Baicalein ameliorated obesity-induced cardiac dysfunction by regulating the mitochondrial unfolded protein response through NRF2 signaling.

BACKGROUND: The mitochondrial unfolded protein response (UPRmt) is the first line of defense against mitochondrial dysfunction in several diseases. Baicalein, which is an extract of Scutellaria baicalensis Georgi roots, exerts mitoprotective effects on metabolic disorders and cardiovascular diseases. However, it remains unclear whether baicalein alleviates obesity-induced cardiac damage through the UPRmt. PURPOSE: The present research designed to clarify the role of baicalein in lipotoxicity-induced myocardial apoptosis and investigated the UPRmt-related mechanism. METHODS: In the in vitro experiment, palmitic acid (PA)-treated AC16 cardiomyocytes were established to mimic obesity-induced myocardial injury. After pretreatment of AC16 cells with baicalein, the levels of cell vitality, apoptosis, mitochondrial membrane potential, mitochondrial oxidative stress, and UPRmt-related proteins were determined. Additionally, AC16 cells were treated with ML385 or siRNA to explore the regulation of the UPRmt by NRF2 signaling. In the in vivo experiment, male db/db mice administered with baicalein for 8 weeks were used to validate the effects of baicalein on cardiac damage induced by obesity, the UPRmt, and the NRF2-related pathway. RESULTS: In AC16 cardiomyocytes, PA dose-dependently increased the expression of UPRmt markers (HSP60, LONP1, ATF4, and ATF5). This increase was accompanied by enhanced production of mitochondrial ROS, reduced mitochondrial membrane potential, and elevated the expression levels of cytochrome c, cleaved caspase-3, and Bax/Bcl2, eventually leading to cell apoptosis. Baicalein treatment reversed UPRmt activation and mitochondrial damage and impeded mitochondrial-mediated cell apoptosis. Moreover, NRF2 downregulation by its inhibitor ML385 or siRNA diminished baicalein-mediated NRF2 signaling activation and UPRmt inhibition and triggered mitochondrial dysfunction. Additionally, NRF2 deficiency more intensely activated the UPRmt, resulting in mitochondrial oxidative stress and apoptosis of PA-induced cardiomyocytes, thus indicating that NRF2 plays a vital role in mitochondrial homeostasis regulation. In the in vivo study in db/db mice, baicalein inhibited the UPRmt, enhanced the antioxidant capacity, and attenuated cardiac dysfunction through a NRF2-activated pathway. CONCLUSION: To our best knowledge, these results provide the first insight that baicalein inhibits the UPRmt to induce a protective effect against lipotoxicity-induced mitochondrial damage and cardiomyocyte apoptosis via activating NRF2 signaling and suggest a new role of NRF2 in UPRmt regulation.

Galangin attenuates doxorubicin-induced cardiotoxicity via activating nuclear factor erythroid 2-related factor 2/heme oxygenase 1 signaling pathway to suppress oxidative stress and inflammation.

Doxorubicin (DOX) has aroused contradiction between its potent anti-tumor capacity and severe cardiotoxicity. Galangin (Gal) possesses antioxidant, anti-inflammatory, and antiapoptotic activities. We aimed to explore the role and underlying mechanisms of Gal on DOX-induced cardiotoxicity. Mice were intraperitoneally injected with DOX (3 mg/kg, every 2 days for 2 weeks) to generate cardiotoxicity model and Gal (15 mg/kg, 2 weeks) was co-administered via gavage daily. Nuclear factor erythroid 2-related factor 2 (Nrf2) specific inhibitor, ML385, was employed to explore the underlying mechanisms. Compared to DOX-insulted mice, Gal effectively improved cardiac dysfunction and ameliorated myocardial damage. DOX-induced increase of reactive oxygen species, malondialdehyde, and NADPH oxidase activity and downregulation of superoxide dismutase (SOD) activity were blunted by Gal. Gal also markedly blocked increase of IL-1ß, IL-6, and TNF-α in DOX-insulted heart. Mechanistically, Gal reversed DOX-induced downregulation of Nrf2, HO-1, and promoted nuclear translocation of Nrf2. ML385 markedly blunted the cardioprotective effects of Gal, as well as inhibitive effects on oxidative stress and inflammation. Gal ameliorates DOX-induced cardiotoxicity by suppressing oxidative stress and inflammation via activating Nrf2/HO-1 signaling pathway. Gal may serve as a promising cardioprotective agent for DOX-induced cardiotoxicity.

