Protective effects of pogostone against LPS-induced acute lung injury in mice via regulation of Keap1-Nrf2/NF-κB signaling pathways.

Pogostone, a major component of Pogostemon cablin, has been demonstrated to possess antibacterial, anti-fungal, immunosuppressive and anti-inflammatory properties. To investigate the potential therapeutic effect of pogostone on lipopolysaccharide (LPS)-induced acute lung injury (ALI), mice were pretreated with pogostone prior to LPS exposure. After LPS challenge, the lungs were excised and the histological changes, wet to dry weight ratios, MPO activity reflecting neutrophil infiltration, and MDA activity reflecting oxidative stress were examined. The inflammatory cytokines in the BALF were determined by ELISA assay. Moreover, the expressions of p65 and phosphorylated p65 subunit of NF-κB, and Nrf2 in the nucleus in lung tissues were measured by Western blot analysis, and meanwhile the dependent genes of NF-κB and Nrf2 were assessed by RT-qPCR. The results showed that pretreatment with pogostone markedly improved survival rate, attenuated the histological alterations in the lung, reduced the MPO and MDA levels, decreased the wet/dry weight ratio of lungs, down-regulated the level of pro-inflammatory mediators including TNF-a, IL-1β and IL-6. Furthermore, pretreatment with pogostone enhanced the Nrf2 dependent genes including NQO-1, GCLC and HO-1 but suppressed NF-κB regulated genes including TNF-α, IL-1β and IL-6. The mechanism behind the protective effect was correlated with its regulation on the balance between Keap1-Nrf2 and NF-κB signaling pathways. Therefore, pogostone may be considered as a potential therapeutic agent for preventing and treating ALI.

Sun CY ，Xu LQ ，Zhang ZB ，Chen CH ，Huang YZ ，Su ZQ ，Guo HZ ，Chen XY ，Zhang X ，Liu YH ，Chen JN ，Lai XP ，Li YC ，Su ZR ... -  《-》

β-Patchoulene from patchouli oil protects against LPS-induced acute lung injury via suppressing NF-κB and activating Nrf2 pathways.

β-Patchoulene (β-PAE), a tricyclic sesquiterpene isolated from the essential oil of the leaves and stems of Pogostemon cablin (Blanco) Benth., has been reported to have potent anti-inflammatory activity. The aim of this study was to evaluate the potential protective effect of β-PAE on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and to illuminate the underlying mechanisms. ALI was induced by intracheal instillation of LPS into lung, and dexamethasone (DEX) was used as a positive control. Results indicated that pretreatment with β-PAE significantly decreased the mortality rate of mice and lung W/D weight ratio, ameliorated lung pathological changes as compared to model group. Meanwhile, β-PAE pretreatment markedly inhibited the increase of TNF-α, IL-6 and IL-1β secretions in the bronchoalveolar lavage fluid, and prevented LPS-induced elevations of MPO activity and MDA level in the lung. Additionally, β-PAE pretreatment significantly elevated miR-146a expression and suppressed the LPS-induced activation of NF-κB and expression of its mediated genes (TNF-α, IL-6 and IL-1β). β-PAE was also observed to markedly upregulate the Nrf2 and HO-1 expression and activate the antioxidant genes (NQO-1, GCLC and HO-1). Taken together, β-PAE possessed protective effect against LPS-induced ALI, which might be associated with its differential regulation of NF-κB and Nrf2 activities and up-regulation of expression of miR-146a. The results rendered β-PAE a promising anti-inflammatory agent worthy of further development into a pharmaceutical drug for the treatment of ALI.

Chen XY ，Dou YX ，Luo DD ，Zhang ZB ，Li CL ，Zeng HF ，Su ZR ，Xie JH ，Lai XP ，Li YC ... -  《-》

The protective effect of Trillin LPS-induced acute lung injury by the regulations of inflammation and oxidative state.

Inflammation response and oxidative stress have been reported to be involved in the pathogenesis of acute lung injury (ALI). Accordingly, anti-inflammatory treatment is proposed to be a possible efficient therapeutic strategy for ALI. The purpose of our present study was to evaluate the anti-inflammatory efficacy of trillin (Tr) on ALI induced by lipopolysaccharide (LPS) in mice and explore the underlying mechanism. BALB/c mice received Tr (50, 100 mg/kg) intraperitoneally 1 h prior to the intratracheal instillation of lipopolysaccharide (LPS) challenge. Pretreatment with Tr at the dose of 50, 100 mg/kg markedly ameliorated lung wet-to-dry weight (W/D) ratio, myeloperoxidase (MPO) activity and pulmonary histopathological conditions. In addition, the protective efficacy of Tr might be attributed to the down-regulations of neutrophil infiltration, malondialdehyde (MDA), inflammatory cytokines and the up-regulations of super-oxide dismutase (SOD), catalase(CAT), glutathione(GSH), Glutathione Peroxidase(GSH-Px) in bronchoalveolar lavage fluid (BALF). Meanwhile, our study revealed some correlations between (NF-E2-related factor 2) Nrf2/heme oxygenase (HO)-1/nuclear factor-kappa B (NF-κB) pathways and the beneficial effect of Tr, as evidenced by the significant up-regulations of HO-1 and Nrf2 protein expressions as well as the down-regulations of p-NF-κB and p-inhibitor of NF-κB (IκB) in lung tissues. Taken together, our results indicated that Tr exhibited protective effect on LPS-induced ALI by the regulations of related inflammatory events via the activations of Nrf2, HO-1 and NF-κB pathway. The current study indicated that Tr could be a potentially effective candidate medicine for the treatment of ALI.

