Ginkgolide B Protects Cardiomyocytes from Angiotensin II-Induced Hypertrophy via Regulation of Autophagy through SIRT1-FoxO1

Ellagic acid protects against angiotensin II-induced hypertrophic responses through ROS-mediated MAPK pathway in H9c2 cells

The early myocardial response of hypertension is an elevation of angiotensin-II (Ang-II) concentration, leading to heart failure and cardiac hypertrophy. This hypertrophic event of the heart is mediated by the interaction of Ang type 1 receptors (AT-R1), thereby modulating NADPH oxidase activity in cardiomyocytes, which alters redox status in cardiomyocytes. Ellagic acid (EA) has anti-inflammatory and anti-oxidative capacities. Thus, EA has potential preventive effects on cardiovascular diseases and diabetes. In the last decades, because the protective effect of EA on Ang-II-induced hypertrophic responses is unclear, this study aims to investigate the protective effect of EA in cardiomyocytes. H9c2 cells were treated to Ang-II 1 μM for 24 h to induce cellular damage. We found that EA protected against Ang-II-increased cell surface area and pro-hypertrophic gene expression in H9c2. EA reduced Ang-II-caused AT-R1 upregulation, thereby inhibiting oxidative stress NADPH oxidase activation. EA mitigated Ang-II-enhanced p38 and extracellular-signal-regulated kinase (ERK) phosphorylation. Moreover, EA treatment under Ang-II stimulation also reversed NF-κB activity and iNOS expression. This study shows that EA protects against Ang-II-induced myocardial hypertrophy and attenuates oxidative stress through reactive oxygen species-mediated mitogen-activated protein kinase signaling pathways in H9c2 cells. Thus, EA may be an effective compound for preventing Ang-II-induced myocardial hypertrophy.

The potential of herbal drugs to treat heart failure: The roles of Sirt1/AMPK

Heart failure (HF) is a highly morbid syndrome that seriously affects the physical and mental health of patients and generates an enormous socio-economic burden. In addition to cardiac myocyte oxidative stress and apoptosis, which are considered mechanisms for the development of HF, alterations in cardiac energy metabolism and pathological autophagy also contribute to cardiac abnormalities and ultimately HF. Silent information regulator 1 (Sirt1) and adenosine monophosphate-activated protein kinase (AMPK) are nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases and phosphorylated kinases, respectively. They play similar roles in regulating some pathological processes of the heart through regulating targets such as peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), protein 38 mitogen-activated protein kinase (p38 MAPK), peroxisome proliferator-activated receptors (PPARs), and mammalian target of rapamycin (mTOR). We summarized the synergistic effects of Sirt1 and AMPK in the heart, and listed the traditional Chinese medicine (TCM) that exhibit cardioprotective properties by modulating the Sirt1/AMPK pathway, to provide a basis for the development of Sirt1/AMPK activators or inhibitors for the treatment of HF and other cardiovascular diseases (CVDs).

The Current State of Research on Sirtuin-Mediated Autophagy in Cardiovascular Diseases

Sirtuins belong to the class III histone deacetylases and possess nicotinamide adenine dinucleotide-dependent deacetylase activity. They are involved in the regulation of multiple signaling pathways implicated in cardiovascular diseases. Autophagy is a crucial adaptive cellular response to stress stimuli. Mounting evidence suggests a strong correlation between Sirtuins and autophagy, potentially involving cross-regulation and crosstalk. Sirtuin-mediated autophagy plays a crucial regulatory role in some cardiovascular diseases, including atherosclerosis, ischemia/reperfusion injury, hypertension, heart failure, diabetic cardiomyopathy, and drug-induced myocardial damage. In this context, we summarize the research advancements pertaining to various Sirtuins involved in autophagy and the molecular mechanisms regulating autophagy. We also elucidate the biological function of Sirtuins across diverse cardiovascular diseases and further discuss the development of novel drugs that regulate Sirtuin-mediated autophagy.

Sesamin suppresses angiotensin-II-enhanced oxidative stress and hypertrophic markers in H9c2 cells

Myocardial hypertrophy plays a crucial role in cardiovascular disease (CVD) development. Myocardial hypertrophy is an adaptive response by myocardial cells to stress after cardiac injury to maintain cardiac output and function. Angiotensin II (Ang-II) regulates CVD through the renin-angiotensin-aldosterone system, and its signaling in cardiac myocytes leads to excessive reactive oxygen species (ROS) production, oxidative stress, and inflammation. Sesamin (SA), a natural compound in sesame seeds, has anti-inflammatory and anti-apoptotic effects. This study investigated whether SA could attenuate hypertrophic damage and oxidative injuries in H9c2 cells under Ang-II stimulation. We found that SA decreased the cell surface area. Furthermore, Ang-II treatment reduced Ang-II-increased ANP, BNP, and β-MHC expression. Ang-II enhanced NADPH oxidase activity, ROS formation, and decreased Superoxide Dismutase (SOD) activity. SA treatment reduces Ang-II-caused oxidative injuries. We also found that SA mitigates Ang-II-induced apoptosis and pro-inflammatory responses. In conclusion, SA could attenuate Ang-II-induced cardiac hypertrophic injuries by inhibiting oxidative stress, apoptosis, and inflammation in H9c2 cells. Therefore, SA might be a potential supplement for CVD management.