Preparation, characterization, and antioxidant and antiapoptotic activities of biosynthesized nano­selenium by yak-derived Bacillus cereus and chitosan-encapsulated chemically synthesized nano­selenium.

Nano­selenium (SeNPs) is a red elemental selenium with extremely small particles, which can be absorbed by the body and has biological activity. Currently, the most commonly used synthetic methods for SeNPs are biosynthesis and chemical synthesis. In this study, YC-3-SeNPs were biosynthesized by a strain of yak-gut Bacillus cereus YC-3, and meanwhile, CST-SeNPs were chemically synthesized and encapsulated with chitosan. A series of characterizations proved that YC-3-SeNPs and CST-SeNPs are spherical particles with excellent stability, and both have an excellent ability to scavenge free radicals in vitro. The particles of YC-3-SeNPs were encapsulated with polysaccharides, fiber, and protein, and it was less toxic than that of CST-SeNPs. Additionally, YC-3-SeNPs and CST-SeNPs may inhibit H2O2-induced oxidative stress in cardiomyocytes by activating the Keap1/Nrf2/HO-1 signaling pathway thereby scavenging ROS. Meanwhile, they may exert anti-apoptotic activity in cardiomyocytes by stabilizing mitochondrial membrane potential (∆Ψm) and balancing Bax/Bcl-2 protein, thereby reducing the protein expression of Cyt-c and Cleaved-caspase 3. Given the above, YC-3-SeNPs and CST-SeNPs with excellent antioxidant and anti-apoptotic activities may have broad application potential in the field of cardiovascular diseases.

Mitochondrial disorder and treatment of ischemic cardiomyopathy: Potential and advantages of Chinese herbal medicine.

Mitochondrial dysfunction is the main cause of damage to the pathological mechanism of ischemic cardiomyopathy. In addition, mitochondrial dysfunction can also affect the homeostasis of cardiomyocytes or endothelial cell dysfunction, leading to a vicious cycle of mitochondrial oxidative stress. And mitochondrial dysfunction is also an important pathological basis for ischemic cardiomyopathy and reperfusion injury after myocardial infarction or end-stage coronary heart disease. Therefore, mitochondria can be used as therapeutic targets against myocardial ischemia injury, and the regulation of mitochondrial morphology, function and structure is a key and important way of targeting mitochondrial quality control therapeutic mechanisms. Mitochondrial quality control includes mechanisms such as mitophagy, mitochondrial dynamics (mitochondrial fusion/fission), mitochondrial biosynthesis, and mitochondrial unfolded protein responses. Among them, the increase of mitochondrial fragmentation caused by mitochondrial pathological fission is the initial factor. The protective mitochondrial fusion can strengthen the interaction and synthesis of paired mitochondria and promote mitochondrial biosynthesis. In ischemia or hypoxia, pathological mitochondrial fission can promote the formation of mitochondrial fragments, fragmented mitochondria can lead to damaged mitochondrial DNA production, which can lead to mitochondrial biosynthesis dysfunction, insufficient mitochondrial ATP production, and mitochondrial ROS. Burst growth or loss of mitochondrial membrane potential. This eventually leads to the accumulation of damaged mitochondria. Then, under the leadership of mitophagy, damaged mitochondria can complete the mitochondrial degradation process through mitophagy, and transport the morphologically and structurally damaged mitochondria to lysosomes for degradation. But once the pathological mitochondrial fission increases, the damaged mitochondria increases, which may activate the pathway of cardiomyocyte death. Although laboratory studies have found that a variety of mitochondrial-targeted drugs can reduce myocardial ischemia and protect cardiomyocytes, there are still few drugs that have successfully passed clinical trials. In this review, we describe the role of MQS in ischemia/hypoxia-induced cardiomyocyte physiopathology and elucidate the relevant mechanisms of mitochondrial dysfunction in ischemic cardiomyopathy. In addition, we also further explained the advantages of natural products in improving mitochondrial dysfunction and protecting myocardial cells from the perspective of pharmacological mechanism, and explained its related mechanisms. Potential targeted therapies that can be used to improve MQS under ischemia/hypoxia are discussed, aiming to accelerate the development of cardioprotective drugs targeting mitochondrial dysfunction.

