Therapeutic window of globular adiponectin against cerebral ischemia in diabetic mice: the role of dynamic alteration of adiponectin/adiponectin receptor expression

Pro- and Anti-inflammatory Biomarkers Responses after Aerobic Training in Heart Transplant Recipients: A Systematic Review and Meta-analysis

BACKGROUND

Physical exercise (PE) may improve plasma concentration of interleukin- 6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and adiponectin (adpN) in heart transplant (HT) patients. However, no consistent data is available on this population.

AIM

Thus, we aimed to conduct a systematic review and meta-analysis on the effects of PE over these pro- and anti-inflammatory biomarkers in HT patients.

METHODS

Following the guidelines established by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement, we conducted a systematic literature search in the PubMed, Cochrane, and Scopus databases. Outcomes included IL-6, TNF-alpha, and adpN. Effect size (ES) was calculated using the standardized mean difference with a 95% confidence interval (CI).

RESULTS

The PE group (aerobic modality) was associated with reduced IL-6 compared to the control group (ES: -0.53; 95% CI: -0.99 to -0.06 pg/mL; P = 0.026). However, the PE group did not show a significant effect on TNF-alpha and adpN levels (ES: -0.33; 95% CI: -0.79 to 0.13; P = 0.16 and ES: -0.20; 95% CI: -0.70 to 0.30 pg/mL; P = 0.444, respectively).

CONCLUSION

PE is associated with IL-6 reductions, although TNF alpha and adpN did not change after this intervention in HT patients. Therefore, PE is an effective intervention to downregulate IL-6 in post-HT patients.

Pharmacological and physiological roles of adipokines and myokines in metabolic-related dementia

Dementia is a detrimental neuropathologic condition with considerable physical, mental, social, and financial impact on patients and society. Patients with metabolic syndrome (MetS), a group of diseases that occur in tandem and increase the risk of neurologic diseases, have a higher risk of dementia. The ratio between muscle and adipose tissue is crucial in MetS, as these contain many hormones, including myokines and adipokines, which are involved in crosstalk and local paracrine/autocrine interactions. Evidence suggests that abnormal adipokine and myokine synthesis and release may be implicated in various MetS, such as atherosclerosis, diabetic mellitus (DM), and dyslipidemia, but their precise role is unclear. Here we review the literature on adipokine and myokine involvement in MetS-induced dementia via glucose and insulin homeostasis regulation, neuroinflammation, vascular dysfunction, emotional changes, and cognitive function.

Adiponectin/AdiopR1 signaling prevents mitochondrial dysfunction and oxidative injury after traumatic brain injury in a SIRT3 dependent manner

Mitochondrial dysfunction and oxidative injury, which contribute to worsening of neurological deficits and poor clinical outcomes, are hallmarks of secondary brain injury after TBI. Adiponectin (APN), beyond its well-established regulatory effects on metabolism, is also essential for maintaining normal brain functions by binding APN receptors that are ubiquitously expressed in the brain. Currently, the significance of the APN/APN receptor (AdipoR) signaling pathway in secondary injury after TBI and the specific mechanisms have not been conclusively determined. In this study, we found that APN knockout aggravated brain functional deficits, increased brain edema and lesion volume, and exacerbated oxidative stress as well as apoptosis after TBI. These effects were significantly alleviated after APN receptor agonist (AdipoRon) treatment. Moreover, we found that AdipoR1, rather than AdipoR2, mediated the protective effects of APN/AdipoR signaling against oxidative stress and brain injury after TBI. In neuron-specific AdipoR1 knockout mice, mitochondrial damage was more severe after TBI, indicating a potential association between APN/AdipoR1 signaling inactivation and mitochondrial damage. Mechanistically, neuron-specific knockout of SIRT3, the most important deacetylase in the mitochondria, reversed the neuroprotective effects of AdipoRon after TBI. Then, PRDX3, a critical antioxidant enzyme in the mitochondria, was identified as a vital downstream target of the APN/SIRT3 axis to alleviate oxidative injury after TBI. Finally, we revealed that APN/AdipoR1 signaling promotes SIRT3 transcription by activating the AMPK-PGC pathway. In conclusion, APN/AdipoR1 signaling plays a protective role in post-TBI oxidative damage by restoring the SIRT3-mediated mitochondrial homeostasis and antioxidant system.

