Isoquercetin ameliorated hypoxia/reoxygenation-induced H9C2 cardiomyocyte apoptosis via a mitochondrial-dependent pathway

Isoquercetin Ameliorates Osteoarthritis via Nrf2/NF-κB Axis: An In Vitro and In Vivo Study

Osteoarthritis (OA) is a progressive joint disease characterized by extracellular matrix (ECM) degradation and inflammation, which is involved with pathological microenvironmental alterations induced by damaged chondrocytes. However, current therapies are not effective in alleviating the progression of OA. Isoquercetin is a natural flavonoid glycoside compound that has various pharmacological effects including anticancer, anti-diabetes and blood lipid regulation. Previous evidence suggests that isoquercetin has anti-inflammatory properties in various diseases, but its effect on OA has not been investigated yet. In this study, through western bolt, qRT-PCR and ELISA, it was found that isoquercetin could reduce the increase of ADAMTS5, MMP13, COX-2, iNOS and IL-6 induced by IL-1β, suggesting that isoquercetin could inhibit the inflammation and ECM degradation of chondrocytes. Through nuclear-plasma separation technique, western blot and immunocytochemistry, it can be found that Nrf2 and NF-κB pathways are activated in this process, and isoquercetin may rely on this process to play its protective role. In vivo, the results of X-ray and SO staining show that intra-articular injection of isoquercetin reduces the degradation of cartilage in the mouse OA model. In conclusion, the present work suggests that isoquercetin may benefit chondrocytes by regulating the Nrf2/NF-κB signaling axis, which supports isoquercetin as a potential drug for the treatment of OA.

Lappaconitine sulfate inhibits proliferation and induces mitochondrial-mediated apoptosis via regulating PI3K/AKT/GSK3β signaling pathway in HeLa cells

Lappaconitine (LA), a diterpenoid alkaloid extracted from the root of Aconitum sinomontanum Nakai, exhibits broad pharmacological effects, including anti-tumor activity. The inhibitory effect of lappaconitine hydrochloride (LH) on HepG2 and HCT-116 cells and the toxicity of lappaconitine sulfate (LS) on HT-29, A549, and HepG2 cells have been described. But the mechanisms of LA against human cervical cancer HeLa cells still need to be clarified. This study was designed to investigate the effects and molecular mechanisms of lappaconitine sulfate (LS) on the growth inhibition and apoptosis in HeLa cells. The cell viability and proliferation were evaluated using the Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2´-deoxyuridine (EdU) assay, respectively. The cell cycle distribution and apoptosis were detected by flow cytometry analysis and 4', 6-diamidino-2-phenylindole (DAPI) staining. The mitochondrial membrane potential (MMP) was determined through the 5, 5', 6, 6'-tetrachloro-1, 1', 3, 3'-tetraethylbenzimi-dazolyl carbocyanine iodide (JC-1) staining. The cell cycle arrest-, apoptosis-, and the phosphatidylinositol-3-kinase/protein kinase B/glycogen synthase kinase 3β (PI3K/AKT/GSK3β) pathway-related proteins were estimated by western blot analysis. LS markedly reduced the viability and suppressed the proliferation of HeLa cells. LS induced G0/G1 cell cycle arrest through the inhibition of Cyclin D1, p-Rb, and induction of p21 and p53. Furthermore, LS triggered apoptosis through the activation of mitochondrial-mediated pathway based on decrease of Bcl-2/Bax ratio and MMP and activation of caspase-9/7/3. Additionally, LS led to constitutive downregulation of the PI3K/AKT/GSK3β signaling pathway. Collectively, LS inhibited cell proliferation and induced apoptosis through mitochondrial-mediated pathway by suppression of the PI3K/AKT/GSK3β signaling pathway in HeLa cells.

Glycosylation of Quercetin by Selected Entomopathogenic Filamentous Fungi and Prediction of Its Products' Bioactivity

Quercetin is the most abundant flavonoid in food products, including berries, apples, cauliflower, tea, cabbage, nuts, onions, red wine and fruit juices. It exhibits various biological activities and is used for medical applications, such as treating allergic, inflammatory and metabolic disorders, ophthalmic and cardiovascular diseases, and arthritis. However, its low water solubility may limit quercetin's therapeutic potential. One method of increasing the solubility of active compounds is their coupling to polar molecules, such as sugars. The attachment of a glucose unit impacts the stability and solubility of flavonoids and often determines their bioavailability and bioactivity. Entomopathogenic fungi are biocatalysts well known for their ability to attach glucose and its 4-O-methyl derivative to bioactive compounds, including flavonoids. We investigated the ability of cultures of entomopathogenic fungi belonging to Beauveria, Isaria, Metapochonia, Lecanicillium and Metarhizium genera to biotransform quercetin. Three major glycosylation products were detected: (1), 7-O-β-D-(4″-O-methylglucopyranosyl)-quercetin, (2) 3-O-β-D-(4″-O-methylglucopyranosyl)-quercetin and (3) 3-O-β-D-(glucopyranosyl)-quercetin. The results show evident variability of the biotransformation process, both between strains of the tested biocatalysts from different species and between strains of the same species. Pharmacokinetic and pharmacodynamic properties of the obtained compounds were predicted with the use of cheminformatics tools. The study showed that the obtained compounds may have applications as effective modulators of intestinal flora and may be stronger hepato-, cardio- and vasoprotectants and free radical scavengers than quercetin.

Selenium-Modified Chitosan Induces HepG2 Cell Apoptosis and Differential Protein Analysis

INTRODUCTION

Chitosan is the product of the natural polysaccharide chitin removing part of the acetyl group, and exhibits various physiological and bioactive functions. Selenium modification has been proved to further enhance the chitosan bioactivities, and has been a hot topic recently.

