1 and 2 (50 mg/kgb.w.) daily for 28 days in STZ induced diabetic rats, resulted in a significant decrease in blood glucose, glycosylated hemoglobin, SGOT, SGPT, ALP serum urea and creatinine with significant rise in plasma insulin level. Test compounds 1 and 2 showed antihyperlipidemic activities as evidenced by significant decrease in serum TC, TG, LDL-C, VLDL-C levels coupled together with elevation of HDL-C level in diabetic treated rats when compared to diabetic untreated rats, indicate the protective role against liver and kidney damage. The results of histopathology also showed 1 and 2 protected tissues (pancreas, liver and kidney) against peroxidation damage and maintained tissue integrity. Further, the molecular interaction study of the ligands 1, 2 and glibenclamide with various diabetes mellitus related protein targets like glucokinase (PDB ID: 1V4S), fructose-1, 6-bisphosphatase 1 (PDB ID: 2JJK) 11-β-hydroxysteroid dehydrogenase (PDB ID: 2BEL) and modeled protein sulfonylurea receptor 1 (SUR1) showed that ligand 1 and 2 possess binding affinity with all protein targets except for 2BEL target protein for which ligand 1 has no interaction. The ligand pose with 2BEL and SUR1 protein target of ligand 2 gave the best binding conformation. Hence 1 and 2 can be considered for developing into a potent antidiabetic drug.

Effects of N-adamantyl-4-methylthiazol-2-amine on hyperglycemia, hyperlipidemia and oxidative stress in streptozotocin-induced diabetic rats

Thiazole derivatives are attractive candidates for drug development because they can be efficiently synthesized and are active against a number of diseases and conditions, including diabetes. In our present study, we investigated the anti-inflammatory and antioxidant properties of N-adamantyl-4-methylthiazol-2-amine (KHG26693), a new thiazole derivative, in a streptozotocin (STZ)-induced model of diabetes mellitus. STZ-induced diabetic rats were intraperitoneally administered KHG26693 (3mg/kg-body weight/day) for 4 weeks. KHG26693 administration significantly decreased blood glucose, triglycerides, and cholesterol and increased insulin. KHG26693 also suppressed several inflammatory responses in STZ-induced diabetic rats, as evidenced by decreased levels of serum tumor necrosis factor-α, interleukin-1β, and nitric oxide. Additionally, KHG26693 significantly modulated hepatic lipid peroxidation, catalase and superoxide dismutase activity, and the nonenzymatic antioxidant status (e.g., vitamins C and E), and reduced the glutathione content. These anti-inflammatory/antioxidative actions occurred as a result of the downregulation of inducible nitric oxide synthase and nuclear factor-kappa B. Taken together, our results suggest that KHG26693 successfully reduces the production of oxidative stress in STZ-induced diabetic rats by regulating the oxidation-reduction system, specifically increasing antioxidant capacity. Furthermore, KHG26693 treatment significantly reverted the key enzymes of glucose metabolism, such as glucokinase, glucose-6-phosphatase, glycogen synthase, glycogen phosphorylase, and fructose-1,6-bisphosphatase, to near-normal levels in liver tissues. These results indicate that KHG26693 normalizes disturbed glucose metabolism by enhancing glucose utilization and decreasing liver glucose production via insulin release, suggesting the possibility of future diabetes treatments.

Antidiabetic activity of Ficus amplissima Smith. bark extract in streptozotocin induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ficus amplissima commonly known as kal-itchchi have a long history of use in Ayurveda, Siddha and Unani herbal preparations in Indian traditional system of medicine. It has been used in folklore medicine for the treatment of diabetes.

AIM

The aim of the present study was to evaluate the effect of methanolic extract of the bark of Ficus amplissima (FAB) in streptozotocin-induced diabetic rats.

MATERIALS AND METHODS

Oral administration of FAB bark at the doses of 50mg/kg, 100mg/kg and 150 mg/kg was studied in normal, glucose-loaded and STZ-induced diabetic rats.

RESULTS

The three doses caused significant reduction in blood glucose levels in all the models. The effect was more pronounced in 50mg/kg and 100mg/kg than 150 mg/kg. FAB also showed significant increase in serum insulin and body weight. The glycogen content in liver, skeletal muscle, total protein contents were markedly increased and marker enzymes of hepatic function of STZ-induced diabetic rats while there was significant reduction in the levels of serum triglyceride and total cholesterol. FAB also showed significant anti-lipid peroxidative effect in the pancreas of STZ-induced diabetic rats. The anti-diabetic effect of FAB was compared with glibenclamide, a well known hypoglycemic drug. Histological analysis showed the regenerative effect of FAB on the β-cells of diabetic rats.

