Thymol and Carvacrol Prevent Doxorubicin‐Induced Cardiotoxicity by Abrogation of Oxidative Stress,Inflammation, and Apoptosis in Rats

The aim of this study was to assess the possible protective effects of thymol and carvacrol (CAR) against doxorubicin (DOX)‐induced cardiotoxicity. A single dose of DOX (10 mg/kg i.v.) injected to male rats revealed significant increases in serum lactate dehydrogenase, creatine kinase, creatine kinase isoenzyme‐MB, aspartate transaminase, tumor necrosis factor‐alpha, and cardiac troponin levels. It also increased heart contents of malondialdehyde and caspase‐3 accompanied by a significant reduction in heart content of reduced glutathione as well as catalase and superoxide dismutase activity as compared with the control group. In contrast, administration of thymol (20 mg/kg p.o.) and/or CAR (25 mg/kg p.o.) for 14 days before DOX administration and for 2 days after DOX injection ameliorated the heart function and oxidative stress parameters. Summarily, thymol was more cardioprotective than CAR. Moreover, a combination of thymol and CAR had a synergistic cardioprotective effect that might be attributed to antioxidant, anti‐inflammatory, and antiapoptotic activities.     

Curcumin ameliorates doxorubicin‐induced cardiotoxicity by abrogation of inflammation,apoptosis, oxidative DNA damage,and protein oxidation in rats

Doxorubicin (DXR) is a highly effective drug for chemotherapy. However, cardiotoxicity reduces its clinical utility in humans. The present study aimed to assess the ameliorative effect of curcumin against DXR‐induced cardiotoxicity in rats. Rats were subjected to oral treatment of curcumin (100 and 200 mg/kg body weight) for 7 days. Cardiotoxicity was induced by single intraperitoneal injection of DXR (40 mg/kg body weight) on the 5th day and the rats sacrificed on 8th day. Curcumin ameliorated DXR‐induced lipid peroxidation, glutathione depletion, decrease in antioxidant (superoxide dismutase, catalase, and glutathione peroxidase) enzyme activities, and cardiac toxicity markers (CK‐MB, LDH, and cTn‐I). Curcumin also attenuated activities of Caspase‐3, cyclooxygenase‐2, inducible nitric oxide synthase, and levels of nuclear factor kappa‐B, tumor necrosis factor‐α, and interleukin‐1β, and cardiac tissue damages that were induced by DXR. Moreover, curcumin decreased the expression of 8‐OHdG and 3,3′‐dityrosine. This study demonstrated that curcumin has a multi‐cardioprotective effect due to its antioxidant, anti‐inflammatory, and antiapoptotic properties.     

Antioxidant and antiapoptotic effects of proanthocyanidin and ginkgo biloba extract against doxorubicin‐induced cardiac injury in rats

Grape seed proanthocyanidins (GSPE) and ginkgo biloba extract (EGb761) are considered to have protective effects against several diseases. The cardiotoxicity of doxorubicin (DOX) has been reported to be associated with oxidative damage. This study was conducted to evaluate the cardioprotective effects of GSPE and EGb761 against DOX‐induced heart injury in rats. DOX was administered as a single i.p. dose (20 mg kg^–1) to adult male rats. DOX‐intoxicated rats were orally administered GSPE (200 mg kg^–1 day^–1) or EGb761 (100 mg kg^–1 day^–1) for 15 consecutive days, starting 10 days prior DOX injection. DOX‐induced cardiotoxicity was evidenced by a significant increase in serum aspartate transaminase (AST), creatine phosphokinase isoenzyme (CK‐MB), lactate dehydrogenase (LDH), total cholesterol (TC) and triglyceride (TG) activities and levels. Increased oxidative damage was expressed by the depletion of cardiac reduced glutathione (GSH), elevation of cardiac total antioxidant (TAO) level and accumulation of the lipid peroxidation product, malondialdehyde (MDA). Significant rises in cardiac tumour necrosis factor‐alpha (TNF‐α) and caspase‐3 levels were noticed in DOX‐intoxicated rats. These changes were ameliorated in the GSPE and EGb761‐treated groups. Histopathological analysis confirmed the cardioprotective effects of GSPE and EGb761. In conclusion, GSPE and EGb761 mediate their protective effect against DOX‐induced cardiac injury through antioxidant, anti‐inflammatory and antiapoptotic mechanisms. Copyright © 2012 John Wiley & Sons, Ltd.     

