Protective role of Moringa oleifera leaf extract on cardiac antioxidant status and lipid peroxidation in streptozotocin induced diabetic rats.

Moringa oleifera is a medicinal plant with great therapeutic potential. The leaves of Moringa oleifera are used by Indians in herbal medicines to treat diabetes. The present study is aimed to determine the protective role of Moringa oleifera in cardiac tissues under diabetic conditions. Diabetic rats were treated orally with methanolic extract of Moringa oleifera leaves at a dose of 300 mg/Kg body weight for 60 days. The effect of extract on serum glucose, glycated hemoglobin, plasma insulin and the levels of thiobarbituric acid reactive substances (TBARS), hydroperoxides (HP), conjugated dienes (D), activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-reductase (GRD) and reduced glutathione content (GSH) were estiated. Metformin and atorvastatin were used as standard drugs. A significant increase in plasma insulin, activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-reductase (GRD) and reduced glutathione content (GSH) and a significant decrease in serum glucose, glycated hemoglobin, thiobarbituric acid reactive substances (TBARS), hydroperoxides (HP) and conjugated dienes (CD) were observed in the treated groups. This study evaluated the antioxidant potential of methanolic extract of Moringa oleifera leaves. These findings suggest the protective role of Moringa oleifera against oxidative stress in the heart of diabetic rats.

Attenuation of high glucose induced apoptotic and inflammatory signaling pathways in RIN-m5F pancreatic ß cell lines by Hibiscus rosa sinensis L. petals and its phytoconstituents.

ETHNOPHARMACOLOGICAL RELEVANCE: Hibiscus rosa sinensis petals possess wide range of pharmacological properties, with remarkable nutritional values. Diabetes is one of the most devastating diseases affecting the world today. A few side effects associated with the use of insulin and oral hypoglycemic agents prompted us to search new bioactive principles from antidiabetic plants used in traditional medicine. AIM OF THE STUDY: The anti-diabetic therapeutic potential of the flavonoids rich ethyl acetate fraction of Hibiscus rosa sinensis petals (EHRS) was evaluated. MATERIALS AND METHODS: High glucose (25 mM) induced apoptotic model of diabetes in RIN-m5F pancreatic ß-cells was used for the study. RESULTS: EHRS elevated the release of insulin in pancreatic cells and modulated apoptotic signaling cascades. It significantly reduced NF-κB nuclear translocation, thereby down-regulated the expressions of major inflammatory cytokines and up-regulated expressions of pancreatic ß-cell functional genes such as, foxO-1, Ucn-3, Pdx-1, MafA and Nkx6.1. On comparison with its constituent phytochemicals, superior protective effect shown by EHRS may be due to the additive action of these phytoconstituents. CONCLUSIONS: Results of the present study suggest hibiscus petals as a natural source and functional food of potential therapeutics to protect pancreatic ß-cells in experimental diabetes mellitus.

Averrhoa bilimbi fruits attenuate hyperglycemia-mediated oxidative stress in streptozotocin-induced diabetic rats.

Hyperglycemia-mediated oxidative stress plays a major role in the development of diabetic complications. Averrhoa bilimbi Linn. (Oxalidaceae) is a medicinal plant with fruits reported to possess antidiabetic activity. This study evaluated the beneficial effects of the ethyl acetate fraction of A. bilimbi fruit (ABAEE) on the antioxidant/oxidant status in diabetes mellitus. Diabetic rats were treated orally with the ethyl acetate fraction of A. bilimbi fruits at a dose of 25 mg/kg body weight for 60 days. Serum glucose, glycated hemoglobin, plasma insulin, hepatic toxicity markers, antioxidant enzymes, lipid peroxidation products, and liver histopathology were assayed checked after 60 days of extract treatment. Diabetic rats administered ABAEE showed a significant decline in serum glucose, glycated hemoglobin, and also significantly increases the level of plasma insulin, as well as a notable attenuation in thiobarbituric acid-reactive substances, conjugated dienes, and hydroperoxides. ABAEE also modulated hepatic antioxidant potential by significantly increasing the activities of catalase, glutathione peroxidase, glutathione reductase, superoxide dismutase, and reducing glutathione content. The results associated with ABAEE were more significant than those observed following treatment with the standard drug metformin. Histopathological observations showed that ABAEE effectively rescued hepatocytes from oxidative damage without affecting cellular function and structural integrity. High-performance liquid chromatography analysis of ABAEE indicated the presence of phenolic compound, quercetin, indicating that the antidiabetic effect of the extract might be related to quercetin. These results demonstrated the potential beneficial effect of ABAEE on streptozotocin-induced diabetes in rats.

