Siwang Wang

Cardioprotective Effect of Paeonol and Danshensu Combination on Isoproterenol-Induced Myocardial Injury in Rats

Background Traditional Chinese medicinal herbs Cortex Moutan and Radix Salviae Milthiorrhizaeare are prescribed together for their putative cardioprotective effects in clinical practice. However, the rationale of the combined use remains unclear. The present study was designed to investigate the cardioprotective effects of paeonol and danshensu (representative active ingredient of Cortex Moutan and Radix Salviae Milthiorrhizae, respectively) on isoproterenol-induced myocardial infarction in rats and its underlying mechanisms. Methodology Paeonol (80 mg kg−1) and danshensu (160 mg kg−1) were administered orally to Sprague Dawley rats in individual or in combination for 21 days. At the end of this period, rats were administered isoproterenol (85 mg kg−1) subcutaneously to induce myocardial injury. After induction, rats were anaesthetized with pentobarbital sodium (35 mg kg−1) to record electrocardiogram, then sacrificed and biochemical assays of the heart tissues were performed. Principal Findings Induction of rats with isoproterenol resulted in a marked (P<0.001) elevation in ST-segment, infarct size, level of serum marker enzymes (CK-MB, LDH, AST and ALT), cTnI, TBARS, protein expression of Bax and Caspase-3 and a significant decrease in the activities of endogenous antioxidants (SOD, CAT, GPx, GR, and GST) and protein expression of Bcl-2. Pretreatment with paeonol and danshensu combination showed a significant (P<0.001) decrease in ST-segment elevation, infarct size, cTnI, TBARS, protein expression of Bax and Caspase-3 and a significant increase in the activities of endogenous antioxidants and protein expression of Bcl-2 and Nrf2 when compared with individual treated groups. Conclusions/Significance This study demonstrates the cardioprotective effect of paeonol and danshensu combination on isoproterenol-induced myocardial infarction in rats. The mechanism might be associated with the enhancement of antioxidant defense system through activating of Nrf2 signaling and anti-apoptosis through regulating Bax, Bcl-2 and Caspase-3. It could provide experimental evidence to support the rationality of combinatorial use of traditional Chinese medicine in clinical practice.

The in vitro and in vivo antiviral effects of salidroside from Rhodiola rosea L. against coxsackievirus B3

The aim of this study was to investigate the antiviral effects of salidroside, a major component of Rhodiola rosea L. First, the antiviral effects of salidroside against coxsackievirus B3 (CVB3) were determined in vitro and in vivo. Then, the effect of salidroside on the mRNA expression of some important cytokines was measured in hearts of infected BALB/c mice by RT-PCR. Salidroside exhibited obvious antiviral effects both in in vitro and in vivo experiments. Salidroside was found to modulate the mRNA expression of interferon-gamma (IFN-gamma), interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-alpha), and interleukin-2 (IL-2). In conclusion, salidroside possesses antiviral activities against CVB3 and it may represent a potential therapeutic agent for viral myocarditis.

Cardioprotective effect of polydatin against ischemia/reperfusion injury: Roles of protein kinase C and mito KATP activation

Polydatin preconditioning (PPC) has been reported to be protective against brain and intestine ischemia/reperfusion injury (I/R injury), but whether polydatin exerts cardioprotective effect against myocardial ischemia/reperfusion and the underlying mechanisms remain unclear. Previous studies have demonstrated that oxidative stress plays an important role in the process of I/R. Elevation of oxidative agents and decline in anti-oxidant substance would promote I/R. Meanwhile, the activation of PKC signaling seems to mediate the cardioprotective effects of many drugs by alleviating Ca(2+) influx. In the present study, we reported for the first time that intravenous administration of polydatin before I/R significantly limited the infarct size, creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) leakage from the damaged myocardium after I/R. The activity of SOD and the content of MDA remarkably changed in the presence of polydatin as well. However, the cardiac function-preserving and myocardial enzymes leakage-limiting effects of polydatin vanished in the presence of PKC inhibitors and mito K(ATP) channel blockers. But there was not a significant change in the activity of SOD and MDA content. We therefore conclude that PPC exerts cardioprotective effect by the activation of PKC-K(ATP)-dependent signaling and the direct anti-oxidative stress mechanisms.

