Epidemiology of Heart Failure and the Discovery of the Cardioprotective Effects of SGLT2 Inhibitors.

In this video, Javed Butler, MD, introduces the series on the use of SGLT2 inhibitors in heart failure. He discusses the epidemiology of heart failure and the effects of SGLT2 inhibitors on heart failure outcomes. Jonathan Rich, MD, joins to summarize the effects of SGLT2 inhibitors from dedicated trials in patients with heart failure.

Growth/differentiation factor 15 (GDF15) expression in the heart after myocardial infarction and cardioprotective effect of pre-ischemic rGDF15 administration.

Growth/differentiation factor-15 (GDF15) is considered an unfavourable prognostic biomarker for cardiovascular disease in clinical data, while experimental studies suggest it has cardioprotective potential. This study focuses on the direct cardiac effects of GDF15 during ischemia-reperfusion injury in Wistar male rats, employing concentrations relevant to patients at high cardiovascular risk. Initially, we examined circulating levels and heart tissue expression of GDF15 in rats subjected to ischemia-reperfusion and sham operations in vivo. We then evaluated the cardiac effects of GDF15 both in vivo and ex vivo, administering recombinant GDF15 either before 30 min of ischemia (preconditioning) or at the onset of reperfusion (postconditioning). We compared infarct size and cardiac contractile recovery between control and rGDF15-treated rats. Contrary to our expectations, ischemia-reperfusion did not increase GDF15 plasma levels compared to sham-operated rats. However, cardiac protein and mRNA expression increased in the infarcted zone of the ischemic heart after 24 h of reperfusion. Notably, preconditioning with rGDF15 had a cardioprotective effect, reducing infarct size both in vivo (65 ± 5% in control vs. 42 ± 6% in rGDF15 groups) and ex vivo (60 ± 4% in control vs. 45 ± 4% in rGDF15 groups), while enhancing cardiac contractile recovery ex vivo. However, postconditioning with rGDF15 did not alter infarct size or the recovery of contractile parameters in vivo or ex vivo. These novel findings reveal that the short-term exogenous administration of rGDF15 before ischemia, at physiologically relevant levels, protects the heart against ischemia-reperfusion injury in both in vivo and ex vivo settings. The ex vivo results indicate that rGDF15 operates independently of the inflammatory, endocrine and nervous systems, suggesting direct and potent cardioprotective properties against ischemia-reperfusion injury.

Shen'ge Formula Protects Cardiac Function in Rats with Pressure Overload-Induced Heart Failure.

Background: In China, Shen'ge formula (SGF), a Traditional Chinese Medicine blend crafted from ginseng and gecko, holds a revered place in the treatment of cardiovascular diseases. However, despite its prevalent use, the precise cardioprotective mechanisms of SGF remain largely uncharted. This study aims to fill this gap by delving deeper into SGF's therapeutic potential and underlying action mechanism, thus giving its traditional use a solid scientific grounding. Methods: In this study, rats were subjected to abdominal aortic constriction (AAC) to generate pressure overload. Following AAC, we administered SGF and bisoprolol intragastrically at specified doses for two distinct durations: 8 and 24 weeks. The cardiac function post-treatment was thoroughly analyzed using echocardiography and histological examinations, offering insights into SGF's influence on vital cardiovascular metrics, and signaling pathways central to cardiac health. Results: SGF exhibited promising results, significantly enhanced cardiac functions over both 8 and 24-week periods, evidenced by improved ejection fraction and fractional shortening while moderating left ventricular parameters. Noteworthy was SGF's role in the significant mitigation of myocardial hypertrophy and in fostering the expression of vital proteins essential for heart health by the 24-week mark. This intervention markedly altered the dynamics of the Akt/HIF-1α/p53 pathway, inhibiting detrimental processes while promoting protective mechanisms. Conclusion: Our research casts SGF in a promising light as a cardioprotective agent in heart failure conditions induced by pressure overload in rats. Central to this protective shield is the modulation of the Akt/HIF-1α/p53 pathway, pointing to a therapeutic trajectory that leverages HIF-1α promotion and p53 nuclear transport inhibition.