CONCLUSION

Results of this experimental study indicated that FAB possessed anti-diabetic and antioxidant activities. Hence it could be used as a natural source of antidiabetic (Type-I) and antioxidant drug.

Antioxidant Effect of Tinospora cordifolia Extract in Alloxan-induced Diabetic Rats

Many plants are claimed to possess antidiabetic and antioxidant activity. In practice, it is being increasingly recognized to be an alternative approach to modern medicine. This study assess the antioxidant capacity of Tinospora cordifolia stem methanol extract in daily oral administration of 500 mg/kg of body weight for 40 days in alloxan induced diabetic rats. The erythrocytes membrane lipid peroxide and catalase activity was increased where as the activities of superoxide dismutase, glutathione peroxidase were found to be decreased significantly (P<0.01) in alloxan-induced diabetic rats. The levels of lipid peroxide in liver of diabetic rats increased significantly (P<0.01) and catalase, superoxide dismutase, glutathione peroxidase in liver was significantly decreased in alloxan-induced diabetic rats, when compared to normal rats. After treatment of methanol Tinospora cordifolia stem extract brings back to normal (P<0.01) in the erythrocytes membrane and liver cell enzymes activities.

Hypolipidemic and hypoglycemic effects of Orostachys japonicus A. Berger extracts in streptozotocin-induced diabetic rats

The hypolipidemic and hypoglycemic effects of two dietary dosages (0.1% and 0.5%) of water and 80% ethanol extracts from hot-air dried Orostachys japonicus A. Berger were evaluated in the serum and organ tissues of streptozotocin-induced diabetic rats. The STZ-induced diabetic groups supplemented with the O. japonicus extracts showed significantly higher body weight compared to a diabetic control group at the end of experiment. The extracts exhibited substantial hypoglycemic effects by significant reductions of fasting blood glucose levels at all time points tested compared to the initial stage before treatment of the extracts. Declines of serum and hepatic triglyceride levels were greater than declines of total cholesterol in the groups treated with the 0.5% O. japonicus extract (DBW2 and DBE2) when compared to the DBC group. Hepatic glycogen content was higher in the groups treated with O. japonicus extract, while lipid peroxide content was decreased in these treated groups compared to the DBC group. Hepatic antioxidant activity was significantly increased in the groups supplemented with the O. japonicus ethanol extract. The hypolipidemic and hypoglycemic effects of the O. japonicus ethanol extract were significantly greater than the effects of the water extract. Based on this study, it seems that O. japonicus ethanol extract, due to its higher phenolic and flavonoid components than the water extract, may control blood glucose and alleviate hyperlipidemia in diabetes.

Immunomodulatory activity of polyphenols derived from Cassia auriculata flowers in aged rats

The immunomodulatory activity of Cassia auriculata (CA)-derived polyphenols was tested on aged rats. Rats (24-26 months old) were given CA polyphenols supplementation at doses of 25, 50, and 100 mg/kg for 28 days. Flow cytometry analysis of CA polyphenols-treated aged rats showed increased T and B cells percentage along with enhanced proliferation of splenocytes in both resting and LPS-stimulated cells. Increased percentage of pan T cells is further supported by an elevation of CD4+, CD8+, and CD4+CD25+ regulatory cells. In terms of innate immune cell activity, CA polyphenol supplementation reduced the oxidative burst activity of neutrophils in response to PMA and Escherichia coli activation. Our results collectively show that polyphenols derived from CA boost T cell immunity by increasing the number of T cells and its sensitivity towards stimulants and decreasing ROS production by neutrophils that could potentially harm multiple biological systems in aged individuals.

Cassia auriculata: Aspects of Safety Pharmacology and Drug Interaction

Safety pharmacology studies help in identifying preclinical adverse drug reactions. We carried out routine safety pharmacology with focus on cardiovascular variables and pharmacokinetic herb-drug interaction studies on rats fed with standardized traditional hydro-alcoholic extract and technology-based supercritical extract of Cassia auriculata for 12 weeks. Our studies indicate that both these extracts are pharmacologically safe and did not show any significant adverse reactions at the tested doses. The traditional hydro-alcoholic extract did not show any significant effect on pharmacokinetics; however, the technology-based supercritical extract caused a significant reduction in absorption of metformin. Our results indicate the need to include pharmacokinetic herb-drug interaction studies as evidence for safety especially for technology-based extracts.

