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Objective: To investigate the effect of paeonol on lipopolysaccheride (LPS)-induced rat mesenteric microcirculatory dysfunctions.

Lipopolysaccharide (LPS) causes microvascular barrier disruption, leading to albumin leakage from microvessels resulting in a range of disastrous sequels. Salvianolic acid B (SalB) is a major water-soluble component derived from Salvia miltiorrhiza. Previous studies showed its potential to attenuate microvascular barrier dysfunction, but the underlying mechanism is not fully understood. The present study was intended to investigate the impact of SalB on endothelial cell barrier in vivo in rat mesenteric venules as well as in vitro in human umbilical vein endothelial cells (HUVECs), aiming at disclosing the mechanism thereof, particularly the role of Src in its action. Male Wistar rats were challenged by infusion of LPS (2 mg/kg/h) through left femoral vein for 90 min. SalB (5 mg/kg/h) was administrated either simultaneously with LPS or 30 min after LPS infusion through the left jugular vein. Vesicles in venular walls were observed by electron microscopy. HUVECs were incubated with LPS with or without SalB. The expression of Zonula occluden-1 (ZO-1), VE-cadherin, caveolin-1 and Src in HUVECs was assessed by Western blot and confocal microscopy, binding of SalB to Src was measured using Surface Plasmon Resonance and BioLayer Interferometry. Treatment with SalB inhibited albumin leakage from rat mesenteric venules and inhibited the increase of vesicle number in venular endothelial cells induced by LPS. In addition, SalB inhibited the degradation of ZO-1, the phosphorylation and redistribution of VE-cadherin, the expression and phosphorylation of caveolin-1, and phosphoirylation of Src in HUVECs exposed to LPS. Furthermore, SalB was found able to bind to Src. This study demonstrates that protection of SalB against microvascular barrier disruption is a process involving both para- and trans-endothelial cell pathway, and highly suggests Src as the key enzyme for SalB to work.

Objective. The aim of this study was to investigate the expression of smoothened protein (Smo), a sonic hedgehog (Shh) signalling component, in synovium of RA and its role in the survival and apoptosis of endothelial cells. Methods. The expression of Smo pxrotein in RA synovial tissue was examined by immunohistochemistry. Real-time PCR and western blotting techniques were employed to measure the expression of Shh signalling components in EA.hy926 endothelial cells exposed to TNF-α in the presence or absence of cyclopamine (a Smo-specific antagonist). Lastly, the effect of cyclopamine and Smo small interfering RNA on apoptosis induced by TNF-α and actinomycin D (ActD) was determined. Results. We found that Smo was highly expressed in synovial tissues of RA, especially in endothelial cells, compared with the trauma group. TNF-α significantly increased the expression of Shh signalling components in EA.hy926 endothelial cells, while cyclopamine decreased the expression of Shh signalling components. EA.hy926 endothelial cells treated with various concentrations of cyclopamine (2–8 μmol/l) showed a significant decrease in cell viability and cell survival rate, and an increase in the rate of cell apoptosis compared with endothelial cells treated with TNF-α and ActD ( P < 0.05). EA.hy926 endothelial cells transfected with Smo-siRNA also showed a lower cell survival rate and higher apoptotic rate, compared with cells in the control group ( P < 0.05). Conclusion. The Shh signalling pathway plays a role in regulating endothelial cell apoptosis in a Smo-dependent manner. [ABSTRACT FROM AUTHOR]

Intestinal ischemia and reperfusion (I/R) is a clinical problem occurred for diverse causes with high mortality. Prophylaxis and treatment of intestinal I/R remains a challenge for clinicians. The purpose of the present study was to explore the role of Notoginsenoside R1 (R1), a major component form of Panax notoginseng, in management of intestinal I/R injury. Intestinal I/R was induced in male Sprague-Dawley rats by clamping the superior mesenteric artery for 90 min followed by reperfusion for 60 min or 3 days. R1 (10 mg·kg-1·h-1) was administered either 20 min before ischemia or 20 min after reperfusion. Intestinal microcirculation was evaluated by intravital microscopy over 60 min reperfusion. Sixty minutes or 3 days after reperfusion, rats were killed for histological examination of the jejunum tissue and immunohistochemical localization of myeloperoxidase and CD68. ATP, ADP, and AMP content in jejunum tissue was assessed by ELISA. Activation of nuclear factor-κB (NF-κB) and expression of ATP5D and tight junction proteins were determined by Western blotting. The results demonstrated that R1 is capable of attenuating intestinal I/R-induced microvascular hyperpermeability, inflammatory cytokine production, NF-κB activation, and loss of tight junction proteins, as well as improving energy metabolism during I/R. The results of the present study suggest R1 as an option in protecting against intestinal I/R injury. [ABSTRACT FROM AUTHOR]

