Syed Ehtaishamul Haque

Edaravone protects rats against oxidative stress and apoptosis in experimentally induced myocardial infarction: Biochemical and ultrastructural evidence

Objectives: The present study was designed to evaluate the cardioprotective potential of edaravone on oxidative stress, anti-apoptotic, anti-inflammatory and ultrastructure findings in isoproterenol (ISO) induced myocardial infarction (MI) in rats. Methods: Rats were pretreated with edaravone (1, 3, 10 mg/kg body weight-1 day-1) intraperitoneally. MI was induced by subcutaneous administration of ISO (85 mg/kg body weight-1) at two doses with 24h interval. Results: ISO treated rats showed significant increase in the levels of thiobarbituric acid reactive substances (TBARS) and decreased levels of reduced glutathione, glutathione perdoxidase, glutathione reductase and glutathione-S- transferase in the cardiac tissues. Moreover, significant increase in the levels of lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB), C - reactive protein and caspase-3 activity was observed in ISO treated group. Pretreatment of ISO intoxicated rats with edaravone showed significant decrease in the level of TBARS, increased activities of antioxidant enzymes and significantly decreased levels of LDH and CK-MB. Moreover, results also showed decreased C-reactive protein level, caspase-3 activity and maintained ultrastructure of the myocardial cells. Discussion: Our study suggests that edaravone possess strong cardioprotective potential. Edaravone may have exhibited cardioprotective effects by restoring antioxidant defense mechanism, maintaining integrity of myocardial cell membrane, reducing apoptosis and inflammation against ISO induced MI and associated oxidative stress.

Benidipine prevents oxidative stress, inflammatory changes and apoptosis related myofibril damage in isoproterenol-induced myocardial infarction in rats

Abstract Objective: The effects of benidipine on oxidative stress and myocardial apoptosis were assessed in isoproterenol (ISO)-induced myocardial infarction (MI) in wistar rats. Materials and method: Animals were pretreated with benidipine (1, 3, 10 μg/kg/day Body weight) intravenously for a period of 28 days. After pretreatment, ISO (85 mg/kg Body weight, subcutaneous) was injected in rats at an interval of 24 h to induce MI. Myocardial oxidative stress, cardiac biomarkers, apoptosis, inflammatory mediators, and ultrastructural architecture of the cardiac tissue were assessed in ISO-induced MI in rats. Result: Significant variation in the level of TBA, antioxidant enzymes (GSH, CAT, SOD, GPx, GRx, GST) in myocardium, cardiac biomarkers (CK-MB, LDH) in serum, Caspase-3, C-reactive protein (CRP), and alteration in ultrastructural architecture of cardiac tissue confirmed the cardiotoxicity induced by ISO. Pretreatment with benidipine preserved the lipid peroxide and antioxidant enzymes, and furthermore showed maintained levels of myocardial biomarker, CRP and caspase-3. Ultrastructure architecture of cardiac tissue was also found to be well preserved. Conclusion: The present study suggested cardioprotective effect of benidipine which may possibly be due to its antioxidant activity and antiapoptotic nature.

Diclofenac sodium, a nonselective nonsteroidal anti-inflammatory drug aggravates doxorubicin-induced cardiomyopathy in rats.

The cardiotoxic effects of selective cyclo-oxygenase-2 inhibitors are well documented. Recently, concerns have been raised over the cardiovascular safety of nonselective nonsteroidal anti-inflammatory drugs. The aim of this study was to assess the cardiac effects of diclofenac sodium on doxorubicin-induced cardiomyopathy in rats. Male Wistar rats were treated with doxorubicin (15 mg/kg intraperitoneally, single dose), diclofenac sodium (2.5 and 10 mg/kg/day, respectively, by gavage for 5 days) alone and doxorubicin + diclofenac sodium treatment, 24 hours after doxorubicin administration. Doxorubicin-induced a significant (P < 0.001) increase in the serum lactate dehydrogenase, cardiac thiobarbituric acid-reactive substance and catalase levels and a significant (P < 0.001) decrease in the cardiac glutathione and superoxide dismutase levels, which were significantly (P < 0.001) aggravated by diclofenac sodium treatment. Diclofenac sodium alone also showed a significant change in these parameters compared with the control. Ultrastructural studies showed that doxorubicin causes apoptosis in myocardium, which was characterized by condensation of chromatin network at the margins of nuclear membrane. Apoptosis induced by doxorubicin was exacerbated by diclofenac sodium treatment. Thus, our study indicates that diclofenac sodium, a nonaspirin nonsteroidal anti-inflammatory drug, is not free from cardiotoxicity and aggravates doxorubicin-induced cardiomyopathy in rats.

