Naringin Inhibits ROS‐activated MAPK Pathway in High Glucose‐induced Injuries in H9c2 Cardiac Cells

Abstract

Naringin, an active flavonoid isolated from citrus fruit extracts, exhibits biological and pharmacological properties, such as antioxidant activity and antidiabetic effect. Mitogen-activated protein kinase (MAPK) signalling pathway has been shown to participate in hyperglycaemia-induced injury. The present study tested the hypothesis that naringin protects against high glucose (HG)-induced injuries by inhibiting MAPK pathway in H9c2 cardiac cells. To examine this, the cells were treated with 35 mM glucose (HG) for 24 hr to establish a HG-induced cardiomyocyte injury model. The cells were pre-treated with 80 lM naringin for 2 hr before exposure to HG. The findings of this study showed that exposure of H9c2 cells to HG for 24 hr markedly induced injuries, as evidenced by a decrease in cell viability, increases in apoptotic cells and reactive oxygen species (ROS) production, as well as dissipation of mitochondrial membrance potential (MMP). These injuries were significantly attenuated by the pre-treatment of cells with either naringin or SB203580 (a selective inhibitor of p38 MAPK) or U0126 (a selective inhibitor of extracellular signal regulated kinase 1/2, ERK1/2) or SP600125 (a selective inhibitor of c-jun N-termanal kinase, JNK) before exposure to HG, respectively. Furthermore, exposure of cells to HG increased the phosphorylation of p38 MAPK, ERK1/2 and JNK. The increased activation of MAPK pathway was ameliorated by pre-treatment with either naringin or N-acetyl-L-cysteine (NAC), a ROS scavenger, which also reduced HG-induced cytotoxicity and apoptosis, leading to increase in cell viability and decrease in apoptotic cells. In conclusion, our findings provide new evidence for the first time that naringin protects against HGinduced injuries by inhibiting the activation of MAPK (p38 MAPK, ERK1/2 and JNK) and oxidative stress in H9c2 cells.Hyperglycaemia, the most important feature of diabetes mellitus (DM), is believed to be a risk factor for the development of diabetic cardiovascular complications, such as diabetic cardiomyopathy (DCM) [1,2]. The mechanisms responsible for the deteriorative effects of hyperglycaemia on cardiomyocytes are complicated. Multiple factors, such as reactive oxygen species (ROS) production [3][4][5][6][7][8], decline of antioxidant defence systems [6-10], pro-inflammatory cytokine [11][12][13], activation of mitogen-activated protein kinase (MAPK) [14][15][16] and mitochondrial damage [17,18] have been reported to contribute to hyperglycaemia-induced injuries. Sustained hyperglycaemia has been identified as a principle mediator of ROS generation in diabetes [3,4,14,19], which leads to oxidative myocardial injury [14,20]. Furthermore, hyperglycaemia significantly increases phosphorylation of p38 MAPK and extracellular signal regulated kinase (ERK) 1/2 (members of MAPK) in left ventricle tissue of diabetic rats [14], the increased activation of MAPK is associated with the development of diabetic cardiomyopathy [14]. In streptozotocin (STZ)-induced diabetic rats, hyperglycaemia...

Naringin protects cardiomyocytes against hyperglycemia-induced injuries in vitro and in vivo

“…To confirm our hypothesis, we secondarily observed the influence of K ATP channel activation on HG-induced injury. In agreement with our recent studies (Zhu et al 2011, Chen et al 2014a, the findings of this study showed that treatment of H9c2 cardiac cells with HG induced considerable injuries, including a decrease in cell viability. However, pretreatment of H9c2 cardiac cells with DZ or Pin markedly attenuated the HG-induced injuries, as evidenced by an increase in cell viability.…”

“…As with oxidative stress, mitochondrial damage has been shown to be involved in HG-induced cardiomyocyte injury (Chen et al 2014a,b, Xu et al 2015. It was shown that exposure of the cells to 35 mM glucose for 24 h elicited mitochondrial damage, as manifested by the dissipation of MMP (Fig.…”

“…NRG is recognized by more and more people due to its comprehensive physiological and pharmacological effects, including antioxidant (Jung et al 2003, Jeon et al 2004, Rajadurai & Prince 2007, Bodas et al 2011, Jain & Parmar 2011, Mahmoud et al 2012, antihypercholesterolemic (Jung et al 2003, Kim et al 2004, Jung et al 2006, anti-inflammatory (Jung et al 2003, Bodas et al 2011, Mahmoud et al 2012, cardioprotection (Huang et al 2013, Chen et al 2014a and anti-apoptotic effects (Jagetia et al 2003, Kanno et al 2003. Furthermore, Huang et al (2013) and Chen et al (2014a,b) demonstrated that NRG inhibited the MAPK pathway (p38 MAPK, ERK1/2 and JNK) in HG-induced injuries in H9c2 cardiac cells.…”

Myricitrin Attenuates High Glucose-Induced Apoptosis through Activating Akt-Nrf2 Signaling in H9c2 Cardiomyocytes

“…A previous study demonstrated that HG increases the level of ROS leading to cell apoptosis [20]. Accordingly, we investigated ROS production in response to HG simulation and its regulation by myricitrin in H9c2 cells.…”

Exogenous H2S protects H9c2 cardiac cells against high glucose-induced injury and inflammation by inhibiting the activation of the NF-κB and IL-1β pathways

“…Multiple factors have been reported to contribute to hyperglycemia-induced cardiac damage, such as oxidative stress (3)(4)(5)(6), mitochondrial dysfunction (5)(6)(7)(8), apoptosis (5-9) and activation of several signaling molecules, including mitogen-activated protein kinase (MAPK) (3,5,10,11), leptin (6,12) and p53 (7,9). Another signaling molecule involved in hyperglycemia-induced cardiomyocyte damage may be nuclear factor-κB (NF-κB).…”