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Antioxidant Action (antioxidant + action)

Distribution by Scientific Domains

Medical Sciences	64%
Chemistry	21%
Life Sciences	14%

Selected Abstracts

Antioxidant action of Tinospora cordifolia root extract in alloxan diabetic rats

PHYTOTHERAPY RESEARCH, Issue 3 2001
P. Stanely Mainzen Prince
Abstract Tinospora cordifolia is widely used in Indian Ayurvedic medicine for the treatment of diabetes mellitus. Oral administration of 2.5,g and 5.0,g/kg body weight of the aqueous extract of the roots for 6 weeks resulted in a significant reduction in thiobarbituric acid reactive substances (TBARS) and an increase in reduced glutathione (GSH), catalase (CAT) and superoxide dismutase (SOD) in alloxan diabetic rats. The effect of Tinospora cordifolia root extract (TCREt) was most prominently seen in the case of rats given 5.0,g/kg body weight. The effect of TCREt was more effective than glibenclamide. Thus our study shows that TCREt exhibits antioxidant action in alloxan diabetes. Copyright © 2001 John Wiley & Sons, Ltd. [source]

The ameliorative effect of cysteine prodrug l -2-oxothiazolidine-4-carboxylic acid on cisplatin-induced nephrotoxicity in rats

FUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 5 2007
B.H. Ali
Abstract Pathogenesis of nephrotoxicity of the synthetic anticancer drug cisplatin (CP) involves generation of reactive oxygen species and free radicals in the kidney cortex, and cysteine prodrug l -2-oxothiazolidine-4-carboxylic acid (OTC) has been confirmed to have a strong antioxidant action. Therefore, in the present work, we aimed at testing the possible protective or palliative effect of OTC on CP nephrotoxicity in rats. OTC was given at an oral dose of 150 mg/kg/day for 7 days. On day 7, some of these rats were given a single intraperitoneal injection of CP (or vehicle) at a dose of 6 mg/kg. Rats were killed, blood and urine samples were collected, and the kidneys were removed 6 days after CP treatment. Nephrotoxicity was evaluated histopathologically by light microscopy, and biochemically by measuring the concentrations of creatinine and urea in serum, reduced glutathione (GSH) concentration and superoxide dismutase (SOD) activity in renal cortex, and by urinalyses. CP significantly increased the concentrations of urea and creatinine (P < 0.05) by about 128% and 170% respectively. CP treatment reduced cortical GSH concentration by about 34% (P < 0.05), and the activity of SOD by about 28% (P < 0.05). CP treatment significantly increased urine volume and N -acetyl- , - d -glucosaminidase (NAG) activity, and significantly decreased osmolality and protein concentrations. OTC significantly mitigated all these effects. Sections from saline- and OTC-treated rats showed apparently normal proximal tubules. However, kidneys of CP-treated rats had a moderate degree of necrosis. This appeared to be lessened when CP was given simultaneously with OTC. The concentration of CP in the cortical tissues was not significantly altered by OTC treatment. The results suggested that OTC had ameliorated the histopathological and biochemical indices of nephrotoxicity in rats. Pending further pharmacological and toxicological studies, OTC may potentially be useful as a nephroprotective agent. [source]

Hepatoprotective and antioxidant effects of gallic acid in paracetamol-induced liver damage in mice

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 5 2010
Mahaboob Khan Rasool
Abstract Objectives The aim of this research paper was to investigate the hepatoprotective and antioxidant effects of gallic acid in paracetamol-induced liver damage in mice. Methods In the present study, the hepatoprotective and antioxidant effects of gallic acid were evaluated against paracetamol-induced hepatotoxicity in mice and compared with the silymarin, a standard hepatoprotective drug. The mice received a single dose of paracetamol (900 mg/kg body weight i.p.). Gallic acid (100 mg/kg body weight i.p.) and silymarin (25 mg/kg body weight i.p.) were administered 30 min after the injection of paracetamol. After 4 h, liver marker enzymes (aspartate transaminase, alanine transaminase and alkaline phosphatase) and inflammatory mediator tumour necrosis factor-alpha (TNF-,) were estimated in serum, while the lipid peroxidation and antioxidant status (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione- S -transferase and glutathione) were determined in liver homogenate of the control and experimental mice. Key findings Increased activities of liver marker enzymes and elevated TNF-, and lipid peroxidation levels were observed in mice exposed to paracetamol (P < 0.05), whereas the antioxidant status was found to be depleted (P < 0.05) when compared with the control group. However gallic acid treatment (100 mg/kg body weight i.p.) significantly reverses (P < 0.05) the above changes by its antioxidant action compared to the control group as observed in the paracetamol-challenged mice. Conclusions The results clearly demonstrate that gallic acid possesses promising hepatoprotective effects. [source]

