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

Abstract

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.

RETRACTED: The cardioprotective effects of a combination of quercetin and α‐tocopherol on isoproterenol‐induced myocardial infarcted rats

“…Therapeutic intervention that could improve impaired antioxidant defense mechanisms or diminish free radical production in the ischemic myocardium has been of great interest 16. Previously, we reported the combined protective effects of quercetin and α‐tocopherol on lipids, glycoprotein components, and mitochondrial dysfunction in ISO‐treated rats 17,18. Quercetin and α‐tocopherol are abundantly present in vegetables and fruits, and these are daily consumed in our diet.…”

Isoproterenol‐induced cardiac ischemia and fibrosis: Plant‐based approaches for intervention

“…Amelioration of lysosomal enzymes was implicated behind the observed protection . In another study, electron microscopy-based investigations showed significant improvements of mitochondrial structure and correlated with biochemical results (Punithavathi & Stanely Mainzen Prince, 2010). Li et al proved that quercetin provides superior cardioprotective effects compared with its glycoside derivative rutin.…”

Berbamine ameliorates isoproterenol‐induced myocardial infarction by inhibiting mitochondrial dysfunction and apoptosis in rats

“…Recently, a study published by Punithavathi and Prince. 4 suggested that intake of quercetin and α-tocopherol and other dietary supplements offers protection against ISO-induced mitochondrial damage by increasing the activities of mitochondrial enzymes in rats. Our results are consistent with the observation of Khatua et al 40 where garlic and diallyl disulfide functioned as a scavenger of toxic reactants and increased the activities of Kreb cycle enzymes.…”

“…3 Thus, ROS generation in large amounts leads to structural changes and myocardial necrosis of the heart tissue. Punithavathi and Prince 4 reported that the lack of oxygen supply during infarction caused damage to the mitochondrial ETC, which results in accumulation of toxic metabolites, adenosine triphosphate (ATP) depletion, intracellular Ca 2+ overload, mitochondrial membrane depolarization, mitochondrial swelling, and finally cell death.…”