Pharmacological properties of total flavonoids in Scutellaria baicalensis for the treatment of cardiovascular diseases.

BACKGROUND: Scutellaria baicalensis, a medicinal herb belonging to the Lamiaceae family, has been recorded in the Chinese, European, and British Pharmacopoeias. The medicinal properties of this plant are attributed to the total flavonoids of Scutellaria baicalensis (TFSB), particularly the main component, baicalin. This study provides a systematic and comprehensive list of the identified TFSB components and their chemical structures. The quality control process, pharmacokinetics, clinical application, and safety of Scutellaria baicalensis are discussed, and its pharmacological effect on cardiovascular diseases (CVDs) is detailed. Finally, the future research trends and prospects of this medicinal plant are provided. METHODS: The Chinese and English papers related to TFSB were collected from the PubMed and CNKI databases using the relevant keywords. To highlight the pharmacological mechanism, clinical application, and safety of TFSB, the collected articles were screened and classified based on their research content. RESULTS: TFSB contains at least 100 different kinds of flavonoids, of which baicalin, baicalein, wogonin, wogonoside, scutellarin, and scutellarein are the main active ingredients. The preparation process of TFSB is relatively well established, and the extraction rate can be significantly increased by enzymatic pretreatment and ultrasonication. The low oral availability of TFSB may be effectively enhanced using nanoformulations. The available pharmacokinetic data show that flavonoid glycosides and aglycones with the same parent nucleus may be converted to structures that are conducive to absorption in vivo. Moreover, TFSB can protect against CVDs by inhibiting apoptosis, regulating oxidative stress response, participating in inflammatory response, protecting against myocardial fibrosis, inhibiting myocardial hypertrophy, and regulating blood vessels. In terms of clinical application and animal safety, the available studies show that TFSB can be applied in a wide range of clinical treatments and is safe to use is animals. CONCLUSION: This article systematically reviews the therapeutic effect and underlying pharmacological mechanism of TFSB against CVDs. The available studies clearly suggest that TFSB has great potential for the treatment of CVDs and is worthy of in-depth research and development.

The effects of aerobic exercise training with octopamine supplementation on cardiomyocyte apoptosis induced by deep-frying oil: The role of caspase and procaspase 3.

BACKGROUND AND AIM: Clinicians who understand how the body responds to exercise, how aerobic training enhances cardiovascular fitness and the benefits and essentials of prescribing aerobic exercise can effectively encourage patients to be active. Deep-frying is a standard cooking method accompanied by the production of carcinogenesis substances such as acrolein. Acrolein is a toxic byproduct of lipid peroxidation involved in the development of pulmonary, cardiac, and neurodegenerative diseases. This study aimed to explore the effect of aerobic exercise (E.X.E.), and octopamine (OCT) on caspase three expression levels in the heart tissue of rats were fed deep-frying oil (D.F.O.). METHODS: 30 male Wistar rats were divided into 5 groups (n = 6 in each) including (1) control (CO), (2) deep-frying oil (DFO), (3) deep-frying oil + exercise (DFO + EXE), (4) deep-frying oil + octopamine (DFO + OCT), and (5) deep-frying oil + exercise + octopamine (DFO + EXE + OCT). The apoptotic effects of D.F.O. in heart tissue were examined by TUNEL assay. Masson's trichrome stain was used to study cardiomyocytic fibers. Moreover, caspase three gene expression in all groups was evaluated using quantitative real-time PCR and the Western blot method. RESULTS: Data showed a significant increase in apoptotic cells in the D.F.O. group (P < 0.05). In Masson's Trichrome stain analysis, more cardiomyocytic fibers degradation and lymphocytic aggregation cells in the DFO + EXE + OCT group significantly improve this degradation. Also, the expression level of caspase 3 was significantly decreased in the DFO + EXE + OCT group (P < 0.05). CONCLUSION: According to the result of the current study, it can be assumed that D.F.O. can lead to programmed cell death via the activation of caspases in heart tissue. However, it seems that aerobic exercise with octopamine supplementation improves heart tissue function by inhibiting the expression of caspase 3 and pro-caspase 3, leading to a significantly decreased apoptosis in cardiomyocytes of DFO-treated models.