Distribution of Adiponectin Receptors in the Brain of Adult Mouse: Effect of a Single Dose of the Adiponectin Receptor Agonist, AdipoRON, on Ischemic Stroke

Adiponectin exhibits pleiotropic effects, including anti-inflammatory, anti-apoptotic, anti-oxidant, and neuroprotective ones. Although some studies have documented brain expression in different rodent models of its receptors, AdipoR1 and AdipoR2, their global distribution remains incomplete. Here, we demonstrated that both AdipoR are widely distributed in the brains of adult mice. Furthermore, by double immunostaining studies, we showed that AdipoR1 and AdipoR2 are mainly expressed in neurons and blood vessels. Then, considering the wide distribution of both receptors and the neuroprotective effects of adiponectin, we tested the therapeutic effect of a single injection of the adiponectin receptor agonist, AdipoRON (5 mg.kg⁻¹), 24 h after stroke in a model of middle cerebral artery occlusion technique (MCAO). Under our experimental conditions, we demonstrated that AdipoRON did not modulate the infarct volume, cell death, neuroinflammatory parameters including microglia activation and oxidative stress. This study suggests that a protocol based on multiple injections of AdipoRON at a higher dose after MCAO could be considered to promote the therapeutic properties of AdipoRON on the brain repair mechanism and recovery.

Exploring the New Horizon of AdipoQ in Obesity-Related Alzheimer's Dementia

Alzheimer's disease (AD) is the most common form of dementia, which causes abnormalities in learning, thinking, memory, as well as behavior. Generally, symptoms of AD develop gradually and aggravate over time, and consequently severely interfere with daily activities. Furthermore, obesity is one of the common risk factors for dementia. Dysregulation of adipokine and adipocyte dysfunction are assumed to be accountable for the high risk of obesity in people that develop many related disorders such as AD. Moreover, it has been observed that the dysfunction of adipose is connected with changes in brain metabolism, brain atrophy, cognitive decline, impaired mood, neuroinflammation, impaired insulin signaling, and neuronal dysfunction in people with obesity. Conversely, the pathological mechanisms, as well as the molecular players which are involved in this association, have been unclear until now. In this article, we discuss the impact of adiponectin (AdipoQ) on obesity-related Alzheimer's dementia.

Anti-inflammatory and Anti-endoplasmic reticulum stress Effects of catalpol Against myocardial ischemia-reperfusion injury in streptozotocin-induced diabetic rats

The current study was designed to investigate the effects and the mechanism of catalpol on myocardial ischemia-reperfusion (MI/R) injury in a diabetic rat model. Male Sprague-Dawley rats were divided into DM + sham, DM +I/R, and DM +I/R + C groups and diabetes was induced using single injections of streptozotocin (STZ; 70 mg/kg; i.p). After confirming the induction of diabetes, rats were administered physiological saline and catalpol (10 mg/kg; i.p.) daily for 28 days. Subsequently, rats were subjected to left anterior descending (LAD) coronary artery occlusion for 30 min followed by reperfusion for 2 h. Haemodynamic parameters were recorded throughout surgery, and following sacrifice, hearts were isolated for biochemical, histopathological, and molecular analyses. Catalpol treatment significantly ameliorated MI/R injury by improving cardiac function, normalizing myocardial enzyme activities and markers of oxidative stress, and by maintaining myocardial architecture. Furthermore, expression levels of the inflammatory cytokines TNF-α and IL-6 were decreased in biochemical and immunohistochemical studies. Additionally, the cardioprotective effects of catalpol were partly related to reductions in myocardial endoplasmic reticulum stress (ERS). In conclusion, catalpol exerts cardioprotective effects in diabetic rats by attenuating inflammation and inhibiting ERS.

The role of adiponectin in ischemia-reperfusion syndrome: a literature review

Adiponectin, among other diverse adipokines, is produced in greater quantity and has an effect on the adipose tissue and other tissues in the body. Adiponectin plays three main roles: regulatory metabolic and sensitizing function of insulin in the liver and muscles; it acts as an anti-inflammatory cytokine and in vascular protection, besides important cardiac protection in the presence of ischemia-reperfusion syndrome. Since many situations resulting from traumatic accidents or pathologies are due to cell damage caused by ischemia-reperfusion syndrome, it is relevant to study new therapeutic alternatives that will contribute to reducing these lesions. The objective of this study is to carry out a literature review on the role of adiponectin in ischemia-reperfusion syndrome.