Hibiscus rosa sinensis Linn. Petals Modulates Glycogen Metabolism and Glucose Homeostasis Signalling Pathway in Streptozotocin-Induced Experimental Diabetes.

The prevalence of diabetes mellitus is becoming more and more serious and reaches epidemic proportions worldwide. Scientific research is constantly looking for new agents that could be used as dietary functional ingredients in the fight against diabetes. The objective of the present study was to evaluate the effect of ethyl acetate fraction of Hibiscus rosa sinensis Linn. petals on experimental diabetes at a dose of 25 mg/kg body weight and it was compared with standard anti-diabetic drug metformin. The elevated levels of serum glucose (398.56 ± 35.78) and glycated haemoglobin (12.89 ± 1.89) in diabetic rats were significantly decreased (156.89 ± 14.45 and 6.12 ± 0.49, respectively) by Hibiscus rosa sinensis petals (EHRS) administration. Hepatotoxicity marker enzyme levels in serum were normalized. The fraction supplementation restored the glycogen content by regulating the activities of glycogen metabolizing enzymes. It significantly modulated the expressions of marker genes involved in glucose homeostasis signalling pathway. Histopathological analysis of liver and pancreas supported our findings. The overall effect was comparable with metformin. Hence, our study reveals the role of hibiscus petals for alleviation of diabetes complications, thus it can be propagated as a nutraceutical agent.

Ethyl acetate fraction of Cissus quadrangularis stem ameliorates hyperglycaemia-mediated oxidative stress and suppresses inflammatory response in nicotinamide/streptozotocin induced type 2 diabetic rats.

BACKGROUND: Cissus quadrangularis is a plant with great medicinal value and different parts of the plant is traditionally used for the treatment of skin infections, constipation, piles, anaemia, asthma, irregular menstruation, burns and wounds. The stems and leaves of Cissus quadrangularis has been traditionally consumed as a vegetable. OBJECTIVE: The current study was hypothesized to investigate the beneficial effects of ethyl acetate fraction of Cissus quadrangularis stem (CQSF) on hyperglycaemia-mediated oxidative stress and inflammatory responses in nicotinamide/streptozotocin induced diabetes mellitus. MATERIALS AND METHODS: Experimental diabetes was induced by intraperitoneal injection of 110 mg/kg body weight nicotinamide 15 min prior to the injection of 45 mg/kg body weight streptozotocin. Diabetic rats were administered with a daily oral dose of 100 mg/kg CQSF for 60 days after diabetes induction. RESULTS: Diabetic control rats showed significant (p < 0.05) increase in blood glucose, HbA1c, liver toxicity markers, inflammatory markers and lipid peroxidation products and reduction in the activities of antioxidant enzymes. The mRNA expressions of TNF-α, IL-6 and NF-κB in adipose tissue were significantly (p < 0.05) increased in diabetic group. Nuclear translocation of NF-κB p65 subunit level was greater in diabetic rats. CQSF administration significantly reversed these alterations. Histopathological alterations of liver and pancreas were also restored by CQSF treatment. The results were compared with the standard oral hypoglycaemic drug metformin. In addition, the ESI-MS and GC-MS analysis of CQSF confirmed the presence of quercetin and phenol, 2,4-bis(1,1-dimethylethyl)- respectively. CONCLUSIONS: The present study demonstrates that CQSF exerts antidiabetic activity by potentiating the antioxidant defense system and suppressing inflammatory responses.

The regulatory effects of Cissus quadrangularis on some enzymes involved in carbohydrate metabolism in streptozotocin-induced diabetic rats.

CONTEXT: Diabetes mellitus (DM) is probably the single most important metabolic disease and is widely recognized as one of the leading causes of death and disability. Cissus quadrangularis Linn. (Vitaceae) is a medicinal food and is reported to possess hypoglycemic activity. OBJECTIVE: The present study evaluates the effect of ethyl acetate fraction of C. quadrangularis stem (CQSF) on carbohydrate metabolism in hepatic tissues of experimental diabetic rats. The phytochemical compounds present in the CQSF extract were identified by gas chromatography-mass spectrometry (GC-MS) analysis. MATERIALS AND METHODS: Diabetic animals were treated with CQSF (50, 100, and 200 mg/kg body weight) for 45 d. Several indices such as blood glucose, glycated hemoglobin (HbA1c), insulin, liver function tests, hepatic glycogen content, and the activities of carbohydrate-metabolizing enzymes were assayed after 45 d of extract treatment. RESULTS: A pronounced effect was observed with extract doses 100 and 200 mg/kg body weight. CQSF at a dose of 100 mg/kg body weight significantly decreased the altered levels of blood glucose by about 56%. CQSF also modulated the activities of carbohydrate-metabolizing enzymes by significantly increasing the activity of hexokinase (1.9-fold) and pyruvate kinase (2.2-fold) and significantly reducing the activity of glucose-6-phosphatase (41.23%), fructose-1,6-diphosphatase (29.43%), and glycogen phosphorylase (35.07%). GC-MS analysis revealed the presence of 10 chemical constituents, and N-methyl-1-adamantane acetamide was found to be the prevailing compound in the extract. DISCUSSION AND CONCLUSION: The current study suggests the antidiabetic potential of CQSF, mediated through the regulation of carbohydrate metabolic enzyme activities.