METHODS

The present study aimed to investigate the potential inhibitory mechanism of selenium-modified chitosan (SMC) on HepG2 cells through MTT assays, morphological observation, annexin V-FITC/PI double staining, mitochondrial membrane potential determination, cell-cycle detection, Western blotting, and two-dimensional gel electrophoresis (2-DE).

RESULTS

The results indicated that SMC can induce HepG2 cell apoptosis with the cell cycle arrested in the S and G2/M phases and gradual disruption of mitochondrial membrane potential, reduce the expression of Bcl2, and improve the expression of Bax, cytochrome C, cleaved caspase 9, and cleaved caspase 3. Also, 2-DE results showed that tubulin α1 B chain, myosin regulatory light chain 12A, calmodulin, UPF0568 protein chromosome 14 open reading frame 166, and the cytochrome C oxidase subunit 5B of HepG2 cells were downregulated in HepG2 cells after SMC treatment.

DISCUSSION

These data suggested that HepG2 cells induced apoptosis after SMC treatment via blocking the cell cycle in the S and G2/M phases, which might be mediated through the mitochondrial apoptotic pathway. These results could be of benefit to future practical applications of SMC in the food and drug fields.

MicroRNA-582-5p targeting Creb1 modulates apoptosis in cardiomyocytes hypoxia/reperfusion-induced injury

BACKGROUND

Myocardial ischemia-reperfusion injury (MIRI) caused by the reperfusion therapy of myocardial ischemic diseases is a kind of major disease that threatens human health and lives severely. There are lacking of effective therapeutic measures for MIRI. MicroRNAs (miRNAs) are abundant in mammalian species and play a critical role in the initiation, promotion, and progression of MIRI. However, the biological role and molecular mechanism of miRNAs in MIRI are not entirely clear.

METHODS

We used bioinformatics analysis to uncover the significantly different miRNA by analyzing transcriptome sequencing data from myocardial tissue in the mouse MIRI model. Multiple miRNA-related databases, including miRdb, PicTar, and TargetScan were used to forecast the downstream target genes of the differentially expressed miRNA. Then, the experimental models, including male C57BL/6J mice and HL-1 cell line, were used for subsequent experiments including quantitative real-time polymerase chain reaction analysis, western blot analysis, hematoxylin and eosin staining, flow cytometry, luciferase assay, gene interference, and overexpression.

RESULTS

MiR-582-5p was found to be differentially upregulated from the transcriptome sequencing data. The elevated levels of miR-582-5p were verified in MIRI mice and hypoxia/reperfusion (H/R)-induced HL-1 cells. Functional experiments revealed that miR-582-5p promoted apoptosis of H/R-induced HL-1 cells via downregulating cAMP-response element-binding protein 1 (Creb1). The inhibiting action of miR-582-5p inhibitor on H/R-induced apoptosis was partially reversed after Creb1 interference.

CONCLUSIONS

Collectively, the research findings reported that upregulation of miR-582-5p promoted H/R-induced cardiomyocyte apoptosis by inhibiting Creb1. The potential diagnostic and therapeutic strategies targeting miR-582-5p and Creb1 could be beneficial for the MIRI treatment.

Chemical characteristics of Rhodiola Crenulata and its mechanism in acute mountain sickness using UHPLC-Q-TOF-MS/MS combined with network pharmacology analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Rhodiola crenulata (Hook.f. & Thomson) H.Ohba has a long history of clinical application for the prevention and treatment of acute mountain sickness (AMS) in traditional Chinese medicine. However, gaps in knowledge still exist in understanding the underlying mechanisms of Rhodiola crenulata against AMS.

AIMS

To address this problem, a comprehensive method was established by combining UHPLC-Q-TOF-MS/MS analysis and network pharmacology.

MATERIALS AND METHODS

The ingredients of Rhodiola crenulata were comprehensively analyzed using UHPLC-Q-TOF-MS/MS method. On this basis, a network pharmacology method incorporated target prediction, protein-protein interaction network, gene enrichment analysis and components-targets-pathways network was performed. Finally, the possible mechanisms were verified through molecular docking, in vitro and in vivo experiments.

RESULTS

A total of 106 constituents of Rhodiola crenulata were charactered via UHPLC-Q-TOF-MS/MS. The 98 potentially active compounds out of 106 were screened and corresponded to 53 anti-AMS targets. Gene enrichment analysis revealed that hypoxia and inflammation related genes may be the central factors for Rhodiola crenulata to modulate AMS. Molecular docking revealed that TNF, VEGFA and HIF-1α had high affinities to Rhodiola crenulata compounds. Subsequently, Rhodiola crenulata extract was indicated to inhibit the protein expression level of TNF in hypoxia induced H9c2 cells. Lastly, Rhodiola crenulata extract was further verified to ameliorate heart injury and decreased the heart levels of TNF, VEGFA and HIF-1α in acute hypoxia-induced rats.

CONCLUSIONS

This study used UHPLC-Q-TOF-MS/MS analysis and a network pharmacology to provide an important reference for revealing the potential mechanism of Rhodiola crenulata in the prevention and treatment of AMS.

Hydropersulfides (RSSH) Outperform Post-Conditioning and Other Reactive Sulfur Species in Limiting Ischemia-Reperfusion Injury in the Isolated Mouse Heart

Hydrogen sulfide (H₂S) exhibits protective effects in cardiovascular disease such as myocardial ischemia/reperfusion (I/R) injury, cardiac hypertrophy, and atherosclerosis. Despite these findings, its mechanism of action remains elusive. Recent studies suggest that H₂S can modulate protein activity through redox-based post-translational modifications of protein cysteine residues forming hydropersulfides (RSSH). Furthermore, emerging evidence indicates that reactive sulfur species, including RSSH and polysulfides, exhibit cardioprotective action. However, it is not clear yet whether there are any pharmacological differences in the use of H₂S vs. RSSH and/or polysulfides. This study aims to examine the differing cardioprotective effects of distinct reactive sulfur species (RSS) such as H₂S, RSSH, and dialkyl trisulfides (RSSSR) compared with canonical ischemic post-conditioning in the context of a Langendorff ex-vivo myocardial I/R injury model. For the first time, a side-by-side study has revealed that exogenous RSSH donation is a superior approach to maintain post-ischemic function and limit infarct size when compared with other RSS and mechanical post-conditioning. Our results also suggest that RSSH preserves mitochondrial respiration in H9c2 cardiomyocytes exposed to hypoxia-reoxygenation via inhibition of oxidative phosphorylation while preserving cell viability.