Effect of alcohol on blood glucose and antioxidant enzymes in the liver and kidney of diabetic rats

OBJECTIVE

Diabetes mellitus affects every organ in the man including eyes, kidney, heart, and nervous system. Alcohol consumption is a widespread practice. As the effects of chronic alcohol consumption on diabetic state have been little studied, this study was conducted with the objective of evaluating the effect of alcohol in diabetic rats.

MATERIALS AND METHODS

For this study, the rats were divided into five groups (n = 6 in each group): normal control (NC), alcohol treatment (At), diabetic control (DC), diabetic plus alcohol treatment (D + At), diabetic plus glibenclamide treatment (D + Gli). Alcohol treatment was given to the diabetic rats for 30 days. During the period the blood glucose levels, and body weight changes were observed at regular intervals. The antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) levels were assayed in the liver and kidney tissues.

RESULTS

The blood glucose levels were significantly (P < 0.001) elevated and body weight significantly (P < 0.001) decreased in alcohol-treated diabetic rats. SOD and CAT activities were decreased and the MDA level increased significantly (P < 0.001) in alcohol-treated diabetic rats. Histopathological studies showed that alcohol damages the liver and kidney tissues in diabetic rats.

CONCLUSION

These finddings concluded that the consumption of alcohol in diabetic rats worsens the condition. So the consumption of alcohol by diabetic subjects may be potentially harmful.

Antioxidative action of corni fructus aqueous extract on kidneys of diabetic mice

This study investigated the antioxidative action of Corni Fructus aqueous extract on kidneys of diabetic mice. The electron donating abilities of Corni Fructus aqueous extract and its antioxidant activities (XO, SOD, CAT, GST, eNOS) in kidneys of C57BL/6 or db/db mice were evaluated. For in vivo study, seven week-old male mice were divided into normal control group (NC, C57BL/6 mice) , diabetic control group (DC, db/db mice) and Corni Fructus (500 mg/kg/day for 8 weeks) treated diabetic group (DCF, db/db mice) . The electron donating abilities of Corni Fructus aqueous extract exhibited 7%, 24.4%, and 42.7% at concentrations of 100, 500, and 1000 μg/ml, respectively. The activity of XO in the DCF group was significantly lower than the DC group by 35% (p < 0.05) . The SOD activity was significantly higher in the DCF group than the DC group by 26% (p < 0.05) . The activities of CAT and GST were lowered in the DCF group than the DC group by 26% (p < 0.05) and 7.6%, respectively. The mRNA expression of eNOS in kidneys was lower in the DCF group than the DC group by 24%. These results indicate that Corni Fructus reduced oxidation stress as evidenced by the restoration of the enzymatic antioxidative defense system in renal tissues of db/db mice. It is suggested that these antioxidative actions of Corni Fructus on renal tissues in db/db mice could contribute to its renoprotective effects on diabetic nephropathy.

Antidiabetic activity of aqueous bark extract of Cassia glauca in streptozotocin-induced diabetic rats

The leaves and bark of Cassia glauca Lam., a glabrous tree in the family Fabaceae, are used in folk medicine for the treatment of diabetes. The aim of this study was to investigate the antidiabetic activity of the aqueous extract of C. glauca bark. The various parameters that were studied in treated or untreated normoglycemic and STZ-induced diabetic rats included the effect of the aqueous extract on oral glucose tolerance, fasting blood glucose, body weight, serum lipids, liver glycogen, serum insulin, and glycosylated haemoglobin. Oral administration of the aqueous extract of C. glauca bark at a dose of 500 mg/kg significantly reduced the effect of external glucose load. In a chronic treatment model, aqueous extract and glibenclamide (0.25 mg/kg) were administered for 21 days. At the end of the treatment, there was a significant increase in liver glycogen, serum insulin, and HDL cholesterol for both treatments. A significant decrease in fasting blood glucose, glycosylated haemoglobin, total cholesterol, and serum triglycerides was also observed. The body weights of the animals were observed to be consistent throughout the study. The findings showed the significant antidiabetic potential of the extract in ameliorating the diabetic condition in the diabetic rats. No significant activity was found in the normoglycemic rats.