Nootkatone attenuates myocardial oxidative damage,inflammation, and apoptosis in isoproterenol-induced myocardial infarction in rats

BackgroundMyocardial infarction (MI) is a lethal manifestation of cardiovascular diseases. Oxidative stress, inflammation, and subsequent cell death are known to play crucial roles in the pathogenesis of MI. Despite tremendous developments in interventional cardiology, there is need for novel drugs for the prevention and treatment of MI. For the development of novel drugs, usage of natural products has gained attention as a therapeutic approach for ischemic myocardial injury. Among many popular plant-derived compounds, Nootkatone (NKT), a natural bioactive sesquiterpene, abundantly found in grapefruit, has attracted attention for its plausible health benefits and pharmacological properties.PurposeThe present study investigated the cardioprotective effects of NKT in rats against MI induced by isoproterenol (ISO), a synthetic catecholamine and β-adrenergic agonist that produces MI in a physiologically relevant manner.MethodsMI was induced in male Wistar albino rats by subcutaneous injection of ISO (85 mg/kg body weight) on 9^th and 10^th day. Rats were pre- and co-treated with NKT (10 mg/kg) through daily oral administration for eleven days.ResultsISO-induced MI was characterized by a significant decline in cardiac function, increased serum levels of cardiomyocyte injury markers, enhanced oxidative stress, and altered PI3K/Akt and NrF2/Keap1/HO-1 signaling pathways. ISO also elevated the levels of myocardial pro-inflammatory cytokines, promoted lysosomal dysfunction, altered TLR4-NFκB/MAPK signaling, and triggered intrinsic apoptotic pathway in heart tissues. However, NKT administration significantly restored or modulated majority of the altered biochemical and molecular parameters in ISO-treated rats. Furthermore, histopathological observations confirmed the myocardial restoring effect of NKT.ConclusionThe present study concludes the cardioprotective effects and underlying mechanisms of NKT against ISO-induced MI in rats, and suggests that NKT or plants containing NKT could be an alternative to cardioprotective agents in ischemic heart diseases.     

Alpha lipoic acid prevents doxorubicin‐induced nephrotoxicity by mitigation of oxidative stress,inflammation, and apoptosis in rats

This study aimed to evaluate the protective effects of alpha lipoic acid (ALA) against doxorubicin (DOX)‐induced nephrotoxicity in rats. A single dose of DOX (7.5 mg/kg i.v.) induced nephrotoxicity evidenced by significant elevations in kidney weight, kidney/body weight ratio, serum urea, creatinine, tumor necrosis factor alpha, and renal contents of malondialdehyde, nitric oxide, cyclooxygenase‐2, and caspase‐3. Also, it causes significant reduction in final body weight, serum albumin, renal contents of reduced glutathione and superoxide dismutase activity. Histopathological changes in the kidney tissue confirmed the nephrotoxic effect. In contrast, pretreatment with ALA (50 mg/kg, orally) for 14 days before DOX and for 7 days after DOX administration mitigated renal toxicity evidenced by greater improvement in the examined oxidative stress, inflammation, and apoptosis parameters. In conclusion, ALA had promising protective effects against DOX‐induced nephrotoxicity that might be attributed to its antioxidant, anti‐inflammatory, and antiapoptoic activities.     