Promising Therapeutic Candidate for Myocardial Ischemia/Reperfusion Injury: What Are the Possible Mechanisms and Roles of Phytochemicals?

Percutaneous coronary intervention (PCI) is one of the most effective reperfusion strategies for acute myocardial infarction (AMI) despite myocardial ischemia/reperfusion (I/R) injury, causing one of the causes of most cardiomyocyte injuries and deaths. The pathological processes of myocardial I/R injury include apoptosis, autophagy, and irreversible cell death caused by calcium overload, oxidative stress, and inflammation. Eventually, myocardial I/R injury causes a spike of further cardiomyocyte injury that contributes to final infarct size (IS) and bound with hospitalization of heart failure as well as all-cause mortality within the following 12 months. Therefore, the addition of adjuvant intervention to improve myocardial salvage and cardiac function calls for further investigation. Phytochemicals are non-nutritive bioactive secondary compounds abundantly found in Chinese herbal medicine. Great effort has been put into phytochemicals because they are often in line with the expectations to improve myocardial I/R injury without compromising the clinical efficacy or to even produce synergy. We summarized the previous efforts, briefly outlined the mechanism of myocardial I/R injury, and focused on exploring the cardioprotective effects and potential mechanisms of all phytochemical types that have been investigated under myocardial I/R injury. Phytochemicals deserve to be utilized as promising therapeutic candidates for further development and research on combating myocardial I/R injury. Nevertheless, more studies are needed to provide a better understanding of the mechanism of myocardial I/R injury treatment using phytochemicals and possible side effects associated with this approach.

Oxidative Injury in Ischemic Stroke: A Focus on NADPH Oxidase 4

Ischemic stroke is a leading cause of disability and mortality worldwide. Thus, it is urgent to explore its pathophysiological mechanisms and find new therapeutic strategies for its successful treatment. The relationship between oxidative stress and ischemic stroke is increasingly appreciated and attracting considerable attention. ROS serves as a source of oxidative stress. It is a byproduct of mitochondrial metabolism but primarily a functional product of NADPH oxidases (NOX) family members. Nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) is most closely related to the formation of ROS during ischemic stroke. Its expression is significantly upregulated after cerebral ischemia, making it a promising target for treating ischemic stroke. Several drugs targeting NOX4, such as SCM-198, Iso, G-Rb1, betulinic acid, and electroacupuncture, have shown efficacy as treatments of ischemic stroke. MTfp-NOX4 POC provides a novel insight for the treatment of stroke. Combinations of these therapies also provide new approaches for the therapy of ischemic stroke. In this review, we summarize the subcellular location, expression, and pathophysiological mechanisms of NOX4 in the occurrence and development of ischemic stroke. We also discuss the therapeutic strategies and related regulatory mechanisms for treating ischemic stroke. We further comment on the shortcomings of current NOX4-targeted therapy studies and the direction for improvement.

Anshen-Buxin-Liuwei pill, a Mongolian medicinal formula could alleviate cardiomyocyte hypoxia/reoxygenation injury via mitochondrion pathway

BACKGROUND

Anshen Buxin Liuwei pill (ABLP) is a Mongolian medicinal formula that is composed of six medicinal materials: the Mongolian medicine Bos taurus domesticus Gmelin, Choerospondias axillaris (Roxb.) Burtt et Hill, Myristica fragrans Houtt., Eugenia caryophμllata Thunb., Aucklandia lappa Decne., and Liqui dambar formosana Hance. ABLP is considered to have a therapeutic effect on symptoms such as coronary heart disease, angina pectoris, arrhythmia, depression and irritability, palpitation, and shortness of breath.

METHODS

H9c2 cardiomyocytes were used to construct a hypoxia/reoxygenation (HR) injury model. CCK-8 assay and Annexin V-FITC cell apoptosis assays were used for cell viability and cell apoptosis determination. The LDH, SOD, MDA, CAT, CK, GSH-Px, Na⁺-K⁺-ATPase, and Ca²⁺-ATPase activities in cells were determined to assess the protective effects of ABLP. The mRNA levels of Sirtuin3 (Sirt3) and Cytochrome C (Cytc) in H9c2 cells were determined by quantitative real-time PCR.

RESULTS

The results indicate that HR-treated cells began to shrink from the spindle in an irregular shape with some floated in the medium. By increasing the therapeutic dose of ABLP (5, 25, and 50 μg/mL), the cells gradually reconverted in a concentration-dependent manner. The release of CK in HR-treated cells was significantly increased, indicating that ABLP exerts a protective effect in H9c2 cells against HR injury and can improve mitochondrial energy metabolism and mitochondrial function integrity. The present study scrutinized the cardioprotective effects of ABLP against HR-induced H9c2 cell injury through antioxidant and mitochondrial pathways.

CONCLUSIONS

ABLP could be a promising therapeutic drug for the treatment of myocardial ischemic cardiovascular disease. The results will provide reasonable information for the clinical use of ABLP.

