Efficacy of Grape Seed Proanthocyanidins on Cardioprotection During Isoproterenol-induced Myocardial Injury in Rats

Reactive oxygen species, toxicity, oxidative stress, and antioxidants: chronic diseases and aging

A physiological level of oxygen/nitrogen free radicals and non-radical reactive species (collectively known as ROS/RNS) is termed oxidative eustress or "good stress" and is characterized by low to mild levels of oxidants involved in the regulation of various biochemical transformations such as carboxylation, hydroxylation, peroxidation, or modulation of signal transduction pathways such as Nuclear factor-κB (NF-κB), Mitogen-activated protein kinase (MAPK) cascade, phosphoinositide-3-kinase, nuclear factor erythroid 2-related factor 2 (Nrf2) and other processes. Increased levels of ROS/RNS, generated from both endogenous (mitochondria, NADPH oxidases) and/or exogenous sources (radiation, certain drugs, foods, cigarette smoking, pollution) result in a harmful condition termed oxidative stress ("bad stress"). Although it is widely accepted, that many chronic diseases are multifactorial in origin, they share oxidative stress as a common denominator. Here we review the importance of oxidative stress and the mechanisms through which oxidative stress contributes to the pathological states of an organism. Attention is focused on the chemistry of ROS and RNS (e.g. superoxide radical, hydrogen peroxide, hydroxyl radicals, peroxyl radicals, nitric oxide, peroxynitrite), and their role in oxidative damage of DNA, proteins, and membrane lipids. Quantitative and qualitative assessment of oxidative stress biomarkers is also discussed. Oxidative stress contributes to the pathology of cancer, cardiovascular diseases, diabetes, neurological disorders (Alzheimer's and Parkinson's diseases, Down syndrome), psychiatric diseases (depression, schizophrenia, bipolar disorder), renal disease, lung disease (chronic pulmonary obstruction, lung cancer), and aging. The concerted action of antioxidants to ameliorate the harmful effect of oxidative stress is achieved by antioxidant enzymes (Superoxide dismutases-SODs, catalase, glutathione peroxidase-GPx), and small molecular weight antioxidants (vitamins C and E, flavonoids, carotenoids, melatonin, ergothioneine, and others). Perhaps one of the most effective low molecular weight antioxidants is vitamin E, the first line of defense against the peroxidation of lipids. A promising approach appears to be the use of certain antioxidants (e.g. flavonoids), showing weak prooxidant properties that may boost cellular antioxidant systems and thus act as preventive anticancer agents. Redox metal-based enzyme mimetic compounds as potential pharmaceutical interventions and sirtuins as promising therapeutic targets for age-related diseases and anti-aging strategies are discussed.

Synergetic Effect of Lupeol and Naringin Against Bile Duct Ligation Induced Cardiac Injury in Rats via Modulating Nitrite Level (eNos) and NF-kB /p65 Expression

Cardiac dysfunction such as cirrhotic cardiomyopathy is more common in liver cirrhosis related disorders including primary biliary cholangitis or biliary cirrhosis and primary sclerosing cholangitis. Bile duct ligation (BDL) is an effective model of biliary cholestasis, producing oxidative damage and fibrosis. This research was designed to evaluate the effect of Lupeol and Naringin and its combination on bile duct ligation induced cardiac injury in rats. For pharmacological evaluation, rats were randomly divided into seven groups; intrahepatic cholestasis induced by ligation of the bile duct might lead to cirrhotic cardiomyopathy. The results were analyzed by physical, biochemical and histological examination. The Lupeol (100 mg/kg, p.o.), Naringin (100 mg/kg, p.o.) and its combination (100 mg/kg each) treated group significantly improved physical infarct size, biochemical (Nitrite, SOD, CAT, and GSH) and histological (heart tissue- mitochondrial function/integrity and fibrosis) alterations occurs due to BDL-ligation. This study was concluded that oral administration of Lupeol, Naringin, and its combination has a curative potential against BDL-induced cardiac injury in rats by reducing oxidative stress and inflammatory reactions, resulting in reduced heart necrosis/myocardial infarction and increased myocardial activity. It also inhibits cardiac damage in the rat heart, these effects may be linked to the NO level (eNOS) is increased and the inactivation of the NF-kB-p65 expression pathways.This study also provides new insights into the development of lupeol and Naringin combination that can be used as supportive therapy for cardiovascular diseases.