Experimental evidence for the protective effects of coffee against liver fibrosis in SD rats

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 3 2010
Jang-Woo Shin
Abstract BACKGROUND: Coffee is one of the most commonly consumed beverages worldwide. Accumulating clinical evidence has shown an inverse relationship between coffee and liver cirrhosis. We investigated the protective effect of coffee against liver fibrosis and underlying molecular mechanisms using a dimethylnitrosamine (DMN)-induced liver fibrosis model. RESULTS: Coffee administration significantly prevented the deterioration of body weight, organ weight, and serum biochemistry by DMN treatment. Histopathological examination revealed that necrosis/inflammation and fibrotic septa decreased significantly in coffee-treated rats compared to those treated with DMN and water. Coffee administration also significantly inhibited the accumulation of hydroxyproline (P < 0.001) and the production of malondialdehyde (P < 0.05), as well as stellate cell activation caused by DMN injection. Coffee protected the depletion of glutathione, superoxide dismutase, and catalase in liver tissue. In addition, coffee treatment inhibited the gene expression of inducible nitric oxide synthase, transforming growth factor (TGF)-,, tumor necrosis factor-,, interleukin-1, and platelet-derived growth factor (PDGF)-, in liver tissues, and lowered the concentration of TGF-, and PDGF-, in liver. Coffee inhibited NO production by macrophages. CONCLUSION: Coffee exerts protective effects against liver fibrosis via antioxidant action and the suppression of fibrogenic cytokines, TGF-, and PDGF-,. Copyright © 2009 Society of Chemical Industry [source]

Concentration-dependent effect of (,) epicatechin in hypertensive patients

PHYTOTHERAPY RESEARCH, Issue 10 2010
Navneet Kumar
Abstract Non-vitamin polyphenolic compounds are ubiquitous in food plants and therefore potentially present in human plasma in a diet-dependent concentration. The aim of this study was to evaluate the concentration-dependent effect of (,) epicatechin, a polyphenol present in green tea with antioxidant activity, on various biomarkers of oxidative stress. The current study examined the in vitro concentration-dependent (10,4,M to 10,7,M) effects of (,) epicatechin on biomarkers of oxidative stress viz. malondialdehyde (MDA), reduced glutathione (GSH), membrane sulfhydryl (-SH) group and protein carbonyl content in hypertensive patients and normal ones. This effect seems to be due to ability of (,) epicatechin to reduce MDA and protein carbonyl content while increase in GSH and membrane -SH group in hypertensive patients. It can be concluded that (-) epicatechin exerts an antioxidant action inside the cell, responsible for the observed modulation of cellular response to oxidative challenges. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Antiinflammatory and antiulcer properties of tannins from Myracrodruon urundeuva Allemão (Anacardiaceae) in Rodents

PHYTOTHERAPY RESEARCH, Issue 3 2007
S. M. C. Souza
Abstract Myracrodruon urundeuva Allemão is a plant utilized in Northeast Brazil as an antiinflammatory, wound healing and in gynecological illnesses. The objectives of the present study were to evaluate the antiinflammatory and antiulcer properties of the tannin-enriched fraction (TEF) isolated from the stem bark of M. urundeuva, in the formalin test, in mice, and in carrageenan-induced paw edema and gastric ulcer models, in rats. The results showed that TEF dose-dependently inhibited both phases of the formalin test. However, the effect was predominant in the 2nd phase of the response where inhibitions of 47%, 76% and 85% were observed, with doses of 5, 10 and 50 mg/kg, i.p. In the carrageenan-induced paw edema, significant inhibitions were observed at 3 h (44%) and 4 h (28%), with a dose of 10 mg/kg, i.p. TEF also significantly decreased by 37%, 43% and 57% gastric ulceration induced by indomethacin, at doses of 10, 20 and 50 mg/kg p.o. In the ethanol-induced gastric ulcer model, TEF was less effective, and significant inhibitions (42% to 46%) were observed only with doses of 100 and 200 mg/kg, p.o., respectively. In conclusion, it was shown that TEF presents antiinflammatory and antiulcer effects, partly due to its antioxidant action, known to be present in polyphenols, including tannins. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Antioxidant availability of turmeric in relation to its medicinal and culinary uses