Edaravone, a potent free radical scavenger and a calcium channel blocker attenuate isoproterenol induced myocardial infarction by suppressing oxidative stress, apoptotic signaling and ultrastructural damage:

Objectives: In the present study, we investigated whether combination therapy of low-dose benidipine with the potent free radical scavenger edaravone has a cardioprotective effect against isoproterenol (ISO)-induced myocardial infarction (MI) in Wistar rats. Methods: Rats were pretreated with concurrent doses of benidipine and edaravone (1 μg/kg/day + 1 mg/kg/day and 3 μg/kg/day + 3 mg/kg/day) by intravenous (i.v.) and intraperitoneal (i.p.) routes respectively for 28 days, followed by MI induction using ISO (85 mg/kg) by subcutaneous route for two days at 24 h intervals. After the treatment period, blood was withdrawn and the heart was preserved for biochemical estimations. Results: The activities of the cardiac biomarkers (lactate dehydrogenase and creatine kinase-MB), and the level of malondialdehyde (MDA) significantly increased, while antioxidant markers (reduced glutathione, catalase, superoxidase dismutase, glutathione peroxidase, glutathione reductase) were significantly decreased in the ISO intoxicated group compared with the control group. Moreover, the level of C-reactive protein (CRP) and Caspase-3 activity significantly increased in ISO-intoxicated group. An ultrastructure study was also carried out. Pretreatment with a combination of benidipine and edaravone significantly attenuated the activities of the cardiac biomarkers and the level of MDA, and significantly increased the antioxidant markers compared with the ISO-intoxicated group. Furthermore, pretreatment with the combination of benidipine and edaravone significantly decreased the level of CRP and Caspase-3 activity as compared to the ISO-treated group. The ultrastructure study of myocardium revealed that pretreated groups preserved the mitochondrial shape, the membrane and its internal structures. Conclusion: Taken together these results suggest that the combination of benidipine and edaravone showed significant protective effect in ISO-induced MI.

Combinational effect of resveratrol and atorvastatin on isoproterenol-induced cardiac hypertrophy in rats.

Introduction: Resveratrol is a natural polyphenol present mainly in grapes. It has been shown to offer strong cardio protection in animal models due to its ability to correct lipid peroxidation and maintain antioxidants level. Atorvastatin, a HMG-CoA reductase inhibitor, lowers cholesterol level and is commonly prescribed to heart patients. Our aim in this study was to see the combination effect of these two drugs against Isoproterenol-induced cardiac hypertrophy in rats. Materials and Methods: Wister Albino rats were treated with resveratrol (20 mg/kg/day, p.o), atorvastatin (20 mg/kg/day, p.o) and in combination (resveratrol [10 mg/kg/day, p.o] + atorvastatin [10 mg/kg/day, p.o]) for a period of 25 days and from 15th till 25th day Isoproterenol (5 mg/kg/day, s.c) was co-administered to rats to induce cardiac hypertrophy. Results: A significant increase in creatine kinase, lactate dehydrogenase, aspartate transaminase and lipid peroxidation with the significant decrease in reduced glutathione, superoxide dismutase and catalase were observed in Isoproterenol treated rats. Resveratrol, atorvastatin and their combination significantly reversed the effect. The histopathological studies and myocardial infarct size evaluation also confirmed the protection. Conclusion: Comparing the data we came to this conclusion that atorvastatin although showed the protection along all the parameters, the extent of protection offered by resveratrol alone and in combination were more effective. Hence, it can be concluded that resveratrol, an herbal nutritional supplement, alone and in combination is better against cardiac hypertrophy.

Formulation, preclinical and clinical evaluation of a new submicronic arginine respiratory fluid for treatment of chronic obstructive pulmonary disorder.

