Xia Gong

Resolvin D1 protects mice from LPS-induced acute lung injury.

Resolvin D1 (RvD1), an endogenous lipid molecule derived from docosahexaenoic acid (DHA), has been described to promote inflammatory resolution. The present study aimed to determine the protective effects and the underlying mechanisms of RvD1 on lipopolysaccharide (LPS)-induced acute lung injury (ALI). Pretreatment RvD1 to mice 30 min before inducing ALI by LPS decreased the mortality and improved lung pathological changes, inhibited LPS-induced increases in polymorphonulear and mononuclear leukocytes recruitment, total proteins content, tumor necrosis factor (TNF-α) and interleukin-6 (IL-6) production in the bronchoalveolar lavage fluids (BALFs). In addition, RvD1 markedly reduced LPS-induced the expression of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and adhesion molecules, as well as myeloperoxidase (MPO) activity. Moreover, RvD1 markedly inhibited LPS-induced the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB). Furthermore, pretreatment with Boc, a lipoxin A4 receptor (ALX) antagonist, significantly reversed these beneficial effects of RvD1 on LPS-induced acute lung injury in mice. Taken together, our study showed that RvD1 improved survival rate and attenuated ALI in mice induced by LPS, and the protective mechanisms might be related to selective reaction with ALX, which inhibits MAPKs and NF-κB pathway.

Protective effect of baicalin against Lipopolysaccharide/d-galactosamine-induced liver injury in mice by up-regulation of Heme oxygenase-1

Baicalin, a traditional anti-inflammatory drug, has been found to protect against liver injury in several experimental animal hepatitis models; however, the mechanisms underlying the hepatoprotective properties of baicalin are poorly understood. In the present study,we investigated the effects of baicalin on the acute liver injury in mice induced by Lipopolysaccharide/D-galactosamine (LPS/D-GalN). Baicalin (50, 150, and 300 mg/kg) was pretreated intraperitoneally (i.p.) at 2, 24, and 48 h respectively before LPS/D-GalN injected in mice. The mortality, hepatic tissue histology, hepatic tissue Tumor necrosis factor-alpha (TNF-alpha) and myeloperoxidase (MPO), plasma levels of TNF-alpha and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were analyzed. Besides, western blotting analyses of nuclear factor kappa B (NF-kappaB) translocation and Heme oxygenase-1(HO-1) protein expression, as well as HO-1 activity were determined. The results showed that baicalin protected against LPS/D-GalN-induced liver injury, including dose-dependent alleviation of mortality and hepatic pathological damage, decrease of ALT/AST release and the rise of MPO. Baicalin reduced nuclear translocation of NF-kappa B, TNF-alpha mRNA and protein levels in hepatic tissues and plasma levels of TNF-alpha induced by LPS/D-GalN. Moreover, baicalin dose-dependently increased HO-1 protein expression and activity. Further, inhibition of HO-1 activity significantly reversed the protective effect of baicalin against LPS/D-GalN-induced liver injury. These results suggest that baicalin can effectively prevent LPS/D-GalN-induced liver injury by inhibition of NF-kappa B activity to reduce TNF-alpha production and the underlying mechanism may be related to up-regulation of HO-1 protein and activity.

Protective effects of Asiaticoside on acute liver injury induced by lipopolysaccharide/D-galactosamine in mice

Asiaticoside (AS), a triterpenoid product isolated from Centella asiatica, has been described to exhibit anti-in fl ammatory activities in several inflammatory models. However, the effects of AS on liver injury are poorly understood. The present study was undertaken to investigate whether AS is efficacious against Lipopolysaccharide (LPS) /D-galactosamine (D-GalN)-induced acute liver injury in mice and its potential mechanisms. AS (5, 10 and 20 mg/kg/d) was pretreated orally once daily for 3 days before LPS/D-GalN injected in mice. The mortality, hepatic tissue histology, plasma levels of Tumor necrosis factor-alpha (TNF-alpha) and alanine aminotransferase (ALT) and aspartate aminotransferase (AST), hepatic tissue TNF-alpha and caspase-3 activity were measured. Besides, western blotting analysis of phospho-p38 mitogen-activated protein kinase (phospho-p38 MAPK), phospho-c-jun N-terminal kinase (phospho-JNK) and phospho-extracellular signal regulated kinase (phospho-ERK) were determined. As a result, AS showed significant protection as evidenced by the decrease of elevated aminotransferases, hepatocytes apoptosis and caspase-3, alleviation of mortality and improvement of liver pathological injury in a dose-dependent manner. Further, we found that AS dose-dependently reduced the elevation of phospho-p38 MAPK, phospho-JNK, phospho-ERK protein and TNF-alpha mRNA expression in liver tissues and plasma TNF-alpha. These results suggest that AS has remarkable hepatoprotective effects on LPS/D-GalN-induced liver injury and the possible mechanism is related to inhibition of TNF-alpha and MAPKs.