Anti-apoptotic potential of gymnemic acid phospholipid complex pretreatment in Wistar rats with experimental cardiomyopathy

Cardiomyocyte apoptosis in heart failure has been the topic of research in many recent studies. In the present investigation, the potential cardioprotective effect of gymnemic acid phospholipid complex (GPC) on myocardial apoptosis and cardiac function was studied in doxorubicin (DOX; 30 mg/kg/ip/single dose)-induced cardiomyopathy model in rats. Doxorubicin induced cardiomyopathy was evidenced by significant hemodynamic changes (increased systolic, diastolic, mean arterial pressure and heart rate), decreased heart weight to body weight ratio, increase in serum lactate dehydrogenase (LDH) and Ca2+ levels and decrease in myocardial Na+/K+ ATPase levels along with caspase-3 activation. A marked reduction in glutathione, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, superoxide dismutase and catalase levels along with increase in the levels of thiobarbituric acids (TBARS) were also observed in rat myocardium. In addition, DNA laddering observed on agarose gel electrophoresis and cardiac histopathology study further supplemented myocardial apoptosis. Pre-treatment with GPC significantly reduced DOX-induced cardiac toxicity, including improvement of hemodynamic variables and heart weight to body weight ratio, decreased serum Ca2+ level and LDH levels, myocardial caspase-3 levels, increased Na+/K+ ATPase levels and decreased myocardial TBARS levels and elevated antioxidant enzymes as compared to pathogenic control group. Further, the anti-apoptotic effect of GPC was verified by prevention of internucleosomal DNA laddering on agarose gel electrophoresis and attenuation of histopathological perturbations by doxorubicin. These observations demonstrate that GPC might serve as a cardioprotective formulation in DOX-induced cardiomyopathy in rats.     

Protective effects of thymol on altered plasma lipid peroxidation and nonenzymic antioxidants in isoproterenol-induced myocardial infarcted rats

This study evaluates the protective effects of thymol on altered plasma lipid peroxidation products and nonenzymic antioxidants in isoproterenol (ISO)‐induced myocardial infarcted rats. Male albino Wistar rats were pre and cotreated with thymol (7.5 mg/kg body weight) daily for 7 days. ISO (100 mg/kg body weight) was subcutaneously injected into rats on 6th and 7th day to induce myocardial infarction (MI). Increased activity/levels of serum creatine kinase‐MB (CK‐MB), plasma thiobarbituric acid reactive substances, lipid hydroperoxides, and conjugated dienes with decreased levels of plasma reduced glutathione (GSH), vitamin C, and vitamin E were observed in ISO‐induced myocardial infarcted rats. Pre and cotreatment with thymol (7.5 mg/kg body weight) showed normalized activity of serum CK‐MB and near normalized levels of plasma lipid peroxidation products, reduced GSH, vitamin C, and vitamin E in myocardial infarcted rats. Furthermore, the in vitro study on reducing power of thymol confirmed its potent antioxidant action. Thus, thymol protects ISO‐induced MI in rats by its antilipid peroxidation and antioxidant properties. © 2012 Wiley Periodicals, Inc. J Biochem Mol Toxicol 26:368–373, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/jbt.21431     

Attenuation of diabetic cardiomyopathy by relying on kirenol to suppress inflammation in a diabetic rat model

