Chinnadurai Veeramani

Ameliorative effect of kaempferol, a flavonoid, on oxidative stress in streptozotocin-induced diabetic rats

Abstract Objective The aim of the present study was to evaluate the protective effect of kaempferol against oxidative stress in streptozotocin (STZ)-induced diabetic rats. Methods Diabetes was induced in male, adult albino rats of the Wistar strain, by intraperitoneal administration of STZ (40 mg/kg body weight (BW)). Kaempferol (100 mg/kg BW) or glibenclamide (600 µg/kg BW) was administered orally once daily for 45 days to normal and STZ-induced diabetic rats. Results The STZ-induced diabetic rats showed significantly increased levels of plasma glucose, thiobarbituric acid reactive substances, lipid hydroperoxides, and conjugated dienes in plasma, liver, kidney, and heart whereas they showed significantly decreased level of plasma insulin. The levels of non-enzymic antioxidants (vitamin C, vitamin E, reduced glutathione) in plasma, liver, kidney, and heart and the activities of enzymatic antioxidants (superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase) in liver, kidney, and heart were significantly decreased in diabetic rats. Administration of kaempferol to diabetic rats was showed brought back in plasma glucose, insulin, lipid peroxidation products, enzymatic, and non-enzymatic antioxidants to near normal. Conclusion The present study indicates that kaempferol has a good antioxidant property, as evidenced by its increase of antioxidant status and decrease of lipid peroxidation markers, thus providing protection from the risks of diabetic complications.

Effect of Piper betle on plasma antioxidant status and lipid profile against D-galactosamine-induced hepatitis in rats

Abstract Betle leaf chewing is an old traditional practice in India and other countries of East Asia. We have investigated the antioxidant and antihyperlipidaemic potential of an alcoholic leaf-extract of Piper betle against D-galactosamine (D-GalN; 400 mg/kg body weight, i.p. single dose) intoxication in male albino Wistar rats. Rats were treated with leaf-extract (200 mg/kg body weight) by intragastric intubations daily for 20 days. The animals were divided randomly into five groups of six animals each as control, control plus extract, D-GalN control, D-GalN-rats on treatment with extract or silymarin, a standard drug. We observed an increase in the plasma levels of thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides, and a decrease in vitamin C, vitamin E and reduced glutathione concentrations. Very low density lipoprotein cholesterol and low density lipoprotein cholesterol increased significantly while high density lipoprotein cholesterol decreased. Further, increase in the levels of total cholesterol, phospholipids, triglycerides, free fatty acids in the plasma and tissues of liver and kidney were observed in D-GalN-treated rats. Administration of P. betle leaf-extract prevented the increase or decrease of these parameters and brought towards normality. These results suggest that P. betle could afford a significant antioxidant and antihyperlipidaemic effect against D-GalN-intoxication.

Galangin, a dietary flavonoid, improves antioxidant status and reduces hyperglycemia-mediated oxidative stress in streptozotocin-induced diabetic rats

ABSTRACT Objective: To examine the effect of galangin on hyperglycemia-mediated oxidative stress in streptozotocin (STZ)-induced diabetic rats. Methods: Diabetes was induced by intraperitoneal administration of low-dose STZ (40 mg/kg body weight (BW)) into male albino Wistar rats. Galangin (8 mg/kg BW) or glibenclamide (600 µg/kg BW) was given orally, once daily for 45 days to normal and STZ-induced diabetic rats. Results: Diabetic rats showed significantly increased levels of plasma glucose, thiobarbituric acid reactive substances, lipid hydroperoxides, and conjugated dienes. The levels of insulin and non-enzymatic antioxidants (vitamin C, vitamin E, reduced glutathione) and the activity of enzymatic antioxidants (superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase (GST)) were decreased significantly in diabetic control rats. These altered plasma glucose, insulin, lipid peroxidation products, enzymatic and non-enzymatic antioxidants ions were reverted to near-normal level after the administration of galangin and glibenclamide. Conclusion: The present study shows that galangin decreased oxidative stress and increased antioxidant status in diabetic rats, which may be due to its antidiabetic and antioxidant potential.