Suppressive effects of swainsonine on C6 glioma cell in vitro and in vivo

Swainsonine, an extract from Astragalus membranaceus, is known for its anti-cancer effects and could prevent metastases. In order to investigate the effects and mechanisms of swainsonine in C6 glioma cells, we carry out correlated experiments in vitro and in vivo. After treatment with swainsonine, the effective dose and IC(50) value of swainsonine in the C6 glioma cell were examined using the MTT assay. Cell cycle distribution and apoptotic rates were analyzed using FCM and [Ca(2+)](i) was measured by LSCM. Expressions of p16 and p53 protein were evaluated by immunocytochemical methods. Simultaneously, glioma-bearing rats were administered swainsonine at doses of 2, 4 and 8 mg/kg body wt. The inhibition rate was calculated and pathological sections were observed. The results indicated that the growth of C6 glioma cells is inhibited by swainsonine in vitro, with an IC(50) value within 24h of 0.05 microg/ml. Increases in swainsonine correlate with S phase percentages of 11.3%, 11.6% and 12.4%, respectively. Moreover, the expression of apoptosis inhibiting p53 and p16 protein decreases gradually. Tumor weight in vivo decreased clearly and HE dyeing of tumor tissue showed gray, its texture was soft, with necrosis and hemorrhagic concentrated inward. Swainsonine could inhibit the proliferation of C6 glioma cells in vitro and the growth of C6 glioma in vivo. The mechanisms of swainsonine-induced apoptosis may relate with the expression of apoptosis-related genes and overloading-[Ca(2+)](i)-induced endoplasmic reticulum stress.

HPLC analysis of Ganoderma lucidum polysaccharides and its effect on antioxidant enzymes activity and Bax, Bcl-2 expression

The polysaccharides from Ganoderma lucidum (GLP) were prepared using boiling water extraction methods. High performance liquid chromatography (HPLC) showed that GLP was composed of five monosaccharides and disaccharides, including xylose, fructose, glucose, sucrose and maltose, were identified for polysaccharides from Ganoderma lucidum. The relative molar percentages of xylose, fructose, glucose, sucrose and maltose in polysaccharides from Ganoderma lucidum were 0.4%, 14.4%, 12.8%, 0.7% and 50.9%, respectively. GLP (100, 200, 300mg/kg) was administered to diabetic rats. Effect of extract on antioxidant enzymes activities and lipid peroxidation levels of pancreas was studied in diabetic rats. The mechanism of anti-apoptosis of GLP in STZ-induced diabetic rats was further investigated using Bax/Bcl-2 ratio and protein. Result showed that GLP extracts effectively reduced oxidative injury and inhibited apoptosis by increasing antioxidant enzyme activities and modifying bcl-2 expression and bax/bcl-2 ratio. The GLP extract exhibited potent antioxidant effect in vivo. The effect can contribute, at least in part, to the inhibition of apoptosis.

Neuroprotective effects of tetramethylpyrazine against dopaminergic neuron injury in a rat model of Parkinson's disease induced by MPTP.

Parkinsons disease (PD) is the second most prevalent progressive neurodegenerative disease. Although several hypotheses have been proposed to explain the pathogenesis of PD, apoptotic cell death and oxidative stress are the most prevalent mechanisms. Tetramethylpyrazine (TMP) is a biological component that has been extracted from Ligusticum wallichii Franchat (ChuanXiong), which exhibits anti-apoptotic and antioxidant roles. In the current study, we aimed to investigate the possible protective effect of TMP against dopaminergic neuron injury in a rat model of Parkinsons disease induced by MPTP and to elucidate probable molecular mechanisms. The results showed that TMP could notably prevent MPTP-induced dopaminergic neurons damage, reflected by improvement of motor deficits, enhancement of TH expression and the content of dopamine and its metabolite, DOPAC. We observed MPTP-induced activation of mitochondrial apoptotic death pathway, evidenced by up-regulation of Bax, down-regulation of Bcl-2, release of cytochrome c and cleavage of caspase 3, which was significantly inhibited by TMP. Moreover, TMP could prevent MPTP-increased TBARS level and MPTP-decreased GSH level, indicating the antioxidant role of TMP in PD model. And the antioxidant role of TMP attributes to the prevention of MPTP-induced reduction of Nrf2 and GCLc expression. In conclusion, in MPTP-induced PD model, TMP prevents the down-regulation of Nrf2 and GCLc, maintaining redox balance and inhibiting apoptosis, leading to the attenuation of dopaminergic neuron damage. The effectiveness of TMP in treating PD potentially leads to interesting therapeutic perspectives.

The effect of hyperoside on the functional recovery of the ischemic/reperfused isolated rat heart: Potential involvement of the extracellular signal-regulated kinase 1/2 signaling pathway

One of the leading causes of death in the world is ischemia/reperfusion (I/R)-mediated acute myocardial infarction. There are a lot of Chinese traditional patent medicines, such as Xinan capsules, Xin Xuening tablets, and so on, which have protective effects against myocardial I/R injury and have been routinely used in treating cardiac diseases for a long time in China. Hyperoside (Hyp) is the chief component of these medicines. This study investigated the action of Hyp in isolated myocardial I/R injury, as well as its possible mechanisms. Using the Langendorff model, isolated Sprague-Dawley rat hearts were subjected to 30 min of global ischemia and 50 min of reperfusion. Cardiac function was measured, and infarct size was evaluated by triphenyltetrazolium chloride staining at the end of the reperfusion. Coronary effluent was analyzed for lactate dehydrogenase (LDH) and creatine kinase (CK). Myocardium was also measured for total superoxide dismutase (SOD) activity and malondialdehyde (MDA) content. Phosphorylation of extracellular signal-regulated protein kinase (ERK) was analyzed by Western blotting. We report for the first time that administration of Hyp before/after I/R significantly improved heart contraction and limited the infarct size and CK and LDH leakage from the damaged myocardium after I/R. The activity of SOD and the MDA content remarkably changed in the presence of Hyp as well. Phosphorylation of ERK was significantly increased in Hyp-treated hearts compared to controls (p<0.01). Hyp-induced ERK phosphorylation was inhibited by PD98059. We therefore conclude that Hyp can protect cardiomyocytes from I/R-induced oxidative stress through the activation of ERK-dependent signaling.

