Valencene post-treatment exhibits cardioprotection via inhibiting cardiac hypertrophy, oxidative stress, nuclear factor- κB inflammatory pathway, and myocardial infarct size in isoproterenol-induced myocardial infarcted rats; A molecular study.

The growing burden of myocardial infarction (MI) becomes a major global health issue that is accountable for considerable mortality worldwide. Hence, it is obligatory to develop a new treatment for MI having lesser side effects. Cardiac hypertrophy, oxidative stress, and inflammatory pathways play crucial roles in the pathogenesis of MI. This investigation established the anti-cardiac hypertrophic, antioxidant, anti-inflammatory, and myocardial infarct size limiting effects of valencene. Rats were induced MI by isoproterenol (100 mg/kg body weight) and then treated with valencene and cardiac sensitive markers, cardiac hypertrophy, oxidative stress, markers of inflammation, nuclear factor- κB inflammatory pathway, and myocardial infarct size was estimated/determined. The serum cardiac diagnostic markers, cardiac hypertrophy, conjugated dienes, markers of inflammation, pro-inflammatory cytokines, and myocardial infarct size were significantly (P < 0.05) increased by isoproterenol. Further, antioxidant enzymes and anti-inflammatory cytokine gene were significantly (P < 0.05) decreased in the heart. The 2, 3, 5-triphenyl tetrazolium chloride dye staining revealed a larger infarct size. Moreover, histological results of myocardial infarcted rat's cardiac tissue revealed separation of cardiac muscle fibers, necrosis, and inflammatory cells. Post-treatment with valencene (12 mg/kg body weight) orally, daily, for two weeks to isoproterenol-induced myocardial infarcted rats reversed all above said structural, biochemical, molecular, and histological parameters investigated, by its anti-cardiac hypertrophic, antioxidant, anti-inflammatory, and myocardial infarct size limiting effects. Thus, valencene is a potential candidate for inhibiting cardiac hypertrophy, oxidative stress, nuclear factor- κB inflammatory pathway, and myocardial infarct size and exhibited cardioprotection in MI.

Sinapic acid safeguards cardiac mitochondria from damage in isoproterenol-induced myocardial infarcted rats.

Myocardial infarction (MI) is a life-threatening disease. In this study, we examined the anti-mitochondrial damaging effects of sinapic acid (SA) in isoproterenol (ISO)-induced myocardial infarcted rats. Myocardial infarcted rats were prepared by injecting ISO (100 mg/kg body weight) on the 9th and 10th day. Rats were pretreated and cotreated with SA (12 mg/kg body weight) orally, daily for 10 days. A considerable increase in serum lactate dehydrogenase, creatine kinase, myoglobin, and cardiac troponin-T was noticed in the ISO-induced rats. ISO also significantly amplified lipid peroxidation and calcium ions, and depleted the antioxidant system and mitochondrial enzymes in rat's heart mitochondria. SA treatment improved the distorted above- mentioned biochemical parameters in ISO-treated rats with its anti-mitochondrial damaging effects. This ultrastructural study on heart mitochondria and in vitro studies also confirmed the effects of SA. The current findings are suggestive of SA's cardioprotective effects.

Diosmin Prevents Isoproterenol-Induced Heart Mitochondrial Oxidative Stress in Rats.

Cardiac mitochondrial oxidative stress causes mitochondrial damage that plays an important role in the pathology of myocardial infarction. The preventive effects of diosmin on cardiac mitochondrial oxidative stress in isoproterenol-induced myocardial infarcted rats were evaluated. Rats were pretreated with diosmin (10 mg/kg body weight) daily for 10 days. Myocardial infarction was induced in rats by isoproterenol (100 mg/kg body weight) injection twice at an interval of 24 h (on 11th and 12th day). Isoproterenol-induced myocardial infarcted rats showed a significant increase in the levels of cardiac diagnostic markers, heart mitochondrial lipid peroxidation, calcium ion, and a significant decrease in the levels of heart mitochondrial glutathione peroxidase, reduced glutathione, glutathione-S-transferase, isocitrate, malate, α-ketoglutarate, and succinate dehydrogenases. Transmission electron microscopic findings revealed damaged mitochondria with loss of cristae, swelling, and vacuolation in isoproterenol-induced rats' heart. Diosmin pretreatment showed significant preventive effects on all the biochemical parameters, and the structure of mitochondria was evaluated. Furthermore, the transmission electron microscopic study confirms the biochemical findings. The antioxidant and negative inotropic effects of diosmin inhibited cardiac mitochondrial oxidative stress and prevented mitochondrial damage in myocardial infarcted rats.

