H2O2-induced H9c2 Cardiomyocyte Research Articles

Three Isoflavonoid Glycosides from the Rhizomes of Achyranthes bidentata and their Protective Effects on H2O2 Induced H9c2 Cardiomyocytes Injury

Three Isoflavonoid Glycosides from the Rhizomes of Achyranthes bidentata and their Protective Effects on H2O2 Induced H9c2 Cardiomyocytes Injury

Schisandra chinensis bee pollen\u2019s chemical profiles and protective effect against H2O2-induced apoptosis in H9c2 cardiomyocytes

BackgroundSchisandra chinensis (Turcz.) Baill bee pollen extract (SCBPE) is often used as a functional food in China due to its good antioxidant property. However, its chemical compositions and effects on H9c2 cardiomyocytes against H2O2-induced cell injury still lacks of reports thus far. This study aimed to characterize the main components of SCBPE and investigate its protective effects against H2O2-induced H9c2 cardiomyocyte injury.MethodsThe main components of SCBPE were analyzed via ultraperformance liquid chromatography–quadrupole time-of-flight tandem mass spectrometry (UPLC–QTOF MS/MS). The three main nucleosides in SCBPE were quantitatively analyzed via ultraperformance liquid chromatography–diode array detection. Furthermore, the potential mechanism by which SCBPE exerts protective effects against H2O2-induced H9c2 cardiomyocyte injury was explored for the first time via cell survival rate measurements; cell morphological observation; myocardial superoxide dismutase (SOD) activity and malondialdehyde (MDA) and glutathione (GSH) level determination; flow cytometry; and quantitative polymerase chain reaction.ResultsTwo carbohydrates, three nucleosides, and nine quinic acid nitrogen-containing derivatives in SCBPE were identified or tentatively characterized via UPLC–QTOF MS/MS. The nine quinic acid nitrogen-containing derivatives were first reported in bee pollen. The contents of uridine, guanosine, and adenosine were 2.4945 ± 0.0185, 0.1896 ± 0.0049, and 1.8418 ± 0.0157 μg/mg, respectively. Results of in vitro experiments showed that cell survival rate, myocardial SOD activity, and GSH level significantly increased and myocardial MDA level significantly decreased in SCBPE groups compared with those in H2O2 group. Cell morphology in SCBPE groups also markedly improved compared with that in H2O2 group. Results indicated that SCBPE protected H9c2 cardiomyocytes from H2O2-induced apoptosis by downregulating the mRNA expressions of Bax, cytochrome C, and caspase-3 and upregulating the Bcl-2 mRNA expression.ConclusionsThis study is the first to report that SCBPE could protect against oxidative stress injury and apoptosis in H2O2-injured H9c2 cells. Results indicated that the nucleosides and quinic acid nitrogen-containing derivatives could be the main substances that exert protective effects against H2O2-induced H9c2 cardiomyocyte injury.

Cardioprotective effect exerted by Timosaponin BⅡ through the regulation of endoplasmic stress-induced apoptosis

BackgroundTimosaponin BⅡ (TBⅡ), one of the primary bioactive compounds from Anemarrhena asphodeloides Bunge, possesses potential cardioprotective effects. However, the mechanism underlying TBⅡ-mediated cardioprotection, especially the involvement of endoplasmic reticulum stress, remains largely unknown. PurposeThis study was designed to evaluate the role of TBⅡ in myocardial injury protection and explore its possible mechanisms. MethodsIn vivo models of isoproterenol-induced myocardial injury and H2O2-induced cytotoxicty were established to investigate the effect of anti-myocardial injury of TBⅡ. The potential mechanisms were investigated in vitro and in vivo using multiple detection methods like electrocardiography, histo-pathological examination, JC-1 staining, TUNEL staining, ELISA technology, and western blot analysis. ResultsIn vivo study revealed that TBⅡ improved electrocardiography and heart vacuolation, reduced myocyte apoptosis, and improved the antioxidant potential. In vitro investigation demonstrated that TBⅡ pretreatment inhibited ER stress-mediated apoptosis pathways. Further investigation of the underlying mechanisms revealed that TBⅡ prevented H2O2-induced H9c2 cardiomyocytes injury by the PI3K/Akt pathways, whereas the addition of LY294002, the pharmacologic antagonist of PI3K, attenuated TBⅡ-induced expression of apoptotic protein and cytoprotective effects. ConclusionThese results suggested that TBⅡ protects against myocardial injury in vitro and enhances cellular defense capacity by inhibiting ER stress-mediated apoptosis pathways in vivo by activating the PI3K/Akt pathways.