Antihypertensive effect of Melothria maderaspatana leaf fractions on DOCA-salt-induced hypertensive rats and identification of compounds by GC-MS analysis.

The present study was designed to investigate the antihypertensive effect of Melothria maderaspatana leaf fractions on deoxycorticosterone acetate (DOCA)-salt-induced hypertensive rats and to identify compounds from the active fraction by GC–MS analysis. Administration of DOCA salt significantly increased the systolic and diastolic blood pressure compared to sham-operated control rats. When treated with chloroform (CFM), ethyl acetate (EAFM) or methanol fractions of M. maderaspatana (MFM), EAFM alone significantly lowered the systolic and diastolic blood pressure. The levels of magnesium and copper significantly increased in plasma and decreased in tissues while the zinc level significantly increased in plasma and tissues, and administration of EAFM brought these parameters back to sham-operated control levels. By GC–MS analysis, phytochemicals such as coumarin, vallinic acid, p-coumaric acid, gallic acid, caffeic acid, and ferulic acid were identified in EAFM. In conclusion, the EAFM controls blood pressure in DOCA-salt hypertensive rats and reverts the metabolic alterations in magnesium, copper and zinc.

Antihyperlipidemic effect of Melothria maderaspatana leaf extracts on DOCA-salt induced hypertensive rats.

OBJECTIVE To investigate the antihyperlipidemic effect of crude ethanolic extract of Melothria maderaspatana (M. maderaspatana) leaf (CEEM) on deoxycorticosterone acetate (DOCA)-salt hypertensive rats. METHODS A midscapular incision was made on each rat and the left kidney was excised after ligation of the renal artery. The surgical wound was closed using an absorbable suture. After one week recovery period, hypertension was induced by subcutaneous injection of DOCA-salt solution, twice a week, and the rats received a 1% sodium chloride solution as drinking water throughout the experimental period. CEEM or nifedipine was administered orally once a day for 6 weeks. RESULTS In DOCA-salt hypertensive rats, the level of plasma and tissues of total cholesterol (TC), triglycerides (TG), free fatty acids (FFA) and phospholipids (PL) significantly increased and administration of CEEM significantly reduced these parameters towards normality. Further, the levels of low density lipoprotein-cholesterol (LDL-C) and very low density lipoprotein-cholesterol (VLDL-C) significantly increased while high density lipoprotein-cholesterol (HDL-C) decreased in hypertensive rats and administration of CEEM brought these parameters to normality which proved their antihyperlipidemic action. Histopathology of liver, kidney and heart on DOCA-salt induced rats treated with CEEM showed reduced the damages towards normal histology. CONCLUSIONS These findings provided evidence that CEEM was found to be protecting the liver, kidney and heart against DOCA-salt administration and the protective effect could attribute to its antihyperlipidemic activities.

Protective effect of Cardiospermum halicacabum leaf extract on glycoprotein components on STZ–induced hyperglycemic rats

OBJECTIVE To investigate the protective role of Cardiospermum halicacabum (C. halicacabum) leaf extract on glycoprotein metabolism in streptozotocin (STZ)-induced diabetic rats. METHODS Diabetes was induced in male albino Wistar rats by intraperitonial administration of STZ. The C. halicacabum leaf extract (CHE) was administered orally to normal and STZ-diabetic rats for 45 days. The effects of C. halicacabum leaf extract (CHE) on plasma and tissue glycoproteins (hexose, hexosamine, fucose and sialic acid) were determined. RESULTS The levels of plasma and tissues glycoproteins containing hexose, hexosamine and fucose were significantly increased in STZ-induced diabetic rats. In addition, the level of sialic acid significantly increased in plasma and liver while decreased in kidney of STZ-induced diabetic rats. After administration of CHE to diabetic rats, the metabolic alteration of glycoprotein reverted towards normal levels. CONCLUSIONS The present study indicates that the CHE possesses a protective effect on abnormal glycoprotein metabolism in addition to its antihyperglycemic activity.