Anti-inflammatory and anti-thrombotic effects of zingerone in a rat model of myocardial infarction.

Myocardial infarction continues to be a major public health problem. Reduction in mortality rate and prevention of myocardial infarction are of utmost importance. Inflammation and thrombosis play an important role in the pathogenesis of myocardial infarction. The anti-inflammatory and anti-thrombotic effects of zingerone were evaluated in isoproterenol induced myocardial infarcted rats. Rats were pretreated with zingerone (6mg/kg body weight) daily for 14 days and were then induced myocardial infarction with isoproterenol (100mg/kg body weight) on 15th and 16th day. Isoproterenol induced myocardial infarcted rats showed significant (P<0.05) increase in the levels/ activities of cardiac troponin-I (cTnI), high sensitive C-reactive protein (Hs CRP), lysosomal hydrolases in the serum and concentration of heart lysosomal lipid peroxidation (LPO) products. RT-PCR study revealed over expression of myocardial tumour necrosis factor - alpha (TNF-α), interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) genes in the myocardial infarcted rats. Histopathology of heart and coronary artery revealed marked inflammation and coronary thrombosis. Zingerone pretreatment significantly (P<0.05) decreased serum cTnI, Hs CRP, lysosomal hydrolases and heart lysosomal LPO and down regulated myocardial TNF-α, IL-1ß and IL-6 genes and prevented coronary thrombosis in isoproterenol induced myocardial infarcted rats. The observed effects of zingerone could be attributed to its anti-inflammatory and anti-thrombotic properties.

Antihyperlipidaemic, antihypertrophic, and reducing effects of zingerone on experimentally induced myocardial infarcted rats.

The present study aims to evaluate the antihyperlipidaemic, antihypertrophic, and reducing effects of zingerone on isoproterenol-induced hyperlipidaemia and hypertrophy in rats. Rats were pretreated with zingerone (6 mg/kg body weight) daily for a period of 14 days and then induced myocardial infarction with isoproterenol (100 mg/kg body weight) on days 15 and 16. Isoproterenol increased serum creatine kinase and lactate dehydrogenase activities in the rats. Increased levels/concentrations of serum and heart cholesterol and triglycerides were observed in isoproterenol-induced myocardial infarcted rats. Isoproterenol also altered serum lipoproteins and the activity of liver 3-hydroxy-3-methyl glutaryl-coenzyme-A-reductase in the rats. The in vitro study revealed a very convincing reducing power of zingerone. Pretreatment with zingerone prevented hyperlipidaemia and cardiac hypertrophy, by virtue of its antihyperlipidaemic, antihypertrophic, and reducing properties in isoproterenol-induced myocardial infarcted rats.

p-Coumaric acid attenuates apoptosis in isoproterenol-induced myocardial infarcted rats by inhibiting oxidative stress.

BACKGROUND: Cardiac apoptosis plays an important role in the pathology of myocardial infarction. The protective effects of p-coumaric acid on cardiac apoptosis were evaluated in isoproterenol induced myocardial infarcted rats. METHODS: Rats were pretreated with p-coumaric acid (8 mg/kg body weight) daily for a period of 7 days. After pretreatment, isoproterenol (100 mg/kg body weight) was injected subcutaneously into rats at an interval of 24 h for 2 days to induce myocardial infarction. Cardiac diagnostic markers, heart lipid peroxidation, antioxidant system, histopathological changes of the heart and apoptosis were evaluated in isoproterenol induced myocardial infarcted rats. RESULTS: Isoproterenol induced myocardial infarcted rats showed a significant increase in the levels of serum cardiac diagnostic markers, heart lipid peroxidation products and a significant decrease in the activities/levels of heart antioxidants. Histopathological findings of myocardial infarcted rats revealed marked necrosis and edema. Reverse Transcription Polymerase Chain Reaction study revealed an increase in the myocardial expression of Bax, caspase-8, caspase-9 and Fas genes and a decrease in the myocardial expression of Bcl-2 and Bcl-xL genes. p-Coumaric acid pretreatment showed protective effects on apoptosis by inhibiting oxidative stress. p-Coumaric acid pretreated isoproterenol induced myocardial infarcted heart also confirmed these findings. The possible mechanisms for the protective effects of p-coumaric acid could be attributed to antilipid peroxidative, antioxidant and antiapoptotic properties. CONCLUSION: Thus, p-coumaric acid protected the myocardial infarcted rat's heart against apoptosis by inhibiting oxidative stress.