Jiang W ，Luo F ，Lu Q ，Liu J ，Li P ，Wang X ，Fu Y ，Hao K ，Yan T ，Ding X ... -  《-》

Pogostone attenuates TNF-α-induced injury in A549 cells via inhibiting NF-κB and activating Nrf2 pathways.

Pogostone (PO), a major component of Pogostemon cablin, displays potent protective effects against lipopolysaccharide-induced acute lung injury (ALI) in mice. This study aimed to investigate the protective effect of PO on TNF-α-induced cell injury in human alveolar epithelial cells in vitro and its underlying mechanism. The cell viability was measured using the MTS method. The cell apoptosis was determined using flow cytometry. The activities of reactive oxygen species (ROS) were detected using a fluorescence microscope. The pro-inflammatory cytokines and antioxidant genes were assessed using reverse transcription-polymerase chain reaction. The protein expression of Kelch-like ECH-associated protein 1 (Keap1), nuclear factor erythroid 2-related factor 2 (Nrf2), nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha (IκBα), and nuclear factor-kappa B (NF-κB) p65 was analyzed using the Western blot analysis. PO alleviated cell apoptosis and inhibited ROS production. It alleviated TNF-α-induced cell injury, suppressed the levels of inflammatory cytokines [interleukin (IL)-6, IL-1β, and IL-8], and enhanced the expression of antioxidant genes (quinine oxidoreductase 1, glutamate cysteine ligase catalytic subunit, heme oxygenase-1). It increased the expression of Keap1 and promoted the activation of Nrf2. However, the phosphorylation of IκBα and the nuclear expression of NF-κB p65 decreased. The anti-inflammatory and antioxidant effects of PO were abrogated following Nrf2 and NF-κB p65 knockdown. The results indicated a protective effect of PO against TNF-α-induced cell injury in A549 cells by modulating the balance between Nrf2 and NF-κB p65 signaling pathways. They verified PO as a promising anti-inflammatory adjuvant drug for treating ALI.

Yang HM ，Zhuo JY ，Sun CY ，Nie J ，Yuan J ，Liu YL ，Lin RF ，Lai XP ，Su ZR ，Li YC ... -  《-》

Protective effect of taraxasterol on acute lung injury induced by lipopolysaccharide in mice.

Taraxasterol, a pentacyclic-triterpene isolated from Taraxacum officinale, has been reported to have potent anti-inflammatory properties. However, the effect of taraxasterol on lipopolysaccharide (LPS)-induced mice acute lung injury has not been investigated. The aims of this study were to investigate whether taraxasterol could ameliorate the inflammation response in LPS-induced acute lung injury and to clarify the possible mechanism. Male BALB/c mice were pretreated with taraxasterol 1h before intranasal instillation of LPS. 7h after LPS administration, the myeloperoxidase (MPO) in lung tissues, lung wet/dry ratio and inflammatory cells in the bronchoalveolar lavage fluid (BALF) were detected. The levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β) in the BALF were measured by ELISA. The extent of phosphorylation of IκB-α, p65 NF-κB, p46-p54 JNK, p42-p44 ERK, and p38 were determined by western blotting. The results showed that taraxasterol attenuated the infiltration of inflammatory cells, the activity of myeloperoxidase (MPO), lung wet/dry ratio, and the expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) in a dose-dependent manner. Additionally, western blotting results showed that taraxasterol inhibited the phosphorylation of IκB-α, p65 NF-κB, p46-p54 JNK, p42-p44 ERK, and p38 caused by LPS. Our data suggest that anti-inflammatory effects of taraxasterol against the LPS-induced ALI may be due to its ability of inhibition of the NF-κB and MAPK signaling pathways.

San Z ，Fu Y ，Li W ，Zhou E ，Li Y ，Song X ，Wang T ，Tian Y ，Wei Z ，Yao M ，Cao Y ，Zhang N ... -  《-》