Effects of dapagliflozin against streptozotocin and isoproterenol-induced heart failure via investigating NLRP3 and PPAR-γ signaling.

Heart failure is a condition in which the heart's one or both ventricles are unable to either receive an adequate amount of blood or eject an adequate amount of blood. Diabetes is considered one of the major risk factors for cardiovascular diseases. The current research is designed to evaluate the cardioprotective effects of dapagliflozin in streptozotocin and isoproterenol-induced comorbid rats. The COX-2, TNF-α, NF-КB, NLRP3, PPAR-γ, CKMB, TROP-I, AR, GP and SGLT were docked against dapagliflozin, propranolol and metformin. Dapagliflozin restored adequate blood flow and halted myofibril damage. Moreover, it's evident from this study that dapagliflozin significantly decreased serum concentration of various blood markers, decreased relative growth rate and QT interval prolongation, as compared to the negative control group. However, it improved the ventricular ejection fraction in rats of the treatment group. The GST, GSH and CAT levels were increased, as compared to normal. On the contrary, a decrease in LPO concentrations was observed. Evaluation of the coronal section of heart tissues showed the anti-inflammatory expressions evaluated through H & E staining and immunohistochemical techniques and with ELISA and PCR. In a nutshell, dapagliflozin reverses myocardial necrosis and apoptosis.

Comparative efficacy of volume expansion, inotropes and vasopressors in preterm neonates with probable transitional circulatory instability in the first week of life: a systematic review and network meta-analysis.

BACKGROUND: There exists limited agreement on the recommendations for the treatment of transitional circulatory instability (TCI) in preterm neonates OBJECTIVE: To compare the efficacy of various interventions used to treat TCI METHODS: Medline and Embase were searched from inception to 21st July 2023. Two authors extracted the data independently. A Bayesian random effects network meta-analysis was used. Recommendations were formulated using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) framework. INTERVENTIONS: Dopamine, dobutamine, epinephrine, hydrocortisone, vasopressin, milrinone, volume and placebo. MAIN OUTCOME MEASURES: Mortality, major brain injury (MBI) (intraventricular haemorrhage > grade 2 or cystic periventricular leukomalacia), necrotising enterocolitis (NEC) ≥stage 2 and treatment response (as defined by the author). RESULTS: 15 Randomized Controlled Trials (RCTs) were included from the 1365 titles and abstracts screened. Clinical benefit or harm could not be ruled out for the critical outcome of mortality. For the outcome of MBI, epinephrine possibly decreased the risk when compared to dobutamine and milrinone (very low certainty). Epinephrine was possibly associated with a lesser risk of NEC when compared with dopamine, dobutamine, hydrocortisone and milrinone (very low certainty). Dopamine was possibly associated with a lesser risk of NEC when compared with dobutamine (very low certainty). Vasopressin possibly decreased the risk of NEC compared with dopamine, dobutamine, hydrocortisone and milrinone (very low certainty). Clinical benefit or harm could not be ruled out for the outcome response to treatment. CONCLUSIONS: Epinephrine may be used as the first-line drug in preterm neonates with TCI, the evidence certainty being very low. We suggest future trials evaluating the management of TCI with an emphasis on objective criteria to define it.

[Identification of cardioprotective substances in Panax ginseng/P. notoginseng based on mitochondrial morphological characteristics and UPLC-Triple-TOF-MS].