25-Hydroxyl-protopanaxatriol protects against H2O2-induced H9c2 cardiomyocytes injury via PI3K/Akt pathway and apoptotic protein down-regulation

Oxidative stress injury and apoptosis are the main mechanisms of myocardial ischemia-reperfusion injury (MI/RI). Compounds with anti-oxidant properties can treat MI/RI. Therefore, identification of natural antioxidants such as herbs or botanical drugs is an ideal strategy to develop safe and effective anti-MI/RI drugs. Cardioprotective effects of Ginseng are well documented and are attributable to its anti-oxidant, anti-inflammatory, anti-tumorigenic, anti-arrhythmic, anti-ischemic properties. Ginseng monomer 20®-dammarane -3 beta,6 alpha,12 beta,20,25-pentol(25-hydroxyl-Protopanaxatriol,25-OH-PPT), a novel compound, which belongs to panaxatriol category, is extracted from the leaves and stem of ginseng. It was first investigated for its anti-tumorigenic properties. In this study, we explored whether 25-OH-PTT plays a role in antioxidant stress injury and anti-apoptosis in cardiomyocytes. We also explored the mechanisms in order to provide a theoretical basis to develop 25-OH-PPT as a new drug for treatment of MI/RI. First, we used H2O2 to induce H9c2 cardiomyocytes in vitro resulting in an oxidative stress injury model and pretreated with 25-OH-PPT. Secondly, we examined the viability of H9c2 cells by MTT assay, the reactive oxygen species (ROS) content and mitochondrial membrane potential by flow cytometry as well as cell apoptosis by flow cytometry Annexin-FITC/PI and Hoechst 33258 staining. Furthermore, we pretreated H9c2 cells with PI3K inhibitor, LY294002, and observed the above phenomenon. Lastly, we examined the expressions of proteins related to the PI3K/Akt signaling pathway and the apoptotic proteins. We found that 25-OH-PPT can protect H9c2 cells against H2O2-induced injury, decrease apoptosis of H9c2 cells and ROS generation, and increase the mitochondrial membrane potential. It can also upregulate the protein expressions of p-Akt, p-eNOS, and Bcl-2 and down-regulate apoptotic proteins Bax and Caspase-3. Our results indicate that 25-OH-PPT inhibits H2O2-induced H9c2 cardiomyocytes injury through PI3K/Akt pathway. It may become a potential safe and effective traditional Chinese medicine monomer for treatment of MI/RI.

Congmujingnosides B-G, triterpene saponins from the stem of Aralia chinensis and their protective effects against H2O2-induced myocardial cell injury

Phytochemical investigation of the stem of Aralia chinensis yielded six new oleanane-type triterpene saponins named as congmujingnosides B-G (1–6). The new ones were elucidated on the basis of the chemical and spectroscopic analysis. Protective effects of compounds 1−6 were tested against H2O2-induced H9c2 cardiomyocyte injury, and the data showed that compounds 1 and 5 had significant cell-protective effects. No significant DPPH radical scavenging activity was observed for compounds 1−6.