Protective effect of Melothria maderaspatana leaf fraction on electrolytes, catecholamines, endothelial nitric oxide synthase and endothelin-1 peptide in uninephrectomized deoxycorticosterone acetate–salt hypertensive rats

This study was designed to investigate the protective effect of ethyl acetate fraction of Melothria maderaspatana (EAFM) leaf on electrolytes, catecholamines, endothelial nitric oxide synthase (eNOS) and endothelin-1 (ET-1) peptide in uninephrectomized deoxycorticosterone acetate (DOCA)–salt hypertensive rats. Administration of DOCA–salt significantly increased the systolic and diastolic blood pressure and treatment with EAFM significantly lowered the blood pressure. In DOCA–salt rats, the levels of sodium and chloride increased significantly while potassium level decreased and administration of EAFM brought these parameters to normality. The levels of epinephrine and norepinephrine increased significantly in DOCA–salt rats and administration of EAFM significantly decreased these parameters to normality. DOCA–salt hypertensive rats exhibited significantly decreased L-arginine and nitrite + nitrate levels and administration of EAFM brought these parameters to normality. DOA–salt hypertensive rats showed down-regulation of eNOS and up-regulation of ET-1 protein expressions in heart and kidney, and treatment with EAFM prevented down-regulation of eNOS and significantly down-regulated the ET-1 protein expressions. In conclusion, EAFM provides good blood pressure control by enhancing potassium and decreasing sodium levels, decreasing levels of epinephrine and norepinephrine, and preventing down-regulation of eNOS and significantly down-regulating ET-1 protein expression.

Lavatera critica, a green leafy vegetable, controls high fat diet induced hepatic lipid accumulation and oxidative stress through the regulation of lipogenesis and lipolysis genes

BACKGROUND Lipid accumulation is the most vital risk factor for inducing nonalcoholic fatty liver disease (NAFLD) and metabolic syndrome. Thus, the development of novel drugs is urgently needed to control obesity related diseases. OBJECTIVE Here, we investigated the protective role of Lavatera critica (LC), a green vegetable, in male C57BL/6J mice fed with high fat (HF) diet for 10 weeks to induce hepatic lipid accumulation and oxidative cellular damage. RESULTS After oral administration of chloroform (CFLC), ethyl acetate (EFLC), or methanol (MFLC) fractions of Lavatera critica to the HF group, EALC alone significantly reduced the activities of hepatic markers such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST); moreover, the results showed that 50 mg/kg dose has the maximum activity. Thus, this active dose of EFLC was used for further analysis. Moreover, EFLC reduced the level of hepatic triglycerides (TG), total cholesterol (TC), free fatty acids (FFA), and prevented further increase in the body weight. Intriguingly, EFLC treatment also reversed the mRNA expression of fatty acid oxidative genes, such as peroxisome proliferator activated receptor-α (PPAR-α), carnitine palmitoyltransferase-1 (CPT-1), and acetyl-CoA carboxylase (ACO), and fatty acid synthesis genes such as fatty acid synthase (FAS), sterol-regulatory-element-binding protein-1c (SREBP-1c), and acetyl-CoA carboxylase (ACC). Furthermore, EFLC treatment also decreased the production of oxidative stress biomarkers, such as conjugated diene (CD), thiobarbituric acid reactive substances (TBARS), and lipid hydroperoxide (LOOH), and significantly enhanced the level of enzymatic antioxidants, such as glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT), as well as non-enzymatic antioxidants, such as reduced glutathione (GSH), vitamin C, and vitamin E in the liver. CONCLUSION Taken together, we conclude that EFLC has a protective effect against HF diet induced hepatic lipid accumulation and oxidative cellular damage through the regulation of lipogenesis and lipolysis genes.