Molecular Mechanistic Pathways Targeted by Natural Antioxidants in the Prevention and Treatment of Chronic Kidney Disease

Chronic kidney disease (CKD) is the progressive loss of renal function and the leading cause of end-stage renal disease (ESRD). Despite optimal therapy, many patients progress to ESRD and require dialysis or transplantation. The pathogenesis of CKD involves inflammation, kidney fibrosis, and blunted renal cellular antioxidant capacity. In this review, we have focused on in vitro and in vivo experimental and clinical studies undertaken to investigate the mechanistic pathways by which these compounds exert their effects against the progression of CKD, particularly diabetic nephropathy and kidney fibrosis. The accumulated and collected data from preclinical and clinical studies revealed that these plants/bioactive compounds could activate autophagy, increase mitochondrial bioenergetics and prevent mitochondrial dysfunction, act as modulators of signaling pathways involved in inflammation, oxidative stress, and renal fibrosis. The main pathways targeted by these compounds include the canonical nuclear factor kappa B (NF-κB), canonical transforming growth factor-beta (TGF-β), autophagy, and Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid factor 2-related factor 2 (Nrf2)/antioxidant response element (ARE). This review presented an updated overview of the potential benefits of these antioxidants and new strategies to treat or reduce CKD progression, although the limitations related to the traditional formulation, lack of standardization, side effects, and safety.

Phytochemical Profile, Antioxidant and Antitumor Activities of Green Grape Juice

(1) Plants, due to their phytochemicals, have long been known for their pharmacological potential and medicinal value. Verjuice, the acidic juice of unripe green grape, is still poorly characterized in terms of its chemical composition and biological activities. (2) In this study, we characterized the chemical composition, antioxidant and antitumor potential of verjuice extract. Folin–Ciocalteu and aluminum chloride reagents were used to identify the total phenol and total flavonoid composition. Various conventional methods were used to quantify the alkaloids and tannins. DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging assay and Neutral Red assay were used to assess the antioxidant and antitumor activities, respectively. (3) We showed that the verjuice extract contains alkaloids, tannins, and a high quantity of total flavonoids and total phenols. Besides its antioxidant activity, verjuice significantly repressed human pulmonary adenocarcinoma (A549) cells’ viability in both dose- and time-dependent manners. Moreover, verjuice extract significantly enhanced the anticancer potential of cisplatin. (4) Altogether, these observations suggest a potential use of verjuice as a natural antitumor remedy.

Evaluation of the Cardiac Protection Conferred by Proanthocyanidins in Grape Seeds against Development of Ehrlich Solid Tumors in Mice

Examination of the antineoplastic effects of a range of chemical compounds is often undertaken via the transplantable tumor model of Ehrlich solid tumor (EST), which is a simulation of breast cancer. The purpose of this study was to explore how cardiac toxicity, damage, oxidative stress, and changes in the expressions of TNFα and apoptotic P53 triggered by EST could be countered with grape seed proanthocyanidins (GSPE). To that end, 50 female mice were used, with arbitrary and equal distribution into five groups, namely, the control group (G1), GSPE group (G2), EST group (G3), GSPE + EST (G4; cotreatment consisted of mice that received GSPE treatment at the beginning of EST induction over a period of 14 days), and EST + GSPE (G5; posttreatment consisted of mice with EST that received GSPE treatment for 14 days following the 14 days since the induction of EST). By comparison with the control group, the EST group had significantly higher levels of serum lactate dehydrogenase (LDH), creatine phosphokinase (CPK), creatine kinase MB (CK-MB), myoglobin, cardiac TBARS, nitric oxide (NO), total thiol and hydrogen peroxide, cardiac damage, and expression of P53 and TNFα. On the other hand, the EST group had significantly lower levels of cardiac catalase and total antioxidant (TAC) than the control group. Furthermore, better improvement in cardiac toxicity, oxidative stress, damage, apoptosis, and TNFα expressions was displayed by the cotreated (GSPE + EST) group than by the posttreated (EST + GSPE) group. This led to the conclusion that GSPE conferred cardiac protective and antioxidant effects against EST. This finding calls for more investigation on the benefits of grape seeds as adjuvant agents to prevent and treat cardiac toxicity.

Grape seed proanthocyanidins and metformin combination attenuate hepatic endoplasmic reticulum stress in rats subjected to nutrition excess

CONTEXT

Endoplasmic reticulum (ER) stress in the liver is a pathological outcome of nutrient excess and is suggested to be one of the hits for progressive liver injury.

OBJECTIVE

This study investigated whether grape seed proanthocyanidins (GSP) and metformin (MET) alone or in combination can relieve hepatic ER stress induced in rats subjected to calorie excess.

MATERIAL AND METHODS

Male albino Wistar rats were given high calorie diet (HCD) for 45 days, while GSP (100 mg/kg body weight) and MET (50 mg/kg body weight) were administered either alone or in combination for last 15 days.