Xanthones isolated from Gentianella acuta and their protective effects against H2O2-induced myocardial cell injury

In the present study, two new xanthones, (5′S,8′S)-1,3,5,8-tetrahydroxyxanthone(7→2′)-1,3,5,8-tetrahydroxy-5′,6′,7′,8′-tetrahydroxanthone (1), 5-hydroxy-3,4,6-trimethoxyxanthone-1-O-β-D-glucopyranoside (2), and eight known xanthones (3–10) were isolated from the whole plants of Gentianella acuta. Their structures were identified by the spectroscopic analyses (HR-ESI-MS, and 1D and 2D NMR). Meanwhile, cell-protective effects against H2O2-induced H9c2 cardiomyocyte injury and cytotoxic activities of compounds 1–10 were also determined.

Studies on chemical constituents of Clinopodium chinense

Twenty-eight compounds were isolated and purified from Clinopodium chinense by Sephedax LH-20, ODS, MCI and preparative HPLC. Their structures were identified as apigenin (1), apigenin-7-O-β-D-glucopyranoside (2), apigenin-7-O-β-D-glucuronopyranoside (3), thellungianol (4), apigenin-7-O-β-D-rutinoside (5), luteolin (6), luteolin-4'-O-β-D-glucopyranoside (7), apigenin-7-O-β-D-pyranglycuronate butyl ester (8), luteolin-7-O-β-D-rutinoside (9), luteolin-7-O-β-D-noehesperidoside (10), acacetin (11), acacetin-7-O-β-D-glucuronopyranoside (12), buddleoside (13), naringenin (14), pruning (15), nairutin (16), isosakuranetin (17), isosakuranin (18), didymin (19), hesperidin (20), kaempferol (21), quercetin (22), kaempferol-3-O-α-L-rahmnoside (23), p-hydroxycinnamic acid (24), caffeic acid (25), cis-3-[2-[1-(3,4-dihydroxy-phenyl)-1 -hydroxymethyl]-1,3-ben-zodioxol-5-yl]-(E)-2-propenoic acid (26), mesaconic acid (27), gentisic acid 5-O-β-D-(6'-salicylyl)-glucopyranoside (28). Among them, compounds 7, 9-10, 12, 23, 26-28 were isolated from the Clinopodium for the first time. The protective effects of compounds 1-6, 8-17 and 19 against H2O2-induced H9c2 cardiomyocyte injury were tested, compounds 15 exhibited significantly protective effects. Compared with the cell viability of (62.12±6.18)% in the model, pruning exhibited viabilities of (84.25±7.36)% at 25.0 mg•L⁻¹, respectively, using quercetin as a positive control [cell viability of (84.55±8.26)%, 20 mg•L⁻¹].

A polysaccharide of Dendrobium officinale ameliorates H2O2-induced apoptosis in H9c2 cardiomyocytes via PI3K/AKT and MAPK pathways

Dendrobium officinale is one valuable traditional Chinese medicine, which has skyscraping medicinal value. Polysaccharide is the main active ingredient in D. officinale; its antioxidant activity is a hot research topic nowadays. Oxidative stress plays an important role in the pathological progress of a variety of cardiovascular disease, as one of key factors of cardiomyocyte apoptosis. This research adopts a model of H2O2 induction-H9c2 cardiomyocytes apoptosis, aiming to study the effect of Dendrobium officinale Polysaccharide (DOP-GY) for cardiomyocyte apoptosis caused by oxidative stress and its possible mechanism. Our results showed that pretreatment of DOP-GY (low dose: 6.25μg/mL, medium dose: 12.5μg/mL, high dose: 25μg/mL) followed by a 2h incubation with 200μM H2O2 elevated the survival rate, cutted the LDH leakage, reduced lipid peroxidation damage, improved the activity of the endogenous antioxidant enzymes. In addition, the pretreatment of DOP-GY significantly inhibited the production of ROS, declined of the mitochondrial membrane potential, down-regulated pro-apoptosis protein and up-regulated anti-apoptosis protein. The protective effect was correlated with the PI3K/Akt and MAPK signal pathway. Collectively, these observations suggest that DOY-GY has the potential to exert cardioprotective effects against H2O2-induced H9c2 cardiomyocyte apoptosis.

