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To explore the effect and mechanism of taraxasterol on sepsis-induced acute respiratory distress syndrome (ARDS). Twenty-four male SD rats were randomly divided into four groups: the control group, model (lipopolysaccharide, LPS) group, lipopolysaccharide+taraxasterol (LPS + TXL) group, and lipopolysaccharide+ulinastatin (LPS + UTI) group. The model of sepsis-induced ARDS was established by intraperitoneal injection of LPS. The lung water content of the rats in each group was determined by the dry/wet ratio. Pathology of rat lung tissue was observed through HE staining. Wright staining was applied to count the number of neutrophils, macrophages, and total cells. ELISA was utilized to measure the levels of the inflammatory factors TNF-α, IL-1β, and IL-6 in bronchoalveolar lavage fluid (BALF). Biochemical detection was adopted to check the levels of myeloperoxidase (MPO), superoxide dismutase (SOD) and catalase (CAT) in lung tissue. Western blotting was performed to check the protein expression of IL-12, iNOS, Arg-1, and Mrc1 in lung tissue. Compared with the LPS group, both taraxasterol and ulinastatin significantly decreased lung tissue water content, improved lung tissue injury, reduced the number of neutrophils, macrophages and total cells, and decreased the level of inflammatory factors. In addition, taraxasterol and ulinastatin also reduced the content of MPO and the expression of IL-12 and iNOS and increased the activity of SOD and CAT as well as the protein expression of Arg-1 and Mrc1. Taraxasterol can suppress macrophage M1 polarization to alleviate the inflammatory response and oxidative stress, thereby treating sepsis-induced ARDS.

Protectin D1 (PD1), a DHA-derived lipid mediator, has recently been shown to possess anti-inflammatory and pro-resolving properties. To date, little is known about the effect of PD1 on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. The aim of the present study was to investigate the therapeutic effects of PD1 on LPS-induced ALI and its potential mechanisms of action. ALI was induced via an intraperitoneal injection of LPS, where PD1 (2 ng/mouse) was administered intravenously 30 min after LPS challenge. Mice were sacrificed 24 h after modeling. Lung histopathological changes were assessed using hematoxylin and eosin staining and myeloperoxidase (MPO) activity was tested using immunohistochemistry. Tumor necrosis-α and interleukin-6 levels in the bronchoalveolar lavage fluid (BALF) and serum were measured using ELISA. To detect neutrophil extracellular traps produced by infiltrated neutrophils in the lung tissue, immunofluorescence staining was performed using anti-MPO and anti-histone H3 antibodies. The results indicated that PD1 significantly attenuated histological damage and neutrophil infiltration in lung tissue, reduced the lung wet/dry weight ratio, protein concentration and proinflammatory cytokine levels in BALF and decreased proinflammatory cytokine levels in serum. Moreover, neutrophil citrullinated histone H3 (CitH3) expression was also reduced after PD1 administration. In conclusion, PD1 attenuated LPS-induced ALI in mice via inhibition of neutrophil extracellular trap formation in lung tissue. Therefore, PD1 administration may serve to be a new strategy for treating ALI.

Curcumin has been demonstrated to reduce markers of inflammation during acute pancreatitis (AP). However, the underlying mechanisms of the protective effects of curcumin are unknown. In the present study the effects of curcumin in an AP animal model and cell models was examined and the underlying mechanisms were investigated. An AP animal model was established by injection of 5% sodium taurocholate into the biliopancreatic duct of rats, and the cell model was established by treatment with 0.5 nM cerulein with an optimal concentration of lipopolysaccharide in AR42J rat pancreatic cancer cells. Amylase activity and arterial blood gas composition were assessed by automatic biochemical and blood gas analyzers. Pathological alteration of the pancreas was determined by hematoxylin and eosin staining. Interleukin (IL‑6), tumor necrosis factor (TNF)‑α and C‑reactive protein (CRP) levels were measured by ELISA. Cell viability was determined by Cell Counting Kit‑8 and protein expression levels were assessed by western blotting. Curcumin reduced the ascites volume after 12 and 24 h, the weight of pancreas after 12, 24 and 36 h of surgery, but also attenuated injury to the pancreas. Serum expression levels of TNF‑α and CRP were reduced by curcumin. In addition, curcumin decreased the cell viability, amylase activity and the phosphorylation of p38 in AR42J cells, but did not affect the intracellular levels of IL‑6 and TNF‑α. Curcumin may lower the severity and inflammatory response via the mitogen‑activated protein kinase‑signaling pathway, to some extent. However, future studies are required to fully understand the protective effects of curcumin on AP.