Resveratrol protects against asthma-induced airway inflammation and remodeling by inhibiting the HMGB1/TLR4/NF-κB pathway

The aim of the present study was to explore the protective role of resveratrol (RES) in asthma-induced airway inflammation and remodeling, as well as its underlying mechanism. An asthma rat model was induced by ovalbumin (OVA) treatment. Rats were randomly assigned into sham, asthma, 10 mu mol/l RES and 50 mu mol/l RES groups. The amount of inflammatory cells in rat bronchoalveolar lavage fluid (BALF) was detected. Pathological lesions in lung tissues were accessed by hematoxylin and eosin (H&E), and Masson's trichrome staining. Levels of inflammatory factors in lung homogenate were detected via ELISA. The blood serum of asthmatic and healthy children was also collected for analysis. Reverse transcription-quantitative polymerase chain reaction was performed to detect high mobility group box 1 (HMGB1), Tau oll-like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (MyD88) and NF-kappa B expression in asthmatic and healthy children, as well as rats of the different groups. H&E staining demonstrated that multiple inflammatory cell infiltration into the rat airway epithelium of the asthma group occurred whilst the 50 mu mol/l RES group displayed alleviated pathological lesions. Masson staining indicated that there was an increased airway collagen deposition area in the asthma and 10 mu mol/l RES groups compared with the 50 mu mol/l RES group. The number of inflammatory cells in BALF extracted from rats of the asthma and 10 mu mol/l RES groups was higher compared with the 50 mu mol/l RES group. Treatment with 50 mu mol/l RES significantly decreased the thicknesses of the airway wall and smooth muscle. ELISA results illustrated that interleukin (IL)-1, IL-10 and tumor necrosis factor-alpha (TNF-alpha) levels were elevated, whereas IL-12 level was reduced in lung tissues of the asthma and 10 mu mol/l RES groups whilst the 50 mu mol/l RES group demonstrated the opposite trend. HMGB1, TLR4, MyD88 and NF-kappa B mRNA levels were remarkably elevated in rats of the asthma and 10 mu mol/l RES groups compared with the 50 mu mol/l RES group. Serum levels of IL-1, IL-10 and TNF-alpha were elevated, whereas IL-12 was reduced in asthmatic children compared with healthy children. The present results demonstrated that a large dose of RES alleviated asthma-induced airway inflammation and airway remodeling by inhibiting the release of inflammatory cytokines via the HMGB1/TLR4/NF-kappa B pathway.