Protective effects of hyperoside against human umbilical vein endothelial cell damage induced by hydrogen peroxide

ETHNOPHARMACOLOGICAL RELEVANCEnHyperoside (Hyp) is a flavonoid compound isolated from Rhododendron ponticum L. leaves that elicits vascular protective effects in vitro. Treatment with Hyp has been found to attenuate endothelial cell damage induced by oxidative stress, but its mechanisms of action remain unclear. This study investigated the action of Hyp in an endothelial injury model induced by hydrogen peroxide (H(2)O(2)), as well as its possible mechanisms.nnnMATERIALS AND METHODSnHuman umbilical vein endothelial cells (HUVECs) were treated with H(2)O(2) alone or in combination with Hyp. The protective effects of Hyp against H(2)O(2) were evaluated, and the activation of extracellular signal-regulated protein kinase (ERK) in Hyp was assayed in HUVECs.nnnRESULTSnLoss of cell viability as well as excessive cell apoptosis and death were observed in HUVECs after 18 h of challenge with H(2)O(2) (400μM); however, both cell apoptosis and death were attenuated in the Hyp-pretreated cells. Western blot analysis revealed that Hyp increased the expression of Bcl-2 but decreased that of Bax. In addition, Hyp induced the phosphorylation of ERK1/2 in HUVECs.nnnCONCLUSIONnThese observations provide preliminary evidence that Hyp protects HUVECs against H(2)O(2) damage, at least partially, by activating the ERK signaling pathway.

Anticancer Effects of Bufalin on Human Hepatocellular Carcinoma HepG2 Cells: Roles of Apoptosis and Autophagy

The traditional Chinese medicine bufalin, extracted from toad’s skin, has been demonstrated to exert anticancer activities in various kinds of human cancers. The mechanisms of action lie in its capacity to induce apoptosis, or termed type I programmed cell death (PCD). However, type II PCD, or autophagy, participates in cancer proliferation, progression, and relapse, as well. Recent studies on autophagy seem to be controversial because of the dual roles of autophagy in cancer survival and death. In good agreement with previous studies, we found that 100 nM bufalin induced extensive HepG2 cell apoptosis. However, we also noticed bufalin triggered autophagy and enhanced Beclin-1 expression, LC3-I to LC3-II conversion, as well as decreased p62 expression and mTOR signaling activation in HepG2 cells. Blockage of autophagy by selective inhibitor 3-MA decreased apoptotic ratio in bufalin-treated HepG2 cells, suggesting a proapoptotic role of bufalin-induced autophagy. Furthermore, we investigated the underlying mechanisms of bufalin-induced autophagy. Bufalin treatment dose-dependently promoted AMPK phosphorylation while AMPK inhibition by compound C significantly attenuated bufalin-induced autophagy. Taken together, we report for the first time that bufalin induces HepG2 cells PCD, especially for autophagy, and the mechanism of action is, at least in part, AMPK-mTOR dependent.

Burn-induced apoptosis of cardiomyocytes is survivin dependent and regulated by PI3K/Akt, p38 MAPK and ERK pathways

Survivin belongs to the family of genes known as inhibitors of apoptosis, and although it has been implicated in the prevention of cancer, its potential role in burn-induced cardiac injury is unknown. In this study, we investigated the effects of survivin blockade on burn-induced cardiac apoptosis. Using a standardized Sprague-Dawley rat model of third-degree burn injury over 40% of total body surface area, apoptosis was measured in vivo followed by in vitro assessment of burn serum-stimulated cardiomyocytes. Based on the Western blot analyses, real-time PCR, ELISA, and TUNEL, apoptosis and caspase activation both in vivo and in vitro were significantly increased after severe burn injury, while survivin expression was increased (up to 2.90-fold) during the early stage of burn injury and was almost completely abolished 8xa0h after the burn. Survivin-deficient cardiomyocytes, as well as hearts from rats treated with the survivin inhibitor YM155, exhibited increased caspase-3 protein and mRNA expression and apoptosis ratio at different times after the burn. Furthermore, inhibition of ERK, phosphoinositol 3-kinase contributed the burn serum-induced increase in apoptosis and caspase-3 protein expression, and decreased survivin expression, whereas burn serum-induced increase in apoptosis was attenuated by P38 mitogen-activated protein kinase inhibition. These data identify survivin as a critical anti-apoptotic regulator of cardiomyocytes after burn injury. ERK, P38 MAPK and PI3K were found to be upstream regulators of survivin.