Diabetic cardiomyopathy is characterized by diabetes‐induced myocardial abnormalities, accompanied by inflammatory response and alterations in inflammation‐related signalling pathways. Kirenol, isolated from Herba Siegesbeckiae, has potent anti‐inflammatory properties. In this study, we aimed to investigate the cardioprotective effect of kirenol against DCM and underlying the potential mechanisms in a type 2 diabetes mellitus model. Kirenol treatment significantly decreased high glucose‐induced cardiofibroblasts proliferation and increased the cardiomyocytes viability, prevented the loss of mitochondrial membrane potential and further attenuated cardiomyocytes apoptosis, accompanied by a reduction in apoptosis‐related protein expression. Kirenol gavage could affect the expression of pro‐inflammatory cytokines in a dose‐dependent manner but not lower lipid profiles, and only decrease fasting plasma glucose, fasting plasma insulin and mean HbA1c levels in high‐dose kirenol‐treated group at some time‐points. Left ventricular dysfunction, hypertrophy, fibrosis and cell apoptosis, as structural and functional abnormalities, were ameliorated by kirenol administration. Moreover, in diabetic hearts, oral kirenol significantly attenuated activation of mitogen‐activated protein kinase subfamily and nuclear translocation of NF‐κB and Smad2/3 and decreased phosphorylation of IκBα and both fibrosis‐related and apoptosis‐related proteins. In an Electrophoretic mobility shift assay, the binding activities of NF‐κB, Smad3/4, SP1 and AP‐1 in the nucleus of diabetic myocardium were significantly down‐regulated by kirenol treatment. Additionally, high dose significantly enhanced myocardial Akt phosphorylation without intraperitoneal injection of insulin. Kirenol may have potent cardioprotective effects on treating for the established diabetic cardiomyopathy, which involves the inhibition of inflammation and fibrosis‐related signalling pathways and is independent of lowering hyperglycaemia, hyperinsulinemia and lipid profiles.     

Mitochondrial sulfhydryl groups under oligomycin-inhibited, aging, and uncoupling conditions: beneficial influence of cardioprotective drugs

Uncoupling, oligomycin-inhibited, and aging/swelling conditions comprise three models for mitochondrial dysfunction. In these models, the effects of cardioprotective agents on rat heart mitochondrial membrane -SH reactivity have been studied. For -SH detection two different chromophores were used: dithionitrobenzoate (NbS2) and monobromobimane (MB). The objective of this study is to reveal the influence of three cardioprotective substances against the loss of membrane -SH reactivity: (i) The thiol reagent 2-mercaptopropionylglycine (MPG) prevents the decrease of thiols caused by carbonylcyanide-p-trifluoromethoxyphenylhydrazone (FCCP), aging, and oligomycin measured with MB and NbS2, and the diminution by oleate detected with MB. The small amount of MPG (6 nmol/mg protein), necessary for the protection, agrees with oligomycin sensitivity of the -SH groups concerned. (ii) The active metabolite of molsidomine, 3-morpholinosydnonimine (SIN-1), protects against the decrease of thiols by FCCP, oleate, and aging monitored with MB. In the case of oligomycin -SH groups accessible to NbS2 are protected. (iii) Another antianginal drug, isosorbidedinitrate (ISDN) does not protect membrane thiol groups. In contrast to SIN-1, ISDN probably requires enzymatic activation. It is suggested that MPG as well as SIN-1 may help to restitute the original -SH status of the mitochondrial membrane.     

Fat Intake Affects Adiposity,Comorbidity Factors,and Energy Metabolism of Sprague‐Dawley Rats

Objective: Childhood obesity is an emerging health problem. This study assesses the effects of three levels of dietary fat (10%, 32%, and 45% measured by kilocalories) on weight gain, body composition, energy metabolism, and comorbidity factors in rats from weaning through maturation. Research Methods and Procedures: The role of dietary fat on the susceptibility to obesity was assessed by feeding diets containing three levels of dietary fat to rats from weaning through 7 months of age. Body composition was analyzed by DXA after 6 and 12 weeks of dietary treatment. Energy metabolism was measured by indirect calorimetry. Results: Energy intake, weight gain, fat mass, and plasma glucose, cholesterol, triglyceride, free fatty acid, leptin, and insulin levels increased dose‐dependently with increased dietary fat. No difference in absolute lean mass among the three groups was observed. Therefore, the differences in weight gain are accounted for primarily by increased fat accretion. Compared with rats that were relatively resistant to obesity when on a 45% fat diet, diet‐induced obesity‐prone rats were in positive energy balance and had an elevated respiratory quotient, indicating a switch in energy substrate use from fat to carbohydrate, which promotes body‐fat accretion. Discussion: Our data support the hypothesis that administration of increasing amount of dietary fat to very young rats enhances susceptibility to diet‐induced obesity and its comorbidities.     