Green Tea Polyphenols Modulated Cerebral SOD Expression and Endoplasmic Reticulum Stress in Cardiac Arrest/Cardiopulmonary Resuscitation Rats

BACKGROUND

Reducing cerebral ischemia-reperfusion injury is crucial for improving survival and neurologic outcomes after cardiac arrest/cardiopulmonary resuscitation (CA/CPR). The purpose of this study is to investigate the neuroprotective effects of green tea polyphenols (GTPs) concern with the modulation of endogenous antioxidation and endoplasmic reticulum stress.

METHODS

After subjecting to CA/CPR, rats were randomized into the saline group (NS, n = 40) and the GTPs group (GTPs, n = 40) and the GTPs group (GTPs, n = 40) and the GTPs group (GTPs.

RESULTS

Comparing with that in NS group, GTPs increased the expression of SOD1 and SOD2 at 12 h, 24 h, 48 h, 72 h, and the expression of GRP78 at 24 h and 48 h (p < 0.05) butdecreased caspase-12, CHOP, caspase-3 level, and apoptotic number of neurons (p < 0.05) butdecreased caspase-12, CHOP, caspase-3 level, and apoptotic number of neurons (.

CONCLUSION

GTPs exert neuroprotective effects via mechanisms that may be related to the enhancement of endogenous antioxidant capacity and inhibition of endoplasmic reticulum stress in CA/CPR rat models.

Relationships among resistin, adiponectin, and leptin and microvascular complications in patients with type 2 diabetes mellitus

Objective

To investigate the relationships among serum resistin, adiponectin, and leptin and microvascular complications in patients with type 2 diabetes mellitus (T2DM).

Methods

A total of 120 patients with T2DM were divided into non-microangiopathy and microangiopathy groups. Sixty age- and sex-matched healthy subjects were used as a normal control (NC) group. Body height, body mass, waist circumference, and blood pressure were determined, and waist/hip ratio (WHR), body mass index, blood glucose, lipids, resistin, leptin, adiponectin, free fatty acids (FFA), high-sensitivity C-reactive protein (hs-CRP), fasting insulin, hemoglobin A1c, and homeostatic model assessment of insulin resistance (HOMA-IR) were compared among the three groups.

Results

Serum levels of resistin, leptin, FFA, and hs-CRP were significantly higher and levels of adiponectin were significantly lower in patients in the non-microangiopathy (n = 60) and microangiopathy groups (n = 60) compared with the NC group (n = 60). Serum resistin and leptin levels in patients with T2DM were positively correlated with WHR, hs-CRP, FFA, HOMA-IR, and triglycerides, but negatively correlated with high-density lipoprotein-cholesterol (HDL-C). Serum adiponectin levels in patients with T2DM were negatively correlated with WHR, hs-CRP, FFA, HOMA-IR, and triglycerides, but positively correlated with HDL-C.

Conclusion

Serum resistin, adiponectin, and leptin levels correlate with the occurrence of T2DM and microvascular complications.

Iridoid glycosides from Radix Scrophulariae attenuates focal cerebral ischemia‑reperfusion injury via inhibiting endoplasmic reticulum stress‑mediated neuronal apoptosis in rats

Iridoid glycosides of Radix Scrophulariae (IGRS) are a group of the major bioactive components from Radix Scrophulariae with extensive pharmacological activities. The present study investigated the effects of IGRS on cerebral ischemia‑reperfusion injury (CIRI) and explored its potential mechanisms of action. A CIRI model in rats was established by occlusion of the right middle cerebral artery for 90 min, followed by 24 h of reperfusion. Prior to surgery, 30, 60 or 120 mg/kg IGRS was administered to the rats once a day for 7 days. Then, the neurological scores, brain edema and volume of the cerebral infarction were measured. The apoptosis index was determined by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling. The effects of IGRS on the histopathology of the cortex in brain tissues and the endoplasmic reticulum ultrastructure in the hippocampus were analyzed. Finally, the expression of endoplasmic reticulum stress (ERS)‑regulating mediators, endoplasmic reticulum chaperone BiP (GRP78), DNA damage‑inducible transcript 3 protein (CHOP) and caspase‑12, were detected by reverse transcription quantitative polymerase chain reaction (RT‑qPCR) and western blot analysis. The volume of cerebral infarction and brain water content in the IGRS‑treated groups treated at doses of 60 and 120 mg/kg were decreased significantly compared with the Model group. The neurological scores were also significantly decreased in the IGRS‑treated groups. IGRS treatment effectively decreased neuronal apoptosis resulting from CIRI‑induced neuron injury. In addition, the histopathological damage and the endoplasmic reticulum ultrastructure injury were partially improved in CIRI rats following IGRS treatment. RT‑qPCR and western blot analysis data indicated that IGRS significantly decreased the expression levels of GRP78, CHOP and caspase‑12 at both mRNA and protein levels. The results of the present study demonstrated that IGRS exerted a protective effect against CIRI in brain tissue via the inhibition of apoptosis and ERS.