Three new triterpenoids isolated from the aerial parts of Ilex cornuta and protective effects against H2O2-induced myocardial cell injury

In the present study, three new triterpenoids, 23-hydroxyurs-12, 18-dien-28-oic acid 3β-O-α-L-arabinopyranoside (1), 23-hydroxyurs-12, 18-dien-28-oic acid 3β-O-β-D-glucuronopyranoside-6-O-methyl ester (2), and urs-12, 18-dien-28-oic acid 3β-O-β-D-glucuronopyranoside-6-O-methyl ester (3), and a known triterpenoid, 3β-hydroxy-urs-2, 18-dien-28-oic acid (4, randialic acid B), were isolated from the aerial parts of Ilex cornuta. Their structures were identified by the spectroscopic analyses (IR, ESI-MS, HR-ESI-MS, and 1D and 2D NMR) and chemical reactions. Compound 4 showed significant cell-protective effects against H2O2-induced H9c2 cardiomyocyte injury. Compounds 1–4 did not show any significant DPPH radical scavenging activity.

New homoisoflavonoid analogues protect cells by regulating autophagy

As a special group of naturally occurring flavonoids, homoisoflavonoids have been discovered as active components of several traditional Chinese medicines for nourishing heart and mind. In this study, twenty homoisoflavonoid analogues, including different substitution groups on rings A and B, as well as heteroaromatic B ring, were synthesized and evaluated for their cardioprotective and neuroprotective activities. In a H2O2-induced H9c2 cardiomyocytes injury assay, nine homoisoflavonoid analogues showed promising activities in the same level as the positive control, diazoxide. Six cardioprotective compounds with representative structure diversities were then evaluated for their neuroprotective effects on MPP+ induced SH-SY5Y cell injury model. Furthermore, autophagy inducing monodansylcadaverine (MDC) fluorescence staining methods and molecular docking studies indicated the action mechanism of these compounds may involve autophagy regulating via class I PI3K signaling pathway.

Microbial transformation of Pseudoprotodioscin by Chaetomium olivaceum

Pseudoprotodioscin (1) is a steroidal saponin from plants with diverse biological activities. In order to obtain new and useful derivatives for further study, Chaetomium olivaceum was used to transform pseudoprotodioscin. Five new (4, 5, 6, 8, and 9) and three known (2, 3 and 7) steroidal saponins were obtained in this study. These reactions were hard to be achieved through chemical modification. The structures of these metabolites were elucidated on the basis of spectroscopic data. The possible biotransformation pathway of 1 by Chaetomium olivaceum was also proposed. Protective effects against H2O2-induced H9c2 cardiomyocyte injury of compounds 1–9 were evaluated. Compounds 1, 4 and 6 showed some cell-protection activity.

Vascular endothelial growth factor-C protects heart from ischemia/reperfusion injury by inhibiting cardiomyocyte apoptosis.

VEGF-C is a newly identified proangiogenic protein playing an important role in vascular disease and angiogenesis. However, its role in myocardial ischemia/reperfusion (I/R) injury remains unknown. The objective of this study was to determine the role and mechanism of VEGF-C in myocardial ischemia-reperfusion injury. Rat left ventricle myocardium was injected with recombinant human VEGF-C protein (0.1 or 1.0µg/kg b.w.) 1h prior to myocardial ischemia-reperfusion (I/R) injury. 24h later, the myocardial infarction size, the number of TUNEL-positive cardiomyocytes, the levels of creatine kinase (CK), CK-MB, cardiac troponin, malondialdehyde (MDA) content, and apoptosis protein Bax expression were decreased, while Bcl2 and pAkt expression were increased in VEGF-C-treated myocardium as compared to the saline-treated I/R hearts. VEGF-C also improved the function of I/R-injured hearts. In the H2O2-induced H9c2 cardiomyocytes, which mimicked the I/R injury in vivo, VEGF-C pre-treatment decreased the LDH release and MDA content, blocked H2O2-induced apoptosis by inhibiting the pro-apoptotic protein Bax expression and its translocation to the mitochondrial membrane, and consequently attenuated H2O2-induced decrease of mitochondrial membrane potential and increase of cytochrome c release from mitochondria. Mechanistically, VEGF-C activated Akt signaling pathway via VEGF receptor 2, leading to a blockade of Bax expression and mitochondrial membrane translocation and thus protected cardiomyocyte from H2O2-induced activation of intrinsic apoptotic pathway. VEGF-C exerts its cardiac protection following I/R injury via its anti-apoptotic effect.