Panax ginseng is reputed to be capable of replenishing healthy Qi and bolstering physical strength, and P. notoginseng can resolve blood stasis and alleviate pain. P. ginseng and P. notoginseng are frequently employed to treat ischemic heart diseases caused by blockages in the heart vessels. Mitochondrial dysfunction often coexists with abnormal mitochondrial morphology, and mitochondrial plasticity and dynamics play key roles in cardiovascular diseases. In this study, primary neonatal rat cardiomyocytes were exposed to 4 hours of hypoxia(H) followed by 2 hours of reoxygenation(R). MitoTracker Deep Red and Hoechst 33342 were used to label mitochondria and nuclei, respectively. Fluorescence images were then acquired using ImageXpress Micro Confocal. Automated image processing and parameter extraction/calculation were carried out using ImagePro Plus. Subsequently, representative parameters were selected as indicators to assess alterations in mitochondrial morphology and function. The active compounds of P. ginseng and P. notoginseng were screened out and identified based on the UPLC-Triple-TOF-MS results and mitochondrial morphometric parameters. The findings demonstrated that RS-2, RS-4, SQ-1, and SQ-4 significantly increased the values of three key morphometric parameters, including mitochondrial length, branching, and area, which might contribute to rescuing morphological features of myocardial cells damaged by H/R injury. Among the active components of the two medicinal herbs, 20(R)-ginsenoside Rg_3, ginsenoside Re, and gypenoside ⅩⅦ exhibited the strongest protective effects on mitochondria in cardiomyocytes. Specifically, 20(R)-ginsenoside Rg_3 might upregulate expression of optic atrophy 1(OPA1) and mitofusin 2(MFN2), and ginsenoside Re and gypenoside ⅩⅦ might selectively upregulate OPA1 expression. Collectively, they promoted mitochondrial membrane fusion and mitigated mitochondrial damage, thereby exerting protective effects on cardiomyocytes. This study provides experimental support for the discovery of novel therapeutic agents for myocardial ischemia-reperfusion injury from P. ginseng and P. notoginseng and offers a novel approach for large-scale screening of bioactive compounds with cardioprotective effects from traditional Chinese medicines.

[Discrimination of anti-tumor and cardioprotective effect quality markers from Aidi Injection based on "spider web" mode].

Chinese medicinal preparations play an equally important role in reducing toxicity and treating tumors. Few studies discriminate the quality markers(Q-markers) conferring different therapeutic effects of traditional Chinese medicine preparations. Therefore, we take Aidi Injection(AD) as an example to comprehensively identify the Q-markers of anti-tumor and cardioprotective effects based on the "spider web" mode. Firstly, based on the principle of measurability, the chemical components in the prescription were qualitatively analyzed, and then the components with high content and capable to be measured were quantitatively analyzed as measurable evaluation indexes. Based on the principle of stability, the effects of light and temperature on the content of each component of AD were investigated as indicators of stability. Based on the principle of compatibility, the compounds were classified according to the law of compatibility of sovereign, minister, assistant, and guide medicinal materials in the prescription. Based on the principle of efficacy, the anti-tumor and antiangiogenic activities of the Q-markers were evaluated, and their synergistic effects with doxorubicin(DOX) in inhibiting tumorigenesis and angiogenesis and lowering cardiotoxicity were evaluated as the evaluation indexes of effectiveness. The seven-dimensional spider web of "compatibility-content-stability-antitumor activity-synergistic anti-tumor activity with DOX-antiangiogenic activity-synergistic anti-angiogenic activity with DOX" and the four-dimensional spider web of "compatibility-content-stability-protective effects against DOX-induced myocardial toxicity" were established, on the basis of which the Q-markers of anti-tumor and cardioprotective effects of AD were comprehensively analyzed. The results showed that 12 components were selected as the Q-markers of AD, among which cantharidin, ginsenoside Re, ginsenoside Rb_1, astragaloside Ⅱ, cryptochlorogenic acid, and ginsenoside Rg_2 were the anti-tumor Q-markers of AD. Ginsenoside Rd, isofraxidin, syringin, eleutheroside E, calycosin-7-O-ß-D-glucoside, and azelaic acid were the cardioprotective Q-markers of AD. Taking into account both the anti-tumor and cardioprotective effects, these Q-markers could cover the four herbs constituting the prescription. The findings provides a scientific basis for the quality control of AD and an effective method for identifying comprehensive and reasonable Q-markers for the two effects of Chinese medicinal preparations.