Preventive effects of p-coumaric acid on cardiac hypertrophy and alterations in electrocardiogram, lipids, and lipoproteins in experimentally induced myocardial infarcted rats.

The present study evaluated the preventive effects of p-coumaric acid on cardiac hypertrophy and alterations in electrocardiogram, lipids, and lipoproteins in experimentally induced myocardial infarcted rats. Rats were pretreated with p-coumaric acid (8 mg/kg body weight) daily for a period of 7 days and then injected with isoproterenol (100mg/kg body weight) on 8th and 9th day to induce myocardial infarction. Myocardial infarction induced by isoproterenol was indicated by increased level of cardiac sensitive marker and elevated ST-segments in the electrocardiogram. Also, the levels/concentrations of serum and heart cholesterol, triglycerides and free fatty acids were increased in myocardial infarcted rats. Isoproterenol also increased the levels of serum low density and very low density lipoprotein cholesterol and decreased the levels of high density lipoprotein cholesterol. It also enhanced the activity of liver 3-hydroxy-3 methyl glutaryl-Coenzyme-A reductase. p-Coumaric acid pretreatment revealed preventive effects on all the biochemical parameters and electrocardiogram studied in myocardial infarcted rats. The in vitro study confirmed the free radical scavenging property of p-coumaric acid. Thus, p-coumaric acid prevented cardiac hypertrophy and alterations in lipids, lipoproteins, and electrocardiogram, by virtue of its antihypertrophic, antilipidemic, and free radical scavenging effects in isoproterenol induced myocardial infarcted rats.

(-) Epicatechin attenuates mitochondrial damage by enhancing mitochondrial multi-marker enzymes, adenosine triphosphate and lowering calcium in isoproterenol induced myocardial infarcted rats.

Cardiac mitochondrial damage plays an important role in the pathology of myocardial infarction. The protective effects of (-) epicatechin on cardiac mitochondrial damage in isoproterenol induced myocardial infarction were evaluated in rats. Rats were pretreated with (-) epicatechin (20 mg/kg body weight) daily for a period of 21 days. After the pretreatment period, isoproterenol (100 mg/kg body weight) was injected subcutaneously into rats twice at an interval of 24 h to induce myocardial infarction. Isoproterenol induced myocardial infarcted rats showed a significant increase in the levels of cardiac diagnostic markers, heart mitochondrial lipid peroxidation, calcium, and a significant decrease in the activities/levels of heart mitochondrial glutathione peroxidase, glutathione reductase, reduced glutathione, isocitrate, succinate, malate, α-ketoglutarate and NADH-dehydrogenases, cytochrome-C-oxidase and adenosine triphosphate. (-) Epicatechin pretreatment showed significant protective effects on all the biochemical parameters evaluated. The in vitro study revealed the superoxide and hydroxyl radical scavenging activity of (-) epicatechin. The possible mechanisms for the beneficial effects of (-) epicatechin on cardiac mitochondria could be attributed to scavenging of free radicals, decreasing calcium, increasing multi-enzymes (antioxidant, tricarboxylic acid cycle and respiratory chain enzymes), reduced glutathione and adenosine triphosphate. Thus, (-) epicatechin attenuated mitochondrial damage in isoproterenol induced myocardial infarcted rats.

Preventive effects of p-coumaric acid on lysosomal dysfunction and myocardial infarct size in experimentally induced myocardial infarction.