Effect of combined therapy of diabinese and nicotinic acid on liver enzymes in rabbits with dithizone-induced diabetes

The effects of diabinese, a known antidiabetic drug, and the combined effects of diabinese and nicotinic acid, a vitamin and antilipidemic drug, were studied in rabbits with dithizone-induced diabetes. Side effects of diabinese include hypoglycemia and liver toxicity. Dithizone was used to induce partial experimental diabetes and to increase blood glucose significantly (P < 0.05) by 31.3%, 23.5%, 19.5, 24.7%, and 23.9% in groups A (single therapy of diabinese 10 mg/kg body weight), B (10 mg of diabinese and nicotinic acid 150 mg/kg), C (10 mg diabinese and nicotinic acid 200 mg/kg), D (10 mg diabinese and nicotinic acid 250 mg/kg) and E control (distilled water 5 mL), respectively. Dithizone administration also increased bilirubin, alkaline phosphatase (ALP), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels by 28.9%-35.6%, 41.2%-54.8%, 40.1%-46.1%, and 60.9%-68.4%, respectively. Diabinese monotherapy reduced bilirubin levels, while combined therapy reduced glucose, ALP, AST, and ALT levels more than single therapy. Reduction from the hyperglycemic level 48 hours after drug administration was 20.0%, 24.6%, 41.0%, and 42.0% for groups A, B, C, and D, respectively, and was concentration-dependent. Also, combined therapy produced a significant (P < 0.05) decrease in AST and ALT levels, especially at 72 hours after drug administration, but did not affect ALP levels. No significant changes in glucose, bilirubin, ALP, AST, and ALT levels were observed in Group E (control). This study shows that liver toxicity and the hypoglycemic side effects of diabinese could be managed by the concomitant administration of nicotinic acid.

Perturbation in kidney lipid metabolic profiles in diabetic rats with reference to alcoholic oxidative stress

Diabetes is a major threat to global public health, and the number of diabetic patients is rapidly increasing worldwide. Evidence suggests that oxidative stress is involved in the pathophysiology of diabetic complications and alcoholic diseases. The aim of this study is to find out the impact of alcohol on lipid metabolic profiles in kidney tissue under streptozotocin induced diabetic condition. No study has been reported so far on the effect of alcohol on diabetic condition and also with reference to lipid metabolic profiles. Hence, the present study has been designed to elucidate the impact of alcoholism on diabetic condition. Male wistar strain albino rats were randomly divided into four groups: control (saline treated) NC, alcohol-treated (At), diabetic control (DC), and alcohol-treated diabetic rats (D+At). In alcohol-treated diabetic rats, we observed high levels of MDA, total cholesterol, triglycerides, phospholipids and also high levels of blood glucose than other groups. Moreover, degenerative changes of renal cells in alcohol-treated diabetic group were maximized by administration of alcohol as evinced by histopathological examination. This study suggests that alcohol consumption could be an aggravation factor which contributes for the formation of free radicals in diabetic condition. Therefore, consumption of alcohol during diabetic condition is harmful.

Bacopa monnieri modulates antioxidant responses in brain and kidney of diabetic rats

Role of oxidative stress has been reported in various diabetic complications including neuropathy, nephropathy and cardiopathy. This study was undertaken to evaluate the protective effect of Bacopa monnieri, a medicinal plant, on tissue antioxidant defense system and lipid peroxidative status in streptozotocin-induced diabetic rats. Extract of B. monnieri was administered orally, once a day for 15 days (at doses 50, 125 and 250mg/(kgbw)) to diabetic rats. Activity of antioxidant enzymes (SOD, Catalase, and GPx), levels of GSH and lipid peroxidation were estimated in kidney, cerebrum, cerebellum and midbrain of diabetic rats and compared to reference drug, Glibenclamide. Administration of plant extract to diabetic rats showed significant reversal of disturbed antioxidant status and peroxidative damage. Significant increase in SOD, CAT, GPx activity and levels of GSH was observed in extract treated diabetic rats. The present study indicates that extract of B. monnieri modulates antioxidant activity, and enhances the defense against ROS generated damage in diabetic rats.