Anti-inflammatory effects of mangiferin on sepsis-induced lung injury in mice via up-regulation of heme oxygenase-1.

Sepsis, a serious unbalanced hyperinflammatory condition, is a tremendous burden for healthcare systems, with a high mortality and limited treatment. Increasing evidences indicated that some active components derived from natural foods have potent anti-inflammatory properties. Here we show that mangiferin (MF), a natural glucosyl xanthone found in both mango and papaya, attenuates cecal ligation and puncture-induced mortality and acute lung injury (ALI), as indicated by reduced systemic and pulmonary inflammatory responses. Moreover, pretreatment with MF inhibits sepsis-activated mitogen-activated protein kinases and nuclear factor kappa-light-chain-enhancer of activated B cells signaling, resulting in inhibiting production of proinflammatory mediators. Notably, MF dose-dependently up-regulates the expression and activity of heme oxygenase (HO)-1 in the lung of septic mice. Further, these beneficial effects of MF on the septic lung injury were eliminated by ZnPP IX, a specific HO-1 inhibitor. Our results suggest that MF attenuates sepsis by up-regulation of HO-1 that protects against sepsis-induced ALI through inhibiting inflammatory signaling and proinflammatory mediators. Thereby, MF may be effective in treating sepsis with ALI.

Madecassoside attenuates inflammatory response on collagen-induced arthritis in DBA/1 mice

Madecassoside (MA), a triterpenoid product isolated from Centella asiatica, has been described to exhibit antioxidant and anti-inflammatory activities. The present study was undertaken to determine whether madecassoside (MA) is efficacious against collagen-induced arthritis (CIA) in mice and its possible mechanisms. DBA/1J mice were immunized with bovine type II collagen and treated with MA (3, 10 and 30 mg/kg d, i.g.) from days 21 to 42 after immunization. Arthritis was evaluated by hind paw swelling, polyarthritis index, and histological examination. In vitro proliferation of spleen cells was examined using 3-[4,5-dimethylthylthiazol-2-yl]-2, 5-diphenyltetrazoliumbromide (MTT) assay. Plasma levels of cytokines tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), interleukin-10 (IL-10) and the expression of prostaglandin E(2) (PGE(2)), cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) in synovial tissues were also determined. The results showed that comparing with untreated CIA mice, treated with MA dose-dependently suppressed the clinical arthritis score and joints tissues pathological damage, reduced the proliferation of spleen cells, plasma levels of TNF-alpha and IL-6, synovial tissues PGE(2) production and COX-2 protein expression, however, the expression of COX-1 in synovial tissues did not change and the plasma levels of IL-10 were increased. These results suggest that MA can effectively alleviate inflammatory response on CIA, and anti-inflammatory effects of MA can be attributed, at least partially, to the inhibition of pro-inflammatory mediators, including COX-2 expression, PGE(2) production, TNF-alpha and IL-6 levels and the up-regulation anti-inflammatory molecule IL-10.

Tetrandrine enhances cytotoxicity of cisplatin in human drug-resistant esophageal squamous carcinoma cells by inhibition of multidrug resistance-associated protein 1

Multidrug resistance is one of the major causes limiting the efficacy of chemotherapeutic agents to control esophageal cancer. Herein, we investigated that the effect and mechanism of tetrandrine (TET) in the human esophageal squamous carcinoma cisplatin-resistant cell line YES-2/DDP. The human esophageal squamous carcinoma cisplatin-resistant cell line YES-2/DDP was isolated by stepwise selection in increasing concentrations of cisplatin. The CCK-8 method was carried out to measure the cell viability when cells were exposed to TET with or without cisplatin, and the IC50 and resistance index (RI) of cisplatin was then calculated. Real-time RT-PCR and western blotting were used to detect the mRNA and protein expression of multidrug resistance 1 (MDR1), multidrug resistance-associated protein 1 (MRP1) and breast cancer resistance protein (BCRP), respectively. Flow cytometry was adopted to determine CMFDA efflux and cell apoptosis, respectively. The resulting cell line YES-2/DDP was 16.4-fold resistant to cisplatin, the cytotoxicity of cisplatin to YES-2/DDP cells was enhanced by TET in a dose-dependent manner. Further, it was found that the expression of MDR1 and BCRP was similar in different treated cells. In contrast, the expression of MRP1 was markedly increased in YES-2/DDP cells, which was dose-dependently decreased by TET. In agreement with the results, MRP1 activity was also reversed by TET. In conclusion, TET possesses a reversal effect on drug resistance in YES-2/DDP cells through downregulation of MRP1, and has the potential to be an adjunct to chemotherapy for esophageal cancer.

