The Role of Mitochondria in Piperine Mediated Cardioprotection in Isoproterenol Induced Myocardial Ischemia.

BACKGROUND: Several pharmacological therapeutic interventions are being used as therapeutic agents against myocardial infarction/ischemia (MI) but their usage is constrained by toxicity and nonselective pharmacological actions. Our preliminary report depicted the cardioprotective effect of piperine against isoproterenol (ISO)-induced MI. AIM: Current study determined the protective efficacy of piperine by modulating mitochondrial function in rat models of isoproterenol (ISO)-induced myocardial ischemia. METHODS: The above aim was achieved by analyzing mitochondrial antioxidant status, mitochondrial calcium, mitochondrial enzyme activity, ATP level, and apoptosis. Ultra-structural alterations in heart tissue were determined by TEM analysis. RT-PCR studies and Western blotting were executed to determine apoptotic and proapoptotic gene expression, and apoptotic protein expression, respectively. RESULTS: The results elucidate that piperine pre-treatment prevents ISO induced alterations in the mitochondrial antioxidant status, Krebs cycle as well as mitochondrial respiratory chain enzyme activities (MRCEs). ISO induced ultrastructural changes of heart mitochondria were significantly reduced in the group that received piperine pretreatment followed by ISO injection. Piperine maintains mitochondrial calcium homeostasis and inhibits ISO-induced myocardial apoptosis. A significant increase in the expression levels of proapoptotic genes such as Bax, caspases (caspase 9, caspase 3), and cytochrome-c with a concomitant decrease in Bcl-2 expression (anti-apoptotic gene) was observed in ISO injected group compared to the control group. The group that received the piperine pretreatment followed by ISO administration showed a significant decrease in the expression profile of proapoptotic genes with a concomitant increase in the anti-apoptotic gene expression than the ISO injected group. Apoptotic protein expressions including Bax, cytochrome-c, caspase-3, and cleaved PARP were upregulated & Bcl-2 was downregulated with ISO treatment, whereas piperine pre-treatment prevented these changes in apoptotic protein expressions during ISO-induced myocardial cell damage. CONCLUSION: Current results demonstrate the efficacy of piperine for attenuating ISO-induced myocardial ischemia by enhancing mitochondria function. This study described that piperine could be used as a nutritional intervention against ISO-induced myocardial ischemia.

The protective effect of piperine against isoproterenol-induced inflammation in experimental models of myocardial toxicity.

Myocardial infarction (MI) eventually exacerbates inflammatory response due to the release of inflammatory and pro-inflammatory factors. The aim of this study is to explore the protective efficacy of piperine supplementation against the inflammatory response in isoproterenol (ISO)-induced MI. Masson Trichome staining was executed to determine myocardial tissue architecture. Immunohistochemistry was performed for IL-6, TNF-α. RT-PCR studies were performed to ascertain the gene expression of IL-6, TNF-α, iNOS, eNOS, MMP-2, MMP-9, and collagen-III. Western blotting was performed to determine expression of HIF-1α, VEGF, Nrf-2, NF-ƙB, Cox-2, p-38, phospho-p38, ERK-1/2, phospho-ERK-1/2, and collagen-I. HIF-1α, VEGF, and iNOS expression were significantly upregulated with concomitant decline in eNOS expression in the heart myocardial tissue of rats received ISO alone whereas piperine pretreatment prevented these changes in ISO administered rats. Current results revealed ROS-mediated activation of MAPKs, namely, p-p38, p-ERK1/2 in the heart tissue of ISO administered group. Piperine pretreatment significantly prevented these changes in ISO treated group. NF-κB is involved in the modulation of gene expressions responsible for tissue repair. ISO-induced NF-κB-p65 expression was significantly reduced in the group pretreated with piperine and mitigated extent of myocardial inflammation. A significant increase in cardiac fibrosis upon ISO treatment was reported due to the increased hydroxyproline content, MMP-2 & 9 and upregulation of collagen-I protein compared to control group. All these cardiac hypertrophy markers were decreased in 'piperine pretreated ISO administered group' compared to group received ISO injection. Current findings concluded that piperine as a nutritional intervention could prevent inflammation of myocardium in ISO-induced MI.