Adiponectin Protects Against Cerebral Ischemic Injury Through AdipoR1/AMPK Pathways

Excitotoxicity induced by excessive N-methyl-D-aspartate (NMDA) receptor activation underlies the pathology of ischemic injury. Adiponectin (APN) is an adipocyte-derived protein hormone that modulates a number of metabolic processes. APN exerts a wide range of biological functions in the central nervous system. However, the role of APN and its receptors in cerebral ischemia/reperfusion (I/R)-induced injury and the related mechanisms remain to be clarified. Here, we found that APN and APN receptor agonist AdipoRon (APR) were protective against excitotoxicity induced by oxygen and glucose deprivation/reperfusion (OGD/R) and NMDA in primary neurons. Adiponectin receptor 1 (AdipoR1) knockdown reversed the protection conferred by either APN or APR. Moreover, the protective effects offered by both APN and APR were compromised by compound C, an inhibitor of amp-activated protein kinase (AMPK) phosphorylation. Both APN and APR protected the dissipation of the ΔΨm caused by OGD/R. They also up-regulated the PGC-1α expression, which was reversed by compound C. Furthermore, both APN and APR ameliorated but APN knockout aggravated the infarct volume and neurological deficient induced by transient middle cerebral artery occlusion (tMCAO) in vivo. Taken together, these findings show that APN and APR protect against ischemic injury in vitro and in vivo. The protective mechanism is mainly related to AdipoR1-dependent AMPK phosphorylation and PGC-1α up-regulation.

The Role of Leptin and Adiponectin in Obesity-Associated Cognitive Decline and Alzheimer's Disease

Cross-talk between adipose tissue and central nervous system (CNS) underlies the increased risk of obese people to develop brain diseases such as cognitive and mood disorders. Detailed mechanisms for how peripheral changes caused by adipose tissue accumulation in obesity impact the CNS to cause brain dysfunction are poorly understood. Adipokines are a large group of substances secreted by the white adipose tissue to regulate a wide range of homeostatic processes including, but not limited to, energy metabolism and immunity. Obesity is characterized by a generalized change in the levels of circulating adipokines due to abnormal accumulation and dysfunction of adipose tissue. Altered adipokine levels underlie complications of obesity as well as the increased risk for the development of obesity-related comorbidities such as type 2 diabetes, cardiovascular and neurodegenerative diseases. Here, we review the literature for the role of adipokines as key mediators of the communication between periphery and CNS in health and disease. We will focus on the actions of leptin and adiponectin, two of the most abundant and well studied adipokines, in the brain, with particular emphasis on how altered signaling of these adipokines in obesity may lead to cognitive dysfunction and augmented risk for Alzheimer's disease. A better understanding of adipokine biology in brain disorders may prove of major relevance to diagnostic, prevention and therapy.

Adiponectin confers neuroprotection against cerebral ischemia-reperfusion injury through activating the cAMP/PKA-CREB-BDNF signaling

Ischemic stroke is a severe cerebrovascular disease. Although great progress has been made, the consequent ischemia-reperfusion (I/R) injury is inevitable and affects the therapeutic effect. Adiponectin (APN) is a fat-derived plasma protein that has beneficial actions on cardiovascular disorders. The present study aims to investigate the effect of APN on I/R injury and the potential underlying mechanisms. In step 1, APN were administered for three times (once every 8 h) 24 h before middle cerebral artery occlusion (MCAO). The results indicated that APN treatment reduced infarct volume, neurological deficits and brain water content after I/R injury. Meanwhile, APN was proved to increase the expression of cAMP, PKA, CREB, and BDNF. In step 2, mice were randomly assigned into the Vehicle + I/R, APN + I/R, PKA activator + I/R, PKA inhibitor + APN + I/R groups. PKA activator, PKA inhibitor, as well as APN were administered for three times before MCAO. The results indicated that PKA inhibitor downregulated the expressions of cAMP, PKA, CREB, and BDNF which subsequently weakened the protective effects of APN on cerebral I/R injury. In conclusion, our findings further suggest that APN exerts protective effect against cerebral I/R injury might through the cAMP/PKA-CREB-BDNF signaling pathway. APN is a novel candidate in the treatment of I/R diseases in the future.