Antioxidant and pancreas-protective effect of aucubin on rats with streptozotocin-induced diabetes

Oxidative stress has been suggested as a contributory factor in development and complication of diabetes. The aim of the present study was to determine the protective effect of aucubin on lipid peroxidation and activities of antioxidant defense systems and to conduct immunohistochemical evaluation of pancreas in streptozotocin-induced diabetic rats. Lipid peroxidation was determined by assessing the concentration of malondialdehyde and activities of antioxidant enzymes - catalase, glutathione peroxidase and superoxide dismutase in liver and kidneys of rats were determined. Changes of blood glucose and immunohistochemical evaluation on pancreas were also investigated as part of the pathology of diabetes. In our study, aucubin treatment lowered blood glucose. Diabetic rats exhibited an increase in the level of lipid peroxidation and decrease in activities of antioxidant enzymes in liver and kidneys as compared to control rats. Administration of aucubin to diabetic rats for 15 days significantly reversed damage associated with diabetes. In addition, diabetic rats showed an obvious decrease in insulin immunoreactivity and the number of beta cells in pancreas, but the pancreas of aucubin-treated rats were improved and the number of immunoreactive beta cells were significantly increased. These results indicated that aucubin may have value as a safe preventive or therapeutic agent against diabetes mellitus.

Tetrahydrocurcumin prevents brain lipid peroxidation in streptozotocin-induced diabetic rats

Oxidative damage has been suggested to be a contributory factor in the development and complication of diabetes. To investigate the effect of tetrahydrocurcumin (THC) on the occurrence of oxidative stress in the brain of rats during diabetes, we investigated the extent of oxidative damage as well as the status of the antioxidant defense system. Oral administration of THC at 80 mg/kg of body weight to diabetic rats for 45 days resulted in a significant reduction in blood glucose and significant increase in plasma insulin levels. In addition, THC caused significant increases in the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, and reduced glutathione in the brains of diabetic rats with significant decrease in the lipid peroxidative markers thiobarbituric acid-reactive substances and hydroperoxides in brain, suggesting efficacy for protection against lipid peroxidation-induced membrane damage. The effect of THC was greater than that of curcumin. Results of the present study suggest that THC showed antioxidant effects in addition to its antidiabetic effect in type 2 diabetic rats.

POSSIBLE ANTIDIABETIC AND ANTIHYPERLIPIDAEMIC EFFECT OF FERMENTED PARKIA BIGLOBOSA (JACQ) EXTRACT IN ALLOXAN-INDUCED DIABETIC RATSs

1. The hypoglycaemic effect of fermented seeds of Parkia biglobosa (PB; African locust bean), a natural nutritional condiment that features frequently in some African diets as a spice, was investigated in the present study in alloxan-induced diabetic rats. Its effect was compared with that of glibenclamide (Daonil; Sanofi-Aventis, Paris, France), a reference antidiabetic drug. The effects of PB on lipid profiles were also examined. 2. In order to assess the hypoglycaemic and hypolipidaemic effects of aqueous and methanolic extracts of PB on experimental animals, fasting plasma glucose (FPG), total cholesterol, triglyceride, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) were determined. In addition, the weight of each animal was determined to assess any possible weight gain or loss in the experimental animals (diabetic rats treated with Daonil (group C), the aqueous extract of PB (group D) or the methanolic extract of PB (group E)) compared with control groups (non-diabetic (group A) and non-treated diabetic (group B)). 3. A single dose of 120 mg/kg, i.v., alloxan administered to rats resulted in significant increases in the FPG (P < 0.001) of test animals compared with controls. However, dietary supplementation with PB (6 g/kg extract for 4 weeks administered orally using an intragastric tube) ameliorated the alloxan-induced diabetes in a manner comparable with that of the reference antidiabetic drug glibenclamide. Aqueous and methanolic extracts of PB (6% w/w) elicited 69.2% and 64.4% reductions, respectively, in FPG compared with 70.4% in 0.01 mg/150 g glibenclamide-treated rats. 4. Although animals treated with the aqueous extract of PB gained weight in manner similar to normal controls, animals given the methanolic extract and glibenclamide lost weight in manner similar to non-treated diabetic rats. In addition, high levels of HDL and low LDL were observed in animals treated with the aqueous extract of PB, a pattern similar to that seen in normal controls. Low levels of HDL and high levels of LDL were observed in animals treated with the methanolic extract of PB, a pattern similar to that seen in non-treated diabetic controls. 5. The results of the present study demonstrate that both aqueous and methanolic extracts of fermented seeds of PB exert a hypoglycaemic effect; hence, PB has an antidiabetic property. However, only the aqueous extract of PB ameliorated the loss of bodyweight usually associated with diabetes. Although the aqueous extract has a favourable lipid profile, which is probably an indication of its possible anti-arteriogenic property (hypertension and ischaemic heart diseases being common complications in diabetes mellitus), the methanolic extract shows possible contraindication to ischaemic heart diseases.