Peptides Are Cardioprotective Drugs of the Future: The Receptor and Signaling Mechanisms of the Cardioprotective Effect of Glucagon-like Peptide-1 Receptor Agonists.

The high mortality rate among patients with acute myocardial infarction (AMI) is one of the main problems of modern cardiology. It is quite obvious that there is an urgent need to create more effective drugs for the treatment of AMI than those currently used in the clinic. Such drugs could be enzyme-resistant peptide analogs of glucagon-like peptide-1 (GLP-1). GLP-1 receptor (GLP1R) agonists can prevent ischemia/reperfusion (I/R) cardiac injury. In addition, chronic administration of GLP1R agonists can alleviate the development of adverse cardiac remodeling in myocardial infarction, hypertension, and diabetes mellitus. GLP1R agonists can protect the heart against oxidative stress and reduce proinflammatory cytokine (IL-1ß, TNF-α, IL-6, and MCP-1) expression in the myocardium. GLP1R stimulation inhibits apoptosis, necroptosis, pyroptosis, and ferroptosis of cardiomyocytes. The activation of the GLP1R augments autophagy and mitophagy in the myocardium. GLP1R agonists downregulate reactive species generation through the activation of Epac and the GLP1R/PI3K/Akt/survivin pathway. The GLP1R, kinases (PKCε, PKA, Akt, AMPK, PI3K, ERK1/2, mTOR, GSK-3ß, PKG, MEK1/2, and MKK3), enzymes (HO-1 and eNOS), transcription factors (STAT3, CREB, Nrf2, and FoxO3), KATP channel opening, and MPT pore closing are involved in the cardioprotective effect of GLP1R agonists.

Cardioprotective potentials of myricetin on doxorubicin-induced cardiotoxicity based on biochemical and transcriptomic analysis.

Doxorubicin (DOX) is a commonly used anthracycline in cancer chemotherapy. The clinical application of DOX is constrained by its cardiotoxicity. Myricetin (MYR) is a natural flavonoid widely present in many plants with antioxidant and anti-inflammatory properties. However, MYR's beneficial effects and mechanisms in alleviating DOX-induced cardiotoxicity (DIC) remain unknown. C57BL/6 mice were injected with 15 mg/kg of DOX to establish the DIC, and MYR solutions were administrated by gavage to investigate its cardioprotective potentials. Histopathological analysis, physiological indicators assessment, transcriptomics analysis, and RT-qPCR were used to elucidate the potential mechanism of MYR in DIC treatment. MYR reduced cardiac injury produced by DOX, decreased levels of cTnI, AST, LDH, and BNP, and improved myocardial injury and fibrosis. MYR effectively prevented DOX-induced oxidative stress, such as lowered MDA levels and elevated SOD, CAT, and GSH activities. MYR effectively suppressed NLRP3 and ASC gene expression levels to inhibit pyroptosis while regulating Caspase1 and Bax levels to reduce cardiac cell apoptosis. According to the transcriptomic analysis, glucose and fatty acid metabolism were associated with differential gene expression. KEGG pathway analysis revealed differential gene enrichment in PPAR and AMPK pathways, among others. Following validation, MYR was found to alleviate DIC by regulating glycolipid metabolism and AMPK pathway-related genes. Our findings demonstrated that MYR could mitigate DIC by regulating the processes of oxidative stress, apoptosis, and pyroptosis. MYR is critical in improving DOX-induced myocardial energy metabolism abnormalities mediated by the AMPK signaling pathway. In conclusion, MYR holds promise as a therapeutic strategy for DIC.

Nicotinamide riboside attenuates myocardial ischemia-reperfusion injury via regulating SIRT3/SOD2 signaling pathway.