RESULTS

GSP, MET or both had reduced the levels of ER stress markers and chaperons, and suppressed the activation of lipogenic and inflammatory mediators in rat liver.

DISCUSSION

Though GSP and MET had reduced ER stress and inflammation individually, combination treatment with GSP + MET was more effective.

CONCLUSION

We suggest intervention with GSP and MET intake has to be considered for the management of liver disorders.

Histological and immunohistochemical study of cardiac telocytes in a rat model of isoproterenol-induced myocardial infarction with a reference to the effect of grape seed extract

INTRODUCTION

Cardiac telocytes (TCs) represent a unique type of cells that make a supportive network for stem cells that contribute in cardiac renewal, but their role during myocardial infarction (MI) is not clear. Grape seed extract (GSE) is a powerful natural antioxidant.

AIM OF THE WORK

Quantitative study of cardiac TCs in a rat model of Isoproterenol (ISO)-induced MI, and to evaluate the effect of GSE on TCs and MI progression.

MATERIALS AND METHODS

Seventy adult male albino rats were assigned into 4 groups; group I; control rats, group II received GSE (100mg/kg/day) dissolved in distilled water orally, group III received 2 intra-peritoneal injections of 85mg/kg ISO dissolved in saline on 14th and 15th day to induce MI, and group IV received GSE and ISO. Myocardium was obtained 1 and 14days after ISO i.e. on day 16 and day 30 respectively. Tissue was prepared for histological and immunohistochemical study of CD117 and CD34 as two markers for TCs. CD34 was used also as a marker for angiogenesis.

RESULTS

Group III showed focal areas of myocardial infarction 1day and 14days after ISO. Degenerated cardiomyocytes showed loss of striation and hypereosinophilic vacuolated cytoplasm with condensed nuclei. Mononuclear cell infiltration and a significantly increased percentage area of fibrosis 14days after ISO were observed. CD117 and CD34 positive TCs were hardly detected 1day after ISO. Their number slightly increased 14days after ISO with insignificant difference to control. There was also a significant increase in the number of CD34 positive blood vessels 14days after ISO. Group IV showed much better histological picture with a significant decrease in the percentage area of fibrosis and a significant increase in the number of CD117 and CD34 positive TCs and the number of CD34 positive blood vessels as compared to group III.

CONCLUSION

Telocytes were significantly decreased in MI. GSE reduced ISO-induced histological changes and increased the number of TCs that improved angiogenesis.

Cardioprotective Effect of Grape Seed Extract on Chronic Doxorubicin-Induced Cardiac Toxicity in Wistar Rats

Purpose: The aim of the present study was to determine the ability of grape seed extract (GSE) as a powerful antioxidant in preventing adverse effect of doxorubicin (DOX) on heart function. Methods: Male rats were divided into three groups: control, DOX (2 mg/kg/48h, for 12 days) and GSE (100 mg/kg/24h, for 16 days) plus DOX. Left ventricular (LV) function and hemodynamic parameters were assessed using echocardiography, electrocardiography and a Millar pressure catheter. Histopathological analysis and in vitro antitumor activity were also evaluated. Results: DOX induced heart damage in rats through decreasing the left ventricular systolic and diastolic pressures, rate of rise/decrease of LV pressure, ejection fraction, fractional shortening and contractility index as demonstrated by echocardiography, electrocardiography and hemodynamic parameters relative to control group. Our data demonstrated that GSE treatment markedly attenuated DOX-induced toxicity, structural changes in myocardium and improved ventricular function. Additionally, GSE did not intervene with the antitumor effect of DOX. Conclusion: Collectively, the results suggest that GSE is potentially protective against DOX-induced toxicity in rat heart and maybe increase therapeutic index of DOX in human cancer treatment.

Effect of electronic stimulation at Neiguan (PC 6) acupoint on gene expression of adenosine triphosphate-sensitive potassium channel and protein kinases in rats with myocardial ischemia

OBJECTIVE

To investigate the effects of electronic stimulation at acupoints Neiguan (PC 6) and Lieque (LU 7) on the gene expression of the adenosine triphosphate (ATP)-Sensitive potassium channel (KATP: Kir6.1, Kir6.2, SUR2A, and SUR2B) and protein kinases (PKA, PKG, and PKCβ2) in myocardial cells of rats with myocardial ischemia (MI) induced by isoproterenol (ISO).

METHODS

Rats were randomly divided into a control, model, Neiguan (PC 6), Lieque (LU 7), and non-acupoint groups. The MI model was established by injecting rats with ISO. Electro-acupuncture treatment was given to the acupuncture groups, once a day for 7 days. Gene expression was analyzed with real-time PCR.

