Effects of N-acetylcysteine on oxidative stress and inflammation reactions in a rat model of allergic rhinitis after PM2.5 exposure
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
Authors: Wang, Jinchao; Guo, Zhiqiang; Zhang, Ruxin; Han, Zhijin; Huang, Yu; Deng, Congrui; Dong, Weiyang; Zhuang, Guoshun
Particulate matter 2.5 (PM2.5) exposure can increase the prevalence of allergic rhinitis (AR), the mechanism underlying which may include oxidative stress and inflammatory response. As a ROS quenching agent, N-acetylcysteine (NAC) can attenuate the accumulation of inflammatory cells and hyper-responsiveness in animal asthma models. To explore the effect of NAC on the oxidative stress and inflammatory reactions in AR rats exposed to PM2.5, we analyzed the components of PM2.5 and examined the nasal symptoms, redox level in nasal mucosa, Th1/Th2-related serum cytokines, nasal mucosal histopathology and ultrastructure in AR rat models with NAC intervention after PM2.5 exposure. The results showed that the high concentrations of metal cations and PAHs in PM2.5 could aggravate Th2-dominant allergic inflammation in AR model and cause redox imbalance, accompanied by nasal epithelial cell stripping and eosinophil infiltration, while NAC intervention could alleviate the clinical symptoms of AR model after PM2.5 exposure, correct the redox imbalance, reduce the Th2 cytokines, reduce eosinophil infiltration, and promote the moderate regeneration of epithelial cells. The mechanism of NAC reversing PM2.5-mediated action may be related to its anti-oxidant and anti-inflammatory effects, which may provide some new insights for the prevention of AR exacerbated by exposure to PM2.5. (C) 2020 Elsevier Inc. All rights reserved.
The effects of toxigenic Clostridium perfringens types A and D on survival, as well as innate immune, inflammatory and oxidative stress responses in Nile tilapia
Authors: El-Houseiny, Walaa; Khalil, Alshimaa A.
This study was performed to assess the ability of Clostridium perfringens types A and D to induce immunological and inflammatory alterations, and mortalities in Nile tilapia (Oreochromis niloticus). Healthy Nile tilapia (n = 90) with an average body weight of 35 +/- 0.5 g were randomly divided into three triplicate groups with ten fish in each aquarium. Fish were injected intraperitoneally (IP) with 0.1 mL of 2.4 x 10(8) CFU/mL of C. perfringens type A in the first group (G(1)) and type D in the second group (G(2)). Fish in the third group (G(3)) were IP injected with sterile saline and served as control. Clinical signs and postmortem lesions of infected fish started appearing on day 1 post-infection (PI), and the cumulative mortality rates were recorded as 50%, 73%, and 0% in G(1), G(2), and G(3) groups, respectively. Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activities in the G(1) and G(2) showed a significant gradual decrease, and reached a peak on day 14, compared to the control group, whereas malondialdehyde (MDA) activity was significantly increased at all-time intervals in G(1) and G(2). TNF-alpha showed a significant increase only on day 14 in G(1) and G(2) compared to the control group. Myeloperoxidase activity (MPO) of both G(1) and G(2) was increased significantly on day 7 and day 14 compared to the control group and other time periods of exposure. Nitric oxide (NO) activity decreased gradually at 24 h and on day 7 and day 14 for G(1) and G(2), respectively. The inflammatory biomarker IL-1 beta showed a significant gradual increase, which reached a peak on day 7 for both G(1) and G(2) in comparison to control. IL-6 reached a peak on day 14 for G(1) and on day 7 for G(2). Significant down-regulation of IL-10 occurred on days 7 and 14 post challenge. There was a gradual increase in serum proteins in G(1) and G(2) which attained a peak on day 14, except gamma-globulin, which showed a significant decrease in the same trend. The albumin level decreased gradually in G(1) and G(2) and among the different periods, and reached a peak at 24 h, followed by on day 7 and finally, on day 14. Lysozyme activity and IgM initially showed a significant increase at 24 h in the G(1) and G(2) groups compared to the control group and other time periods of exposure; later, decreased gradually on day 7 and day 14. There was a significant decline in complement 3 in G(1) and G(2) on day 14, followed by day 7 and a significant increase at 24 h. This study has shown that C. perfringens types A and D could be important causative agents of disease and mortality in cultured Nile tilapia species.