The present study was designed to evaluate the preventive effects of p-coumaric acid on lysosomal dysfunction and myocardial infarct size in isoproterenol induced myocardial infarcted rats. Male albino Wistar rats were pretreated with p-coumaric acid (8 mg/kg body weight) daily for a period of 7 days after which isoproterenol (100mg/kg body weight) was injected subcutaneously into rats twice at an interval of 24h (8th and 9th day).The activity/levels of serum cardiac diagnostic markers, heart lysosomal lipid peroxidation products and the activities of lysosomal enzymes (ß-glucuronidase, ß-galactosidase, cathepsin-B and cathepsin-D) were significantly (P<0.05) increased in the serum and heart of isoproterenol induced myocardial infarcted rats. Isoproterenol also lowered the activities of ß-glucuronidase and cathepsin-D in the lysosomal fraction. The pretreatment with p-coumaric acid significantly (P<0.05) prevented the changes in the levels of lysosomal lipid peroxidation products and the activities of lysosomal enzymes. In addition, p-coumaric acid greatly reduced myocardial infarct size. p-Coumaric acid pretreatment (8 mg/kg body weight) to normal rats did not show any significant effect. Thus, this study showed that p-coumaric acid prevents lysosomal dysfunction against cardiac damage induced by isoproterenol and brings back the levels of lipid peroxidation products and activities of lysosomal enzymes to near normal levels. The in vitro study also revealed the free radical scavenging activity of p-coumaric acid. Thus, the observed effects are due to p-coumaric acid's free radical scavenging and membrane stabilizing properties.

Preventive effects of (-) epicatechin on altered adenosine triphosphatases and minerals in isoproterenol-induced myocardial infarcted rats.

The present study was aimed to evaluate the preventive effects of (-) epicatechin on alterations in the activities/levels of adenosine triphosphatases and minerals in isoproterenol-induced myocardial infarcted rats. Male albino Wistar rats were pretreated with (-) epicatechin (20 mg/kg body weight) daily for a period of 21 days. After the pretreatment period, rats were induced myocardial infarction by isoproterenol (100 mg/kg body weight) on 22nd and 23rd day. The activity of sodium/potassium-dependent adenosine triphosphatase was decreased, and the activities of calcium- and magnesium-dependent adenosine triphosphatases were increased in the heart of isoproterenol-induced myocardial infarcted rats. In addition, the concentrations of potassium were decreased and the concentrations of sodium and calcium were increased in the heart of isoproterenol-induced rats. Elevated plasma lipid peroxidation was noted in isoproterenol-induced rats. Prior treatment with (-) epicatechin significantly prevented the alterations in the activities and concentrations of adenosine triphosphatases, minerals, and plasma lipid peroxidation. The in vitro study confirmed the reducing property of (-) epicatechin. The observed effects in this study are attributed to the membrane-stabilizing and antioxidant properties of (-) epicatechin. The findings of this study will be beneficial to prevent the occurrence of myocardial infarction.

Protective effects of N-acetyl cysteine on membrane-bound adenosine triphosphatases and minerals in isoproterenol-induced myocardial-infarcted rats: an in vivo and in vitro study.

The present study was aimed to evaluate the protective effects of N-acetyl cysteine (NAC) on changes in the activities/levels of adenosine triphosphatases and minerals in isoproterenol-induced myocardial-infarcted rats. Male albino Wistar rats were pretreated with NAC (10 mg/kg body weight) daily for a period of 14 days. After pretreatment period, rats were induced myocardial infarction (MI) by isoproterenol (100 mg/kg body weight). The activity of sodium/potassium-dependent adenosine triphosphatase was decreased, and the activities of calcium- and magnesium-dependent adenosine triphosphatases were increased in the heart of isoproterenol-induced myocardial-infarcted rats. Furthermore, the levels of potassium were lowered and the levels of sodium and calcium were increased in the heart of isoproterenol-induced rats. Increased plasma lipid peroxidation was observed in isoproterenol-induced rats. Pretreatment with NAC showed protective effects on adenosine triphosphatases, minerals, and lipid peroxidation. The in vitro study confirmed the reducing property of NAC. The observed effects are due to the membrane-stabilizing and antioxidant effects of NAC. The results of this study will be useful for the prevention of MI.

Protective effects of caffeic acid on lactate dehydrogenase isoenzymes, electrocardiogram, adenosine triphosphatases, and hematology on isoproterenol-induced myocardial infarcted rats.