Yiqi Huoxue Recipe inhibits cardiomyocyte apoptosis caused by heart failure through Keap1/Nrf2/HIF-1α signaling pathway.

Yiqi Huoxue Recipe (YHR) is commonly used in China to treat diseases such as heart failure (HF). It has been reported that YHR can treat HF and has a certain protective effect on myocardial cell damage. The purpose of this study is to determine the cardioprotective effects of YHR on HF-induced apoptosis and to clarify its mechanism of action. Oxygen glucose deprivation/recovery (OGD/R) induces H9C2 cell apoptosis model. Ligation of the left anterior descending artery (LAD) coronary artery can induce an animal model of HF. We found that YHR protected H9C2 cells from OGD/R-induced apoptosis, reduced the level of reactive oxygen species (ROS) in H9C2 cells, and increased the mitochondrial membrane potential in H9C2 cells. The results of in vivo animal experiments showed that in the HF model, YHR could reduce infarct area of heart tissue and cardiomyocyte apoptosis rate. YHR regulated the expression of key apoptotic molecules, including increasing the ratio of Bcl-2 and Bax, and reducing the expression of Kelch-like ECH-associated protein 1 (Keap1) and caspase-3. Interestingly, YHR also regulates the expression of NF-E2-related factor 2 (Nrf2) in the nucleus. In summary, YHR may provide cardioprotective effects in heart failure through inhibiting the Keap1/Nrf2/HIF-1α apoptosis pathway.

Study on the protective effects of danshen-honghua herb pair (DHHP) on myocardial ischaemia/reperfusion injury (MIRI) and potential mechanisms based on apoptosis and mitochondria.

CONTEXT: Danshen, the dried root and rhizome of Salvia miltiorrhiza Bunge (Labiatae) and honghua, the dried flower of Carthamus tinctorius L. (Compositae) as the herb pair was used to treat cardiovascular diseases (CVD). OBJECTIVE: To study the effects of DHHP on MIRI and mechanisms based on apoptosis and mitochondria. MATERIALS AND METHODS: 36 SD rats (n = 6) were randomly divided into control group (Con), the ischaemia-reperfusion group (IR), positive control (Xinning tablets, XNT, 1 g/kg/d) and DHHP (1.2, 2.4, and 4.8 g/kg/d). Except for Con, the other groups were intragastrically administrated for 5 d, the rat hearts were isolated to establish the MIRI model in vitro for evaluating the effects of DHHP on MIRI. 24 SD rats (n = 6) were randomly divided into Con, IR, DPPH2.4 (2.4 g/kg/d) and DPPH 2.4 + Atractyloside (ATR) (2.4 + 5 mg/kg/d), administered intragastrically for 5 d, then treated with ATR (5 mg/kg/d) by intraperitoneal injection in DPPH2.4 + ATR group, took rat hearts to establish MIRI model in vitro for revealing mechanism. RESULTS: Myocardial infarct sizes were, respectively, 0.35%, 40.09%, 15.84%, 30.13%, concentrations of NAD+ (nmol/gw/w) were 144, 83, 119, and 88, respectively, in Con, IR, DHHP2.4, DHHP2.4 + ATR group. Cleaved caspase-3 were 0.3, 1.6, 0.5 and 1.3% and cleaved caspase-9 were 0.2, 1.1, 0.4 and 0.8%, respectively, in Con, IR, DHHP2.4 and DHHP2.4 + ATR group. The beneficial effects of DHHP on MIRI were reversed by ATR. CONCLUSIONS: The improvement of MIRI by DHHP may be involved in inhibiting MPTP opening, decreasing oxidative damage, alleviating ischaemic injury and inhibiting cardiomyocyte apoptosis.