Therapeutic Effects and Safe Uses of Plant-Derived Polyphenolic Compounds in Cardiovascular Diseases: A Review

Polyphenols have long been recognized as health-promoting entities, including beneficial effects on cardiovascular disease, but their reputation has been boosted recently following a number of encouraging clinical studies in multiple chronic pathologies, that seem to validate efficacy. Health benefits of polyphenols have been linked to their well-established powerful antioxidant activity. This review aims to provide comprehensive and up-to-date knowledge on the current therapeutic status of polyphenols having sufficient heed towards the treatment of cardiovascular diseases. Furthermore, data about the safety profile of highly efficacious polyphenols has also been investigated to further enhance their role in cardiac abnormalities. Evidence is presented to support the action of phenolic derivatives against cardiovascular pathologies by following receptors and signaling pathways which ultimately cause changes in endogenous antioxidant, antiplatelet, vasodilatory, and anti-inflammatory activities. In addition, in vitro antioxidant and pre-clinical and clinical experiments on anti-inflammatory as well as immunomodulatory attributes of polyphenols have revealed their role as cardioprotective agents. However, an obvious shortage of in vivo studies related to dose selection and toxicity of polyphenols makes these compounds a suitable target for clinical investigations. Further studies are needed for the development of safe and potent herbal products against cardiovascular diseases. The novelty of this review is to provide comprehensive knowledge on polyphenols safety and their health claims. It will help researchers to identify those moieties which likely exert protective and therapeutic effects towards cardiovascular diseases.

Current Updates on Potential Role of Flavonoids in Hypoxia/Reoxygenation Cardiac Injury Model

Clinically, timely reperfusion strategies to re-establish oxygenated blood flow in ischemic heart diseases seem to salvage viable myocardium effectively. Despite the remarkable improvement in cardiac function, reperfusion therapy could paradoxically trigger hypoxic cellular injury and dysfunction. Experimental laboratory models have been developed over the years to explain better the pathophysiology of cardiac ischemia-reperfusion injury, including the in vitro hypoxia-reoxygenation cardiac injury model. Furthermore, the use of nutritional myocardial conditioning techniques have been successful. The cardioprotective potential of flavonoids have been greatly linked to its anti-oxidant, anti-apoptotic and anti-inflammatory properties. While several studies have reviewed the cardioprotective properties of flavonoids, there is a scarce evidence of their function in the hypoxia-reoxygenation injury cell culture model. Hence, the aim of this review was to lay out and summarize our current understanding of flavonoids' function in mitigating hypoxia-reoxygenation cardiac injury based on evidence from the last five years. We also discussed the possible mechanisms of flavonoids in modulating the cardioprotective effects as such information would provide invaluable insight on future therapeutic application of flavonoids.

Natural Antioxidants Improve the Vulnerability of Cardiomyocytes and Vascular Endothelial Cells under Stress Conditions: A Focus on Mitochondrial Quality Control

Cardiovascular disease has become one of the main causes of human death. In addition, many cardiovascular diseases are accompanied by a series of irreversible damages that lead to organ and vascular complications. In recent years, the potential therapeutic strategy of natural antioxidants in the treatment of cardiovascular diseases through mitochondrial quality control has received extensive attention. Mitochondria are the main site of energy metabolism in eukaryotic cells, including myocardial and vascular endothelial cells. Mitochondrial quality control processes ensure normal activities of mitochondria and cells by maintaining stable mitochondrial quantity and quality, thus protecting myocardial and endothelial cells against stress. Various stresses can affect mitochondrial morphology and function. Natural antioxidants extracted from plants and natural medicines are becoming increasingly common in the clinical treatment of diseases, especially in the treatment of cardiovascular diseases. Natural antioxidants can effectively protect myocardial and endothelial cells from stress-induced injury by regulating mitochondrial quality control, and their safety and effectiveness have been preliminarily verified. This review summarises the damage mechanisms of various stresses in cardiomyocytes and vascular endothelial cells and the mechanisms of natural antioxidants in improving the vulnerability of these cell types to stress by regulating mitochondrial quality control. This review is aimed at paving the way for novel treatments for cardiovascular diseases and the development of natural antioxidant drugs.

Tsantan Sumtang Restored Right Ventricular Function in Chronic Hypoxia-Induced Pulmonary Hypertension Rats

Background: Tsantan Sumtang originated from Four Tantras, which consisted of Choerospondias axillaris (Roxb.) B. L. Burtt and A. W. Hill, Santalum album L., and Myristica fragrans Houtt. The three herbs are in ratio 1:1:1. This medication is widely used for cardiovascular diseases.

Aims: The purpose of this study was to explore the effect of Tsantan Sumtang on right ventricular (RV) function in hypoxia-induced pulmonary hypertension (HPH) rats and investigate the underlying mechanism.

Methods: Sixty male Sprague-Dawley (SD) rats were divided into control, hypoxia, and hypoxia + Tsantan Sumtang (1.0, 1.25, and 1.5 g•kg⁻¹•d⁻¹) groups. Chronic hypoxia was induced by putting the rats inside a hypobaric chamber for four weeks and adjusting the inner pressure and oxygen content to match an altitude of 4500 m. Echocardiography was used to assess RV function and right ventricular-pulmonary arterial (RV-PA) coupling. The physiological parameters of the animals were also evaluated. Morphological characteristics of RV were assessed by hematoxylin and eosin (H&E) staining and TEM. Masson’s trichrome staining, immunohistochemical staining, western blotting, and TUNEL assay were used to assess fibrosis and apoptosis levels. The antioxidant and anti-apoptosis properties of Tsantan Sumtang were also evaluated. The effect of Tsantan Sumtang on ROCK signaling pathway was evaluated using real-time quantitative PCR and western blotting.