The present study aims to evaluate the protective effects of caffeic acid on isoproterenol-treated myocardial infarction. Male albino Wistar rats were pretreated with caffeic acid (15 mg/kg) daily for 10 days. After the pretreatment, rats were injected with isoproterenol (100 mg/kg) at an interval of 24 h for 2 days to induce myocardial infarction. Isoproterenol-treated rats showed increased intensity of lactate dehydrogenase-1 and 2 isoenzyme bands and elevated ST segments. The activity of the heart sodium potassium adenosine triphosphatase was decreased, and the activities of the heart magnesium adenosine triphosphatase and calcium adenosine triphosphatase were increased in isoproterenol-treated rats. Isoproterenol-treated rats also showed a significant increase in the concentration of heart calcium. Furthermore, it significantly increased the counts of red blood cells, hemoglobin, white blood cells, and neutrophils and decreased significantly the concentration of erythrocyte sedimentation rate and the counts of lymphocytes and eosinophils. Pretreatment with caffeic acid showed protective effects on all the biochemical parameters, hematology and minimized alterations in lactate dehydrogenase isoenzymes and electrocardiogram. In vitro study confirmed the free radical scavenging potential of caffeic acid. The observed effects might be due to the free radical scavenging and membrane-stabilizing property of caffeic acid.

Protective effects of gallic acid on hepatic lipid peroxide metabolism, glycoprotein components and lipids in streptozotocin-induced type II diabetic Wistar rats.

We evaluated the protective effects of gallic acid (3,4,5-trihydroxybenzoic acid) on hepatic lipid peroxidation products, antioxidants, glycoprotein components, and lipids in streptozotocin-induced type II diabetic rats. To induce type II diabetes, rats were injected with streptozotocin intraperitoneally at a single dose of 40 mg/kg. Gallic acid (10 and 20 mg/kg) treatment was given to diabetic rats orally using an intragastric tube daily for 21 days. Streptozotocin-induced diabetic rats showed a significant increase in the levels of blood glucose, hepatic lipid peroxidation products, glycoprotein components, lipids, and the activity of HMG-CoA reductase and a significant decrease in the levels of plasma insulin and liver glycogen. In addition to this, the activities/levels of hepatic antioxidants were decreased in diabetic rats. Gallic acid (10 and 20 mg/kg) treatment showed significant protective effects on all the biochemical parameters studied in diabetic rats. Thus, our study shows the antihyperglycemic, antilipid peroxidative, antioxidant, and antilipidemic effects of gallic acid in streptozotocin-induced type II diabetic rats. A diet containing gallic acid may be beneficial to type II diabetic patients.

The cardioprotective effects of a combination of quercetin and α-tocopherol on isoproterenol-induced myocardial infarcted rats.

The present study aims to evaluate the combined protective effects of quercetin and α-tocopherol on isoproterenol-treated myocardial infarcted rats. Male albino Wistar rats were pretreated with a combination of quercetin (10 mg/kg) and α-tocopherol (10 mg/kg) daily for 14 days. After the pretreatment, rats were injected isoproterenol (100 mg/kg) to induce myocardial infarction. Isoproterenol-treated rats showed increased levels of serum troponins and increased intensities of serum lactate dehydrogenase-1 and -2 isoenzyme bands. Isoproterenol treatment also showed significant decreased levels of antioxidant system and significant increased levels of plasma lipid peroxidation, plasma uric acid, and the heart calcium. Furthermore, isoproterenol-treated rat's electrocardiogram showed elevated ST segments. Combined pretreatment with quercetin and α-tocopherol normalized all the biochemical parameters and minimized the alterations in electrocardiogram. Histopathology of myocardium also confirmed the cardioprotective effects of quercetin and α-tocopherol. In vitro studies confirmed the mechanism of action of quercetin and α-tocopherol. Thus, quercetin and α-tocopherol exhibited cardioprotective effects against isoproterenol-induced cardiotoxicity due to their scavenging free radicals, improving antioxidants and maintaining Ca(2+) levels. Our study also showed that combined pretreatment (quercetin and α-tocopherol) was highly effective than single pretreatment (quercetin or α-tocopherol).

Effects of gallic acid on brain lipid peroxide and lipid metabolism in streptozotocin-induced diabetic Wistar rats.