Seven new triterpenoids from the aerial parts of Ilex cornuta and protective effects against H2O2-induced myocardial cell injury

Seven new triterpenoids (1–7), together with two known ones (8–9), were isolated from the aerial parts ofIlex cornuta. The leaves of I. cornuta are the major source of “Kudingcha”, a popular herbal tea consumed in China and other countries. The structures of compounds 1–7 were determined as 20-epi-urs-12,18-dien-28-oic acid 3β-O-α-l-arabinopyranoside (1), 20-epi-urs-12,18-dien-28-oic acid 2′-O-acetyl-3β-O-α-l-arabinopyranoside (2), 20-epi-urs-12,18-dien-28-oic acid 3β-O-β-d-glucuronopyranoside-6-O-methyl ester (3), 3β,23-dihydroxy-20-epi-urs-12,18-dien-28-oic acid (4), 23-hydroxy-20-epi-urs-12,18-dien-28-oic acid 3β-O-α-l-arabinopyranoside (5), 23-hydroxy-20-epi-urs-12,18-dien-28-oic acid 3β-O-β-d-glucuronic acid (6), 23-hydroxy-20-epi-urs-12,18-dien-28-oic acid 3β-O-β-d-glucuronopyranoside-6-O-methyl ester (7), on the basis of spectroscopic analyses (IR, ESI–MS, HR-ESI–MS, 1D and 2D NMR) and chemical reactions. Protective effects against H2O2-induced H9c2 cardiomyocyte injury were tested in vitro for compounds 1–9, and the data showed that compound 4 had significant cell-protective effect. Compounds 1-9 did not show significant DPPH radical scavenging activity.

Two new triterpenoid saponins from Ilex cornuta

Two new triterpenoid saponins (1 and 2) were isolated from the stems of Ilex cornuta, along with two known triterpenoids (3 and 4). The structures of compounds 1 and 2 were determined as ursane-12,19-diene-28-oic acid 3β-O-β-d-glucuronopyranoside-6-O-methyl ester (1), 3α,23α-dihydroxy-olean-9(11),12-diene-28-oic acid 28-O-β-d-glucopyranosyl ester (2), on the basis of hydrolysis and spectral evidence, including 1D and 2D NMR and high resolution electrospray ionization mass spectrometry (HR-ESI-MS) analyses. Protective effects of compounds 1–4 were tested against H2O2-induced H9c2 cardiomyocyte injury, and the data showed that all these compounds had no cell-protective effect.

Study on protective effect of Sijunzi decoction (red/white ginseng) on H2O2-induced H9c2 cardiomyocytes apoptosis

In this study, efforts were made to screen out the drug concentration of Sijunzi decoction (red ginseng) for in vitro intervention of H9c2 cardiomyocytes, select high, medium and low groups for subsequent experiments, establish the H2O2-induced myocardial cell apoptosis to investigate the protective effect of Sijunzi decoction (white/red ginseng), provide reference ginseng ingredients in Sijunzi decoction used to treat ischemic heart disease and reflect its curative effect, and observe its impacts on SOD, MAD, LDH and other indexes to preliminarily define the action mechanism. According to the results, red ginseng in Sijunzi decoction showed a better protective effect on H2O2-induced myocardial cell injury than that of white ginseng. Both of them could enhance SOD activity and reduce MDA production and LDH release, so as to significantly reduce the amount of apoptotic myocardial cells and play protective role.