Cissus quadrangularis extract attenuates hyperglycaemia-mediated oxidative stress in streptozotocin-induced diabetic rats.

OBJECTIVE: Hyperglycaemia-mediated oxidative stress plays a major role in the progression of diabetic complications. This study was aimed at evaluating the beneficial effects of Cissus quadrangularis stem extract on antioxidant/oxidant status in diabetes mellitus. MATERIALS AND METHODS: The antioxidant activities of an ethyl acetate fraction of Cissus quadrangularis stem (CQSF) at three different doses (50, 100, and 200 mg/kg body weight) were evaluated in rats with experimentally induced diabetes. High performance liquid chromatography analysis was carried out to identify the active components present in the plant fraction. RESULTS: Induction of diabetes caused deleterious effects including hyperglycaemia, liver dysfunction, significant decline in antioxidants and elevated lipid peroxidation indices. C. quadrangularis supplementation significantly improved insulin sensitivity, reduced liver damage, and oxidative changes, and brought back the antioxidants towards normal. Histopathological analysis of the liver also reinforced our findings. Pronounced changes were observed at the doses 100 and 200 mg/kg body weight. In addition, high performance liquid chromatography analysis of C. quadrangularis fraction revealed the presence of quercetin. DISCUSSION: This study suggests an anti-diabetic potential of CQSF, mediated through the modulation of the antioxidant defence system. The ethyl acetate fraction of Cissus quadrangularis is rich in quercetin and this indicates that the supplementation of CQSF might be beneficial as a food supplement for the attenuation of diabetic complications.

Ethanol extract of Butea monosperma bark modulates dyslipidemia in streptozotocin-induced diabetic rats.

CONTEXT: Dyslipidemia is one of the major risk factors for cardiovascular disease in diabetes mellitus (DM). The availability of multiple lipid-lowering drugs and supplements provides new opportunities for patients to regulate lipid levels. OBJECTIVE: The present study was designed to evaluate the effect of Butea monosperma Lam. (Fabaceae) bark extract in diabetes-induced dyslipidemia. MATERIALS AND METHODS: A daily dose of B. monosperma bark extract (BMBE, 500 mg/kg body weight) was given orally to streptozotocin (STZ)-induced diabetic rats for 60 d. Several indices such as blood glucose, insulin, glycosylated hemoglobin, TC, TG, high-density lipoprotein-cholesterol (HDL-C), apo A1, apo B, activities of lipogenic enzymes in tissues, liver function tests, and histopathology of liver were analyzed to assess the modulation of STZ-induced diabetic dyslipidemia by B. monosperma bark. RESULTS: BMBE significantly reduced blood glucose (40.79%) and increased plasma insulin (37.5%) levels in diabetic rats. Altered levels of serum lipids, lipoproteins, and activities of lipogenic enzymes in tissues were partially restored upon the administration of BMBE in diabetic rats. Liver function tests and histopathological examination revealed that consumption of BMBE at a dose of 500 mg/kg body weight had no toxic effects in experimental rats. CONCLUSION: The findings suggest that BMBE supplementation could ameliorate dyslipidemia in DM.

Antioxidant, antiglycation and inhibitory potential of Saraca ashoka flowers against the enzymes linked to type 2 diabetes and LDL oxidation.

