Effects of salidroside on the secretion of inflammatory mediators induced by lipopolysaccharide in the co-culture of rat alveolar macrophages and type II alveolar epithelial cells / 生理学报

The aim of the present study was to investigate the effect of salidroside (Sal) on inflammatory activation induced by lipopolysaccharide (LPS) in the co-culture of rat alveolar macrophages (AM) NR 8383 and type II alveolar epithelial cells (AEC II) RLE-6TN. CCK-8 colorimetric method was used to detect cell proliferation percentage. The enzyme-linked immunosorbent assay (ELISA) was used to determine the content of tumor necrosis factor alpha (TNF-α), macrophage inflammatory protein-2 (MIP-2) and interleukin-10 (IL-10) in the supernatant. Western blot was used to examine the expression levels of phosphorylated AKT (p-AKT) and total AKT protein. The results showed that pretreatment of RLE-6TN cells or co-culture of RLE-6TN and NR 8383 cells with 32 and 128 µg/mL Sal for 1 h, followed by continuous culture for 24 h, significantly increased the cell proliferation (P < 0.05). Compared with control group, 32 and 128 µg/mL Sal pretreatment significantly increased the ratio of p-AKT/AKT in RLE-6TN cells (P < 0.05). Pretreatment of 32 µg/mL Sal not only inhibited the secretion of TNF-α and MIP-2 by NR 8383 cells induced by LPS (P < 0.05), but also enhanced the inhibitory effect of RLE-6TN and NR 8383 cells co-culture on the secretion of TNF-α and MIP-2 by NR 8383 cells induced by LPS (P < 0.05). In addition, 32 µg/mL Sal pretreatment promoted LPS-induced IL-10 secretion by NR 8383 cells (P < 0.05), and enhanced the promoting effect of co-culture of RLE-6TN and NR 8383 cells on the IL-10 secretion by LPS-induced NR 8383 cells (P < 0.05). In conclusion, Sal may directly inhibit LPS-induced inflammatory activation of AM (NR 8383), promote the proliferation of AEC II (RLE-6TN) through PI3K/AKT signaling pathway, and enhance the regulatory effect of AEC II on LPS-induced inflammatory activation of AM.

Protective effect of synthetic salidroside on acute lung injury in rats / 生理学报

To study the protective effect and mechanism of synthetic salidroside on acute lung injury (ALI) induced by lipopolysaccharide (LPS), male Sprague-Dawley (SD) rats were randomly divided into saline control group, 3 mg/kg LPS model group, different doses of salidroside groups (5, 20 and 80 mg/kg), and 5 mg/kg dexamethasone group. Intratracheal LPS instillation was used to establish the ALI model 0.5 h after intraperitoneal injection of salidroside or dexamethasone, and the rats were sacrificed 6 h later. Lung wet/dry weight ratio (W/D) was calculated. Lung tissue pathology and lung injury score (LIS) were observed and evaluated through hematoxylin and eosin (HE) staining. The centrifugal sediment of bronchoalveolar lavage fluid (BALF) was used to count the polymorphonuclear leukocyte (PMN) number by Wright's staining, and the centrifugal supernatant of BALF was used to determine the contents of protein and inflammatory factors (TNF-α, IL-1β and IL-6). The contents of myeloperoxidase (MPO) and malondialdehyde (MDA) in lung tissue were determined. Western blot was used to detect the expression levels of phosphorylated and total nuclear factor kappa B (NF-κB)/p65 protein in lung tissue. The results showed that, compared with LPS group, the intervention of synthetic salidroside alleviated the pathological damage in lung tissue, decreased the LIS and lung W/D ratio (P < 0.05), reduced the PMN number, the contents of protein and inflammatory factors in BALF (P < 0.05), reduced the contents of MPO and MDA in lung tissue (P < 0.05), and inhibited the expression of p-NF-κB in lung tissue (P < 0.05). The results suggest that synthetic salidroside has a protective effect on ALI induced by LPS, and its mechanism is related to inhibiting the phosphorylation of NF-κB and reducing the aggregation of PMN in the lung.

Comparison of mannitol and hypertonic saline in treatment of intracranial hypertension of rabbits / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To compare the effects of mannitol and hypertonic saline (HS) in treatment of intracranial hypertension (ICH) of rabbits.</p><p><b>METHODS</b>The animal mode of ICH was established by perfusing artificial cerebrospinal fluids (aCSF) with controlled pressure into the cerebral ventricles of rabbits. The mean arterial pressure, respiratory rate, tidal volume, perfusion rate of aCSF and water content of cerebrum were investigated in rabbits with ICH after a single bolus of 20% mannitol (5 ml/kg), 7.5% HS (2.2 ml/kg) or 23.4% HS (2.2 ml/kg).</p><p><b>RESULTS</b>After the intracranial pressure was elevated from 15 cmH₂O to 75 cmH₂O, the mean arterial pressure was increased and the tidal volume was decreased. After treatment by 20% mannitol, 7.5% HS or 23.4% HS, the increased percentage of mean arterial pressure and the decreased percentage of tidal volume were similar to the changes in control group. However, the perfusion rate of CSF was increased and water content of cerebrum was decreased after treatment by either 20% mannitol or 23.4% HS, but not by 7.5% HS. No different effects were found between 20% mannitol and 23.4% HS.</p><p><b>CONCLUSION</b>With the similar osmotic burden, 20% mannitol is more effective in treating ICH than 7.5% HS. With higher osmotic load, the efficacy of HS is enhanced, and 23.4% HS may be used as an alternative to mannitol in treatment of ICH.</p>

Effects of trichostatin A on the expressions of inflammatory cytokines and toll-like receptor 4 and the acetylation of nuclear factor-κB induced by lipopolysaccharide in macrophage / 生理学报

The present study aims to explore the possible mechanisms that trichostatin A (TSA), a histone deacetylases inhibitor (HDACi), affects the inflammatory signaling pathways of lipopolysaccharide/toll-like receptor 4/nuclear factor-κB (LPS/TLR4/NF-κB). Murine macrophage cell line RAW264.7 cells were employed. MTT assay was used to assess cell viability. The contents of TNF-α, IL-1β and IL-6 in culture supernatant were assayed by enzyme-linked immunosorbent assay (ELISA). TLR4 expression and NF-κB/p65 (Lys310) acetylation were examined by Western blotting. DNA binding activity of NF-κB/p65 was detected by using TransAM(TM) NF-κB/p65 activity assay kit. The results showed that, compared with control group, which was treated by DMSO, the cells treated with TSA (20, 40, 80 ng/mL) showed decreased percentages of cell survival (P < 0.05). The contents of TNF-α, IL-1β and IL-6 in culture supernatant were all increased by LPS (100 ng/mL), whereas reduced by 40 ng/mL TSA pretreatment (P < 0.05). TSA pretreatment inhibited LPS-induced up-regulation of TLR4 protein expression. Acetylation of NF-κB/p65(Lys310), which was already increased by LPS, was further enhanced by TSA (P < 0.05). On the contrary, LPS-increased DNA binding activity of NF-κB/p65 was decreased by pretreatment with TSA (P < 0.05). The results suggest that TSA-induced anti-inflammation may be attributed to decreases in the expression of TLR4 and DNA binding activity of NF-κB/p65.