Interaction of Semecarpus anacardium L. with propranolol against isoproterenol induced myocardial damage in rats

With a view to evaluate the cardioprotective effect of ethanolic extract of S. anacardium nut and the possible interaction with propranolol against isoproterenol induced myocardial damage in rats, female Sprague-Dawley rats were pre-treated with propranolol (10 mg/kg for 7 days), low and high doses of S. anacardium (100 and 500 mg/kg for 21 days) and their combination orally and subsequently subjected to isoproterenol administration (150 mg/kg, sc) for two consecutive days. The influence of prophylactic treatment was analysed by quantification of biomarkers and antioxidants, electocardiographic parameters and histopathological observations. The activities of lactate dehydrogenase and creatinine phosphokinase-MB were reduced in serum and raised in heart tissue with concurrent elevation in superoxide dismutase and catalase activities as well as reduction in thiobarbituric acid reactive species levels significantly in all treated groups compared to isoproterenol group. Similarly, electrocardiographic changes were restored to normalcy in all treated groups. To conclude, combination of high dose of S. anacardium with propranolol was found to be most effective in alleviating the abnormal conditions induced by isoproterenol.     

黄芪注射液对阿霉素性心肌细胞凋亡、内质网应激与缝隙连接蛋白表达的影响

目的：研究黄芪注射液对阿霉素（ADR）所致心肌病大鼠心肌细胞凋亡、内质网应激与缝隙连接蛋白表达的影响。方法：36只Wistar雄性大鼠随机分为3组（n=12）：对照组、ADR组及黄芪注射液组。对照组腹腔注射0.9% Nacl （10 ml/kg体重）;ADR组腹腔注射ADR 2 mg/kg体重;黄芪注射液组在每次腹腔注射ADR 2 mg/kg体重的同时,注射黄芪注射液10 g/kg体重,每周注射1次,共注射3次。实验第7周末,3组大鼠行心脏彩超检测左室舒张末期内径、左室收缩末期内径及左室射血分数;处死大鼠后取左心室组织行HE、Masson、醋酸铀及柠檬酸铅染色,于光镜及透射电镜下观察心肌病理及超微结构改变;采用TUNEL法检测大鼠心肌细胞凋亡,用免疫组化技术检测大鼠心肌细胞缝隙连接蛋白Cx43及p-Cx43表达,采用real time PCR检测大鼠心肌细胞内质网应激伴侣蛋白Grp78,ATF-4及CHOP表达。结果：与对照组比较,ADR组大鼠LVEDD、LVESD增大,LVEF减少;心肌纤维排列紊乱,心肌纤维间质水肿,大量淋巴细胞浸润;线粒体肿胀、破坏,呈空泡样;心肌细胞凋亡数明显增多（P<0.01）;内质网应激相关蛋白Grp78、ATF-4及CHOP表达明显增高（P<0.01）;缝隙连接蛋白Cx43表达减少,而p-Cx43表达增多。与ADR组比较,黄芪注射液组大鼠LVEDD、LVESD减少,LVEF增加;心肌病理及超微结构明显改善,同时心肌细胞凋亡数明显减少（P<0.01）;内质网应激伴侣蛋白Grp78、ATF-4及CHOP表达明显减少（P<0.01）;缝隙连接蛋白Cx43表达增多,而p-Cx43减少。结论：黄芪注射液可有效改善阿霉素导致的心肌损伤,其机制可能与黄芪注射液抑制ADR诱导的内质网应激及缝隙连接蛋白磷酸化有关。     

The protective effects of grape seed procyanidin B2 against asporin mediates glycated low‐density lipoprotein induced‐cardiomyocyte apoptosis and fibrosis

