Methanol extract of Desmodium gangeticum DC root mimetic post-conditioning effect in isolated perfused rat heart by stimulating muscarinic receptors

The Protective Effects of Pharmacologic Postconditioning of Hydroalcoholic Extract of Nigella sativa on Functional Activities and Oxidative Stress Injury During Ischemia-Reperfusion in Isolated Rat Heart

Oxidative stress is known to act as the trigger of cardiac damage during ischemia-reperfusion (I/R) injury. Postconditioning (PoC) is employed to minimize the consequences of ischemia at the onset of reperfusion. Regarding the well-known antioxidant properties of Nigella sativa (Ns), the aim of this study was to investigate whether Nigella sativa postconditioning (Ns-PoC) could reduce IRI by lowering the formation of reactive oxygen species (ROS). Isolated rat hearts were perfused with the Langendorff apparatus, which were subjected to 20 min of preperfusion, 20 min of global ischemia, followed by 40 min of reperfusion. At the onset of reperfusion, based on the type of intervention group, a 10-min period of Krebs flow was developed along with the treatment, and then the reperfusion with Krebs solution was conducted for 30 min. Heart rate (HR) and left ventricular pressure (LVP) were recorded by isometric transducers connected to a data acquisition system. Thiobarbituric acid reactive substances (TBARS), 4-hydroxynonenal (4-HNE) levels, total thiol groups (-SH) levels, superoxide anion dismutase (SOD), and catalase (CAT) activities in myocardial tissues were detected to evaluate the oxidative stress damage degree. Ns-PoC significantly improved cardiodynamic parameters including left ventricular developed pressure (LVDP), rate pressure product (RPP), and the maximum up/down rate of the left ventricular pressure (± dp/dt) as well as SH groups, SOD, and CAT activities. Moreover, it decreased MDA and 4-HNE levels during early reperfusion. The results of this study showed that Ns-PoC ameliorated cardiac functions in isolated rat heart during I/R injuries by improving myocardial oxidative stress states, which may be related to the antioxidant effect of Ns.

Sensitivity of Interfibrillar and Subsarcolemmal Mitochondria to Cobalt Chloride-induced Oxidative Stress and Hydrogen Sulfide Treatment

Oxidative stress plays a significant role not only in cardiovascular disease but also in non-communicable diseases, where it plays a significant role the mortality rate. Hydrogen sulfide, the biological gaseous signaling molecule that preserves mitochondria in its mode of action, is an effective cardioprotective drug. However, cardiac mitochondria comprise of two distinct populations, namely interfibrillar and subsarcolemmal mitochondria, which respond distinctly in cardiovascular disease. This study was designed to determine the direct impact of cobalt chloride-induced oxidative stress in isolated mitochondrial subpopulations with an intention to examine the efficacy of hydrogen sulfide in preserving interfibrillar and subsarcolemmal mitochondria functional activities when they were incubated as pretreated, co-treated and post-treated agent. Mitochondrial subpopulations were isolated from the heart of male Wistar rats and subjected to cobalt chloride treatment (500 μM) for 20 min, followed by incubation with 10 μM sodium hydrosulfide in three different ways (Pre, Co, and Post-cobalt chloride treatment). Mitochondrial oxidative stress was measured by the concentration of thiobarbituric acid reactive species, reduced glutathione and the activities of enzymes like superoxide dismutase, catalase and glutathione peroxidase. Mitochondrial membrane potential, swelling behavior and enzyme activities were measured to assess its function. The increased level of lipid peroxidation and the decreased level of reduced glutathione in cobalt chloride-induced group confirm the induction of oxidative stress and were more predominant in the subsarcolemmal mitochondria. Hydrogen sulfide treatment to interfibrillar and subsarcolemmal mitochondria preserved their functional activities, but the effect was prominent only with co-treated group. In conclusion, the present study demonstrated that subsarcolemmal mitochondria are more prone to oxidative stress and the co-treatment of the mitochondria with hydrogen sulfide preserved the enzyme activity in the in vitro conditions.

Effects and mechanisms of chinese herbal medicine in ameliorating myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion (MIR) injury is a major contributor to the morbidity and mortality associated with coronary artery disease, which accounts for approximately 450,000 deaths a year in the United States alone. Chinese herbal medicine, especially combined herbal formulations, has been widely used in traditional Chinese medicine for the treatment of myocardial infarction for hundreds of years. While the efficacy of Chinese herbal medicine is well documented, the underlying molecular mechanisms remain elusive. In this review, we highlight recent studies which are focused on elucidating the cellular and molecular mechanisms using extracted compounds, single herbs, or herbal formulations in experimental settings. These studies represent recent efforts to bridge the gap between the enigma of ancient Chinese herbal medicine and the concepts of modern cell and molecular biology in the treatment of myocardial infarction.