Inhibition of Myocardial Remodeling and Heart Failure by Traditional Herbal Medications: Evidence from Ginseng and ginkgo biloba

Herbal-based medications have been used as therapeutic agents for thousands of years, particularly in Asian cultures. It is now well established that these herbal medications contain potent bioactive phytochemicals which exert a plethora of beneficial effects such as those seen on the cardiovascular system. Among the most widely studied of these herbal agents is ginseng, a member of the genus Panax, which has been shown to produce beneficial effects in terms of reducing cardiac pathology, at least in experimental studies. The beneficial effects of ginseng observed in such studies are likely attributable to their constituent ginsenosides, which are steroid-like saponins of which there are at least 100 and which vary according to ginseng species. Many ginseng species such as Panax ginseng (also known as Asian ginseng) and P quinquefolius (North American ginseng) as well as specific ginsenosides have been shown to attenuate hypertrophy as well as other indices of myocardial remodeling in a wide variety of experimental models. Ginkgo biloba on the other hand has been much less studied although the leaf extract of the ancient ginkgo tree has similarly consistently been shown to produce anti-remodeling effects. Ginkgo's primary bioactive constituents are thought to be terpene trilactones called ginkgolides, of which there are currently seven known types. Ginkgo and ginkgolides have also been shown to produce anti-remodeling effects as have been shown for ginseng in a variety of experimental models, in some cases via similar mechanisms. Although a common single mechanism for the salutary effects of these compounds is unlikely, there are a number of examples of shared effects including antioxidant and antiapoptotic effects as well as inhibition of pro-hypertrophic intracellular signaling such as that involving the calcineurin pathway which results in the upregulation of pro-hypertrophic genes. Robust clinical evidence represented by large scale phase 3 trials is lacking although there is limited supporting evidence from small trials at least with respect to ginseng. Taken together, both ginseng and ginkgo as well as their bioactive components offer potential as adjuvant therapy for the treatment of myocardial remodeling and heart failure.

Activation of the sirtuin silent information regulator 1 pathway inhibits pathological myocardial remodeling

Myocardial remodeling refers to structural and functional disorders of the heart caused by molecular biological changes in the cardiac myocytes in response to neurological and humoral factors. A variety of heart diseases, such as hypertension, coronary artery disease, arrhythmia, and valvular heart disease, can cause myocardial remodeling and eventually lead to heart failure. Therefore, counteracting myocardial remodeling is essential for the prevention and treatment of heart failure. Sirt1 is a nicotinamide adenine dinucleotide⁺-dependent deacetylase that plays a wide range of roles in transcriptional regulation, energy metabolism regulation, cell survival, DNA repair, inflammation, and circadian regulation. It positively or negatively regulates myocardial remodeling by participating in oxidative stress, apoptosis, autophagy, inflammation, and other processes. Taking into account the close relationship between myocardial remodeling and heart failure and the involvement of SIRT1 in the development of the former, the role of SIRT1 in the prevention of heart failure via inhibition of myocardial remodeling has received considerable attention. Recently, multiple studies have been conducted to provide a better understanding of how SIRT1 regulates these phenomena. This review presents the progress of research involving SIRT1 pathway involvement in the pathophysiological mechanisms of myocardial remodeling and heart failure.

G protein-coupled receptor 39 alleviates mitochondrial dysfunction and hepatocyte lipid accumulation via SIRT1/Nrf2 signaling

OBJECTIVE

Data in the GEO database (GSE63067) showed that G protein-coupled receptor 39 (GPR39) was down-regulated in tissues from patients with non-alcoholic fatty liver disease (NAFLD). It was intended to explore the mechanism of GPR39 in NAFLD.

METHODS

HepG2 cells were treated with a mixture of oleic acid and palmitic acid (OA/PA) to mimic NAFLD cell models. The level of GPR39 and the functions of GPR39 on cellular oxidative stress, lipid accumulation, the SIRT1/Nrf2 signaling and mitochondrial dysfunction were assessed. To verify the mediation of the SIRT1 signaling pathway in GPR39 regulation, cells were subjected to SIRT1 inhibitor EX-527 treatment. Afterwards, the abovementioned aspects of cells were all determined.

RESULTS

GPR39 presented a downward trend in response to OA/PA. GPR39 overexpression could suppress oxidative stress, lipid accumulation and activate the SIRT1/Nrf2 signaling. GPR39 overexpression likewise alleviated mitochondrial dysfunction, whereas EX-527 treatment disturbed the effects of GPR39 overexpression on these aspects.

CONCLUSION

The present study found that GPR39 reduced oxidative stress and maintained mitochondrial homeostasis in a cellular model of NAFLD, a process mediated by SIRT1/Nrf2 signaling.

Therapeutic potential of traditional Chinese medicine against atherosclerosis: Targeting trimethylamine N-oxide

BACKGROUND

Recent studies have shown that plasma trimethylamine-N-oxide (TMAO) level is highly correlated with the risk of atherosclerosis (AS), and the elevated level is significantly positively correlated with the incidence of AS.

PURPOSE

The purpose of this article is to offer a useful summary of the correlation between TMAO and AS, and the effect of herbal monomers, herbal extracts, and formulas on anti-atherosclerosis mediated by TMAO.

METHOD

The data contained in this article comes from PubMed, Web of Science, and China National Knowledge Infrastructure.

RESULTS

This review discusses the main mechanism of AS induced by TMAO, including endothelial dysfunction, macrophage foaming, platelet reactivity, and cholesterol metabolism, and summarizes 6 herb monomers, 5 herb extracts, and 2 formulas that have been tested for their anti-TMAO activity.

CONCLUSION

The current understanding of possible ways to reduce TMAO generation is discussed, with the effect and potential of herb monomers, herb extracts, and formulas highlighted.