[Clinical efficacy and mechanism of total glucosides from white paeony for radioactive liver damage].

To discuss the effects of total glucosides from white paeony on preventing and treating radioactive liver damage, and explore its possible mechanisms. Thirty-six patients with primary hepatic carcinoma from 105th Hospital of Chinese PLA were treated with 3-dimensional conformal radiotherapy and randomly divided into simple irradiation group, total glucosides from white paeony group, and control group. The levels of AST, ALT, HA, LN, PCⅢ, CIV and TGF-ß1 in serum of various groups were determined by using ELISA method. As compared with the simple irradiation group and control group, total glucosides from white paeony could obviously decrease the levels of AST, ALT, HA, LN, PCⅢ, CIV and TGF-ß1(P<0.05, P<0.01). The results showed that the total glucosides from white paeony could effectively prevent and treat radioactive liver damage, and its mechanism might be associated with decreasing the levels of TGF-ß1, and inhibiting the synthesis of collagen synthesis.

Acid-sensing ion channel 1a contributes to the effect of extracellular acidosis on NLRP1 inflammasome activation in cortical neurons.

BACKGROUND: Acid-sensing ion channels (ASICs) are cation channels which were activated by extracellular acidosis and involved in various physiological and pathological processes in the nervous system. Inflammasome is a key component of the innate immune response in host against harmful and irritable stimuli. As the first discovered molecular platform, NLRP1 (nucleotide-binding oligomerization domain (NOD)-like receptor protein 1) inflammasome is expressed in neurons and implicated in many nervous system diseases such as brain injury, nociception and epilepsy. However, little is known about the effect of ASICs on NLRP1 inflammasome activation under acidosis. METHODS: The expression of inflammasome complex protein (NLRP1, ASC (apoptosis-associated speck-like protein containing a caspase-activating recruitment domain) and caspase-1), inflammatory cytokines (IL-1ß and IL-18), and apoptosis-related protein (Bax, Bcl-2, and activated caspase-3) was detected by Western blot. Large-conductance Ca(2+) and voltage-activated K(+) (BK) channel currents were recorded by whole-cell patch-clamp technology. Measurement of [K(+)] i was performed by fluorescent ion imaging system. Co-expression of ASICs and BK channels was determined by dual immunofluorescence. Cell viability was assessed by MTT and LDH kit. RESULTS: ASICs and BK channels were co-expressed in primary cultured cortical neurons. Extracellular acidosis increased the expression of NLRP1, ASC, caspase-1, IL-1ß, and IL-18. Further mechanistic studies revealed that acidosis-induced ASIC1a activation results in the increase of BK channel currents, with the subsequent K(+) efflux and a low concentration of intracellular K(+), which activated NLRP1 inflammasome. Furthermore, these effects of acidosis could be blocked by specific ASIC1a inhibitor PcTX1 and BK channel inhibitor IbTX. The data also demonstrated neutralization of NLRP1-protected cortical neurons against injury induced by extracellular acidosis. CONCLUSIONS: Our data showed that NLRP1 inflammasome could be activated by extracellular acidosis though ASIC-BK channel K(+) signal pathway and was involved in extracellular acidosis-induced cortical neuronal injury.

MicroRNA-29b promotes high-fat diet-stimulated endothelial permeability and apoptosis in apoE knock-out mice by down-regulating MT1 expression.

BACKGROUND: High-fat diet has been reported to be associated with cardiovascular diseases which is implicated in atherosclerosis. However, the underlying mechanisms remain unknown. MicroRNAs (miRNAs) are non-coding small RNAs that control gene expression at the post-transcriptional level. Dysregulated miRNAs have been shown to be involved in atherosclerosis. METHODS AND RESULTS: This study examined whether microRNA-29b (miR-29b) regulates high-fat diet induced endothelial permeability and apoptosis by targeting MT1, a known melatonin membrane receptor. In apoE knock-out mice, a high-fat diet increased miR-29b expression and induced apoptosis as determined by up-regulation of caspase-3 activity. However, a standard diet did not alter apoptosis. miR-29b antagomir decreased endothelial permeability and apoptosis in high-fat diet-stimulated mice. In contrast, a miR-29b mimic enhanced endothelial permeability and apoptosis. The induction of miR-29b correlated with a reduction in Bcl-2 and MT1 in high-fat diet-stimulated mice. miR-29b have an effect on the marker of inflammation (NF-κB) and cell adhesion molecule (ICAM-1). We further showed that miR-29b targeted and inhibited MT1 expression through a target site located in the 3'un-translational region of MT1 mRNA. This study demonstrates a role of miR-29b in atherosclerosis and identifies MT1 as a direct target of miR-29b. CONCLUSIONS: The effect of miR-29b on endothelial permeability and apoptosis is mediated through the down-regulation of MT1. Thus, miR-29b may be a new therapeutic target for atherosclerosis.