New monoterpene glycosides from sunflower seeds and their protective effects against H2O2-induced myocardial cell injury

Three new monoterpene glycosides (1–3) and eleven known compounds (4–14) were isolated from seeds of Helianthus annuus L. (sunflower). Their structures were determined by spectroscopic and chemical methods. All the compounds were isolated from sunflower seeds for the first time. Protective effects of compounds 1–14 against H2O2-induced H9c2 cardiomyocyte injury were evaluated, and compounds 1 and 2 showed some cell-protective effects. No significant DPPH radical scavenging activity was observed for compounds 1–14.

Five new triterpenoidal saponins from the roots of Ilex cornuta and their protective effects against H2O2-induced cardiomyocytes injury

Five new ursane-type triterpenoidal saponins (1–5), together with five known ones (6–10), were isolated from the EtOH extract of the roots of Ilex cornuta. The structures of saponins 1–5 were elucidated as 19α-hydroxyurs-12-en-28-oic acid 3β-O-β-D-glucuronopyranoside (1), 19α-hydroxyurs-12-en-28-oic acid 3β-O-β-D-glucuronopyranoside-6-O-ethyl ester (2), 19α-hydroxyurs-12-en-28-oic acid 3β-O-α-L-arabinopyranosyl-(1→2)-β-D-glucuronopyranoside (3), 3β-O-[α-L-arabinopyranosyl-(1→2)-β-D-glucuronopyranosyl]-19α-hydroxyurs-12-en-28-oic acid 28-O-β-D-glucopyranosyl ester (4) and 3β-O-[α-L-arabinopyranosyl-(1→2)-β-D-glucuronopyranoside-6-O-methyl ester]-19α-hydroxyurs-12-en-28-oic acid 28-O-β-D-glucopyranosyl ester (5), on the basis of spectroscopic analyses (IR, ESI-MS, HR-ESI-MS, 1D and 2D NMR) and chemical reactions. Protective effects of compounds 1–10 against H2O2-induced H9c2 cardiomyocyte injury were tested. Compounds 1–5, 7, and 10 showed cell-protective effects. Among them compound 5 exhibited the highest activity. No significant DPPH radical scavenging activity was observed for compounds 1–10.

New Triterpenoid Saponins from Ilex cornuta and Their Protective Effects against H2O2-Induced Myocardial Cell Injury

Five new triterpenoid saponins, 1-5, together with 10 known ones, 6-15 were isolated from the aerial parts of Ilex cornuta. The structures of compounds 1-5 were determined as 3β-O-α-L-arabinopyranosyl-19α,23-dihydroxy-20α-urs-12-en-28-oic acid 28-O-β-D-glucopyranosyl ester, 1; 3β-O-β-D-glucopyranosyl-(1→2)-α-L-arabinopyranosyl-19-hydroxy-20α-urs-12-en-28-oic acid 28-O-β-D-glucopyranosyl ester, 2; 19α,23-dihydroxyurs-12-en-28-oic acid 3β-O-β-D-glucuronopyranoside-6-O-methyl ester, 3; 19α,23-dihydroxyurs-12-en-28-oic acid 3β-O-[β-D-glucuronopyranoside-6-O-methyl ester]-28-O-β-D-glucopyranosyl ester, 4; and 3β-O-[α-L-arabinopyranosyl-(1→2)-β-D-glucuronic acid]-oleanolic acid 28-O-β-D-glucopyranosyl ester, 5, on the basis of spectroscopic analyses (IR, ESI-MS, HR-ESI-MS, 1D and 2D NMR) and chemical reactions. Protective effects of compounds 1-15 were tested against H2O2-induced H9c2 cardiomyocyte injury, and the data showed that compounds 1, 4, 6, and 13 had significant cell-protective effects. No significant DPPH radical scavenging activity was observed for compounds 1-15.