Results: We established an HPH rat model as indicated by the significant increases in the physiological parameters of the rats. Tsantan Sumtang showed a significant cardiac-protective function and an improved effect on RV-PA coupling. Moreover, Tsantan Sumtang treatment inhibited fibrosis and alleviated apoptosis and oxidative stress in RV. In terms of mechanism, Tsantan Sumtang reduced the expression of ROCK (ROCK1, ROCK2) in RV, inhibited cardiac remodeling-related transcription factors (NFATc3, P-STAT3), and regulated apoptosis-related proteins.

Conclusion: Tsantan Sumtang was able to restore RV function, improve RV-PA coupling, recover hemodynamic and hematological indexes, and protect RV against structural maladaptive remodeling in the HPH rats. These findings demonstrated that Tsantan Sumtang protects the function of RV in HPH rats. The antioxidant and anti-apoptosis properties of Tsantan Sumtang may be responsible for inhibiting the ROCK signaling pathway.

The optimization conditions of establishing an H9c2 cardiomyocyte hypoxia/reoxygenation injury model based on an AnaeroPack System

Ischemia-reperfusion (I/R) injury is a major cause of cardiomyocyte apoptosis after vascular recanalization, which was mimicked by a hypoxia/reoxygenation (H/R) injury model of cardiomyocytes in vitro. In this study, we explored an optimal H/R duration procedure using the AnaeroPack System. To study the H/R procedure, cardiomyocytes were exposed to the AnaeroPack System with sugar and serum-free medium, followed by reoxygenation under normal conditions. Cell injury was detected through lactate dehydrogenase (LDH) and cardiac troponin (c-Tn) release, morphological changes, cell apoptosis, and expression of apoptosis-related proteins. The results showed that the damage to H9c2 cells increased with prolonged hypoxia time, as demonstrated by increased apoptosis rate, LDH and c-Tn release, HIF-1α expression, as well as decreased expression of Bcl-2. Furthermore, hypoxia for 10 h and reoxygenation for 6 h exhibited the highest apoptosis rate and damage and cytokine release; in addition, cells were deformed, small, and visibly round. After 12 h of hypoxia, the majority of the cells were dead. Taken together, this study showed that subjecting H9c2 cells to the AnaeroPack System for 10 h and reoxygenation for 6 h can achieve a practicable and repeatable H/R injury model.

Isoquercitrin Ameliorates Cisplatin-Induced Nephrotoxicity Via the Inhibition of Apoptosis, Inflammation, and Oxidative Stress

Cisplatin is extensively used and is highly effective in clinical oncology; nevertheless, nephrotoxicity has severely limited its widespread utility. Isoquercitrin (IQC), a natural flavonoid widely found in herbage, is well known and recognized for its antioxidant, anti-inflammatory, and anti-apoptotic properties. However, the potential effects and mechanism of IQC in cisplatin-induced acute kidney diseases remain unknown. In this study, we postulated the potential effects and mechanism of IQC upon cisplatin exposure in vivo and in vitro. For the in vivo study, C57BL/6J mice were pretreated with IQC or saline (50 mg/kg/day) by gavage for 3 days before cisplatin single injection (25 mg/kg). Renal function, apoptosis, inflammation, oxidative stress and p-ERK were measured to evaluate kidney injury. In vitro, mouse proximal tubular cells (mPTCs) and human proximal tubule epithelial cell line (HK2) were pretreated with or without IQC (80 μM for mPTCs and 120 μM for HK2) for 2 h and then co-administrated with cisplatin for another 24 h. Apoptosis, inflammation, ROS and p-ERK of cells were also measured. In vivo, IQC administration strikingly reduced cisplatin-induced nephrotoxicity as evidenced by the improvement in renal function (serum creatinine and blood urea nitrogen), kidney histology (PAS staining), apoptotic molecules (cleaved caspase-3, caspase-8, Bax and Bcl-2), inflammatory cytokines (IL-1β, IL-6, TNF-α, and COX-2), oxidative stress (MDA and total glutathione) and p-ERK. In line with in vivo findings, IQC markedly protected against cisplatin-induced cell injury in mPTCs and HK2 cells. Collectively, these findings demonstrated that IQC administration could significantly protect against cisplatin nephrotoxicity possibly through ameliorating apoptosis, inflammation and oxidative stress accompanied by cross talk with p-ERK. Furthermore, IQC may have potential therapeutic uses in the treatment of cisplatin-induced acute kidney injury.

Energy Metabolism Mechanism of Anticardiogenic Shock Effect Component Ginsenoside Rc of Shenfu Injection on H9c2 Myocardial Injury Cells Induced by Hypoxia/Reoxygenation

Shenfu Injection (SFI) is a common drug used to treat cardiovascular diseases and has a significant effect on cardiogenic shock. Ginsenoside Rc (G-Rc) was an anticardiogenic shock effect component of SFI screened by UHPLC-Q-TOF/MS and multivariate statistical analysis and further selected by molecular docking experiment in our previous study. However, most studies on SFI in the treatment of cardiogenic shock focus on the overall efficacy, and little is known about its effective component on energy metabolism in hypoxia/reoxygenation- (H/R-) induced myocardial injury cells. Therefore, the present study was performed to investigate the dose-effect and time-effect relationship of G-Rc in protecting hypoxic injury of H9c2 cardiomyocytes, and its mechanism on the energy metabolism-related indicators, i.e., adenosine triphosphate (ATP) content, lactate dehydrogenase (LDH) release, and creatine kinase (CK) activity of the myocardial cells, was explored. In this paper, a stable and reliable H/R model of H9c2 cardiomyocytes was established. Compared with the control group, the activity of cardiomyocytes in the H/R group was significantly reduced (P<0.01). The dose-effect and time-effect studies showed that G-Rc could significantly increase cell viability at certain point compared with the H/R group (P<0.01), and the optimum intervention dose and time was 3.33 μmol/L for 12 h. The results concerning energy metabolism mechanism demonstrated that G-Rc pretreatment could improve ATP content, attenuate the LDH leakage, and decrease CK activity and apoptosis rate of H/R cardiomyocytes. Taken together, our findings suggest that G-Rc pretreatment can significantly protect myocardial cells from H/R injury. In addition, G-Rc is able to improve the energy metabolism ability of the injury cardiomyocytes by direct synthesis of ATP and reducing the activity of LDH, CK, and apoptosis rate. These results indicate that G-Rc may be a promising therapeutic candidate for the treatment of cardiovascular disease caused by myocardial H/R injury.