Protocatechualdehyde protects oxygen-glucose deprivation/reoxygenation-induced myocardial injury via inhibiting PERK/ATF6α/IRE1α pathway.

Endoplasmic reticulum (ER) stress has been considered as a promising strategy in developing novel therapeutic agents for cardiovascular diseases through inhibiting cardiomyocyte apoptosis. Protocatechualdehyde (PCA) is a natural phenolic compound from medicinal plant Salvia miltiorrhiza with cardiomyocyte protection. However, the potential mechanism of PCA on cardiovascular ischemic injury is largely unexplored. Here, we found that PCA exerted markedly anti-apoptotic effect in oxygen-glucose deprivation/reoxygenation (OGD/R)-induced H9c2 cells (Rat embryonic ventricular H9c2 cardiomyocytes), which was detected by 3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT), lactate dehydrogenase (LDH), Hoechst 33258 and acridine orange/ethidium bromide (AO/EB) assays. PCA also obviously protected cardiomyocytes in myocardial fibrosis model of mice, which was determined by hematoxylin-eosin (HE) staining and TdT-mediated dUTP Nick-End Labeling (TUNEL) staining. Transcriptomics coupled with bioinformatics analysis revealed a complex pharmacological signaling network especially for PCA-mediated ER stress on cardiomyocytes. Further mechanism study suggested that PCA suppressed ER stress via inhibiting protein kinase R-like ER kinase (PERK), inositol-requiring enzyme1α (IRE1α), and transcription factor 6α (ATF6α) signaling pathway through Western blot, DIOC6 and ER-Tracker Red staining, leading to a protective effect against ER stress-mediated cardiomyocyte apoptosis. Taken together, our observations suggest that PCA is a major component from Salvia miltiorrhiza against cardiovascular ischemic injury by suppressing ER stress-associated PERK, IRE1α and ATF6α signaling pathways.

[Electroacupuncture and moxibustion pretreatments reduce cardiomyocyte apoptosis and autophagy in rats with myocardial ischemia/reperfusion injury].

OBJECTIVE: To observe the effect of "Neiguan" (PC6)-electroacupuncture (EA) or moxibustion (Moxi) pretreatment on myocardial apoptosis and expression of autophagy related proteins light chain (LC) 3-Ⅰ and LC3-Ⅱ in rats with myocardial ischemia/reperfusion injury (MIRI), so as to explore their mechanisms underlying improvement of MIRI. METHODS: Forty SD rats (half male and half female) were randomly divided into sham operation, model, ischemic preconditioning (IP), EA and Moxi groups (n＝8 in each group). EA (10 Hz/50 Hz, 1 mA) or Moxi (ignited moxa stick) was respectively applied to bilateral "Neiguan" (PC6) for 20 min, once daily for 7 days. The MIRI model was established by occlusion of the anterior descending branch of the left coronary artery for 40 min, followed by reperfusion for 60 min. The ultrastructural changes and autophagy of myocardial cells were observed by electron microscopy (EM), and the myocardial cellular apoptosis [apoptotic index ＝ (number of apoptotic cells/total number of cardiomyocytes)×100%] was detected by the terminal deoxyribonucleotidyl transferase mediated dUTP nick end labelling (TUNEL) method. The expressions of LC3-Ⅰ and LC3-Ⅱ proteins (markers for autophagy) in myocardial tissue were detected by Western blot. RESULTS: Following MI, EM observation revealed a vague structure of cardiomyocytes and muscular horizontal grain, dissolution of myofibers, mitochondrial swelling, some autophagic vacuoles and autophagic lysosomes at different degrees and surrounded by a double membrane in the model group, these situations were apparently milder in the EA and Moxi groups. The apoptosis index, myocardial LC3-Ⅰ and LC3-Ⅱ protein expression levels, and the ratio of LC3-Ⅱ/Ⅰ were significantly increased in the model group relevant to the sham operation group (P<0.05). After the treatment, the apoptosis index, the expression level of myocardial LC3-Ⅱ protein and the ratio of LC3-Ⅱ/Ⅰ were considerably down-regulated in the IP, EA and Moxi groups in comparison with those in the model group (P<0.05). The effect of EA was obviously superior to those of IP and Moxi in down-regulating the apoptosis index (P<0.05), but obviously inferior to those of IP and Moxi in down-regulating the levels of LC3-Ⅱ and LC3-Ⅱ/Ⅰ (P<0.05). No significant changes were found in the expression of LC3-Ⅰ after IP, EA and Moxi interventions in comparison with the model group (P>0.05), and no significant differences were observed in the apoptosis index and levels of LC3-Ⅱ and LC3-Ⅱ/Ⅰ between the IP and Moxi groups (P>0.05)．. CONCLUSION: Both EA and moxibustion pretreatments, similar to IP, have a positive role in reducing myocardiocyte apoptosis and regulating autophagy-related protein expression in MIRI rats, which maybe contribute to their protective effects on ischemic myocardium.