This study evaluated the protective effects of gallic acid on brain lipid peroxidation products, antioxidant system, and lipids in streptozotocin-induced type II diabetes mellitus. Streptozotocin-induced diabetic rats showed a significant increase in the levels of blood glucose, brain lipid peroxidation products, and lipids and a significant decrease in the activities of brain enzymic antioxidants. Oral treatment with gallic acid (10 mg and 20 mg/kg) for 21 days significantly decreased the levels of blood glucose, brain lipid peroxidation products, and lipids and significantly increased the activities of brain enzymic antioxidants in diabetic rats. Histopathology of brain confirmed the protective effects of gallic acid. Furthermore, in vitro study revealed the free radical scavenging action of gallic acid. Thus, our study shows the beneficial effects of gallic acid on brain metabolism in streptozotocin-induced type II diabetic rats. A diet containing gallic acid may be beneficial to type II diabetic patients.

Protective effects of combination of quercetin and α-tocopherol on mitochondrial dysfunction and myocardial infarct size in isoproterenol-treated myocardial infarcted rats: biochemical, transmission electron microscopic, and macroscopic enzyme mapping evidences.

Mitochondrial dysfunction plays an important role in the pathology of myocardial infarction. We evaluated the combined protective effects of quercetin and α-tocopherol on mitochondrial damage and myocardial infarct size in isoproterenol-induced myocardia- infarcted rats. Rats were pretreated with quercetin (10 mg/kg) alone, α-tocopherol (10 mg/kg) alone, and combination of quercetin (10 mg/kg) and α-tocopherol (10 mg/kg) orally using an intragastric tube daily for 14 days. After pretreatment, rats were induced myocardial infarction by isoproterenol (100 mg/kg) at an interval of 24 h for 2 days. Isoproterenol treatment caused significant increase in mitochondrial lipid peroxides with significant decrease in mitochondrial antioxidants. Significant decrease in the activities of isocitrate, succinate, malate, and α-ketoglutarate and NADH dehydrogenases and cytochrome-c-oxidase, significant increase in calcium, and significant decrease in adenosine triphosphate were observed in mitochondria of myocardial infarcted rats. Combined pretreatment with quercetin and α-tocopherol normalized all the biochemical parameters and preserved the integrity of heart tissue and restored normal mitochondrial function in myocardial-infarcted rats. Transmission electron microscopic findings on heart mitochondria and macroscopic enzyme mapping assay on the size of myocardial infarct also correlated with these biochemical parameters. The present study showed that combined pretreatment was highly effective than single pretreatment.

Preventive effect of (-)epigallocatechin gallate on lipids, lipoproteins, and enzymes of lipid metabolism in isoproterenol-induced myocardial infarction in rats.

This article reports data on the preventive effect of (-)epigallocatechin gallate (EGCG) on lipid metabolism and lipoproteins in isoproterenol (ISO)-induced myocardial infarction (MI) in Wistar rats. The rats were induced MI by ISO (100 mg/kg) at an interval of 24 h for 2 days. EGCG (30 mg/kg) was given to rats as pretreatment for 21 days orally using an intragastric tube. EGCG significantly reduced the increased serum levels of cholesterol, triglycerides, and free fatty acids in the heart and serum phospholipids (PLs) in ISO-treated rats. It also significantly increased the reduced levels of heart PLs in ISO-induced rats. EGCG reduced the levels of serum low-density lipoprotein cholesterol and very low-density lipoprotein cholesterol and increased serum high-density lipoprotein (HDL)-cholesterol in ISO-treated rats. It also reduced the increased cholesterol/PL ratio and atherogenic index and significantly increased the reduced ratio of HDL-cholesterol/total cholesterol. Also EGCG significantly increased the reduced activity of lecithin cholesterol acyl transferase in ISO-treated rats. Thus, EGCG prevented the accumulation of lipids and altered the levels of lipoproteins in myocardial-infarcted rats.

(-)Epigallocatechingallate protects the mitochondria against the deleterious effects of lipids, calcium and adenosine triphosphate in isoproterenol induced myocardial infarcted male Wistar rats.

