Resveratrol ameliorates lipopolysaccharide-induced epithelial mesenchymal transition and pulmonary fibrosis through suppression of oxidative stress and transforming growth factor-ß1 signaling.

BACKGROUND & AIMS: Fibrotic changes seem to be responsible for the high mortality rate observed in patients with acute respiratory distress syndrome (ARDS). The present study aimed to determine whether resveratrol, a natural antioxidant polyphenol, had anti-fibrotic effects in the murine model of lipopolysaccharide (LPS)-induced pulmonary fibrosis. METHODS: Fibrosis was assessed by determination of collagen deposition, hydroxyproline and type I collagen levels in lung tissues. Development of epithelial-mesenchymal transition (EMT) was identified by the loss of E-cadherin accompanying by the acquisition of α-smooth muscle actin (α-SMA). Transforming growth factor (TGF)-ß1 content, levels of phosphorylated Smad2/Smad3 and Smad4, malondialdehyde (MDA) content, total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity, and catalase (CAT) activity in lung tissues were determined. RESULTS: LPS increased collagen deposition, hydroxyproline and type I collagen contents, and meanwhile induced EMT process, stimulated TGF-ß1 production and Smad activation in lung tissues on day 21 to day 28 after LPS administration. In addition, LPS treatment resulted in a rapid induction of oxidative stress as evidenced by increase of MDA and decreases of T-AOC, CAT and SOD activities as early as 7 days after LPS treatment, which was persistent for at least 4 weeks. In contrast, resveratrol treatment attenuated LPS-induced EMT and pulmonary fibrosis, meanwhile it suppressed LPS-induced oxidative stress, TGF-ß1 production and activation of Smad signaling pathway. CONCLUSIONS: Resveratrol may ameliorate LPS-induced EMT and pulmonary fibrosis through suppression of oxidative stress and TGF-ß1/Smad signaling pathway. Application of antioxidants may represent a useful adjuvant pharmacologic approach to reduce ARDS-associated pulmonary fibrosis.

Chronic restraint stress aggravated arthritic joint swell of rats through regulating nitric oxide production.

Stress-related hormone norepinephrine (NE) displayed diverse effects on immune system including macrophages, which influenced many kinds of inflammatory diseases. Nitric oxide (NO) from activated macrophages played an important role in inflammatory diseases. In this study, we investigated under chronic restraint stress how NE influenced the joint swell of Complete Freund's Adjuvant (CFA)-induced arthritis of rats and whether NE regulated macrophage's production of NO through influencing phosphorylation of protein kinases C (PKC). The results showed chronic restraint stress exacerbated paw swell of rats with arthritis. Inhibitor of inducible nitric oxide synthase, S-methylisothiourea (SMT), and 6-hydroxydopamine (6-OHDA) could counteract the effect of restraint stress on arthritis. NE, NO and endotoxin in plasma of rats underwent restraint were improved significantly. In vitro experiments, NE could promote macrophage to produce more NO and iNOS when macrophage was activated by lipopolysaccharide (LPS). This effect could be inhibited by α adrenergic antagonist phentolamine. Nevertheless, through α receptor NE could promote the phosphorylation of PKC and PKC inhibitor staurosporine could counteract NE's enhancive effect on production of NO and iNOS of macrophages. This study revealed that NE could exacerbate arthritic joint swell through promoting NO production, which was in α receptor dependent way through enhancing phosphorylation of PKC for NE to enhance the iNOS expression of activated macrophage.

Methanol extract of Phellodendri cortex alleviates lipopolysaccharide-induced acute airway inflammation in mice.

BACKGROUND AND AIM: The effects of methanol extract of Phellodendri cortex on acute airway inflammation induced by intranasal administration of lipopolysaccharide (LPS, 300mug/kg) were investigated in female BALB/c mice. MATERIALS AND METHODS: At 2 h after LPS exposure, mice were treated orally with methanol extract of Phellodendri cortex (100, 200 and 400 mg/kg). At the end of this study, bronchoalveolar lavage fluids (BALF) were collected and number of total cells, macrophages and neutrophils, protein concentration were analyzed. Tumor necrosis factor-alpha (TNF-alpha), macrophage inflammatory protein (MIP-2), IL-10 levels and nitric oxide (NO) production in BALF were also determined. RESULTS: Methanol extract of Phellodendri cortex dose-dependently alleviated LPS-induced acute airway inflammation via decreasing the infiltration of inflammatory cells and the release of inflammatory mediators. CONCLUSION: The relief of airway inflammation provides a possible therapeutic application of Phellodendri cortex for the treatment of infectious pulmonary diseases.

[Effects of salidroside-pretreatment on neuroethology of rats after global cerebral ischemia-reperfusion].

OBJECTIVE: To study the effects of salidroside-pretreatment on changes of neuroethology in rats with global cerebral ischemia-reperfusion injury so as to investigate its probable mechanism. METHODS: Sixty SD male rats were randomly divided into sham-operated group, untreated group and salidroside-pretreated group. The rats in salidroside-pretreated group were intraperitoneally administered with salidroside for seven days. The dose of salidroside was 12 mg/(kg.d). Thirty minutes after the last administration, the acute global cerebral ischemia-reperfusion in rats of the untreated group and the salidroside-pretreated group was induced by using the modified Pulsinelli's 4-vessel occlusion method. Five rats in each group were killed to obtain their brains 24 hours after reperfusion. The water content in the right brain was measured by calculating the ratio of dry weight to wet weight of the right brain. Activity of superoxide dismutase (SOD) and content of malondialdehyde (MDA) in hippocampus of the rats were measured. Then neurological severity scores (NSSs) of the other 15 rats in each group were observed respectively before and 6, 12, 24, 48 and 96 h after reperfusion. At the fifth day after reperfusion, the test of Morris water maze was carried out to examine the memories and learning abilities of the rats. RESULTS: The content of MDA, the activity of SOD, the NSS, the mean incubation period and the ratio of time in the second quadrant in the untreated group were significant different from those in the sham-operated group (P<0.05). Compared with the untreated group, the brain water content, the content of MDA and the NSS degraded, and the mean incubation period shortened in salidroside-pretreated group. The activity of SOD and the ratio of residence time in the second quadrant increased in salidroside-pretreated group as compared with the untreated group (P<0.05). CONCLUSION: Salidroside can reduce the degree of cerebral edema of rats with global cerebral ischemia-reperfusion injury, relieve the metabolism abnormity of free radical and improve the function of cognition.