Adiponectin Attenuates Oxygen-Glucose Deprivation-Induced Mitochondrial Oxidative Injury and Apoptosis in Hippocampal HT22 Cells via the JAK2/STAT3 Pathway

Ischemic stroke is among the leading causes of morbidity and mortality worldwide. Improving the tolerance of neurons to ischemia and reperfusion injury could be a feasible strategy against ischemia. Adiponectin (APN) is a major adipokine that regulates glucose and lipid metabolism and plays an important role in the protection of the cerebral nervous system. We aimed to investigate the effects of APN on oxygen and glucose deprivation (OGD)-induced neuronal injury in hippocampal neuronal HT22 cells. APN displayed neuroprotective effects against OGD, evidenced by increased cell viability and decreased lactate dehydrogenase release and apoptotic rate. Additionally, APN also maintained mitochondrial ultrastructure and transmembrane potential, attenuated reactive oxygen species and malondialdehyde, and increased superoxide dismutase and glutathione peroxidase activity. Moreover, APN promoted Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) phosphorylation, enhanced STAT3 nuclear translocation, increased the Bcl-2/Bax ratio, and decreased cleaved caspase-3. The aforementioned APN-induced effects were almost reversed by a JAK2 inhibitor, AG490. APN may attenuate OGD-induced hippocampal HT22 neuronal impairment by protecting cells against mitochondrial oxidative stress and apoptosis, mediated by JAK2/STAT3 signaling.

Ischemic stroke and select adipose-derived and sex hormones: a review

Ischemic stroke is the fifth leading cause of death in the USA and is the leading cause of serious, long-term disability worldwide. The principle sex hormones (estrogen, progesterone, and testosterone), both endogenous and exogenous, have profound effects on various stroke outcomes and have become the focus of a number of studies evaluating risk factors and treatment options for ischemic stroke. In addition, the expression of other hormones that may influence stroke outcome, including select adipose-derived hormones (adiponectin, leptin, and ghrelin), can be regulated by sex hormones and are also the focus of several ischemic stroke studies. This review aims to summarize some of the preclinical and clinical studies investigating the principle sex hormones, as well as select adipose-derived hormones, as risk factors or potential treatments for ischemic stroke. In addition, the potential for relaxin, a lesser studied sex hormone, as a novel treatment option for ischemic stroke is explored.

High glucose instigates tubulointerstitial injury by stimulating hetero-dimerization of adiponectin and angiotensin II receptors

Abnormal expression and dysfunction of adiponectin and the cognate receptors are involved in diabetes and diabetic kidney disease (DKD), whereas angiotensin receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors (ACEIs) alleviate diabetic albuminuria and prevent development of DKD through upregulation of adiponectin expression. Here we report that high glucose stimulates expression of angiotensin II (AngII) receptors (AT1 and AT2) in renal proximal tubular epithelial cells (NRK-52E). These receptors underwent hetero-dimerization with adiponectin receptor AdipoR1 and AdipoR2, respectively. High glucose inhibited the dimerization between AT1 and AT2. Interestingly, these hetero-dimers instigated tubulointerstitial injury by inhibiting the cytoprotective action of the adiponectin receptors. These modes of receptor-receptor hetero-dimerization may contribute to high glucose-induced renal tubulointerstitial injury and could be potential therapeutic targets.

2,3,5,4'-Tetrahydroxystilbene-2-O-β-D-glucoside protects murine hearts against ischemia/reperfusion injury by activating Notch1/Hes1 signaling and attenuating endoplasmic reticulum stress