A Chinese 4-herb formula, Yiqi-Huoxue granule, alleviates H2O2-induced apoptosis by upregulating uncoupling protein 2 in H9c2 cells.

BACKGROUND: Although the protective effects of Yiqi-Huoxue granule (YQHX), a Chinese 4-herb formula, on patients with ischemic heart diseases are related to the attenuation of oxidative stress injury, the mechanism(s) underlying these actions remains poorly understood. PURPOSE: Our aim was to investigate the potential protective effects of YQHX treatment against oxidative stress induced by hydrogen peroxide (H2O2) in rat H9c2 cells. METHODS: H9c2 cells were treated with YQHX for 16 h before exposed to 200 µM H2O2 for 6 h. The apoptosis induced by H2O2 was measured using hoechst 33,342 staining and Annexin-V FITC/PI assay. The expression of uncoupling protein 2 (UCP2), Bcl-2, Bax, and caspase-3 were observed using western blot. The effects of UCP2 knockdown on cell apoptosis and intracellular ROS production were also investigated. RESULTS: H2O2 exposure led to significant activation of oxidative stress followed by increased apoptosis and ROS production, as well as decreased UCP2 expression in H9c2 cells. YQHX treatment at the concentration of 0.75 and 1.5 mg/ml remarkably reduced the expression of Bax and caspase-3, whereas increased the protein expression of Bcl-2 and UCP2. These changes were attenuated by transgenic knockdown of UCP2 with Lenti-shUCP2 vector. CONCLUSIONS: Taken together, our study demonstrated that YQHX attenuates H2O2-induced apoptosis by upregulating UCP2 expression in H9c2 Cells, suggesting that YQHX is a promising therapeutic approach for the treatment of I/R injury-mediated apoptosis.

Electroacupuncture and moxibustion pretreatments reduce cardiomyocyte apoptosis and autophagy in rats with myocardial ischemia/reperfusion injury / 针刺研究

OBJECTIVE: To observe the effect of "Neiguan" (PC6)-electroacupuncture (EA) or moxibustion (Moxi) pretreatment on myocardial apoptosis and expression of autophagy related proteins light chain (LC) 3-Ⅰ and LC3-Ⅱ in rats with myocardial ischemia/reperfusion injury (MIRI), so as to explore their mechanisms underlying improvement of MIRI. METHODS: Forty SD rats (half male and half female) were randomly divided into sham operation, model, ischemic preconditioning (IP), EA and Moxi groups (n＝8 in each group). EA (10 Hz/50 Hz, 1 mA) or Moxi (ignited moxa stick) was respectively applied to bilateral "Neiguan" (PC6) for 20 min, once daily for 7 days. The MIRI model was established by occlusion of the anterior descending branch of the left coronary artery for 40 min, followed by reperfusion for 60 min. The ultrastructural changes and autophagy of myocardial cells were observed by electron microscopy (EM), and the myocardial cellular apoptosis [apoptotic index ＝ (number of apoptotic cells/total number of cardiomyocytes)×100%] was detected by the terminal deoxyribonucleotidyl transferase mediated dUTP nick end labelling (TUNEL) method. The expressions of LC3-Ⅰ and LC3-Ⅱ proteins (markers for autophagy) in myocardial tissue were detected by Western blot. RESULTS: Following MI, EM observation revealed a vague structure of cardiomyocytes and muscular horizontal grain, dissolution of myofibers, mitochondrial swelling, some autophagic vacuoles and autophagic lysosomes at different degrees and surrounded by a double membrane in the model group, these situations were apparently milder in the EA and Moxi groups. The apoptosis index, myocardial LC3-Ⅰ and LC3-Ⅱ protein expression levels, and the ratio of LC3-Ⅱ/Ⅰ were significantly increased in the model group relevant to the sham operation group (P0.05), and no significant differences were observed in the apoptosis index and levels of LC3-Ⅱ and LC3-Ⅱ/Ⅰ between the IP and Moxi groups (P>0.05)．. CONCLUSION: Both EA and moxibustion pretreatments, similar to IP, have a positive role in reducing myocardiocyte apoptosis and regulating autophagy-related protein expression in MIRI rats, which maybe contribute to their protective effects on ischemic myocardium.

