%0 Journal Article %A Xu, Tong %A Wang, Cunlian %A Zhang, Ruihua %A Xu, Mingju %A Liu, Baojian %A Wei, Dong %A Wang, Guohua %A Tian, Shufei %T Carnosine markedly ameliorates H9N2 swine influenza virus-induced acute lung injury %D 2015 %J Journal of General Virology, %V 96 %N 10 %P 2939-2950 %@ 1465-2099 %R https://doi.org/10.1099/jgv.0.000238 %I Microbiology Society, %X Oxidative stress injury is an important pathogenesis of influenza virus in critically ill patients. The present study investigated the efficacy of carnosine, an antioxidant and free radical scavenger, on a model of acute lung injury (ALI) induced by H9N2 swine influenza virus. Female specific-pathogen-free BALB/c mice were randomized into four groups and treated as follows: (1) H9N2 group, (2) mock control group, (3) H9N2+carnosine group and (4) carnosine control group. The H9N2 group mice were inoculated intranasally with A/Swine/Hebei/012/2008/ (H9N2) virus (100 μl) in allantoic fluid (AF), whilst mock-infected animals were intranasally inoculated with non-infectious AF. Carnosine [10 mg (kg body mass)− 1] was administered orally (100 μl) for 7 days consecutively. The survival rate, lung water content, TNF-α and IL-1β levels, lung histopathology, myeloperoxidase (MPO) activity, and Toll-like receptor (TLR)-4 levels were determined at 2, 4, 6, 8 and 14 days after inoculation. Carnosine treatment effectively decreased the mortality (43 versus 75 %, P < 0.05), significantly ameliorated pathological lesions in lungs and decreased the lung wet/dry mass ratio (P < 0.05). It also inhibited MPO activity, suppressed TNF-α and IL-1β release, decreased the H9N2 viral titre, and markedly inhibited levels of TLR-4 mRNA and protein in the lungs of infected mice (P < 0.05), which supported the use of carnosine for managing severe influenza cases. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/jgv.0.000238