Protective Mechanisms of Quercetin Against Myocardial Ischemia Reperfusion Injury

Quercetin has attracted more attention in recent years due to its protective role against ischemia/reperfusion injury. Quercetin can alleviate oxidative stress injury through the inhibition of NADPH oxidase and xanthine oxidase, blockage of the Fenton reaction, and scavenging of reactive oxygen species. Quercetin can also exert anti-inflammatory and anti-apoptotic effects by reducing the response to inflammatory factors and inhibiting cell apoptosis. Moreover, it can induce vasodilation effects through the inhibition of endothelin-1 receptors, the enhancement of NO stimulation and the activation of the large-conductance calcium-activated potassium channels. Finally, Quercetin can also antagonize the calcium overload. These multifaceted activities of Quercetin make it a potential therapeutic alternative for the treatment of ischemia/reperfusion injury.

Zishen Huoxue Recipe Protecting Mitochondrial Function of Hypoxic/Reoxygenated Myocardial Cells through mTORC1 Signaling Pathway

Objective

This study focuses on the role of Zishen Huoxue Decoction (ZSHX) in reducing mitochondrial membrane potential and reducing the proportion of apoptosis through the mTORC1 signaling pathway.

Methods

In our experiment, we first constructed an in vitro hypoxia/reoxygenation (H/R) model of H9C2 cells. Then, the cells were divided into control group, model group (hypoxia/reoxygenation, H/R), ZSHX, ZSHX + Rapa, low-dose ZSHX (100 μg/ml), and middle-dose ZSHX. High-dose ZSHX (400 μg/ml) group was treated with Zishen Huoxue Decoction (ZSHX). Western Blot was used to detect the expression of cell-related protein and RT-PCR was used to detect the expression of the cell-related gene in each group. Flow cytometry was used to assay for ROS content and the apoptotic ratio of H9C2 cells, Seahorse Live Cell Energy Meter was used to detect the Mitochondrial Respiratory Function in H9C2 Cells, and confocal laser scanning was used to detect the mitochondrial membrane potential of H9C2 cells.

Results

Western Blot assay showed that the relative expression of mTOR and Raptor in the H/R group was significantly lower than that in the control group (n = 3, P < 0.05). The expression of mTOR and Raptor was upregulated and the relative expression of 4E-BP1 was downregulated in the middle- and high-dose ZSHX groups (n = 3, P < 0.05). In addition, the ROS content of H9C2 cells was detected by flow cytometry, showing the ROS synthesis in H/R group (78.31 + 6.14) higher than that in the control group (34.53 + 6.10) (n = 3, P < 0.01). The ROS value was increased significantly after rapamycin inhibited mTOR (66.18 (+4.03 vs. 52.31 (+6.01), n = 3, P < 0.05). The basal mitochondrial respiration and ATP production in H/R group were significantly lower than those in the control group (38.17 + 17.76); the mitochondrial leakage in H/R model group was significantly higher than that in the control group (H/R: 40.93 + 5.18 vs. Ctrl: 27.17 + 8.92, n = 4, P < 0.05). The apoptotic rate of cardiomyocytes in the H/R model group (70.91 + 4.57) was significantly higher than that in the control group (14.52 + 2.37, n = 3, P < 0.01), and Zishen Huoxue Decoction could decrease the apoptotic rate of hypoxic-reoxygenated cardiomyocytes (ZSHX: 18.24 + 4.17 vs. H/R: 78.91 + 3.48, n = 3, P < 0.01).

Conclusion

ZSHX Decoction has the effects of activating mTORC1, inhibiting the overexpression of 4E-BP1, inhibiting fatty acid oxidation, protecting the respiratory function of mitochondria, reducing ROS and apoptosis, and thus protecting myocardial cells from injury.

miR‑320‑3p is involved in morphine pre‑conditioning to protect rat cardiomyocytes from ischemia/reperfusion injury through targeting Akt3

Morphine pre-conditioning (MPC) can significantly reduce myocardial ischemic injury and inhibit cardiomyocyte apoptosis, but the underlying mechanism still remains unclear. The aim of the present study was to investigate the protective mechanism of MPC in myocardial hypoxia/reoxygenation (H/R) injury at the microRNA (miR) level. H9c2 cells were used as a model of H/R and subjected to morphine pre-treatment. The protective effects of MPC on H/R injury in cardiomyocytes were evaluated using MTT and colorimetric assay, as well as flow cytometry. In addition, reverse transcription-quantitative PCR, western blotting and dual-luciferase reporter assay experiments were performed to determine the relationship between MPC, miR-320-3p and Akt3, and their effects on H/R injury. The present study demonstrated that MPC enhanced cell activity, decreased LDH content, and reduced apoptosis in rat cardiomyocytes, suggesting that MPC could protect these cells from H/R injury. Moreover, MPC partially reversed the increase in miR-320-3p expression and the decrease in Akt3 levels caused by H/R injury. Inhibition of miR-320-3p expression also attenuated the effects of H/R on cardiomyocyte activity, LDH content and apoptosis. Furthermore, Akt3 was predicted to be a target gene of miR-320-3p, and overexpression of miR-320-3p inhibited the expression of Akt3, blocking the protective effects of MPC on the cells. The current findings revealed that MPC could protect cardiomyocytes from H/R damage through targeting miR-320-3p to regulate the PI3K/Akt3 signaling pathway.