Panax notoginseng saponins attenuate cardiomyocyte apoptosis through mitochondrial pathway in natural aging rats.

Panax notoginseng saponins (PNS) have been widely used in the cardiovascular system for the treatment of cardiovascular diseases and stroke in China. In this study, we investigated the anti-apoptotic effect of PNS on cardiomyocytes in the natural aging rat and explored the potential mechanisms regarding oxidative stress and mitochondrial function signaling pathways. Male Sprague-Dawley rats were randomly divided into five groups: adult control (3-month old), aging control (24-month old), and different doses of PNS-treated aging rat groups (10, 30, 60 mg/kg/day, orally). After treatment of PNS or saline for 6 months, the effects of PNS on the cardiomyocytes were evaluated. Results showed that PNS significantly improved the morphological changes in myocardium, prevented the increase of cardiomyocyte apoptosis in the aging rats, and improved mitochondrial dysfunction associated aging in a dose-dependent manner. PNS also significantly reversed the down-regulation of FoxO3a and Mn-SOD and up-regulated PGC-1α, LC3ß, and Beclin-1 levels. Our data demonstrated that during aging, mitochondrial dysfunction caused an increase of oxidative damage, which played a key role in cardiomyocyte apoptosis. PNS exerted an anti-apoptotic effect via attenuating oxidative damage through oxidative stress- and mitochondrial function-related signaling pathways.

Quantitation of ß-carboline and quercetin in alligator weed (Alternanthera philoxeroides (Mart.) Griseb.) by LC-MS/MS and evaluation of cardioprotective effects of the methanol extracts.

Plant invasion is one of the major threats to natural ecosystems. The alligator weed grows rapidly within a small span of time and is easily available all over the world. ß-Carboline and quercetin are considered as excellent bioactive components of the alligator weed. In our study LC-MS/MS methods were performed for the detection and determination of the bioactive constituents, ꞵ-carboline and quercetin in leaves, in multiple reaction monitoring (MRM) mode. The effects of methanol extract on cardiomyocyte apoptosis induced by doxorubicin using H9c2 cells were evaluated by MTT assay and Annexin V-FITC/PI staining assay. A sensitive and selective liquid chromatography tandem mass spectrometry was developed and validated for the determination of ꞵ-carboline and quercetin in this plant. According to in vitro cell evaluation experiments, methanol extracts significantly prevented cardiomyocyte apoptosis induced by doxorubicin.

[Effect of saponins extracted from Panax japonicus on inhibiting cardiomyocyte apoptosis by AMPK/Sirt1/NF-κB signaling pathway in aging rats].