RESULTS

The gene expression of KATP and protein kinases in the model group was higher than those in the control group (P < 0.05). After acupuncture treatment, the KATP and protein kinase expression levels were significantly lower in the Neiguan (PC 6) and Lieque (LU 7) groups compared with the mod- el group (P < 0.05). The Neiguan (PC 6) group lowered these levels significantly more than that of the Lieque (LU 7) group (P < 0.05). No significant differences were observed between the model and non-acupoint groups (P> 0.05).

CONCLUSION

Our findings suggest that electronic needling of Neiguan (PC 6) can both reduce the gene expression of KATP and protein kinases in rats with ISO-induced MI.

The effects of unripe grape extract on systemic blood pressure and serum levels of superoxide dismutase, malondialdehyde and nitric oxide in rat

Backgrounds:

The new lifestyle increases the incidence of hypertension. In Iranian folk medicine, it is believed that Verjuice obtained by unripe grape (Vitis vinifera) could control blood pressure. We tested the effects of unripe grape extract (UGE) in blood pressure alteration, serum antioxidant level and aorta endothelial permeability in rats.

Materials and Methods:

Four groups of rats were treated daily by placebo and three different doses of UGE (50, 150 and 300 mg/kg/day). Four weeks later, the animals were anesthetized and catheterized. The direct mean arterial, systolic and diastolic pressures (MAP, SP and DP) were recorded. The endothelial permeability was determined and the serum levels of superoxide dismutase (SOD), malonaldialdehyde (MDA) and nitrite were measured.

Results:

High dose of UGE increased MAP and SP significantly (P < 0.05) when compared with the control group. Decrease of MDA and increase of SOD and nitrite also were detected statistically in animals treated with high dose of UGE (P < 0.05). No difference in aorta endothelial permeability was observed between the groups.

Conclusion:

The effect of UGE on blood pressure was dose dependent. High dose of UGE increased MAP and SP although its antioxidant activity was significantly high. Such observation mechanisms need to be defined.

Natural bioactive compounds from winery by-products as health promoters: a review

The relevance of food composition for human health has increased consumers' interest in the consumption of fruits and vegetables, as well as foods enriched in bioactive compounds and nutraceuticals. This fact has led to a growing attention of suppliers on reuse of agro-industrial wastes rich in healthy plant ingredients. On this matter, grape has been pointed out as a rich source of bioactive compounds. Currently, up to 210 million tons of grapes (Vitis vinifera L.) are produced annually, being the 15% of the produced grapes addressed to the wine-making industry. This socio-economic activity generates a large amount of solid waste (up to 30%, w/w of the material used). Winery wastes include biodegradable solids namely stems, skins, and seeds. Bioactive compounds from winery by-products have disclosed interesting health promoting activities both in vitro and in vivo. This is a comprehensive review on the phytochemicals present in winery by-products, extraction techniques, industrial uses, and biological activities demonstrated by their bioactive compounds concerning potential for human health.

The effects of bioactive compounds from plant foods on mitochondrial function: a focus on apoptotic mechanisms

Mitochondria are essential organelles for cellular integrity and functionality maintenance and their imparement is implicated in the development of a wide range of diseases, including metabolic, cardiovascular, degenerative and hyperproliferative pathologies. The identification of different compounds able to interact with mitochondria for therapeutic purposes is currently becoming of primary importance. Indeed, it is well known that foods, particularly those of vegetable origin, present several constituents with beneficial effects on health. This review summarizes and updates the most recent findings concerning the mechanisms through which different dietary compounds from plant foods affect mitochondria functionality in healthy and pathological in vitro and in vivo models, paying particular attention to the pathways involved in mitochondrial biogenesis and apoptosis.

The effects of unripe grape extract on systemic blood pressure, nitric oxide production, and response to angiotensin II administration

Background:

Hypertension is the most common disease in the world. In Iranian folk medicine, unripe grape juice has been used as antihypertention remedy, but no data is documented for this popular belief. This study was designed to determine the effect of unripe grape extract (UGE) on blood pressure and the response to angiotensin II in rat.

Materials and Methods:

Unripe grape was collected, air dried, and extracted and concentrated. Four groups of Wistar rats received single doses of 125, 250, and 500 mg/kg of UGE or saline, respectively. The direct blood pressure and the serum nitrite level were measured one hour post UGE administration. The animals also were subjected to the infusion of various angiotensin II concentrations (100, 300, and 1000 μg/kg/min), and blood pressure was determined.