OBJECTIVE: The present study investigated the antioxidant, antiglycation and inhibitory potential of flavonoid fraction of Saraca ashoka flowers (SAF) against alpha-glucosidase and alpha-amylase (the enzymes linked to type 2 diabetes) and LDL oxidation. MATERIALS AND METHODS: Antioxidant capacity of SAF was evaluated by estimating total antioxidant activity (TAA) and its protective effects against the oxidative stress induced by H2O2 on C2C12 cells. Cytotoxicity by MTT assay and markers of oxidative stress: reduced glutathione (GSH), malondialdehyde (MDA) and reactive oxygen species (ROS) were measured. RESULTS: Pre-treatment of C2C12 cells with SAF prevented the increased formation of MDA and depletion of GSH induced by H2O2. The increased ROS generation induced by H2O2 was also reduced by a pretreatment with SAF. Significant inhibitory potential against alpha-glucosidase and alpha-amylase enzymes revealed the therapeutic potential of SAF as an antihyperglycemic agent. SAF also demonstrated potent antiglycation property and inhibited LDL oxidation under in vitro conditions. CONCLUSIONS: The overall results demonstrate that SAF can be used as an ideal natural remedy for preventing oxidative stress and other complications associated with diabetes.

Evaluation of antioxidant, antitumor and immunomodulatory properties of polysaccharide isolated from fruit rind of Punica granatum.

Polysaccharide (PSP001) isolated from Punica granatum was evaluated for its radical scavenging and antitumor activities in vitro. The fruit of Punica granatum (pomegranate) has been reported to possess several vital biological activities. This study aimed to determine the antioxidant and anticancer properties of polysaccharide PSP001 isolated from the fruit rind of pomegranate. Antioxidant activities were evaluated using various assays such as the 1, 1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging assay, ferric reducing antioxidant power assay, linoleic acid emulsion thiocyanate assay, and superoxide, hydroxyl and nitric oxide radical scavenging assays. PSP001 exhibited a dose-dependent enhancement in activity using concentrations from 10 to 1000 µg/ml except for the DPPH assay for which the highest activity was obtained at 200 µg/ml. The anticancer properties of PSP001 evaluated on MCF-7 (breast cancer), KB (nasopharyngeal carcinoma) and K562 (leukemia) cells by MTT assay indicate its potential as an antitumor agent. An IC50 value of 97.21 ± 1.06 µg/-ml and 52.8 ± 0.9 µg/-ml were obtained following 72 h incubation for MCF-7 and K562 cells, respectively. PSP001 showed in vitro growth stimulatory effect on isolated normal lymphocytes, and a proliferative index of 1.21 ± 0.01 at a concentration of 1000 µg/-ml was obtained, indicating immunomodulatory activity. The results of the present study indicate that further studies are required on PSP001 in order to use this compound as an antitumor agent.

In vitro antiperoxidative, free radical scavenging and xanthine oxidase inhibitory potentials of ethyl acetate fraction of Saraca ashoka flowers.

Saraca ashoka is a widely used medicinal herb claimed to cure many diseases. This study investigated the antiperoxidative, free radical scavenging and xanthine oxidase (XO) inhibitory potential of the ethyl acetate fraction of S. ashoka flowers (SAF) and compared it with standard compounds like gallic acid, ascorbic acid, butylated hydroxyl toluene and allopurinol. The ethyl acetate fraction of SAF exhibited free radical scavenging activity against the 1,1-diphenyl-2-picrylhydrazyl radical and superoxide radical, along with hydroxyl radical scavenging activity. Lipid peroxidation inhibitory potential of SAF was studied using a linoleic acid emulsion system, which shows significant antioxidant potential. SAF also demonstrated significant XO (key enzyme linked to inflammation) inhibitory activity, which revealed its therapeutic potential as an antioxidant and XO inhibitor. HPLC profiling of the ethyl acetate fraction of SAF revealed that it contains ellagic acid as a major compound and thus the beneficial effects of this fraction may be due to the presence of this compound.

Influence of coconut kernel protein on lipid metabolism in alcohol fed rats.

Male albino rats were given ethanol (3.76 g/kg body weight/day) to induce hyperlipidemia. The rats showed increased concentration of cholesterol and triglycerides in the serum and tissues. Inclusion of coconut protein and L-arginine into ethanol fed rats produced lower levels of total cholesterol, LDL+ VLDL cholesterol, triglycerides and atherogenic index in the serum. Concentration of tissue cholesterol and triglycerides was also lower in these groups. Administration of coconut protein and L-arginine in the ethanol fed rats caused decreased activity of HMG-CoA reductase in the liver and increased activity of lipoprotein lipase in the heart. The activities of malic enzyme and glucose-6-phosphate dehydrogenase were also lower in these groups. Feeding coconut protein and L-arginine in ethanol treated rats showed increased concentration of hepatic bile acids and fecal excretion of neutral sterols and bile acids. All these effects were comparable in rats fed coconut protein and those fed L-arginine. These observations indicate that the major factor responsible for the hypolipidemic effect of coconut protein is due to the high content of L-arginine.