Tsantan Sumtang attenuated chronic hypoxia-induced right ventricular structure remodeling and fibrosis by equilibrating local ACE-AngII-AT1R/ACE2-Ang1-7-Mas axis in rat

ETHNOPHARMACOLOGICAL RELEVANCE

Tsantan Sumtang, which consists of Choerospondias axillaris (Roxb.) Burtt et Hill, Myristica fragrans Houtt and Santalum album L, is a traditional and common prescription of Tibetan medicine. Tsantan Sumtang originates from Four Tantra with properties of nourishing heart and has been used as a folk medicine for cardiovascular diseases and heart failure in Qinghai, Tibet and Inner Mongolia. Our previous studies found that Tsantan Sumtang showed beneficial effects on right ventricular structure in hypoxia rats, while the underling mechanism remains unclear.

AIM OF THE STUDY

To elucidate the underlying mechanisms of Tsantan Sumtang attenuated right ventricular (RV) remodeling and fibrosis of chronic hypoxia-induced pulmonary arterial hypertension (HPAH) rats.

MATERIALS AND METHODS

Fifty male Sprague Dawley (SD) rats (170 ± 20 g) were randomly divided into control group, hypoxia group, and hypoxia + Tsantan Sumtang groups (1.0 g· kg^-1·day^-1, 1.25 g· kg^-1·day^-1, 1.5 g ·kg^-1·day^-1). Rats in the hypoxia group and hypoxia + Tsantan Sumtang groups were maintained in a hypobaric chamber by adjusting the inner pressure and oxygen content to simulate an altitude of 4500 m for 28 days. The mean pulmonary arterial pressure (mPAP), right ventricle hypertrophy index (RVHI), the ratio of RV weight to tibia length (TL) (RV/TL), heart rate (HR) and RV systolic pressure (RVSP) was determined. Histomorphological assay of RV structure was evaluated by hematoxylin and eosin (HE) staining. RV tissue fibrosis was assessed by collagen proportion area (CPA), collagen I, collagen III and hydroxyproline content. CPA was obtained by picro-sirius red staining (PSR). The expression of collagen I and collagen III were detected by immunohistochemistry and western blotting. The hydroxyproline content was detected by alkaline hydrolysis. In addition, the level of angiotensin II (AngII) and angiotensin 1-7 (Ang1-7) in RV tissue was tested by enzyme-linked immune sorbent assay (ELISA). Protein expression of angiotensin-converting enzyme (ACE), AngII, AngII type 1 receptor (AT1R), angiotensin-converting enzyme 2 (ACE2), Mas receptor (Mas) were determined by immunohistochemistry and western blotting. mRNA level of ACE, AT1R, ACE2, Mas were tested by qPCR. The chemical profile of Tsantan Sumtang was revealed by UHPLC-Q-Exactive hybrid quadrupole-orbitrap mass analysis.

RESULTS

Our results showed that RVHI, RV/TL and RVSP were significantly increased in HPAH rat. Furthermore, levels of collagen I, collagen III and hydroxyproline were up-regulated in RV tissue under hypoxia. We found that RV hypertrophy and fibrosis were associated with increased expression of ACE, AngII, AT1R as well as decreased expression of ACE2, Ang1-7 and Mas. RV remodeling and fibrosis were attenuated after Tsantan Sumtang administration by up-regulating ACE2 and Mas level as well as down-regulating ACE, AngII and AT1R levels in RV tissue. 35 constituents in Tsantan Sumtang were identified.

CONCLUSION

Tsantan Sumtang attenuated RV remodeling and fibrosis in rat exposed to chronic hypoxia. The pharmacological effect of Tsantan Sumtang was based on equilibrating ACE-AngII-AT1R and ACE2-Ang1-7-Mas axis of RV tissue in HPAH rat.

Potential Implications of Quercetin and its Derivatives in Cardioprotection

Quercetin (QCT) is a natural polyphenolic compound enriched in human food, mainly in vegetables, fruits and berries. QCT and its main derivatives, such as rhamnetin, rutin, hyperoside, etc., have been documented to possess many beneficial effects in the human body including their positive effects in the cardiovascular system. However, clinical implications of QCT and its derivatives are still rare. In the current paper we provide a complex picture of the most recent knowledge on the effects of QCT and its derivatives in different types of cardiac injury, mainly in ischemia-reperfusion (I/R) injury of the heart, but also in other pathologies such as anthracycline-induced cardiotoxicity or oxidative stress-induced cardiac injury, documented in in vitro and ex vivo, as well as in in vivo experimental models of cardiac injury. Moreover, we focus on cardiac effects of QCT in presence of metabolic comorbidities in addition to cardiovascular disease (CVD). Finally, we provide a short summary of clinical studies focused on cardiac effects of QCT. In general, it seems that QCT and its metabolites exert strong cardioprotective effects in a wide range of experimental models of cardiac injury, likely via their antioxidant, anti-inflammatory and molecular pathways-modulating properties; however, ageing and presence of lifestyle-related comorbidities may confound their beneficial effects in heart disease. On the other hand, due to very limited number of clinical trials focused on cardiac effects of QCT and its derivatives, clinical data are inconclusive. Thus, additional well-designed human studies including a high enough number of patients testing different concentrations of QCT are needed to reveal real therapeutic potential of QCT in CVD. Finally, several negative or controversial effects of QCT in the heart have been reported, and this should be also taken into consideration in QCT-based approaches aimed to treat CVD in humans.

