Ming-Xia Wang

Protective effects of Notoginsenoside R1 on intestinal ischemia-reperfusion injury in rats.

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.

Emodin improves lipopolysaccharide-induced microcirculatory disturbance in rat mesentery.

Sepsis is a systemic inflammatory response syndrome. Emodin is a major ingredient of Rheum Palmatum, a Chinese herb that is widely used in China for treatment of endotoxemia‐related diseases. This study intended to examine the effect of Emodin on LPS‐induced rat mesenteric microcirculatory disturbance and the underlying mechanisms.

High-dose chlorogenic acid induces inflammation reactions and oxidative stress injury in rats without implication of mast cell degranulation

ETHNOPHARMACOLOGICAL RELEVANCE Chlorogenic acid (CA) exits widely in those Chinese herbal injections that have antibacterial and antiphlogistic effects and belongs to the ethnopharmacological family of medicines. Chinese herbal injections containing high levels of CA have been reported to increase the adverse drug reactions, but the mechanism for which is still unclear. In this study, we investigated the mechanism of the CA derived adverse drug reactions. AIM OF THE STUDY The present study was to explore the potential role of CA in initiating inflammatory reaction and the underlying mechanism. MATERIALS AND METHODS Male Wistar rats were treated with different dosages of CA for different time period. The variables examined included microcirculation by intravital microscopy, histology of ileum tissue, expression of adhesion molecules CD11b and CD18 on leukocytes by flow cytometry, myeloperoxidase activity and maleic dialdehyde content in ileum tissue by spectrophotometry, activity of superoxide dismutase and catalase in serum by ELISA, and expression of NADPH oxidase subunits by PCR and Western blot. RESULTS High-dose CA increased the number of adherent leukocytes, generation of peroxides in the venular walls and induced albumin leakage from mesentery venules. High-dose CA induced changes also included an increase in maleic dialdehyde, myeloperoxidase, inflammatory cytokines and NADPH oxidase activities, and a decline in activity of superoxide dismutase and catalase. CONCLUSION High-dose, but not Low-dose CA induced inflammation reaction, and in this process an imbalance between oxidant and antioxidant mechanism may be involved, providing more information for better understanding the rationale behind the adverse effects of CA.

Inhibitory effect of rhynchophylline on contraction of cerebral arterioles to endothelin 1: Role of rho kinase

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.

Salvianolic Acid B Ameliorates Lipopolysaccharide-Induced Albumin Leakage from Rat Mesenteric Venules through Src-Regulated Transcelluar Pathway and Paracellular Pathway

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.

Astragaloside IV ameliorates 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis implicating regulation of energy metabolism.

Dysfunction of energy metabolism is involved in inflammatory bowel disease (IBD). This study was designed to investigate the potential of astragaloside IV (ASIV), an active ingredient of Radix Astragalus, to ameliorate colonic mucosal injury, with focusing on the implication of energy restoration in the underlying mechanism. Experimental colitis model was established in rats by injecting 2,4,6-trinitrobenzene sulfonic acid (TNBS) through anus. After 24 hours, ASIV was administrated once daily by gavage for 6 days. On day 1 and day 7, colon tissue was collected for macroscopic and histological examination, ELISA, Western blot and immunohistochemical analysis. TNBS impaired colonic mucosa with an injured epithelial architecture, increased inflammatory cell infiltration, and decreased colonic blood flow. Lgr5 positive cell number in crypt and β-catenin nuclear translocation were down-regulated by TNBS treatment. TNBS induced epithelial F-actin disruption and junctional protein degradation. Furthermore, adenosine triphosphate (ATP) content and ATP synthase subunit β expression in the colon tissue were significantly decreased after TNBS stimulation. All of the aforementioned alterations were relieved by ASIV post-treatment. The present study revealed that ASIV promoted mucosal healing process in TNBS-induced colitis, which was most likely attributed to regulating energy metabolism.

Kudiezi Injection(®) Alleviates Blood-Brain Barrier Disruption After Ischemia-Reperfusion in Rats.

This study was designed to examine the effect of KDZ, on the BBB disruption in rat underwent MCAO and reperfusion.

Deepure Tea Improves High Fat Diet-Induced Insulin Resistance and Nonalcoholic Fatty Liver Disease

This study was to explore the protective effects of Deepure tea against insulin resistance and hepatic steatosis and elucidate the potential underlying molecular mechanisms. C57BL/6 mice were fed with a high fat diet (HFD) for 8 weeks to induce the metabolic syndrome. In the Deepure tea group, HFD mice were administrated with Deepure tea at 160 mg/kg/day by gavage for 14 days. The mice in HFD group received water in the same way over the same period. The age-matched C57BL/6 mice fed with standard chow were used as normal control. Compared to the mice in HFD group, mice that received Deepure tea showed significantly reduced plasma insulin and improved insulin sensitivity. Deepure tea increased the expression of insulin receptor substrate 2 (IRS-2), which plays an important role in hepatic insulin signaling pathway. Deepure tea also led to a decrease in hepatic fatty acid synthesis and lipid accumulation, which were mediated by the downregulation of sterol regulatory element binding protein 1c (SREBP-1c), fatty acid synthesis (FAS), and acetyl-CoA carboxylase (ACC) proteins that are involved in liver lipogenesis. These results suggest that Deepure tea may be effective for protecting against insulin resistance and hepatic steatosis via modulating IRS-2 and downstream signaling SREBP-1c, FAS, and ACC.

Paeonol improves lipopolysaccharide-induced microcirculatory disturbance in rat mesentery

Objective: To investigate the effect of paeonol on lipopolysaccheride (LPS)-induced rat mesenteric microcirculatory dysfunctions. Methods: Male Wistar rats were randomly distributed into 5 groups (n=6 in each): Sham group, LPS group, paeonol group, paeonol+LPS group, and LPS+paeonol group. Endotoximia model was conducted by continuous LPS infusion. Changes in mesenteric microcirculatory variables, including diameter of venule, velocity of red blood cells in venule, leukocyte adhesion, free radicals produced in venule and albumin leakage from venule, were observed through an inverted intravital microscope. Meanwhile, the expression of myeloperoxidase (MPO), CD18, intercellular adhesion molecule-1 (ICAM-1), toll-like receptor 4 (TLR4), nuclear factor-kappa B p65 subunit (NF-κB p65), activator protein-1 (AP-1), and Jun N-terminal kinase (JNK) was assessed by Western blot. Results: After infusion of LPS, the number of leukocytes adherent to venular wall, the intensity of dihydrorhodamine 123 (DHR) fluorescence in the venular walls, and albumin leakage from venules were significantly increased, whereas the red blood cell velocity in venule was decreased. All the manifestations were significantly reduced by pre-treatment and post-treatment with paeonol. Moreover, paeonol significantly attenuated the expression of MPO, CD18, ICAM-1, TLR4, NF-κB p65, AP-1 and JNK in rat mesentery after LPS. Conclusions: The results demonstrated that paeonol could protect from and ameliorate the microcirculation disturbance induced by LPS.