The progression of diabetic cardiomyopathy is related to cardiomyocyte dysfunction and apoptosis. Our previous studies showed that asporin (ASPN) was significantly increased in the myocardium of db/db mice through proteomics, and grape seed procyanidin B2 (GSPB2) significantly inhibited the expression of ASPN in the heart of db/db mice. We report here that ASPN played a critical role in glycated low‐density lipoproteins (gly‐LDL) induced‐cardiomyocyte apoptosis. We found that gly‐LDL upregulated ASPN expression. ASPN increased H9C2 cardiomyocyte apoptosis with down‐regulation of Bcl‐2, upregulation of transforming growth factor‐β1, Bax, collagen III, fibronectin, and phosphorylation of smad2 and smad3. However, GSPB2 treatment reversed ASPN‐induced impairments in H9C2 cardiomyocytes. These results provide evidence for the cardioprotective action of GSPB2 against ASPN injury, and thus suggest a new target for fighting against diabetic cardiomyopathy.     

Loperamide‐induced cardiotoxicity in rats: Evidence from cardiac and oxidative stress biomarkers

At therapeutic dose, loperamide is a safe over‐the‐counter antidiarrheal drug but could induce cardiotoxic effect at a supratherapeutic dose. In this study, we use cardiac and oxidative biomarkers to evaluate loperamide‐induced cardiotoxicity in rats. Rats were orally gavaged with 1.5, 3, or 6 mg/kg body weight (BW) of loperamide hydrochloride for 7 days. The results after 7 days administration of loperamide, revealed dose‐dependent increase (P < 0.05) in aspartate aminotransferase, lactate dehydrogenase, creatine kinase‐MB, and serum concentration of cardiac troponin I, total homocysteine, and nitric oxide. A 50% decrease in antioxidant enzymes activity was observed at 6 mg/kg BW. Furthermore, malondialdehyde and fragmented DNA also increased significantly in the heart of the treatment groups. Loperamide provoked cardiotoxicity through oxidative stress, lipid peroxidation, and DNA fragmentation in rats. This study has provided a possible biochemical explanation for the reported cardiotoxicity induced by loperamide overdose.     

Thymol and Carvacrol Prevent Cisplatin‐Induced Nephrotoxicity by Abrogation of Oxidative Stress,Inflammation, and Apoptosis in Rats

The aim of the present study is to assess the possible protective effects of thymol and carvacrol against cisplatin (CP)‐induced nephrotoxicity. A single dose of CP {6 mg/kg, intraperitoneally (i.p.)} injected to male rats revealed significant increases in serum urea, creatinine, and tumor necrosis factor alpha levels. It also increased kidney contents of malondialdehyde and caspase‐3 activity with significant reduction in serum albumin, kidney content of reduced glutathione as well as catalase, and superoxide dismutase activity as compared to that of the control group. In contrast, administration of thymol {20 mg/kg, orally (p.o.)} and/or carvacrol (15 mg/kg, p.o.) for 14 days before CP injection and for 7 days after CP administration restored the kidney function and examined oxidative stress parameters. In conclusion, thymol was more effective nephroprotective than carvacrol. Moreover, a combination of thymol and carvacrol had a synergistic nephroprotective effect that might be attributed to antioxidant, anti‐inflammatory, and antiapoptotic activities.     