Results:

Mean arterial, systolic, and diastolic pressures (MAP, SP, and DP) in all UGE treated groups were less than the control group, but only at the dose of 125 mg/kg (Group 1) they were significantly different (P < 0.05). The level of nitrite in groups 1-3 were significantly greater than the control group (P < 0.05). No significant differences were detected for the MAP, SP, and DP to different concentrations of angiotensin II among these groups.

Conclusion:

UGE potentially attenuate MAP, SP, and DP via vasodilatation induced by nitric oxide production.

Combined effects of quercetin and atenolol in reducing isoproterenol-induced cardiotoxicity in rats: possible mediation through scavenging free radicals

In this investigation, combined effects of quercetin and atenolol in the regulation of isoproterenol (ISO)-induced cardiotoxicity have been evaluated in rats. While ISO administration increased the levels of serum creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH) and glutamate pyruvate transaminase (SGPT) as well as cardiac malondialdehyde (MDA); it reduced the activities of superoxide dismutase, catalase, glutathione peroxidase and the level of reduced glutathione. ISO-induced rats also exhibited ST-segment elevation and tachycardia. Oral administration of atenolol (6 mg/kg) and quercetin (5 mg/kg), along with ISO (5 mg/kg, subcutaneously) every day for 10 days markedly reduced the serum CK-MB, LDH and SGPT levels. Concomitantly the test drugs improved the status of antioxidative enzymes, decreased the cardiac MDA and nearly normalized the electrocardiogram. Electron paramagnetic resonance study also revealed a decrease in 5,5'-dimethyl-1-pyroline-N-oxide-hydroxyl radicals signal intensity when atenolol and quercetin were administered together to ISO-treated rats. In conclusion, the combined treatment of atenolol and quercetin appears to produce a better cardioprotective effect in ISO-induced animals as compared to their individual treatments, and possibly the beneficial actions are associated with the free radical scavenging action of quercetin.

Associations between flavonoids and cardiovascular disease incidence or mortality in European and US populations

Twenty publications from twelve prospective cohorts have evaluated associations between flavonoid intakes and incidence or mortality from cardiovascular disease (CVD) among adults in Europe and the United States. The most common outcome was coronary heart disease mortality, and four of eight cohort studies reported significant inverse associations for at least one flavonoid class (multivariate adjusted p(trend) < 0.05). Three of seven cohorts reported that greater flavonoid intake was associated with lower risk of incident stroke. Comparisons among the studies were difficult because of variability in the flavonoid classes included, demographic characteristics of the populations, outcomes assessed, and length of follow-up. The most commonly examined flavonoid classes were flavonols and flavones combined (11 studies). Only one study examined all seven flavonoid classes. The flavonol and flavone classes were most strongly associated with lower coronary heart disease mortality. Evidence for protection from other flavonoid classes and CVD outcomes was more limited. The hypothesis that flavonoid intakes are associated with lower CVD incidence and mortality requires further study.

A novel phytochemical, digoxigenin-3-O-rutin in the amelioration of isoproterenol-induced myocardial infarction in rat: a comparison with digoxin

INTRODUCTION

The commonly used cardiac glycoside, digoxin (DIG), has a narrow therapeutic window. Although some investigations were made to counteract its toxic effects, no alternate phytochemical is available till date that is more potent and safer than DIG.

AIMS

Our main aim was to isolate a novel cardenolide from the seeds of Trigonella foenum graceium and to evaluate its relative potential in comparison to that of DIG.

EXPERIMENTAL DESIGN

In one experiment effects of the isolated compound at 2.5, 5.0, and 10 mg/kg (p.o.) were evaluated in isoproterenol (ISO)-induced cardiovascular problems in rats. As the test drug (TDR) reversed most of the ISO-induced changes, it was subjected to the phytochemical analyses and was identified as digoxigenin-3-O-rutin. In another experiment effects of DIG and rutin (Rtn) were compared with those of TDR or DIG alone. The hydroxyl radical scavenging activity was also measured by electron spin resonance (EPR).

RESULTS

digoxigenin-3-O-rutin at 10 mg/kg markedly reduced the ISO-induced increase in cardiac lipid peroxidation and in the levels of serum creatinine phosphokinase-MB, glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, lactate dehydrogenase, and creatinine. It also reversed the ISO-induced changes in the cardiac histomorphology. Interestingly TDR appeared to be more effective than DIG alone or DIG and Rtn in combination.

CONCLUSION

The newly isolated digoxigenin-3-O-rutin appears to be more potent and safe than digoxin. Its higher efficacy could be due to its structural specificity and might have been mediated through its better free radical scavenging action.