Tetrandrine attenuates lipopolysaccharide-induced fulminant hepatic failure in D-galactosamine-sensitized mice

Fulminant hepatic failure (FHF) remains an extremely poor prognosis and high mortality; better treatments are urgently needed. Tetrandrine (TET), a traditional anti-inflammatory drug, has been reported to exhibit hepatoprotective activities in several liver injury models. We now investigated the effects and underlying mechanisms of TET on lipopolysaccharide (LPS) and D-galactosamine (D-GalN)-induced FHF in mice. TET (50, 100, and 200 mg/kg) was given intraperitoneally 1h before LPS/D-GalN injection in mice. The mortality and liver injury was evaluated subsequently. The results showed that administering TET to mice reduced mortality and improved liver injury induced by LPS/D-GalN in a dose-dependent manner. In addition, TET dose-dependently inhibited LPS/D-GalN-induced NF-kappaB activation, serum and hepatic tissues tumor necrosis factor-alpha (TNF-alpha) production, caspase-3 activation and hepatocellular apoptosis, myeloperoxidase (MPO) activity, intercellular adhesion molecule-1 (ICAM-1) and endothelial cell adhesion molecule-1 (ECAM-1) expression. Our experimental data indicated that TET might alleviate the FHF induced by LPS/D-GalN through inhibiting NF-kappaB activation to reduce TNF-alpha production.

Protective Effects of Polydatin on Septic Lung Injury in Mice via Upregulation of HO-1

The present study was carried out to investigate the effects and mechanisms of polydatin (PD) in septic mice. The model of cecal ligation and puncture (CLP-)induced sepsis was employed. Pretreatment of mice with PD (15, 45, and 100 mg/kg) dose-dependently reduced sepsis-induced mortality and lung injury, as indicated by alleviated lung pathological changes and infiltration of proteins and leukocytes. In addition, PD inhibited CLP-induced serum tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) production, lung cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase isoform (iNOS) protein expressions and NF-κB activation. Notably, PD upregulated the expression and activity of heme oxygenase (HO-)1 in lung tissue of septic mice. Further, the protective effects of PD on sepsis were abrogated by ZnPP IX, a specific HO-1 inhibitor. These findings indicated that PD might be an effective antisepsis drug.

Protective effects of asiaticoside on septic lung injury in mice.

Asiaticoside (AS), a major triterpenoid saponin component isolated from Centella asiatica, has been described to exhibit antioxidant and anti-inflammatory activities. The present study aimed to determine the protective effects and the underlying mechanisms of AS on septic lung injury induced by cecal ligation and puncture (CLP). Mice were pretreated with the AS (45 mg/kg) or AS as well as GW9662 at 1h before CLP, the survival, lung injury, inflammatory mediators and signaling molecules, and Peroxisome proliferator-activated receptor-γ (PPAR-γ) were determined 24 h after CLP. The results showed that AS significantly decreased CLP-induced the mortality, lung pathological damage, the infiltration of mononuclear, polymorphonuclear (PMN) leucocytes and total proteins. Moreover, AS inhibited CLP-induced the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB), the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) protein in lung tissues, and the production of serum tumor necrosis factor (TNF-α) and interleukin-6 (IL-6). Interestingly, the expression of PPAR-γ protein in lung tissue was up-regulated by AS. Furthermore, GW9662 (the inhibitor of PPAR-γ) significantly reversed these beneficial effects of AS in septic mice. These findings suggest that AS could effectively protect from septic lung injury induced by CLP and the underlying mechanisms might be related to up-regulation of PPAR-γ expression to some extent, which inhibits MAPKs and NF-κB pathway.

Antipyretic and anti-inflammatory effects of asiaticoside in lipopolysaccharide-treated rat through up-regulation of heme oxygenase-1.

Asiaticoside (AS), a triterpenoid isolated from Centella asiatica, has been found to exhibit antioxidant and anti‐inflammatory activities in several experimental animal models. However, the underlying mechanisms remain elusive. In this study, we provide experimental evidences that AS dose‐dependently inhibited lipopolysaccharide (LPS)‐induced fever and inflammatory response, including serum tumor necrosis factor (TNF)‐α and interleukin (IL)‐6 production, liver myeloperoxidase (MPO) activity, brain cyclooxygenase‐2 (COX‐2) protein expression and prostaglandin E2 (PGE2) production. Interestingly, AS increased serum IL‐10 level, liver heme oxygenase‐1 (HO‐1) protein expression and activity. Furthermore, we found that the suppressive effects of AS on LPS‐induced fever and inflammation were reversed by pretreatment with ZnPPIX, a HO‐1 activity inhibitor. In summary, our results suggest that AS has the antipyretic and anti‐inflammatory effects in LPS‐treated rat. These effects could be associated with the inhibition of pro‐inflammatory mediators, including TNF‐α and IL‐6 levels, COX‐2 expression and PGE2 production, as well as MPO activity, which might be mediated by the up‐regulation of HO‐1. Copyright