Aim: To study the growth inhibitory and apoptotic effects of adenosine triphosphate (ATP) and adenosine (ADO) on human gastric carcinoma (HGC)-27 cells in vitro and the mechanisms related to the actions of ATP and ADO. Methods: MTT assay was used to determine the reduction of cell viability. The morphological changes of HGC-27 cells induced by ATP or ADO were observed under fluorescence light microscope by acridine orange/ethidium bromide double-stained cells. The internucleosomal fragmentation of genomic DNA was detected by agarose gel electrophoresis. The apoptotic rate and cell-cycle analysis after treatment with ATP or ADO was determined by flow cytometry. Results: ATP, ADO and the intermediate metabolites, ADP and AMP, and the agonist of purinergic receptors, reduced cell viability of HGC-27 cells at doses of 0.3 and 1.0 mmol·L−1. The distribution of cell cycle phase and proliferation index (PI) value of HGC-27 cells changed when exposed to ATP or ADO at the concentrations of 0.1,0.3 and 1 mmol/L for 48 h. ATP and ADO both altered the distribution of cell cycle phase via G0/G1-phase arrest and significantly decreased PI value. Under light microscope, the tumor cells exposed to 0.3 mmol·L−1 ATP or ADO displayed morphological changes of apoptosis; a ladder-like pattern of DNA fragmentation obtained from HGC-27 cells treated with 0.1–1 mmol·L−1 ATP or ADO appeared in agarose gel electrophoresis; ATP and ADO induced the apoptosis of HGC-27 cells in a dose-dependent manner at concentrations between 0.03–1 mmol–L−1. The maximum apoptotic rate of HGC-27 cells exposed to ATP or ADO for 48 h was 13.53% or 15.9%, respectively. HGC-27 cell death induced by ATP or ADO was significantly inhibited by dipy-ridamole (10 mmol·L−1), an inhibitor of adenosine transporter, but was not affected by aminophylline, a broad inhibitor of P1 receptors and pyridoxal-phosphate-6-azophenyl-2, 4-disulphonic acid tetrasodium salt (30 μmol·L−1), a non-selective antagonist of P2 receptors. Conclusion: Extracellular ATP and ADO reduced the cell viability, arrested cell cycle and induced apoptosis in HGC-27 cell line by intracellular uptake of ADO. One of the main routes of ATP-induced apoptosis in HGC-27 cells is through the breakdown to adenosine. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Rhynchophylline (Rhy) is a major ingredient of Uncaria rhynchophylla (UR) used to reduce blood pressure and ameliorate brain ailments. This study was to examine the role of Rho kinase (ROCK) in the inhibition of Rhy on contraction of cerebral arterioles caused by endothelin 1 (ET-1). Materials and methods Cerebral arterioles of male Wistar rats were constricted with ET-1 for 10 min followed by perfusion of Rhy for 20 min. Changes in the diameters of the arterioles were recorded. The effects of Rhy on contraction of middle cerebral arteries (MCAs) were determined by a Multi-Myograph. Western blotting and immunofluorescent staining were used to examine the effects of Rhy on RhoA translocation and myosin phosphatase target subunit 1 (MYPT1) phosphorylation. Results In vivo, Rhy (30-300 µM) relaxed cerebral arterioles constricted with ET-1 dose-dependently. In vitro, Rhy at lower concentrations (1-100 µM) caused relaxation of rat MCAs constricted with KCl and Bay-K8644 (an agonist of L-type voltage-dependent calcium channels (L-VDCCs)). Rhy at higher concentrations (>100 µM) caused relaxation of rat MCAs constricted with ET-1, which was inhibited by Y27632, a ROCK's inhibitor. Western blotting of rat aortas showed that Rhy inhibited RhoA translocation and MYPT1 phosphorylation. Immunofluorescent staining of MCAs confirmed that phosphorylation of MYPT1 caused by ET-1 was inhibited by Rhy. Conclusions These results demonstrate that Rhy is a potent inhibitor of contraction of cerebral arteries caused by ET-1 in vivo and in vitro. The effect of Rhy was in part mediated by inhibiting RhoA-ROCK signaling. [ABSTRACT FROM AUTHOR]