High mobility group box 1 (HMGB1) is now recognized as a late mediator of sepsis. We tested hypothesis that ascorbic acid (AscA) induces heme oxygenase (HO)-1 which inhibits HMGB1 release in lipopolysaccharide (LPS)-stimulated cells and increases survival of septic mice. AscA increased HO-1 protein expression in a concentration- and time-dependent manner via Nrf2 activation in RAW 264.7 cells. HO-1 induction by AscA was significantly reduced by Nrf2 siRNA-transfected cells. Mutation of cysteine to serine of keap-1 proteins (C151S, C273S, and C288S) lost the ability of HO-1 induction by AscA, due to failure of translocation of Nrf-2 to nucleus. The PI3 kinase inhibitor, LY294002, inhibited HO-1 induction by AscA. Oxyhemoglobin (HbO2), LY294002, and ZnPPIX (HO-1 enzyme inhibitor) reversed effect of AscA on HMGB1 release. Most importantly, administration of AscA (200mg/kg, i.p.) significantly increased survival in LPS-induced endotoxemic mice. In cecal ligation and puncture (CLP)-induced septic mice, AscA reduced hepatic injury and serum HMGB1 and plasminogen activator inhibitor (PAI)-1 in a ZnPPIX-sensitive manner. In addition, AscA failed to increase survival in Nrf2 knockout mice by LPS. Thus, we concluded that high dose of AscA may be useful in the treatment of sepsis, at least, by activation of Nrf2/HO-1 signals.

We investigated the effects of hyperbaric oxygen treatment on the Nrf2 signaling pathway in secondary injury following traumatic brain injury, using a rat model. An improved Feeney freefall method was used to establish the rat traumatic brain injury model. Sixty rats were randomly divided into three groups: a sham surgery group, a traumatic brain injury group, and a group receiving hyperbaric oxygen treatment after traumatic brain injury. Neurological function scores were assessed at 12 and 24 h after injury. The expression levels of Nrf2, heme oxygenase 1 (HO-1), and quinine oxidoreductase 1 (NQO-1) in the cortex surrounding the brain lesion were detected by western blotting 24 h after the injury. Additionally, the TUNEL method was used to detect apoptosis of nerve cells 24 h after traumatic injury and Nissl staining was used to detect the number of whole neurons. Hyperbaric oxygen treatment significantly increased the expression of nuclear Nrf2 protein (P<0.05), HO-1, and NQO-1 in the brain tissues surrounding the lesion after a traumatic brain injury (P<0.05) and also significantly reduced the number of apoptotic and injured nerve cells. The neurological function scores also improved with hyperbaric oxygen treatment (P<0.05). Therefore, hyperbaric oxygen has a neuroprotective role in traumatic brain injury, which is mediated by up-regulation of the Nrf2 signaling pathway.

Hericium erinaceus (HE) is an edible mushroom that has been shown to exhibit anticancer and anti-inflammatory activities. We investigated the antiangiogenic and antioxidant potentials of ethanol extracts of HE in human endothelial (EA.hy926) cells upon tumor necrosis factor-α- (TNF-α-) stimulation (10 ng/mL). The underlying molecular mechanisms behind the pharmacological efficacies were elucidated. We found that noncytotoxic concentrations of HE (50-200 μg/mL) significantly inhibited TNF-α-induced migration/invasion and capillary-like tube formation of endothelial cells. HE treatment suppressed TNF-α-induced activity and/or overexpression of matrix metalloproteinase-9 (MMP-9) and intercellular adhesion molecule-1 (ICAM-1). Furthermore, HE downregulated TNF-α-induced nuclear translocation and transcriptional activation of nuclear factor-κB (NF-κB) followed by suppression of I-κB (inhibitor-κB) degradation. Data from fluorescence microscopy illustrated that increased intracellular ROS production upon TNF-α-stimulation was remarkably inhibited by HE pretreatment in a dose-dependent manner. Notably, HE triggered antioxidant gene expressions of heme oxygenase-1 (HO-1), γ-glutamylcysteine synthetase (γ-GCLC), and glutathione levels, which may contribute to inhibition of ROS. Increased antioxidant status was associated with upregulated nuclear translocation and transcriptional activation of NF-E2 related factor-2 (Nrf2) in HE treated cells.Our findings conclude that antiangiogenic and anti-inflammatory activities of H. erinaceus may contribute to its anticancer property through modulation of MMP-9/NF-κB and Nrf2-antioxidant signaling pathways.

Oxidative stress, inflammation, and foam cell formation in vascular smooth muscle cells (VSMCs) are considered to play crucial roles in the pathogenesis of atherosclerosis. Poria cocos polysaccharides (PCP) has been shown to possess anti-inflammatory, antitumor and anti-oxidative properties. In this study we explored the effects of PCP on ox-LDL-induced inflammation, oxidative stress and foam cell formation in VSMCs. PCP significantly attenuated ox-LDL-induced oxidative stress, as evidenced by the decreased reactive oxygen species (ROS) and MDA levels, and the increased SOD activity in VSMCs. PCP suppressed the induction effect of ox-LDL on inflammatory cytokines and inflammatory mediators. PCP also substantially inhibited VSMCs foam cell formation and intracellular lipids accumulation. Mechanistically, PCP suppressed ox-LDL-induced up-regulation of LOX-1, which is responsible for ox-LDL uptake. Western blotting suggested that PCP activated ERK1/2 signaling pathway, increased Nrf2 translocated from cytoplasm to nucleus and heme oxygenase-1 (HO-1) expression. Up-regulation of PCP on Nrf2/HO-1 signaling was reversed by pretreatment with ERK inhibitor PD98059, indicating the involvement of ERK in PCP activation of Nrf2/HO-1 signaling. In conclusion, these results demonstrated that PCP exerted its protection against oxidative stress and inflammation via the ERK/Nrf2/HO-1 signaling pathway and that PCP may be a promising candidate for the therapy of atherosclerosis.

Recent studies show that low-level laser therapy (LLLT) has an important anti-inflammatory action in acute lung inflammation. The present work explored if laser therapy is able to antagonize eosinophils and allergic inflammation induced by oxidative stress in Balb/c mice. Forty-eight hours after challenge, the leukocyte counting, ROS and nitrite/nitrate level, RANTES, CCL3, CCL8 as well as eotaxins were measured in the bronchoalveolar lavage fluid (BALF) of laser-treated mice or not. Into the lung, some chemokines receptors, the iNOS activity and mRNA expression, and the activities of superoxide dismutase (SOD), catalase, gluthatione, NADPH oxidase activities and thiobarbituric acid reactive species (T-Bars) were measured. Laser-treated allergic mice presented reduction of both the ICAM-1 and eosinophil in the lungs. RANTES, CCL8, CCL3 and eotaxins were reduced in BALF of laser-treated allergic mice. In allergic mice lung LLLT decreased the CCR1 and CCR3 and restored the oxidative stress balance as well. Laser decreased the lipidic peroxidation in allergic mice lung as much as increased SOD, GPx and GR. It shows that LLLT on allergic lung inflammation involves leukocyte-attractant chemokines and endogenous antioxidant. Based on results, LLLT may ultimately become a non- invasive option in allergic lung disease treatment. The top figure illustrates the laser decreasing the eosinophils migration into BALF and the bottom figure shows the laser upregulating the expression of heme-oxygenase (anti-oxidant enzyme) in lung tissue anti-oxidant.