PHYTOTHERAPY RESEARCH, Issue 10 2004
Jai C. Tilak
Abstract Turmeric (Curcuma longa) has been used in Indian cooking, and in herbal remedies. Its possible mechanism of action was examined in terms of antioxidant availability during actual cooking conditions and in therapeutic applications using standardized extracts. The assays involve different levels of antioxidant action such as oxygen radical absorbance capacity (ORAC), radical scavenging abilities using 1,1-diphenyl-2-picryl hydrazyl (DPPH), 2,2,-azobis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS), ferric reducing antioxidant power (FRAP) and protection of membranes examined by inhibition of lipid peroxidation besides the content of phenols and total ,avonoids. The aqueous and ethanol extracts of two major preparations of turmeric, corresponding to its use in cooking and medicine, showed signi,cant antioxidant abilities. In conclusion, the studies reveal that the ability of turmeric to scavenge radicals, reduce iron complex and inhibit peroxidation may explain the possible mechanisms by which turmeric exhibits its bene,cial effects in relation to its use in cooking and medicine. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Antioxidant action of Tinospora cordifolia root extract in alloxan diabetic rats

Melatonin as a potential therapeutic agent in psychiatric illness

HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 5 2009
Maria D. Maldonado
Abstract The aim of this review was to summarize the potential use of melatonin in the treatment of mental disorders, specifically bipolar disorders, depression, and schizophrenia. To date, melatonin has been most commonly used in psychiatry because of its hypnotic, rhythm resynchronizing, and antioxidant actions. Here, we examine other properties of the melatonin including its anti-inflammatory, antinociceptive, anxiolytic, and drug detoxification actions as well as its protective effects against neural loss. The brain is an intricate sensory and motor organ which receives information from both the external and internal environments. It transduces information into complex chemical and electrical signals which are transmitted throughout the central nervous system (CNS) and the organism. The pathogenesis of mental disorders remains ambiguous and neuroinflammation has been proposed as a causative agent. We consider the potential contributions of melatonin as therapeutic agent in CNS and during neuroinflammation in mental disorders. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Neuroprotective effects of bcl-2 overexpression in hippocampal cultures: interactions with pathways of oxidative damage

JOURNAL OF NEUROCHEMISTRY, Issue 4 2002
Sarah Howard
Abstract Overexpression of bcl-2protects neurons from numerous necrotic insults, both in vitro and in vivo. While the bulk of such protection is thought to arise from Bcl-2 blocking cytochrome c release from mitochondria, thereby blocking apoptosis, the protein can target other steps in apoptosis, and can protect against necrotic cell death as well. There is evidence that these additional actions may be antioxidant in nature, in that Bcl-2 has been reported to protect against generators of reactive oxygen species (ROS), to increase antioxidant defenses and to decrease levels of ROS and of oxidative damage. Despite this, there are also reports arguing against either the occurrence, or the importance of these antioxidant actions. We have examined these issues in neuron-enriched primary hippocampal cultures, with overexpression of bcl-2 driven by a herpes simplex virus amplicon: (i) Bcl-2 protected strongly against glutamate, whose toxicity is at least partially ROS-dependent. Such protection involved reduction in mitochondrially derived superoxide. Despite that, Bcl-2 had no effect on levels of lipid peroxidation, which is thought to be the primary locus of glutamate-induced oxidative damage; (ii) Bcl-2 was also mildly protective against the pro-oxidant adriamycin. However, it did so without reducing levels of superoxide, hydrogen peroxide or lipid peroxidation; (iii) Bcl-2 protected against permanent anoxia, an insult likely to involve little to no ROS generation. These findings suggest that Bcl-2 can have antioxidant actions that may nonetheless not be central to its protective effects, can protect against an ROS generator without targeting steps specific to oxidative biochemistry, and can protect in the absence of ROS generation. Thus, the antioxidant actions of Bcl-2 are neither necessary nor sufficient to explain its protective actions against these insults in hippocampal neurons. [source]

Effects of Eriobotrya japonica seed extract on oxidative stress in rats with non-alcoholic steatohepatitis

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 2 2010
Saburo Yoshioka
Abstract Objectives Non-alcoholic steatohepatitis is associated with the deposition of lipid droplets in the liver, and is characterised histologically by the infiltration of inflammatory cells, hepatocellular degeneration and liver fibrosis. Oxidative stress may play an important role in the onset and deterioration of non-alcoholic steatohepatitis. We previously reported that an Eriobotrya japonica seed extract, extracted in 70% ethanol, exhibited antioxidant actions in vitro and in vivo. In this study, we examined the effect of this extract in a rat model of non-alcoholic steatohepatitis. Methods The seed extract was given in the drinking water to fats being fed a methionine-choline-deficient diet for 15 weeks. Key findings Increases in alanine aminotransferase and aspartate aminotransferase levels were significantly inhibited in rats fed the seed extract compared with the group on the diet alone. Formation of fatty droplets in the liver was also inhibited. Antioxidant enzyme activity in liver tissue was higher than in the diet-only group and lipid peroxidation was reduced compared with rats that also received the extract. Expression of 8-hydroxy-2,-deoxyguanosine and 4-hydroxy-2-nonenal was lower in the rats given the seed extract than in the diet-only group. In the former, liver tissue levels of transforming growth factor-, and collagen were also decreased. Conclusions Thus, the E. japonica seed extract inhibited fatty liver, inflammation and fibrosis, suggesting its usefulness in the treatment of non-alcoholic steatohepatitis. [source]