Piperine modulates isoproterenol induced myocardial ischemia through antioxidant and anti-dyslipidemic effect in male Wistar rats.

Myocardial infarction due to ischemia accounts for majority of deaths among cardiovascular disorders. Isoproterenol (ISO) induced myocardial infarction and the protection offered by piperine was investigated in the present report. Lipid profile analysis by determining the levels of cholesterol, phospholipids, triglycerides and lipoproteins in serum and heart tissues showed anti-dyslipidemic action of piperine against ISO induced myocardial injury by modulating the ISO induced altered lipid profiles, maintaining to near control values. ISO treatment increased TBARS levels, PCC, serum markers of heart, depleted antioxidant status (GSH, SOD, CAT, GPx and GST) in tissues and, total, protein- and non-protein-sulfhydryl levels in serum and heart tissues. Piperine pre-treatment decreased the levels of serum markers, lipid peroxidation and PCC with increased antioxidant status in the heart tissues of ISO administered rats. Increased levels of the glycoprotein components in serum and decreased levels in heart tissues upon ISO administration were restored to near normal levels by piperine pre-treatment. Our present reports also showed the modulatory effect of piperine on membrane bound ATPase's showing protection against ISO induced changes in membrane fluidity. The present study proved piperine as a potent therapeutic agent with its antioxidant and anti-dyslipidemic action against ISO induced myocardial infarction.

Tinospora cordifolia extract attenuates cadmium-induced biochemical and histological alterations in the heart of male Wistar rats.

Persistence of cadmium (Cd) in the environment causes serious ecological problems. Tinospora cordifolia is a medicinal herb used in Ayurveda for treating various metabolic disorders and toxic conditions. The present study investigates the protective effect of T. cordifolia stem methanolic extract (TCME) on a heavy metal, Cd-induced cardiotoxicity in male Wistar rats. Male albino Wistar rats were divided into four groups (n=6). The animals after treatment for 28days with Cd and TCME were analysed for biochemical and histological changes in the serum and heart tissues. Cd induced lipid peroxidation and protein carbonylation was significantly reduced by TCME. TCME also reduced the histological alterations induced by Cd treatment in the heart tissues with diminished loss of myocardial fibers. Administration of TCME effectively prevented the altered levels of serum marker enzymes (creatine kinase and lactate dehydrogenase), antioxidants, such as superoxide dismutase, catalase, glutathione, glutathione peroxidase and glutathione-S-transferase, and glycoproteins contents such as hexose, hexoseamine, fucose, and sialic acid by Cd intoxication. TCME also offered protection against the change in levels of Na+K+ATPase, Mg2+ATPase and Ca2+ATPase activities against Cd toxicity. The study suggests TCME as a potent cardioprotective agent against Cd induced toxicity.

Taxifolin curbs NF-κB-mediated Wnt/ß-catenin signaling via up-regulating Nrf2 pathway in experimental colon carcinogenesis.

Aberrations in homeostasis mechanisms including Nrf2, inflammatory, and Wnt/ß-catenin signaling are the major causative factors implicated in colon cancer development. Hence blocking these pathways through natural interventions pave a new channel for colon cancer prevention. Earlier, we reported the chemopreventive effect of taxifolin (TAX) against colon carcinogenesis. In this study, we aimed to understand the ability of TAX, to modulate the Nrf2, inflammatory and Wnt/ß-catenin cascades on 1, 2-dimethyl hydrazine (DMH)-induced mouse colon carcinogenesis. In addition, in silico molecular docking studies were performed to evaluate the binding affinity between TAX and target proteins (Nrf2, ß-catenin, and TNF-α). We perceived that the increase of serum marker enzyme levels (CEA and LDH) and mast cell infiltration that occurs in the presence of DMH is inverted after TAX treatment. Immunoblot expression and docking analysis revealed that TAX could induce antioxidant response pathway, confirming the enhanced level of Nrf2 protein. It also inhibited NF-κB and Wnt signaling by down-regulating the levels of regulatory metabolites such as TNF-α, COX-2, ß-catenin, and Cyclin-D1. Collectively, results of our hypothesis shown that TAX is an effective chemopreventive agent capable of modulating inflammatory, Wnt and antioxidant response pathway proteins in tumor microenvironment which explicating its anticancer property.