Ischemic heart disease invariably leads to devastating damage to human health. Nicotinamide ribose (NR), as one of the precursors of NAD+ synthesis, has been discovered to exert a protective role in various neurological and cardiovascular disorders. Our findings demonstrated that pretreatment with 200 mg/kg NR for 3 h significantly reduced myocardial infarct area, decreased levels of CK-MB and LDH in serum, and improved cardiac function in the rats during myocardial ischemia-reperfusion (I/R) injury. Meanwhile, 0.5 mM NR also effectively increased the viability and decreased the LDH release of H9c2 cells during OGD/R. We had provided evidence that NR pretreatment could decrease mitochondrial reactive oxygen species (mtROS) production and MDA content, and enhance SOD activity, thereby mitigating mitochondrial damage and inhibiting apoptosis during myocardial I/R injury. Further investigations revealed that NR increased NAD+ content and upregulated SIRT3 protein expression in myocardium. Through using of SIRT3 small interfering RNA and the SIRT3 deacetylase activity inhibitor 3-TYP, we had confirmed that the cardioprotective effect of NR on cardiomyocytes was largely dependent on the inhibition of mitochondrial oxidative stress via SIRT3-SOD2 axis. Overall, our study suggested that exogenous supplementation with NR mitigated mitochondrial damage and inhibited apoptosis during myocardial I/R injury by reducing mitochondrial oxidative stress via SIRT3-SOD2-mtROS pathway.

The Effects of Dobutamine in Septic Shock: An Updated Narrative Review of Clinical and Experimental Studies.

The key objective in the hemodynamic treatment of septic shock is the optimization of tissue perfusion and oxygenation. This is usually achieved by the utilization of fluids, vasopressors, and inotropes. Dobutamine is the inotrope most commonly recommended and used for this purpose. Despite the fact that dobutamine was introduced almost half a century ago in the treatment of septic shock, and there is widespread use of the drug, several aspects of its pharmacodynamics remain poorly understood. In normal subjects, dobutamine increases contractility and lacks a direct effect on vascular tone. This results in augmented cardiac output and blood pressure, with reflex reduction in systemic vascular resistance. In septic shock, some experimental and clinical research suggest beneficial effects on systemic and regional perfusion. Nevertheless, other studies found heterogeneous and unpredictable effects with frequent side effects. In this narrative review, we discuss the pharmacodynamic characteristics of dobutamine and its physiologic actions in different settings, with special reference to septic shock. We discuss studies showing that dobutamine frequently induces tachycardia and vasodilation, without positive actions on contractility. Since untoward effects are often found and therapeutic benefits are occasional, its profile of efficacy and safety seems low. Therefore, we recommend that the use of dobutamine in septic shock should be cautious. Before a final decision about its prescription, efficacy, and tolerance should be evaluated throughout a short period with narrow monitoring of its wanted and side effects.

CENTRAL VENOUS-TO-ARTERIAL CARBON DIOXIDE PARTIAL PRESSURE DIFFERENCE AS A GUIDING PARAMETER FOR CARDIOTONIC DRUG ADMINISTRATION IN PATIENTS WITH EARLY-STAGE SEPTIC SHOCK.

ABSTRACT: Objective: This study aimed to investigate the effect of the central venous-to-arterial carbon dioxide partial pressure difference (Pcv-aCO2) on the administration of cardiotonic drugs in patients with early-stage septic shock. Methods: A retrospective study was conducted on 120 patients suffering from septic shock. At admission, the left ventricular ejection fraction (LVEF) and Pcv-aCO2 of the patients were obtained. On the premise of mean arterial pressure ≥ 65 mm Hg, the patients were divided into two groups according to the treatment approaches adopted by different doctors-control group: LVEF ≤50% and observation group: Pcv-aCO2 ≥ 6. Both groups received cardiotonic therapy. Results: The two groups of patients had similar general conditions and preresuscitation conditions ( P > 0.05). Compared with the control group, the observation group had a higher mean arterial pressure, lactic acid clearance rate, and urine output after 6 h of resuscitation ( P < 0.05), but a lower absolute value of lactic acid, total fluid intake in 24 h, and a lower number of patients receiving renal replacement therapy during hospitalization ( P < 0.05). After 6 hours of resuscitation, the percentages of patients meeting central venous oxygen saturation and central venous pressure targets were not significantly different between the control and observation groups ( P > 0.05). There was no difference in the 28-day mortality rate between the two groups ( P > 0.05). Conclusion: Pcv-aCO2 is more effective than LVEF in guiding the administration of cardiotonic drugs in the treatment of patients with septic shock.