To investigate the effects of saponins extracted from Panax japonicus(SPJ) on cardiomyocyte apoptosis in natural aging rats and explore its underlying mechanisms. SD male rats were randomly divided into four groups: young control group, natural aging group, SPJ low dose group and SPJ high dose group, with 10 rats in each group. The rats in natural aging group, SPJ low and high dose groups were respectively treated with normal saline, SPJ 10 and 60 mg•kg-1•d-1 from the beginning of 18 month-old, 6 days per week for 6 months till 24 month-old. Then the animals were sacrificed. Their myocardial morphology changes were observed by using haematoxylin-eoin(HE) staining; cardiomyocyte apoptosis was tested by using Tunel assays; and the protein expression levels of Bcl-2, Bax, IL-1ß, TNF-α, AMPK, p-AMPK, Sirt1, and Ac-NF-κB p65 in myocardial tissues of rats were detected by Western blot. The results showed that SPJ could effectively improve the arrangement disorder of myocardial fibers, reduce the infiltration of inflammatory cells and inhibit cardiomyocyte apoptosis in natural aging rats. At the same time, SPJ could significantly inhibit the protein expression of Bax, IL-1ß, TNF-α and Ac-NF-κB p65, and increase the expression of Bcl-2, Bcl-2/Bax, p-AMPK/AMPK and Sirt1 in the heart tissues of natural aging rats. SPJ can effectively inhibit cardiomyocyte apoptosis in natural aging rats, and its mechanisms may be related with the regulation of inflammatory reaction by AMPK/Sirt1/NF-κB signaling pathway.

Analysis of electroacupuncturing Neiguan points on mitochondrial Ca2+ release and cardiomyocyte apoptosis of diabetic cardiomyopathy in rats / 国际中医中药杂志

Objective To investigate the influence of electroacupuncturing Neiguan points on mitochondrial Ca2+release and cardiomyocyte apoptosis of diabetic cardiomyopathy in rats. Methods 30 Wistar rats were randomly divided into a control group, a model group and a treatment group(10 in each group). In the treatment group, after eight weeks electroacupuncture Neiguan point treating diabetic cardiomyopathy in rats, the myocardium was quickly removed,mitochondrial was extracted,dual-beam UV spectrophotometer was adopted to detecting Ca2+transportation by testing Ca2+indicator A Ⅲ absorbance, and Cardiomyocyte apoptosis was evaluated by terminal-deoxynucleotidyl transferase mediated deoxy-UTP nick end labeling (TUNEL). Results Ca2+ indicator A Ⅲ absorbance detection(0.051±0.014) and cardiomyocyte apoptosis(0.49±0.36)were more depressed in the treatment group than in the model group[(0.077±0.025), (0.53±0.04)], there were significantly different(P<0.05) Conclusion Effect of Electroacupuncturing Neiguan points decreased myocardial apoptosis index in rats with diabetic cardiomyopathy, which may be related to the reduction of mitochondrial Ca2+influx.

Evaluation of antiobesity and cardioprotective effect of Gymnema sylvestre extract in murine model.

OBJECTIVE: Obesity plays a central role in the insulin resistance syndrome, which is associated with hyperinsulinemia, hypertension, hyperlipidemia, type 2 diabetes mellitus, and an increased risk of atherosclerotic cardiovascular disease. The present study was done to assess the effect of Gymnema sylvestre extract (GSE) in the high fat diet (HFD)-induced cellular obesity and cardiac damage in Wistar rats. MATERIALS AND METHODS: Adult male Wistar rats (150-200 g body weight) were used in this study. HFD was used to induce obesity. Body mass index, hemodynamic parameters, serum leptin, insulin, glucose, lipids, apolipoprotein levels, myocardial apoptosis, and antioxidant enzymes were assessed. Organ and visceral fat pad weights and histopathological studies were also carried out. RESULTS: Oral feeding of HFD (20 g/day) for a period of 28 days resulted in a significant increase in body mass index, organ weights, visceral fat pad weight, cardiac caspase-3, cardiac DNA laddering (indicating apoptotic inter-nucleosomal DNA fragment), and lipid peroxide levels of cardiac tissues of rats. Further, mean arterial blood pressure, heart rate, serum leptin, insulin, LDH, LDL-C, total cholesterol, triglycerides, and apolipoprotein-B levels were enhanced significantly, whereas serum HDL-C, apoliporotein-A1 levels, and cardiac Na(+) K(+) ATPase, antioxidant enzymes levels were significantly decreased. Furthermore, treatment with standardized ethanolic GSE (200 m/kg/p.o.) for a period of 28 days resulted in significant reversal of above mentioned changes in the obese Wistar rats. CONCLUSION: The present study has demonstrated the significant antiobesity potential of GSE in murine model of obesity.