Inhalational drugs often suffer from low pulmonary deposition due to their micronized size. Aim of present study was development and evaluation of a novel submicronic L-arginine respiratory fluid formulation for treatment of cardiopulmonary complications associated with chronic obstructive pulmonary disorder (COPD). Objectives were (a) to develop and characterize submicronic L-arginine respiratory fluid formulation, (b) pre-clinical safety/toxicity study in 2-animal species, (c) in vitro and in vivo evaluation in terms of respiratory fraction, and (d) clinical study to assess safety/efficacy in healthy volunteers/COPD patients. Formulation was optimized on the basis of particle size of aerosolized medication with particle size in the range of 400–500 nm. Anderson cascade impaction (ACI) studies were performed to validate the advantage in terms of respirable fraction, which indicated a high respirable fraction (51.61 ± 3.28) for the developed formulation. In vivo pulmonary deposition pattern of optimized formulation was studied using gamma scintigraphy in human volunteers using 99mTc-arginine as radiotracer. It clearly demonstrated a significant pulmonary deposition of the submicronic formulation in various lung compartments. Efficacy of the developed formulation was further assessed in COPD patients (n = 15) by evaluating its effect on various cardiopulmonary parameters (spirometry, pulse-oxymetry, echocardiography and 6-min walk test). A marked improvement was seen in patients after inhalation of submicronic arginine in terms of their cardiopulmonary status. Results suggest that submicronic arginine respiratory fluid has the potential to be developed into an attractive therapeutic option for treating COPD associated cardiopulmonary complications.

Raspberry ketone protects against isoproterenol-induced myocardial infarction in rats

Aim: The cardioprotective role of raspberry ketone (RK) against isoproterenol (ISO)‐induced myocardial infarction (MI) in rats was assessed. Materials and methods: Rats were randomly divided into Group I ‐ Vehicle control; Group II ‐ Toxic control ISO (85 mg/kg, s.c.); Group III, IV and V ‐ RK (50, 100 and 200 mg/kg, respectively) with ISO; Group VI‐ RK (200 mg/kg) alone; Group VII ‐ Propranolol (10 mg/kg) with ISO; and Group VIII ‐ Propranolol (10 mg/kg) alone. After twenty‐four hours of the last dose, animals were sacrificed and creatine kinase‐MB, lactate dehydrogenase, total cholesterol, triglycerides, high‐density‐lipoprotein, low‐density‐lipoprotein, very‐low‐density‐lipoprotein, malondialdehyde, reduced glutathione, superoxide dismutase, catalase, Na+, K+‐ATPase, nitric oxide, histopathological and immunohistochemical analysis (tumor necrosis factor‐&agr; and inducible nitric oxide synthase) were performed. Key findings: Treatment with ISO significantly deviated the biochemical parameters from the normal levels, which were considerably restored by RK at 100 and 200 mg/kg doses. 50 mg/kg dose, however, did not demonstrate any significant cardioprotective action. The histopathological and immunohistochemical analysis further substantiated these findings. Significance: Our study showed a dose‐dependent reduction in oxidative stress, inflammation and dyslipidemia by RK in ISO‐intoxicated rats, which signifies that RK from the European red raspberry plant might be a valuable entity for the management of MI. Graphical abstract: Figure. No caption available. Highlights:The cardioprotective action of raspberry ketone in isoproterenol induced cardiotoxicity was assessed.The cardiac damage due to isoproterenol was significantly prevented by prophylactic treatment of raspberry ketone.The antioxidative, antihyperlipidemic, and anti‐inflammatory properties of raspberry ketone plays role in cardioprotection.The protective effects of raspberry ketone were comparable to that of standard &bgr;‐blocking drug, propranolol.The protective effects of raspberry ketone might be attributed to its PPAR‐&agr; agonistic activity.

Classification and Definitions of Cardiomyopathies

Cardiomyopathies are an important and heterogeneous group of diseases. The awareness and knowledge of these diseases in both the public and medical communities historically has been impaired by persistent confusion surrounding definitions and nomenclature. Classification schemes, of which there have been many, (Thiene et al., 2000, 2004; Richardson et al., 1996) are potentially useful in drawing relationships and distinctions between complex disease states for the purpose of promoting greater understanding; indeed, the precise language used to describe these diseases are profoundly important. Cardiomyopathies are diseases of the heart muscle, characterized by abnormality in chamber size and wall thickness, or functional contractile dysfunctions mainly systolic or diastolic dysfunction in the absence of coronary artery disease, hypertension, valvular disease, or congenital heart disease (Elliott et al., 2008). These diseases are classified as either primary or secondary. Primary cardiomyopathies consist of disorders solely or predominantly confined to the heart muscle, which have genetic, non-genetic, or acquired causes. Secondary cardiomyopathies are disorders that have myocardial damage as a result of systemic or multiorgan disease (Maron et al., 2006). Cardiomyopathies are classified traditionally according to morphological and functional criteria into four categories: dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), restrictive cardiomyopathy (RCM) and arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). These cardiomyopathies can be primary myocardial disorders or develop as a secondary consequence of a variety of conditions, including myocardial ischemia, inflammation, infection, increased myocardial pressure or volume load and toxic agents. The definitions of cardiomyopathies presented here are in concert with the molecular era of cardiovascular disease and have direct clinical applications and implications for cardiac diagnosis. However, the classification of cardiomyopathies presented herein is not intended to provide precise methodologies or strategies for clinical diagnosis. Rather, the classification of cardiomyopathies represents a scientific presentation that offers new perspectives to aid in understanding this complex and heterogeneous group of diseases and basic disease mechanisms.