Cardioprotective effects of curcumin against Diabetic Cardiomyopathies: A systematic review and meta-analysis of preclinical studies.

BACKGROUND: As a common complication of diabetes, diabetic cardiomyopathy (DCM) often leads to further damage to the heart muscle. Curcumin has been proven to have a variety of cardioprotective effects, however, the protective effect against DCM has not been systematically reviewed. PURPOSE: In this study, we aimed to analyze the preclinical (animal model) evidence of curcumin's therapeutic effects in DCM. METHODS: Eight databases and two registry systems were searched from the time of library construction to 1 November 2023. We performed rigorous data extraction and quality assessment. The included studies' methodological quality was appraised using the SYRCLE RoB tool, statistical analyses were carried out using RevMan 5.4 software, and Funnel plots and Egger's test were performed using Stata 17.0 software to assess publication bias. RESULTS: This study included 32 trials with a total of 681 animals. Meta-analysis showed that curcumin significantly improved cardiac function indices (LVEF, LVFS, and LVSd) (p < 0.01), decreased markers of myocardial injury, HW/BW ratio, and randomized blood glucose compared to the control group, in addition to showing beneficial effects on mechanistic indices of myocardial oxidation, inflammation, apoptosis, and autophagy (p < 0.05). CONCLUSIONS: Curcumin may exert cardioprotective effects in DCM through its antioxidant, anti-inflammatory, autophagy-enhancing, and anti-apoptotic effects. Its protective effect is proportional to the dose, and the efficacy may be further increased at a concentration of more than 200 mg/kg, and further validation is needed.

Design, Synthesis, and In Vivo Evaluation of Isosteviol Derivatives as New SIRT3 Activators with Highly Potent Cardioprotective Effects.

Cardiovascular diseases (CVDs) persist as the predominant cause of mortality, urging the exploration of innovative pharmaceuticals. Mitochondrial dysfunction stands as a pivotal contributor to CVDs development. Sirtuin 3 (SIRT3), a prominent mitochondrial deacetylase known for its crucial role in protecting mitochondria against damage and dysfunction, has emerged as a promising therapeutic target for CVDs treatment. Utilizing isosteviol, a natural ent-beyerene diterpenoid, 24 derivatives were synthesized and evaluated in vivo using a zebrafish model, establishing a deduced structure-activity relationship. Among these, derivative 5v exhibited significant efficacy in doxorubicin-induced cardiomyopathy in zebrafish and murine models. Subsequent investigations revealed that 5v selectively elevated SIRT3 expression, leading to the upregulation of SOD2 and OPA1 expression, effectively preventing mitochondrial dysfunction, mitigating oxidative stress, and preserving cardiomyocyte viability. As a novel structural class of SIRT3 activators with robust therapeutic effects, 5v emerges as a promising candidate for further drug development.

Evaluation of Ouabain's Tissue Distribution in C57/Black Mice Following Intraperitoneal Injection, Using Chromatography and Mass Spectrometry.