MicroRNA1 modulates oxLDL-induced hyperlipidemia by down-regulating MLCK and ERK/p38 MAPK pathway.

AIMS: This study was aimed to determine whether microRNA1 (miR1) plays a role in the activation of myosin light chain kinase (MLCK) mediated by oxLDL in human umbilical vein endothelial cells (HUVECs). MAIN METHODS: HUVECs were treated with oxLDL along with a control miR or miR1 mimic. MiR1 expression was assayed by miRNA plate assay kit and mirVana™ miRNA isolation kit. The MLCK protein, transcript, and kinase activity were measured by Western blot, real-time-polymerase chain reaction and γ-(32)P-ATP phosphate incorporation, respectively. In addition, phosphorylation of MLC, ERK and p38 was analyzed by Western blot. KEY FINDINGS: The results showed that upon treatment with oxLDL, miR1 expression was decreased, whereas MLCK expression was increased, in a time- and dose-dependent manner. Consistent with this, miR1 mimic prevented MLCK expression and activation and attenuated the phosphorylation of MLC and ERK/p38 in oxLDL-treated HUVECs. Furthermore, we showed that miR1 was able to bind a site located at the 3'un-translational region of MLCK mRNA and inhibited its expression. SIGNIFICANCE: Taken together, this study demonstrated that the effect of miR1 on hyperlipidemia is mediated through down-regulation of MLCK and the ERK/p38 MAPK pathway.

Cardioprotection of vitexin on myocardial ischemia/reperfusion injury in rat via regulating inflammatory cytokines and MAPK pathway.

This study was conducted to demonstrate myocardial protective effects and possible underlying mechanisms of vitexin on myocardial ischemia/reperfusion (I/R) injury in rats. Occluding the anterior descending artery for 30 min and restoring blood perfusion for 60 min in rat established a model of myocardial I/R. The elevation of the ST segment of Electrocardiograph (ECG) was observed. The infarct size of the rat heart was assessed by triphenyltetrazolium chloride staining (TTC). LDH, CK, SOD activities and MDA content were determined. An immunohistochemical analysis was applied to measure the expression of myocardial NF-κBp65 and TNF-α. ERK/phospho-ERKand c-Jun/phospho-c-Jun protein expression was examined via Western Blot. Vitexin significantly reduced the elevation of the ST segment of ECG and myocardial infarct size. LDH and CK activities and MDA content were attenuated in serum, while SOD activity was markedly enhanced. Vitexin significantly attenuated I/R-induced increases of myocardial NF-κB and TNF-α. Moreover, Western Blot analysis presented that vitexin markedly enhanced the expression of phospho-ERK and weakened the expression of phospho-c-Jun compared to I/R group. The significant protective effect against myocardial ischemical/reperfusion injury in rat, which is exhibited by vitexin, may be related to its antioxidative and anti-inflammatory effects by regulating inflammatory cytokines and the MAPK pathway.

[Protection and mechanism of Fagopyrum cymosum on lung injury in rats with Klebsiella pneumonia].

OBJECTIVE: To study the mechanism of protective effect of Fagopyrum cymosum on lung injury induced by Klebsiella pneumonia in rats. METHODS: The model of rats with Klebsiella pneumonia was established. The male SD rats were randomly divided into control group, model group, Fagopyrum cymosum (6, 3, 1.5 g/kg) three groups, levofloxacin (25 mg/kg) group. The pathological change of lung was observed. The content of IL-1beta, IL-6, IL-8, TNF-alpha, ICAM-1, INF-gamma in serum were measured by radioimmunoassay and Elisa. TNF-alpha, ICAM-1, NF-kappaB p65 protein expressions were measured by immunohistochemistry. MIP-2mRNA expression was detected by in situ hybridization. RESULTS: The rats of model group had obvious lung injury, but those of Fagopyrum cymosum and levofloxacin groups had less injury. The contents of IL-1beta, IL-6, IL-,8, TNF-alpha, ICAM-1 and INF-gamma in serum and the expressions of TNF-a, ICAM-1, NF-kappaB p65 and MIP--2mRNA of model group were significantly higher than those of the control group (P < 0.05 or P < 0.01), while the indexes of Fagopyrum cymosum and levofloxacin groups were significantly lower than those of model group (P < 0.05 or P < 0.01). CONCLUSION: The lung injury induced by Klebsiella pneumonia is related to TNF-alpha, ICAM-1, NF-kappaB p65 and MIP-2mRNA. To decrease the excessive expression of TNF-alpha, ICAM-1, NF-kappaB p65 and MIP-2mRNA might be the main mechanism of protective effect of Fagopyrum cymosum on lung injury.