Galangin, a natural flavonoid reduces mitochondrial oxidative damage in streptozotocin-induced diabetic rats

ABSTRACT Objective: We designed this study to observe the effect of galangin on damaged mitochondria in the liver of diabetic rats. Methods: Male albino Wistar rats were made diabetic by injecting streptozotocin (STZ) intraperitoneally (40 mg kg−1 body weight (BW)). Galangin (8 mg kg−1 BW) or glibenclamide (600 µg kg−1 BW) was given orally daily once for 45 days to both healthy and diabetic rats. Results: Diabetic rats showed significant (P < 0.05) increase in liver mitochondrial oxidant [Thiobarbituric acid reactive substance (TBARS)] level and a significant decrease in enzymatic [superoxide dismutase (SOD), glutathione peroxidase (GPx)] and non-enzymatic (reduced glutathione (GSH)) antioxidant levels when compared with healthy rats. The mitochondrial enzymes isocitrate dehydrogenase (ICDH), alpha-ketoglutarate dehydrogenase (α-KGDH), succinate dehydrogenase (SDH) and malate dehydrogenase (MDH) and mitochondrial respiratory chain enzymes NADH-dehydrogenase and Cytochrome c-oxidase were decreased significantly (P < 0.05) in diabetic rats when compared with healthy rats. A natural flavonoid galangin administered to hyperglycemia-induced rats resulted in the following findings as compared to hyperglycemia-induced control rats: the oxidant levels decreased significantly (P < 0.05); the enzymatic and non-enzymatic antioxidant levels increased significantly (P < 0.05) and the function of mitochondrial enzymes and the mitochondrial respiratory chain enzymes increased significantly (P < 0.05). Conclusion: From the results, we conclude that galangin could maintain liver mitochondrial function in diabetic rats.

Herbacetin, a flaxseed flavonoid, ameliorates high percent dietary fat induced insulin resistance and lipid accumulation through the regulation of hepatic lipid metabolizing and lipid-regulating enzymes

Healthy plants and their constituents have been considered as a safe remedy for the treatment of obesity and obesity associated diseases. Herbacetin is a dietary flavonoid that has been explored for many pharmacological activities; but, the anti-hyperglycaemic and anti-hyperlipidemic properties of herbacetin have not yet been explored. The present study was performed to evaluate the ameliorative effect of herbacetin on high-fat diet-induced hyperglycaemia and hyperlipidemia in 57BL/6 J mice. Obesity associated insulin resistance was induced by continuously feeding the mice with high-fat diet for 10 weeks. Afterwards, mice were subjected to intragastric administration of herbacetin (different doses) daily along with high-fat diet for the next 5 weeks. At the end of 106th day, changes in body weight, blood glucose, insulin, HOMA-IR, and lipids profiles and lipid-regulating enzymes were evaluated. Herbacetin significantly reduced the body weight, plasma glucose, plasma insulin, and HOMA-IR activity in obesity associated insulin resistant mice (OIR). In addition, herbacetin administration significantly reduced the plasma and hepatic total cholesterol, triglycerides, and free fatty acids in OIR mice. Moreover, herbacetin significantly improved the altered hepatic lipid metabolizing and lipid-regulating enzymes such as SREBP-1c, and 2, fatty acid synthase (FAS), fatty acid β-oxidation (β-oxidation), malic enzyme, glucose 6-phosphate dehydrogenase (G6PD), and carnitine palmitoyltransferase (CPT) when compared to OIR control mice. Histopathological examination clearly showed that herbacetin decreases lipid droplets in the liver tissue. Thus, observed results strongly indicate that herbacetin provides remarkable protection against the harmful effects of chronic high-fat diet consumption because of its anti-hyperglycaemic and anti-hyperlipidemic properties through the regulation of hepatic lipid metabolizing and lipid-regulating enzymes.