Cardiotonic steroids (CTSs), such as digoxin, are used for heart failure treatment. However, digoxin permeates the brain-blood barrier (BBB), affecting central nervous system (CNS) functions. Finding a CTS that does not pass through the BBB would increase CTSs' applicability in the clinic and decrease the risk of side effects on the CNS. This study aimed to investigate the tissue distribution of the CTS ouabain following intraperitoneal injection and whether ouabain passes through the BBB. After intraperitoneal injection (1.25 mg/kg), ouabain concentrations were measured at 5 min, 15 min, 30 min, 1 h, 3 h, 6 h, and 24 h using HPLC-MS in brain, heart, liver, and kidney tissues and blood plasma in C57/black mice. Ouabain was undetectable in the brain tissue. Plasma: Cmax = 882.88 ± 21.82 ng/g; Tmax = 0.08 ± 0.01 h; T1/2 = 0.15 ± 0.02 h; MRT = 0.26 ± 0.01. Cardiac tissue: Cmax = 145.24 ± 44.03 ng/g (undetectable at 60 min); Tmax = 0.08 ± 0.02 h; T1/2 = 0.23 ± 0.09 h; MRT = 0.38 ± 0.14 h. Kidney tissue: Cmax = 1072.3 ± 260.8 ng/g; Tmax = 0.35 ± 0.19 h; T1/2 = 1.32 ± 0.76 h; MRT = 1.41 ± 0.71 h. Liver tissue: Cmax = 2558.0 ± 382.4 ng/g; Tmax = 0.35 ± 0.13 h; T1/2 = 1.24 ± 0.7 h; MRT = 0.98 ± 0.33 h. Unlike digoxin, ouabain does not cross the BBB and is eliminated quicker from all the analyzed tissues, giving it a potential advantage over digoxin in systemic administration. However, the inability of ouabain to pass though the BBB necessitates intracerebral administration when used to investigate its effects on the CNS.

The protective effect of Macrostemonoside T from Allium macrostemon Bunge against Isoproterenol-Induced myocardial injury via the PI3K/Akt/mTOR signaling pathway.

Myocardial injury (MI) signifies a pathological aspect of cardiovascular diseases (CVDs) such as coronary artery disease, diabetic cardiomyopathy, and myocarditis. Macrostemonoside T (MST) has been isolated from Allium macrostemon Bunge (AMB), a key traditional Chinese medicine (TCM) used for treating chest stuffiness and pains. Although MST has demonstrated considerable antioxidant activity in vitro, its protective effect against MI remains unexplored. To investigate MST's effects in both in vivo and in vitro models of isoproterenol (ISO)-induced MI and elucidate its underlying molecular mechanisms. This study established an ISO-induced MI model in rats and assessed H9c2 cytotoxicity to examine MST's impact on MI. Various assays, including histopathological staining, TUNEL staining, immunohistochemical staining, DCFH-DA staining, JC-1 staining, ELISA technique, and Western blot (WB), were utilized to explore the potential molecular mechanisms of MI protection. In vivo experiments demonstrated that ISO caused myocardial fiber disorders, elevated cardiac enzyme levels, and apoptosis. However, pretreatment with MST significantly mitigated these detrimental changes. In vitro experiments revealed that MST boosted antioxidant enzyme levels and suppressed malondialdehyde (MDA) production in H9c2 cells. Concurrently, MST inhibited ISO-induced reactive oxygen species (ROS) production and mitigated the decline in mitochondrial membrane potential, thereby reducing the apoptosis rate. Moreover, pretreatment with MST elevated the expression levels of p-PI3K, p-Akt, and p-mTOR, indicating activation of the PI3K/Akt/mTOR signaling pathway and consequent protection against MI. MST attenuated ISO-induced MI in rats by impeding apoptosis through activation of the PI3K/Akt/mTOR signaling pathway. This study presents potential avenues for the development of precursor drugs for CVDs.

Effect and mechanism of gomisin D on the isoproterenol induced myocardial injury in H9C2 cells and mice.

We established myocardial injury models in vivo and in vitro to investigate the cardioprotective effect of gomisin D obtained from Schisandra chinensis. Gomisin D significantly inhibited isoproterenol-induced apoptosis and hypertrophy in H9C2 cells. Gomisin D decreased serum BNP, ANP, CK-MB, cTn-T levels and histopathological alterations, and inhibited myocardial hypertrophy in mice. In mechanisms research, gomisin D reversed ISO-induced accumulation of intracellular ROS and Ca2+. Gomisin D further improved mitochondrial energy metabolism disorders by regulating the TCA cycle. These results demonstrated that gomisin D had a significant effect on isoproterenol-induced myocardial injury by inhibiting oxidative stress, calcium overload and improving mitochondrial energy metabolism.