The present study was undertaken to evaluate the protective effect of (-)epigallocatechin gallate (EGCG) on mitochondrial lipids, lipid peroxides, Na(+)/K(+) ATPase, calcium and adenosine triphosphate in isoproterenol (ISO) induced myocardial infarction in male Wistar rats. Rats were pretreated with EGCG (30 mg kg(-1) body weight) orally using an intragastric tube daily for a period of 21 days. After that, ISO (100 mg kg(-1) body weight) was subcutaneously injected to rats at intervals of 24 h for two days. ISO induced rats showed significant increase in the levels of cholesterol, triglycerides and free fatty acids with subsequent decrease in the levels of phospholipids in mitochondrial fraction of the heart. ISO induction also caused significant increase in lipid peroxidation products (thiobarbituric acid reactive substances and lipid hydroperoxides) and significant decrease in the activity of Na(+)/K(+) ATPase in mitochondrial fraction of the heart. A significant increase in the levels of calcium and significant decrease in the levels of adenosine triphosphate were observed in ISO-induced mitochondrial heart. Prior treatment with EGCG (30 mg kg(-1)) significantly protected these alterations and maintained normal mitochondrial function. Thus, this study confirmed the protective effect of EGCG on mitochondria in experimentally induced cardiotoxicity in Wistar rats.

(-)Epigallocatechin-gallate (EGCG) prevents mitochondrial damage in isoproterenol-induced cardiac toxicity in albino Wistar rats: a transmission electron microscopic and in vitro study.

Altered mitochondrial function and free radical-mediated tissue damage have been suggested as important pathological events in isoproterenol (ISO)-induced cardiotoxicity. This study was undertaken to know the preventive effect of (-)epigallocatechin-gallate (EGCG) on mitochondrial damage in ISO-induced cardiotoxicity in male Wistar rats. Rats were pretreated with EGCG (30 mg/kg) orally using an intragastric tube daily for a period of 21 days. After that, ISO (100mg/kg) was subcutaneously injected to rats at intervals of 24h for 2 days. ISO-induced rats showed significant increase in mitochondrial lipid peroxidation products (thiobarbituric acid reactive substances and lipid hydroperoxides) and significant decrease in mitochondrial antioxidants (superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase, glutathione reductase and reduced glutathione). Also, significantly decreased activities of tricarboxylic acid cycle enzymes such as isocitrate, succinate, malate and alpha-ketoglutarate dehydrogenases and respiratory chain marker enzymes such as NADH-dehydrogenase and cytochrome-c-oxidase were observed in mitochondrial heart of myocardial infarcted rats. Prior treatment with EGCG (30mg/kg body weight) significantly prevented these alterations and restored normal mitochondrial function. Transmission electron microscopic findings also correlated with these biochemical parameters. In vitro studies on the effect of EGCG on scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS(+)), superoxide anion (O(-)), and hydroxyl (OH) radicals also confirmed the free radical scavenging and antioxidant activity of EGCG. Thus, the observed effects are due to the free radical scavenging and antioxidant potential of EGCG. Thus, this study confirmed the preventive effect of EGCG on isoproterenol-induced mitochondrial damage in experimentally induced myocardial infarction in Wistar rats.

Protective effect of (-)-epigallocatechin-gallate (EGCG) on lipid peroxide metabolism in isoproterenol induced myocardial infarction in male Wistar rats: a histopathological study.

This study aims to evaluate the preventive effect of (-)-epigallocatechin-gallate (EGCG) on lipid peroxides, enzymatic and non-enzymatic antioxidants and histopathological findings in isoproterenol (ISO)-induced rats. Myocardial infarction (MI) is induced in rats by subcutaneous injection of ISO (100 mg/kg body weight) at an interval of 24h for 2 days. ISO-treated rats show a significant increase in the levels of thiobarbituric acid reactive substances, lipid hydroperoxides in plasma and heart and plasma uric acid and a significant decrease in the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase in heart and the levels of reduced glutathione, vitamin C and vitamin E in plasma and the heart and ceruloplasmin in plasma. Oral pretreatment with EGCG (10, 20 and 30 mg/kg body weight) daily for a period of 21 days show significant decrease in the levels of lipid peroxidation products and uric acid and improved the antioxidant status by increasing the activities of antioxidant enzymes and non-enzymic antioxidants. Histopathological findings of the myocardial tissue show the protective effect of EGCG in ISO-induced rats. The effect at a dose of 30 mg/kg of EGCG was more pronounced than that of the other two doses (10 and 20 mg/kg body weight). Thus, the present study reveals that EGCG exerts cardioprotective effect against ISO-induced MI due to its free radical scavenging and antioxidant effects, which maintains the tissue defense system against myocardial damage.