Yanhua Xie

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.

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.

Paeonol and danshensu combination attenuates apoptosis in myocardial infarcted rats by inhibiting oxidative stress: Roles of Nrf2/HO-1 and PI3K/Akt pathway.

Paeonol and danshensu is the representative active ingredient of traditional Chinese medicinal herbs Cortex Moutan and Radix Salviae Milthiorrhizae, respectively. Paeonol and danshensu combination (PDSS) has putative cardioprotective effects in treating ischemic heart disease (IHD). However, the evidence for the protective effect is scarce and the pharmacological mechanisms of the combination remain unclear. The present study was designed to investigate the protective effect of PDSS on isoproterenol (ISO)-induced myocardial infarction in rats and to elucidate the potential mechanism. Assays of creatine kinase-MB, cardiac troponin I and T and histopathological analysis revealed PDSS significantly prevented myocardial injury induced by ISO. The ISO-induced profound elevation of oxidative stress was also suppressed by PDSS. TUNEL and caspase-3 activity assay showed that PDSS significantly inhibited apoptosis in myocardia. In exploring the underlying mechanisms of PDSS, we found PDSS enhanced the nuclear translocation of Nrf2 in myocardial injured rats. Furthermore, PDSS increased phosphorylated PI3K and Akt, which may in turn activate antioxidative and antiapoptotic signaling events in rat. These present findings demonstrated that PDSS exerts significant cardioprotective effects against ISO-induced myocardial infarction in rats. The protective effect is, at least partly, via activation of Nrf2/HO-1 signaling and involvement of the PI3K/Akt cell survival 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.

Pharmacokinetic study of cinnamaldehyde in rats by GC–MS after oral and intravenous administration

A selective and sensitive method utilizing gas chromatography-mass spectrometry was developed for simultaneous determination of cinnamaldehyde, cinnamyl alcohol, and methyl cinnamate in rat plasma. Cinnamaldehyde and cinnamyl alcohol can inter-convert to one another in rats, thus simultaneous quantifying both analytes provided a reliable and accurate method of assessment. Three qualifying ions (131 m/z, 105 m/z and 92 m/z) were chosen for simultaneous quantification of cinnamaldehyde and its metabolites. In this study, the calibration curves demonstrated a good linearity and reproducibility over the range of 20-2000ng/ml (r(2)≥0.999) for all analytes. Furthermore, the sensitivity of gas chromatography-mass spectrometry revealed sufficient lower limit of quantitation and detection of 20ng/ml and 5ng/ml, respectively, in the pharmacokinetic analysis. The intra- and inter-day precision variations were less than 10.4% and 12.2%, respectively, whilst accuracy values ranged from -8.6% to 14.8%. All analytes were stable in plasma and in processed samples at room temperature for 24h with no significant degradation after three freeze/thaw cycles. A small amount of the administered cinnamaldehyde had long half-life of 6.7±1.5h. In this study, gas chromatography-mass spectrometry was demonstrated to be a powerful tool for the pharmacokinetic studies of rats after intravenous and oral administration of cinnamaldehyde.

The Bone-Protective Effect of Genistein in the Animal Model of Bilateral Ovariectomy: Roles of Phytoestrogens and PTH/PTHR1 Against Post-Menopausal Osteoporosis

Genistein, a major phytoestrogen of soy, is considered a potential drug for the prevention and treatment of post-menopausal osteoporosis. Mounting evidence suggested a positive correlation between genistein consumption and bone health both in vivo and in vitro. Earlier studies have revealed that genistein acted as a natural estrogen analogue which activated estrogen receptor and exerted anti-osteoporotic effect. However, it remains unclear whether PTH, the most crucial hormone that regulates mineral homeostasis, participates in the process of genistein-mediated bone protection. In the present study, we compared the therapeutic effects between genistein and nilestriol and investigated whether PTH and its specific receptor PTHR1 altered in response to genistein-containing diet in the animal model of ovariectomy. Our results showed that genistein administration significantly improved femoral mechanical properties and alleviates femoral turnover. Genistein at all doses (4.5 mg/kg, 9.0 mg/kg and 18.0 mg/kg per day, respectively) exerted improved bending strength and b-ALP limiting effects than nilestriol in the present study. However, genistein administration did not exert superior effects on bone protection than nilestriol. We also observed circulating PTH restoration in ovariectomized rats receiving genistein at the dose of 18 mg/kg per day. Meanwhile, PTHR1 abnormalities were attenuated in the presence of genistein as confirmed by RT-PCR, Western blot and immunohistochemistry. These findings strongly support the idea that besides serving as an estrogen, genistein could interact with PTH/PTHR1, causing a superior mineral restoring effect than nilestriol on certain circumstance. In conclusion, our study reported for the first time that the anti-osteoporotic effect of genistein is partly PTH/PTHR1-dependent. Genistein might be a potential option in the prevention and treatment of post-menopausal osteoporosis with good tolerance, more clinical benefits and few undesirable side effects.

Effect of Salvianolic Acid b and Paeonol on Blood Lipid Metabolism and Hemorrheology in Myocardial Ischemia Rabbits Induced by Pituitruin

The purpose of this study was to determine the therapeutic effect of salvianolic acid b and paeonol on coronary disease. The ischemia myocardial animal model is induced by administering pituitrin (20 μg·kg−1) intravenously via the abdominal vein. A combination of salvianolic acid b and paeonol (CSAP) (5, 10 and 15 mg/kg BW) was administrated to experimental rabbits. Biochemical indices were evaluated during six weeks of intervention. We found that the compound of salvianolic acid b and paeonol (5, 10 and 15 mg/kg BW) can markedly and dose-dependently reduce fibrinogen and malonaldehyde levels, increase the HDL level, improve blood viscosity and plasma viscosity in rabbits. In addition, the medicine can still reduce the ratio of NO/ET and the contents of lactate dehydrogenase (LDH) and creatine phosphokinase (CPK) in a dose-dependent manner. This study demonstrates that compound of salvianolic acid b and paeonol (5, 10 and 15 mg/kg BW) can improve the blood hemorrheology, decrease oxidative injury and repair the function of blood vessel endothelium, and subsequently prevent the development of Coronary disease.