Microbial Transformation of Prenylquercetins by Mucor hiemalis

Quercetin, one of the most widely distributed flavonoids, has been found to show various biological activities including antioxidant, anticancer, and anti-inflammatory effects. It has been reported that bioactivity enhancement of flavonoids has often been closely associated with nuclear prenylation, as shown in 8-prenylquercetin and 5'-prenylquercetin. It has also been revealed in many studies that the biological activities of flavonoids could be improved after glucosylation. Three prenylated quercetins were prepared in this study, and microbial transformation was carried out in order to identify derivatives of prenylquercetins with increased water solubility and improved bioavailability. The fungus M. hiemalis was proved to be capable of converting prenylquercetins into more polar metabolites and was selected for preparative fermentation. Six novel glucosylated metabolites were obtained and their chemical structures were elucidated by NMR and mass spectrometric analyses. All the microbial metabolites showed improvement in water solubility.

Therapeutic potential of IKK-β inhibitors from natural phenolics for inflammation in cardiovascular diseases

Cardiovascular disease (CVDs) is a chronic disease with the highest morbidity and mortality in the world. Previous studies have suggested that preventing inflammation serves an efficient role in protection against cardiovascular diseases. Modulation of IKK-β activity can be used to treat and control CVDs associated with chronic inflammation, which targets the phosphorylation of IκB following the release of the RelA complex, and then translocates to the nucleus, eventually triggering the transcription of several genes that induce chemokines, cytokines, and adhesion molecules. Most importantly, the IκB kinase (IKK) complex is involved in transcriptional activation by phosphorylating the inhibitory molecule IkBα, enabling activation of NF-κB. Phenolic compounds possess cardioprotective potential that may be related to modulating inflammatory responses involved in CVDs. The SystemsDock analysis was used to explore whether 38 active compounds inhibit IKK-β activity based on literature. Docking results showed that the top docking score of three chemical compounds were icariin, salvianolic acid B, and plantainoside D in all compounds. Icariin, salvianolic acid B, and plantainoside D are the most promising IKKβ inhibitors. These phytochemicals could be helpful to find the lead compounds on designing and developing novel cardioprotective agents.

Antitumor effects of seleno-short-chain chitosan (SSCC) against human gastric cancer BGC-823 cells

Seleno-short-chain chitosan (SSCC) is a derivative of chitosan. In the present study, we sought to investigate the underlying antitumor mechanism of SSCC on human gastric cancer BGC-823 cells in vitro. MTT assay suggested that SSCC exhibited a dose-dependent inhibitory effect on the proliferation of BGC-823 cells. We found the SSCC-treated cells showed typical morphological characteristics of apoptosis in a dose dependent manner by observing on microscope. Annexin V-FITC/PI double staining and cell cycle assay identified that SSCC could induce BGC-823 cells apoptosis by triggering G2/M phase arrest. Our research provided the first evidence that SSCC could effectively induce the apoptosis of BGC-823 cells via an intrinsic mitochondrial pathway, as indicated by inducing the disruption of mitochondrial membrane potential (MMP), the excessive accumulation of reactive oxidative species (ROS), the increase of Bax/Bcl-2 ratio and the activation of caspase 3, caspase 9 and cytochrome C (Cyt-C) in BGC-823 cells. These combined results clearly indicated that SSCC could induce BGC-823 cells apoptosis by the involvement of mitochondrial signaling pathway, which provided precise experimental evidence for SSCC as a potential agent in the prevention and treatment of human gastric cancer.

Selenious-β-lactoglobulin induces the apoptosis of human lung cancer A549 cells via an intrinsic mitochondrial pathway

In this study, the cytotoxic activity of selenious-β-lactoglobulin (Se-β-Lg) and the anticancer mechanism were investigated in human lung cancer A549 cells in vitro. MTT assay showed that Se-β-Lg at 200 μg/mL exhibited a significant suppression effect on A549 cells and the maximum inhibition rate reached 90% after 72 h treatment. Flow cytometry analysis revealed that 200 μg/mL of Se-β-Lg induced cell cycle arrest at G0/G1 phase. Cell apoptosis was induced via the generation of reactive oxygen species (ROS) and the decrease of mitochondrial membrane potential (ΔΨm) in a time-dependent manner. Furthermore, Se-β-Lg suppressed the expression of Bcl-2 and improved the level of Bax, leading to the release of cytochrome c and a higher expression of caspase-3 in A549 cells. In summary, Se-β-Lg could induce apoptosis in A549 cells via an intrinsic mitochondrial pathway and it might serve as a potential therapeutic agent for human lung cancer.

Glycosylation of 3-Hydroxyflavone, 3-Methoxyflavone, Quercetin and Baicalein in Fungal Cultures of the Genus Isaria

Flavonoids are plant secondary metabolites with a broad spectrum of biological activities. In nature, they occur mainly in the form of glycosides, but their extraction is often difficult and expensive, as is chemical synthesis. We have shown that biotransformations are an excellent method for obtaining flavonoid glycosides. We are the first team to describe the use of Isaria microorganisms in biotransformations of flavonoid compounds. In the present study as biocatalysts, we used one strain of Isaria fumosorosea KCH J2 isolated from a spider carcass in green areas of Wroclaw and two strains of I. farinosa (J1.4 and J1.6) isolated from insects found in already unused mines in Lower Silesia. The substrates were 3-hydroxyflavone, 3-methoxyflavone, quercetin (3,3',4',5,7-pentahydroxyflavone), and baicalein (5,6,7-trihydroxyflavone). For all the substrates that were used in this study, we obtained 4-O-methylglucopyranosides. In the case of substrates with a hydroxyl group in the third position, O-β-d-glucopyranosides were also formed. Isoquercetin that was obtained by biotransformation was used as a substrate to check the kinetics of the formation of flavonoid 4-O-methylglucopyranosides in I. fumosorosea KCH J2 culture. We did not observe the attachment of the methyl group to glucose unit in isoquercetin. Our finding suggest that the attachment of 4-O-methylglucopyranose occurs in one step.