2,3,5,4'-Tetrahydroxystilbene-2-O-β-D-glucoside (TSG) is a water-soluble active component extracted from Polygonum multiflorum Thunb. A number of studies demonstrate that TSG exerts cardioprotective effects. Since endoplasmic reticulum (ER) stress plays a key role in myocardial ischemia/reperfusion (MI/R)-induced cell apoptosis, we sought to determine whether modulation of the ER stress during MI/R injury was involved in the cardioprotective action of TSG. Male mice were treated with TSG (60 mg·kg^-1·d^-1, ig) for 2 weeks and then were subjected to MI/R surgery. Pre-administration of TSG significantly improved post-operative cardiac function, and suppressed MI/R-induced myocardial apoptosis, evidenced by the reduction in the myocardial apoptotic index, serum levels of LDH and CK after 6 h of reperfusion. TSG (0.1-1000 μmol/L) did not affect the viability of cultured H9c2 cardiomyoblasts in vitro, but pretreatment with TSG dose-dependently decreased simulated ischemia/reperfusion (SIR)-induced cell apoptosis. Furthermore, both in vivo and in vitro studies revealed that TSG treatment activated the Notch1/Hes1 signaling pathway and suppressed ER stress, as evidenced by increasing Notch1, Notch1 intracellular domain (NICD), Hes1, and Bcl-2 expression levels and by decreasing p-PERK/PERK ratio, p-eIF2α/eIF2α ratio, and ATF4, CHOP, Bax, and caspase-3 expression levels. Moreover, the protective effects conferred by TSG on SIR-treated H9c2 cardiomyoblasts were abolished by co-administration of DAPT (the Notch1 signaling inhibitor). In summary, TSG ameliorates MI/R injury in vivo and in vitro by activating the Notch1/Hes1 signaling pathway and attenuating ER stress-induced apoptosis.

The nuclear melatonin receptor RORα is a novel endogenous defender against myocardial ischemia/reperfusion injury

Circadian rhythm disruption or decrease in levels of circadian hormones such as melatonin increases ischemic heart disease risk. The nuclear melatonin receptors RORs are pivotally involved in circadian rhythm regulation and melatonin effects mediation. However, the functional roles of RORs in the heart have never been investigated and were therefore the subject of this study on myocardial ischemia/reperfusion (MI/R) injury pathogenesis. RORα and RORγ subtypes were detected in the adult mouse heart, and RORα but not RORγ was downregulated after MI/R. To determine the pathological consequence of MI/R-induced reduction of RORα, we subjected RORα-deficient staggerer mice and wild-type (WT) littermates to MI/R injury, resulting in significantly increased myocardial infarct size, myocardial apoptosis and exacerbated contractile dysfunction in the former. Mechanistically, RORα deficiency promoted MI/R-induced endoplasmic reticulum stress, mitochondrial impairments, and autophagy dysfunction. Moreover, RORα deficiency augmented MI/R-induced oxidative/nitrative stress. Given the emerging evidence of RORα as an essential melatonin effects mediator, we further investigated the RORα roles in melatonin-exerted cardioprotection, in particular against MI/R injury, which was significantly attenuated in RORα-deficient mice, but negligibly affected by cardiac-specific silencing of RORγ. Finally, to determine cell type-specific effects of RORα, we generated mice with cardiomyocyte-specific RORα overexpression and they were less vulnerable to MI/R injury. In summary, our study provides the first direct evidence that the nuclear melatonin receptor RORα is a novel endogenous protective receptor against MI/R injury and an important mediator of melatonin-exerted cardioprotection; melatonin-RORα axis signaling thus appears important in protection against ischemic heart injury.

Cardioprotective effects of Notoginsenoside R1 against ischemia/reperfusion injuries by regulating oxidative stress- and endoplasmic reticulum stress- related signaling pathways

Background: Recent reports suggested the involvement of oxidative stress- and endoplasmic reticulum stress (ERS)-associated pathways in the progression of ischemia/reperfusion (I/R) injury. Notoginsenoside R1 (NGR1) is a novel saponin isolated from P. notoginseng, which has a history of prevention and treatment of cardiovascular diseases. Objective: We aimed to examine the cardioprotective effects of NGR1 on I/R-induced heart dysfunction ex vivo and in vitro. Methods: H9c2 cadiomyocytes were incubated with NGR1 for 24 h and exposed to hypoxia/reoxygenation. Isolated rat hearts were perfused by NGR1 for 15 min and then subjected to global ischemia/reperfusion. Hemodynamic parameters were monitored as left ventricular systolic pressure (LVSP), heart rate, and maximal rate of increase and decrease of left ventricular pressure (±dP/dt max/min). Results: NGR1 pretreatment prevents cell apoptosis and delays the onset of ERS by decreasing the protein expression levels of ERS-responsive proteins GRP78, P-PERK, ATF6, IRE, and inhibiting the expression of pro-apoptosis proteins CHOP, Caspase-12, and P-JNK. Besides, NGR1 scavenges free radical, and increases the activity of antioxidase. NGR1 inhibits Tunicamycin-induced cell death and cardic dysfunction. Conclusion: We elucidated the significant cardioprotective effects of NGR1 against I/R injuries, and demonstrated the involvement of oxidative stress and ERS in the protective effects of NGR1.