Hydrogen combined with tetrandrine attenuates silica-induced pulmonary fibrosis via suppressing NF-kappaB/NLRP3 signaling pathway-mediated epithelial mesenchymal transition and inflammation.

Silicosis is a progressive disease characterized by interstitial fibrosis resulting from inhalation of silica particles, and currently lacks specific treatment. Hydrogen (H) has demonstrated antioxidative, anti-inflammatory, and anti-fibrotic properties, yet its efficacy in treating silicosis remains unexplored. In this study, rats exposed to silica were administered interventions of H combined with tetrandrine, and euthanized at 14, 28, and 56 days post-intervention. Lung tissues and serum samples were collected for analysis. Histological examination, MDA assay, enzyme-linked immunosorbent assay, hydroxyproline assay, and Western blotting were employed to assess the impact of H combined with tetrandrine on pulmonary fibrosis. The results revealed that this combination significantly alleviated inflammation in silicosis-afflicted rats, effectively suppressed levels of MDA, TNF-α, and IL-1β expression, and inhibited epithelial-mesenchymal transition (EMT), thereby ameliorating pulmonary fibrosis. Notably, protein expression level of E-cadherin was increased，however protein expression levels of vimentin and α-SMA were reduced, and TGF-β were reduced, alongside a significant decrease in hydroxyproline content. Furthermore, H combined with tetrandrine downregulated protein expression of NF-κB p65, NF-κB p-p65, Caspase-1, ASC, and NLRP3. These findings substantiate the hypothesis that H combined with tetrandrine mitigates inflammation associated with silicosis and suppresses the EMT process to ameliorate fibrosis via the NF-κB/NLRP3 signaling pathway. However, the pressure of airway opening was not assessed in this study and dynamic readings of lung physiological function were not obtained, which is a major limitation of this study.