Protective Effects of 7‐Hydroxycoumarin on Dyslipidemia and Cardiac Hypertrophy in Isoproterenol‐Induced Myocardial Infarction in Rats

This study evaluates the protective effects of 7‐hydroxycoumarin (7‐HC) on dyslipidemia and cardiac hypertrophy in isoproterenol (ISO) induced myocardial infarction (MI) in rats. Rats were pre‐ and co treated with 7‐HC (16 mg/kg) daily for 8 days. ISO (100 mg/kg) was subcutaneously injected into rats on seventh and eighth days to induce MI. Increased activity/levels of serum creatine kinase‐MB (CK‐MB), troponin‐T, plasma lipid peroxidation products, and altered levels of lipids in the serum and heart and serum lipoproteins were noted in ISO‐induced rats. ISO‐induced myocardial infarcted rats revealed increased hypertrophy (cardiac and left ventricular) and hepatic 3‐hydroxyl 3‐methylglutaryl‐coenzyme‐A reductase (HMG‐CoA reductase) activity. Pre and cotreatment with 7‐HC revealed significant protective effects on all the biochemical parameters evaluated. The in vitro study demonstrated its free radical scavenging property. Thus, 7‐HC protects ISO‐induced MI in rats by its free radical scavenging and antihyperlipidaemic and antihypertrophic properties.     

Ameliorative effect of resveratrol against cymoxanil-mancozeb induced toxicity in rats

This study was conducted to evaluate the cymoxanil-mancozeb (CM) toxicity and investigate the ameliorative effect of resveratrol (Res) against cymoxanil-mancozeb toxicity. Forty rats were divided into four groups; the first group was used as a control group, the second group was exposed to Res only at a dose of 20 mg/kg body weight for 4 weeks, and the third group was administered CM only at a dose of 799 mg/kg body weight for 4 weeks, The fourth group was co-treated with Res+CM for 4 weeks. Blood samples were analyzed for hematological and biochemical parameters. The comet assay was done on liver and blood specimens and histopathological examinations of the liver and intestine. The results demonstrated that CM exposure caused a significant increase in WBCs, lymphocytes, granulocytes, monocytes ALT, AST, ALP, and GGT, and total cholesterol and triglycerides levels accompanied by a decrease in HGB, HCT, RBCs and MCV, MCH, MCHC, HDL and glucose levels with no significant DNA damage in liver and blood. CM mixture induced severe pathological changes in small intestine and liver. Co-treatment of Res with CM improved hematological picture, lipid and glucose profiles also liver enzymes and decreased changes in the architecture of the liver and intestine.     

Chrysin ameliorates ANTU‐induced pulmonary edema and pulmonary arterial hypertension via modulation of VEGF and eNOs

Alpha‐naphthylthiourea (ANTU), a rodenticide induces lung toxicity. Chrysin a flavonoid possesses antioxidant, anti‐inflammatory, and antihypertensive potential. The aim of this study was to evaluate the efficacy of chrysin against ANTU‐induced pulmonary edema (PE) and pulmonary arterial hypertension (PAH) in laboratory rats. Sprague‐Dawley rats were used to induce PE (ANTU, 10 mg/kg, ip) and PAH (ANTU, 5 mg/kg, ip, 4 weeks). Animals were treated with chrysin (10, 20, and 40 mg/kg) and various biochemical, molecular, and histological parameters were evaluated. Acute administration of ANTU induces PE revealed by significant (P < 0.05) increase in relative lung weight, pleural effusion volume, lung edema, bronchoalveolar lavage fluid cell counts, total protein, 5‐hydroxytryptamine (5‐HT), lactate dehydrogenase (LDH), and γ‐glutamyl transferase (GGT), whereas pretreatment with chrysin (20 and 40 mg/kg, ip) significantly (P < 0.05) attenuated these ANTU‐induced biochemical and histological alterations. Repeated administration of ANTU caused induction of PAH evaluated by significant (P < 0.05) alterations in electrocardiographic, hemodynamic changes, and left ventricular function, whereas chrysin (20 and 40 mg/kg, p.o.) treatment significantly (P < 0.05) attenuated these alterations. ANTU‐induced hematological and serum biochemical (aspartate transaminase, alanine transaminase, LDH, and creatinine kinase MB) alterations were significantly (P < 0.05) inhibited by chrysin. It also significantly (P < 0.05) decreased elevated levels of oxido‐nitrosative stress in the right ventricle (RV) and lung. Chrysin significantly (P < 0.05) attenuated downregulated endothelial nitric oxide synthase and upregulated vascular endothelial growth factor messenger RNA and protein expressions both in the RV and pulmonary artery. Chrysin inhibited ANTU‐induced PE and PAH via modulation of inflammatory responses (5‐HT, LDH, and GGT), oxido‐nitrosative stress, and VEGF and eNOs levels.     