Effects of Wy14643 on hepatic ischemia reperfusion injury in rats.

AIM: To investigate the effects and possible mechanisms of Wy14643 on hepatic ischemia-reperfusion (I/R) injury in rats. METHODS: Thirty male Sprague-Dawley rats weighing 220-280 g were randomly divided into five experimental groups: sham group (G1, n=6): a sham operation was performed (except for liver I/R); I/R-untreated group (G2, n=6): rats underwent liver ischemia for 90 min followed by reperfusion for 4 h; and I/R+Wy14643 groups (G3, G4, G5; n=6): after the same surgical procedure as in group 2, animals were pretreated with Wy14643 at the dose of 1, 5 and 10 mg/kg 1 h before ischemia, respectively. Hepatic ischemia-reperfusion (I/R) was induced by clamping blood supply to the left lateral and median lobes of the liver for 90 min, and atraumatic clamp was removed for 4 h reperfusion. Blood samples and liver tissues were obtained at the end of reperfusion to assess serum and hepatic tissue homogenate aminotransferase (ALT), aspartate aminotransferase (AST), myeloperoxidase (MPO), serum interleukin-1beta (IL-1beta) and tumor necrosis factor alpha (TNF-alpha), as well as activity of superoxide dismutase (SOD) and content of malondialdehyde (MDA) in the hepatic tissue homogenate. RESULTS: Hepatic I/R induced a significant increase in the serum levels of ALT, AST, TNF-alpha, IL-1beta and MPO, as well as the levels of ALT, AST and MDA in the liver tissue homogenate, which were reduced by pretreatment with Wy14643 at the dose of 1, 5 and 10 mg/kg, respectively. The activity of SOD in the liver tissue homogenate was decreased after hepatic I/R, which was enhanced by Wy14643 pretreatment. In addition, serum and liver tissue homogenate ALT and AST in the Wy14643 10 mg/kg group were lower than in the Wy14643 1 mg/kg and 5 mg/kg groups, respectively. CONCLUSION: Wy14643 pretreatment exerts significant protection against hepatic I/R injury in rats. The protective effects are possibly associated with enhancement of anti-oxidant and inhibition inflammation response.

[Protective effect of injection of Danhong against acute myocardial ischemia in dogs].

OBJECTIVE: To investigate the protective effects of injection of Danhong against acute myocardial ischemia in dogs. METHOD: The myocardial ischemia model were established by ligation of coronary artery in dogs. The degree of myocardial ischemia and the myocardial infarction size were observed before and after giving injection of Danhong. The serum creatine phosphokinase (CK) and lactate dehydrogenase (LDH) activities were also determined. RESULT: Injection of Danhong (1, 2, 4 g x kg(-1)) could significantly decreased the damage degree of myocardial ischemia, redused myocardial infarction size and also reduced the serum LDH and CK activities. CONCLUSION: Injection of Danhong had protective action on myocardial ischemia.

Mechanisms of vitexin preconditioning effects on cultured neonatal rat cardiomyocytes with anoxia and reoxygenation.

This study was aimed at investigating the protective effect and mechanism of vitexin preconditioning (VPC) on cultured neonatal rat cardiomyocytes after anoxia and reoxygenation (A/R). An A/R model was established by using cultured neonatal rat cardiomyocytes. Cellular injury was evaluated by measuring cell viability, the releases of creatine kinase (CK), and lactate dehydrogenase (LDH). The apoptosis rate of cardiomyocytes after Anoxia/reoxygenation and the activities of extracellular signal-regulated protein kinases (ERKs) were measured. The intracellular calcium indicated by the fluorescence in cardiomyocytes was measured by the laser confocal microscope. Vitexin preconditioning (10, 30 and 100 microM) significantly enhanced the cell viability, markedly inhibited A/R-induced increases of LDH and CK release, obviously decreased the number of apoptotic cardiomyocytes and markedly decreased the fluorescence intensity value of [Ca(2+)](i) in cardiomyocytes. Exposure to anoxia or vitexin preconditioning significantly increased the phospho-ERK level, and the increase was markedly inhibited by PD98059, an inhibitor of the upstream kinase of ERK. These results suggest that vitexin preconditioning has a protective effect on cardiomyocytes A/R injury through the improvement of cell viability, decrease of LDH and CK release, such that the protective mechanism may relate to its ability to inhibit the cardiomyocytes apoptosis, reduce the cardiomyocytes calcium overload and increase the abundance of phosphor-ERK1/2 of the cardiomyocytes after anoxia and reoxygenation.