Effects of soy protein and genistein on blood glucose, antioxidant enzyme activities, and lipid profile in streptozotocin-induced diabetic rats

In the current study, the effect of soy protein and genistein, one of the main isoflavones in soybeans, on blood glucose, lipid profile, and antioxidant enzyme activities in streptozotocin (STZ)-induced diabetic rats was investigated. Male Sprague-Dawley rats were divided into nondiabetic control, STZ, STZ-genistein supplemented group (STZ-G; 600 mg/kg diet), and STZ-isolated soy protein supplemented group (STZ-ISP; 200 g/kg diet). Diabetes was induced by a single injection of STZ (50 mg/kg BW) freshly dissolved in 0.1 mol/L citrate buffer (pH 4.5) into the intraperitonium. Diabetes was confirmed by measuring the fasting blood glucose concentration 48-h post-injection. The rats with blood glucose level above 350 mg/dL were considered to be diabetic. Genistein and ISP were supplemented in the diet for 3 weeks. The supplementation of genistein and ISP increased the plasma insulin level but decreased the HbA(IC) level of the STZ-induced diabetic rats. The supplementation of genistein and ISP increased the glucokinase level of the STZ-induced diabetic rats. A significant reduction in glucose-6-phosphatase was observed in the groups treated with genistein and ISP in comparison with the diabetic control group. Hepatic superoxide dismutase, catalase, and glutathione peroxidase activities of the STZ-induced diabetic rats were significantly decreased in comparison with the control rats. Administering genistein and ISP to the STZ-induced diabetic rats significantly increased those enzyme activities. The concentration of thiobarbituric acid reactive substances in the STZ-induced diabetic rats was significantly elevated, while the genistein and ISP supplement decreased it to the control concentration. Genistein and ISP supplements seem to be beneficial for correcting the hyperglycemia and preventing diabetic complications.

Leads from Indian medicinal plants with hypoglycemic potentials

Diabetes mellitus is caused due to deficiency in production of insulin by the pancreas, or by the ineffectiveness of the insulin produced. It is a global problem and number of those affected is increasing day by day. The plants provide a potential source of hypoglycemic drugs because many plants and plant derived compounds have been used in the treatment of diabetes. Several medicinal plants have found potential use as hypoglycemic in the Indian system of medicines, including ayurveda. Many Indian plants have been investigated for their beneficial use in different types of diabetes and reports occur in numerous scientific journals. This article aims to provide a comprehensive review on various plant species from Indian biosphere and their constituents, which have been shown to display potent hypoglycemic activity. The use of herbs as hypoglycemic is a major avenue in Indian perspectives particularly for treating diabetes, which require to be explored more effectively as there are so many literatures available on these aspects. This paper describes the chemistry, activity and usage of the constituents isolated from these plants from India for the treatment of diabetes.

Antioxidant effect of tetrahydrocurcumin in streptozotocin-nicotinamide induced diabetic rats

Oxidative stress has been suggested to be a contributory factor in development and complication of diabetes. In the present study, we have investigated the effect of tetrahydrocurcumin (THC), one of the active metabolites of curcumin on antioxidants status in streptozotocin-nicotinamide induced diabetic rats. Oral administration of THC at 80 mg/kg body weight of diabetic rats for 45 days resulted in significant reduction in blood glucose and significant increase in plasma insulin levels. In addition, THC caused significant increase in the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase, reduced glutathione, vitamin C and vitamin E in liver and kidney of diabetic rats with significant decrease in thiobarbituric acid reactive substances (TBARS) and hydroperoxides formation in liver and kidney, suggesting its role in protection against lipid peroxidation induced membrane damage. These biochemical observations were supplemented by histopathological examination of liver and kidney section. The antidiabetic and antioxidant effects of THC are more potent than those of curcumin at the same dose. Results of the present study indicated that THC showed antioxidant effect in addition to its antidiabetic effect in type 2 diabetic rats.