Suppression of isoproterenol-induced cardiotoxicity in rats by raspberry ketone via activation of peroxisome proliferator activated receptor-α

Abstract The peroxisome proliferator‐activated receptor‐&agr; (PPAR‐&agr;) controls the lipid and glucose metabolism and also affects inflammation, cell proliferation and apoptosis during cardiovascular disease. Raspberry ketone (RK) is a red raspberry (Rubusidaeus, Family‐Rosaceae) plant constituent, which activates PPAR‐&agr;. This study was conducted to assess the cardioprotective action of RK against isoproterenol (ISO)‐induced cardiotoxicity. Wistar rats were randomly divided into six groups (six rats/group). Rats were orally administered with RK (50, 100 and 200 mg/kg, respectively) and fenofibrate (standard, 80 mg/kg) for 28 days and ISO was administered (85 mg/kg, subcutaneously) on 27th and 28th day. Administration of ISO in rats significantly altered hemodynamic and electrocardiogram patterns, total antioxidant capacity, PPAR‐&agr;, and apolipoprotein C‐III levels. These myocardial aberrations were further confirmed during infarct size, heart weight to body weight ratio and immunohistochemical assessments (caspase‐3 and nuclear factor‐&kgr;B). RK pretreatment (100 and 200 mg/kg) significantly protected rats against oxidative stress, inflammation, and dyslipidemia caused by ISO as demonstrated by change in hemodynamic, biochemical and histological parameters. The results so obtained were quite comparable with fenofibrate. Moreover, RK was found to have binding affinity with PPAR‐&agr;, as confirmed by docking analysis. PPAR‐&agr; expression and concentration was also found increased in presence of RK which gave impression that RK probably showed cardioprotection via PPAR‐&agr; activation, however direct binding study of RK with PPAR‐&agr; is needed to confirm this assumption. Graphical abstract Figure. No Caption available.

Cissampelos pareira Linn. ameliorates thyroxin-induced cardiac hypertrophy in rats.

ETHNOPHARMACOLOGICAL RELEVANCE Cissampelos pareira extract has been traditionally used in ayruveda as cardiotonic, diuretics and in heart complains but its pharmacological evaluation in thyroxin-induced cardiac hypertrophy has not yet been explored. AIM OF THE STUDY The aim of this study was to assess the cardioprotective effect of C. pareira root extract in experimentally induced hyperthyroidism in rats. MATERIALS AND METHODS Male Wistar rats were treated with (i) thyroxin (0.1 mg/kg/day, i.p.) for 30 days, (ii) C. pareira extract (200 mg/kg/day, p.o.) alone for 60 days, (iii) C. pareira extract (100 and 200 mg/kg/day, p.o., respectively) for 30 days then with thyroxin for another 30 days, (iv) thyroxin for 30 days then C. pareira extract (100 and 200 mg/kg/day, p.o., respectively) for another 30 days. At the end of experiment, serum calcineurin, nitric oxide, lactate dehydrogenase, and thiobarbituric acid reactive substance as well as serum and/or myocardial antioxidant enzymes activity were estimated. RESULTS Hyperthyroid induced cardiotoxicity was characterized by a significant (P<0.001) increase in heart weight/body weight ratio, serum calcineurin, nitric oxide, lactate dehydrogenase and thiobarbituric acid reactive substance levels as well as a significant decrease in serum reduced glutathione, myocardial glutathione peroxidase, glutathione reductase and glutathione-S-transferase levels, which were significantly (P<0.05 and P<0.01) reverted by C. pareira extract treatment. Reversal of histological changes on treatment with C. pareira extract was also supported the biochemical parameters. These results were quite comparable with amlodipine, the standard drug taken in this study. CONCLUSIONS Treatment with C. pareira extract ameliorates thyroxin-induced oxidative stress and cardiac hypertrophy, probably through amelioration of calcineurin activity and augmentation of antioxidant enzyme activities.