Protective effect of total flavones of rhododendra on ischemic myocardial injury in rabbits.

This study was to investigate the effect of total flavones of rhododendra (TFR) on ischemic myocardial injury in rabbits. Rabbit ischemic myocardial injury was induced by occluding the anterior descent of the left artery (LAD). The ECG was recorded; the plasma creatine kinase (CK), nitric oxide (NO) and endothelin-1 (ET-1) levels were measured using spectrophotometry, Griess method and radioimmunoassay, respectively. The myocardial ischemic size and infarction size were determined by dual staining with Evan's blue and Nitroblue tetrazolium reductionest (N-BT). A typical ECG S-T segment elevation and an increase of plasma CK activity were observed 6 and 24 hours after the induction of ischemia. These changes were inhibited in rabbits treated with either TFR (30, 60 mg/kg) or ginkgo biloba extract (EGB) for 7 days, indicating a protective effect of TFR on ischemic myocardial injury. The myocardial ischemic size and infarction size were 40.7 +/- 3.6% and 36.8 +/- 3.6% respectively in the control group, while TFR (60 mg/kg) pretreatment for 7 days significantly reduced both myocardial ischemic size (32.40 +/- 5.38%, p < 0.05) and infarction size (28.7 +/- 5.8%, p < 0.05). In addition, the occlusion of LAD resulted in an increase of ET-1 and a decrease of NO levels in the plasma, effects that were inhibited by TFR treatment, suggesting a possible mechanism for the protective effect of TFR against myocardial ischemic injury.

Inhibitory effect of total flavone of Abelmoschus manihot L. Medic on NMDA receptor-mediated current in cultured rat hippocampal neurons.

The modulatory effect of Total Flavone of Abelmoschus manihot L. Medic (TFA) on NMDA-activated current (I(NMDA)) was investigated in cultured rat hippocampal neurons using the whole-cell patch-clamp technique. TFA rapidly and reversibly inhibited the I(NMDA) in a concentration-dependent manner. Furthermore, TFA non-competitively inhibited the I(NMDA) by enhancement of the NMDA receptor desensitization. In addition, intracellular application of TFA did not alter the TFA inhibition of I(NMDA). These results suggest that the inhibition of the NMDA receptor response by TFA could be one of the mechanisms for TFA-mediated neuroprotective actions.

Effects of total flavone of Abelmoschl Manihot L. Medic on the function of platelets and its mechanism.

OBJECTIVE: To study the effects of total flavone of Abelmoschl Manihot L. Medic (TFA) on the function of platelets and to explore its mechanism. METHODS: Rat models of artery-veins bypassing thrombus formation were used. The platelets of rabbits were collected. Platelet aggregation was induced by collagen and intracellular calcium ion concentration ([Ca(2+)]i) was assayed by Fura-2 method. RESULTS: TFA (25, 50, 100 mg/kg) significantly and dose-dependently reduced the weight of thrombus. TFA (0.025, 0.05, 0.1 mg/ml) possessed dose-dependant inhibitory effects on rabbits' platelet aggregation induced by collagen. TFA significantly reduced the resting and CaCl(2)-induced increase of free intracellular calcium concentration ([Ca(2+)]i) in rabbit platelet in vitro. CONCLUSION: TFA has an antiplatelet effect via the inhibition on the influx of Ca(2+).

[Anti-aging action of the total lactones of ginkgo on aging mice].

AIM: To investigate the effects of total lactones of ginkgo on aging by using D-galactose induced aging mice and natural aging mice. METHODS: By using D-galactose induced aging mice, to detect the LF content in heart and liver, the Hyp content in liver, the MAO, GSH-Px activities and the NO content in cerebrum. The apoptosis of cerebral cell was determined by terminal deoxy-nucleotidyl transforase-mediated dUTP-digoxigenin nick end-labeling (Tunel) in natural aging mice. RESULTS: TLG was shown to increase the GSH-Px activities, reduce the NO content and decrease the MAO activity in cerebrum. Meanwhile, TLG was found to reduce the LF content in liver and heart and raise the Hyp content in liver. TLG was shown to inhibit apoptosis of cerebral cell and decrease the number of apoptotic cells in the brain. CONCLUSION: TLG possesses effect on antiaging via attenuating lipid peroxidation and NO and apoptosis of cerebral cells.