Effect of stress on fasting‐induced ghrelin,orexin and galanin secretion in male rats fed different levels of their energy requirement

Objective:

Ghrelin, orexin, and galanin are orexigenic factors in rodents and humans which participate in adaptive response to weight loss. On the other hand, weight loss and fasting is accompanied by increased levels of epinephrine (Ep) and cortisol (Cor). In this study, we investigated the effects of Ep and Cor on fasting‐induced ghrelin, orexin, and galanin secretion in rats fed different levels of their energy requirements.

Design:

Forty five male Wistar rats (300‐350 g, 15 per group) were fed a diet containing 100, 50, and 25% of their energy requirement for 10 days followed by 2 days of fasting. Animals were then anesthetized for carotid artery cannulation for injections and blood samplings.

Methods:

Rats received either 3 µg Ep/kg body weight (BW), 3 µg Cor/kg BW, or a combination of those two (0.1 mg in 1 ml of phosphate‐buffered saline). Blood samples were collected before, 30, 60, and 120 min after injection.

Results:

In normal and 50% food restricted groups, fasting ghrelin levels fell after Ep and combination of Ep and Cor injection (P ≤ 0.05), whereas, orexin were decreased by combination of Ep and Cor injection in rats fed 100% of their needs and Ep alone in rats fed 50%. Galanin just fell after combination of Ep and Cor injection in both starved (50%) and normal rats. In contrast, all groups whit 25% fed ad libitum did not response to any injections (P > 0.05).

Conclusions:

These results indicate that Ep suppresses starvation‐induced secretion of ghrelin, orexin, and galanin in normal (100%) and starved (50%) rats and their response to Ep might be affected by weight loss.     

Myeloid differentiation protein 1 protected myocardial function against high‐fat stimulation induced pathological remodelling

Myeloid differentiation 1 (MD‐1) is a secreted protein that regulates the immune response of B cell through interacting with radioprotective 105 (RP105). Disrupted immune response may contribute to the development of cardiac diseases, while the roles of MD‐1 remain elusive. Our studies aimed to explore the functions and molecular mechanisms of MD‐1 in obesity‐induced cardiomyopathy. H9C2 myocardial cells were treated with free fatty acid (FFA) containing palmitic acid and oleic acid to challenge high‐fat stimulation and adenoviruses harbouring human MD‐1 coding sequences or shRNA for MD‐1 overexpression or knockdown in vitro. MD‐1 overexpression or knockdown transgenic mice were generated to assess the effects of MD‐1 on high‐fat diet (HD) induced cardiomyopathy in vivo. Our results showed that MD‐1 was down‐regulated in H9C2 cells exposed to FFA stimulation for 48 hours and in obesity mice induced by HD for 20 weeks. Both in vivo and in vitro, silencing of MD‐1 accelerated myocardial function injury induced by HD stimulation through increased cardiac hypertrophy and fibrosis, while overexpression of MD‐1 alleviated the effects of HD by inhibiting the process of cardiac remodelling. Moreover, the MAPK and NF‐κB pathways were overactivated in MD‐1 deficient mice and H9C2 cells after high‐fat treatment. Inhibition of MAPK and NF‐κB pathways played a cardioprotective role against the adverse effects of MD‐1 silencing on high‐fat stimulation induced pathological remodelling. In conclusion, MD‐1 protected myocardial function against high‐fat stimulation induced cardiac pathological remodelling through negative regulation for MAPK/NF‐κB signalling pathways, providing feasible strategies for obesity cardiomyopathy.