Melatonin ameliorates nonalcoholic fatty liver induced by high-fat diet in rats

JOURNAL OF PINEAL RESEARCH, Issue 1 2006
Min Pan
Abstract:, Nonalcoholic fatty liver disease (NAFLD) is an increasingly recognized condition that may progress to end-stage liver disease, which ranges from simple steatosis to steatohepatitis, advanced fibrosis, and cirrhosis. Oxidative stress and lipid peroxidation are key pathophysiological mechanisms in NAFLD. We investigate the preventive effects of intraperitoneal administration of melatonin (2.5, 5, 10 mg/kg, daily, respectively) in NAFLD rats induced by high-fat diets for 12 wk. Liver damage was evaluated by serological analysis, serum and hepatic lipid assay as well as hematoxylin,eosin staining in liver sections. Oxidative stress and lipid peroxidation were assessed by measuring malondialdehyde (MDA) levels and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in liver. The results showed that high-fat diet induced oxidative stress with extensive liver steatosis in rats. Melatonin (5 or 10 mg/kg) was effective in reducing hepatic steatosis and inflammation with lowering serum alanine aminotransferase, aspartate aminotransferase, and levels liver total cholesterol and triglycerides in high-fat diet rats. Moreover, melatonin (2.5, 5, 10 mg/kg) increased SOD and GSH-Px activities and the 10 mg/kg dose of melatonin reduced MDA levels in liver. This study shows that melatonin exerts protective effects against fatty liver in rats induced by high-fat diet possibly through its antioxidant actions. [source]

A nutrition and health perspective on almonds

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2006
Chung-Yen Chen
Almonds provide a nutrient-dense source of vitamin E, manganese, magnesium, copper, phosphorus, fibre, riboflavin, monounsaturated fatty acids and protein. Although almost 50% of almond weight is fat, incremental intakes of 7 g day,1 of this tree nut reduce low-density lipoprotein (LDL) cholesterol concentration by 1%, especially within the context of diets recommended by the National Cholesterol Education Program. Habitual almond consumption does not lead to weight gain, and their inclusion in low-calorie diets appears to promote more weight loss than a comparable carbohydrate-based low-calorie diet. Also, almonds have a low glycemic index and do not adversely impact insulin sensitivity. Almonds are an excellent source of bioavailable ,-tocopherol, and increasing their intake enhances the resistance of LDL against oxidation. In addition, the polyphenolic constituents of almonds have been characterised recently and found to possess antioxidant actions. While benefits of almonds for cardiovascular health and obesity-related diseases appear promising, the potential allergenic reaction among susceptible individuals can present a risk. Further research is required to achieve a better understanding of the role that the bioavailability and bioaccessibility of almond constituents and the synergy between them play in their associated health outcomes. Copyright © 2006 Society of Chemical Industry [source]

Oxygenolysis of Flavonoid Compounds: DFT Description of the Mechanism for Quercetin

CHEMPHYSCHEM, Issue 11 2004
Sébastien Fiorucci
Abstract Flavonoids are naturally occurring phenol derivatives present in substantial amounts in a large variety of plants, fruits and vegetables daily eaten by humans. Most of these compounds exhibit several interesting biological activities, such as antiradical and antioxidant actions. Indeed, by complexation with specific enzymes, flavonoids are notably liable to metabolize molecular dioxygen. On the basis of experimental results describing oxygenolysis of the flavonoid quercetin, activated by the enzyme quercetin 2,3-dioxygenase (2,3-QD), our attention has focused on the role of metal center in the activation of the substrate quercetin. Thus, in the present study, by means of DFT calculations at the B3LYP/6-31(+)G* level on model molecular systems, we describe different mechanisms for dioxygen metabolization by quercetin. Stationary points are described, and energetic and structural analyses along the reaction paths are reported. Our calculations show that the copper cation must act as an oxidant towards the substrate and that the reaction proceeds through a 1,3-cycloaddition. [source]