Antihyperlipidemic Effect ofScoparia dulcis(Sweet Broomweed) in Streptozotocin Diabetic Rats

We have investigated Scoparia dulcis, an indigenous plant used in Ayurvedic medicine in India, for its possible antihyperlipidemic effect in rats with streptozotocin-induced experimental diabetes. Oral administration of an aqueous extract of S. dulcis plant (200 mg/kg of body weight) to streptozotocin diabetic rats for 6 weeks resulted in a significant reduction in blood glucose, serum and tissue cholesterol, triglycerides, free fatty acids, phospholipids, 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase activity, and very low-density lipoprotein and low-density lipoprotein cholesterol levels. The decreased serum high-density lipoprotein cholesterol, anti-atherogenic index, and HMG-CoA reductase activity in diabetic rats were also reversed towards normalization after the treatment. Similarly, the administration of S. dulcis plant extract (SPEt) to normal animals resulted in a hypolipidemic effect. The effect was compared with glibenclamide (600 microg/kg of body weight). The results showed that SPEt had antihyperlipidemic action in normal and experimental diabetic rats in addition to its antidiabetic effect.

Effect of Scoparia dulcis extract on insulin receptors in streptozotocin induced diabetic rats: studies on insulin binding to erythrocytes

We investigated the insulin-receptor-binding effect of Scoparia dulcis plant extract in streptozotocin (STZ)-induced male Wistar rats, using circulating erythrocytes (ER) as a model system. An aqueous extract of S dulcis plant (SPEt) (200 mg/kg body weight) was administered orally. We measured blood levels of glucose and plasma insulin and the binding of insulin to cell-membrane ER receptors. Glibenclamide was used as standard reference drug. The mean specific binding of insulin to ER was significantly lower in diabetic control rats (DC) (55.0 +/- 2.8%) than in SPEt-treated (70.0 +/- 3.5%)- and glibenclamide-treated (65.0 +/- 3.3%) diabetic rats, resulting in a significant decrease in plasma insulin. Scatchard plot analysis demonstrated that the decrease in insulin binding was accounted for by a lower number of insulin receptor sites per cell in DC rats when compared with SPEt- and glibenclamide-treated rats. High-affinity (Kd1), low-affinity (Kd2), and kinetic analysis revealed an increase in the average receptor affinity in ER from SPEt and glibenclamide treated diabetic rats having 2.5 +/- 0.15 x 10(10) M(-1) (Kd1); 17.0 +/- 1.0 x 10(-8) M(-1) (Kd2), and 2.0 +/- 0.1 x 10(-10) M(-1) (Kd1); 12.3 +/- 0.9 x 10(-8) M(-1) (Kd2) compared with 1.0 +/- 0.08 x 10(-10) M(-1) (Kd1); 2.7 +/- 0.25 x 10(-8) M(-1) (Kd2) in DC rats. The results suggest an acute alteration in the number of insulin receptors on ER membranes in STZ-induced diabetic rats. Treatment with SPEt and glibenclamide significantly improved specific insulin binding, with receptor number and affinity binding (p < 0.001) reaching almost normal non-diabetic levels. The data presented here show that SPEt and glibenclamide increase total ER membrane insulin binding sites with a concomitant significant increase in plasma insulin.

Antihyperlipidemic and antiperoxidative effect of Diasulin, a polyherbal formulation in alloxan induced hyperglycemic rats

BACKGROUND

This study was undertaken to investigation the effect of Diasulin, a poly herbal drug composed of ethanolic extract of ten medicinal plants on blood glucose, plasma insulin, tissue lipid profile, and lipidperoxidation in alloxan induced diabetes.

METHODS

Ethanolic extract of Diasulin a, poly herbal drug was administered orally (200 mg/kg body weight) for 30 days. The different doses of Diasulin on blood glucose and plasma insulin in diabetic rats were studied and the levels of lipid peroxides [TBARS, and hydroperoxide] and tissue lipids [cholesterol, triglyceride, phospholipides and free fatty acids] were also estimated in alloxan induced diabetic rats. The effects were compared with glibenclamide.

RESULT

Treatment with Diasulin and glibenclamide resulted in a significant reduction of blood glucose and increase in plasma insulin. Diasulin also resulted in a significant decrease in tissue lipids and lipid peroxide formation. The effect produced by Diasulin was comparable with that of glibenclamide.

CONCLUSION

The decreased lipid peroxides and tissue lipids clearly showed the antihyperlipidemic and antiperoxidative effect of Diasulin apart from its antidiabetic effect.

Insulin-secretagogue activity and cytoprotective role of the traditional antidiabetic plant Scoparia dulcis (Sweet Broomweed)

Scoparia dulcis (Sweet Broomweed) has been documented as a traditional treatment of diabetes. The administration of an aqueous extract of Scoparia dulcis at a dose of 200 mg/kg body weight significantly decreased the blood glucose with significant increase in plasma insulin level in streptozotocin diabetic rats at the end of 15 days treatment. The insulin secretagogue action of Scoparia dulcis plant extract (SPEt) was further investigated using isolated pancreatic islets from mice. SPEt at a dose of 10 microg/ml evoked 6.0 fold stimulation of insulin secretion from isolated islets indicating its insulin secretagogue activity. In addition the effect of SPEt on streptozotocin induced cell death and nitric oxide (NO) in terms of nitrite production were also examined. SPEt protected against streptozotocin- mediated cytotoxicity (88%) and NO production in rat insulinoma cell line (RINm5F). Above results suggest the glucose lowering effect of SPEt to be associated with potentiation of insulin release from pancreatic islets. Our results revealed the possible therapeutic value of Scoparia dulcis for the better control, management and prevention of diabetes mellitus progression.

Modulatory Effect of Gymnema montanum Leaf Extract on Brain Antioxidant Status and Lipid Peroxidation in Diabetic Rats

The effects of leaf extract from Gymnema montanum, an endangered and endemic plant, were examined on brain lipid peroxidation in experimental diabetic rats. Ethanolic extract of G. montanum leaves was administered orally (50, 100, and 200 mg/kg of body weight) for 3 weeks, and changes in blood glucose, plasma insulin, and lipid peroxidation markers such as thiobarbituric acid-reactive substances (TBARS), hydroperoxides, and levels of antioxidants, namely, superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, and glutathione-S-transferase, were examined in the brain of alloxan-induced diabetic rats. Glibenclamide was used as a standard reference drug. A significant increase in the activities of antioxidants was observed in brain on treatment with G. montanum leaf extract and glibenclamide for 3 weeks. Both the treated groups showed significant decreases in formation of TBARS and hydroperoxides in brain, suggesting a role in protective action against lipid peroxidation-mediated membrane damage. Our findings indicate that G. montanum leaf extract possesses antiperoxidative and antioxidant effects in addition to its antidiabetic activity. This report helps to create awareness on the need for conservation of medicinal plants, and G. montanum is one such plant that needs to be conserved through various propagation trials.

Effect of an aqueous extract of Scoparia dulcis on blood glucose, plasma insulin and some polyol pathway enzymes in experimental rat diabetes

The effects of an aqueous extract of the plant Scoparia dulcis (200 mg/kg) on the polyol pathway and lipid peroxidation were examined in the liver of streptozotocin adult diabetic male albino Wistar rats. The diabetic control rats (N = 6) presented a significant increase in blood glucose, sorbitol dehydrogenase, glycosylated hemoglobin and lipid peroxidation markers such as thiobarbituric acid reactive substances (TBARS) and hydroperoxides, and a significant decrease in plasma insulin and antioxidant enzymes such as glutathione peroxidase (GPx), glutathione-S-transferase (GST) and reduced glutathione (GSH) compared to normal rats (N = 6). Scoparia dulcis plant extract (SPEt, 200 mg kg-1 day-1) and glibenclamide (600 microg kg-1 day-1), a reference drug, were administered by gavage for 6 weeks to diabetic rats (N = 6 for each group) and significantly reduced blood glucose, sorbitol dehydrogenase, glycosylated hemoglobin, TBARS, and hydroperoxides, and significantly increased plasma insulin, GPx, GST and GSH activities in liver. The effect of the SPEt was compared with that of glibenclamide. The effect of the extract may have been due to the decreased influx of glucose into the polyol pathway leading to increased activities of antioxidant enzymes and plasma insulin and decreased activity of sorbitol dehydrogenase. These results indicate that the SPEt was effective in attenuating hyperglycemia in rats and their susceptibility to oxygen free radicals.