Green tea polyphenol alleviates silica particle-induced lung injury by suppressing IL-17/NF-κB p65 signaling-driven inflammation

Background

Silicosis, an interstitial lung disease caused by inhalation of silica particles, poses a significant health concern globally. Green tea polyphenol (TP) stands out as a promising therapeutic candidate, yet its specific protective effects and in-depth mechanisms against silicosis have not been thoroughly investigated.

Purpose

This study aimed to systematically assess the protective potential of TP against silicosis and to elucidate the underlying mechanisms of its action.

Methods

A combination of physiological, transcriptomic, molecular, and computational techniques was employed. HPLC was used to identify the components of TP, and its antioxidant properties were tested with DPPH and ABTS assays. The effects of TP on lung injury were assessed in silicosis mice using histopathology, qRT-PCR, and western blot. Transcriptomic analysis was applied to explore the differentially expressed genes and pathways in response to TP intervention. In vitro studies with mouse alveolar macrophages (MH-S) examined TP's effects on cell viability, proliferation, apoptosis, and inflammation responses. Integrated qRT-PCR, western blot, immunohistochemistry, and molecular docking were performed to confirm the molecular mechanism underlying the protective effects of TP against silicosis.

Results

TP effectively attenuated pulmonary inflammation and fibrosis in silicosis mice, as evidenced by significant reductions in inflammation and fibrotic markers. Moreover, TP's therapeutic benefits were linked to its cytoprotective effects on alveolar macrophages, notably its ability to protect MH-S cells from silica particle-induced apoptosis, inhibition of proliferation, and inflammatory response, underscoring its targeted protective effects at the cellular level. Mechanistically, TP exerted its anti-silicosis activity by targeting key pathways implicated in inflammatory responses, notably through the inhibition of the IL-17/NF-κB p65 signaling cascade. Molecular docking simulations corroborated these findings, demonstrating favorable binding affinities between TP's bioactive components (EGC, ECG, and EGCG) and crucial proteins (IL-17A, IL-17F, p65, TNF-α, IL-6, and IL-1β) involved in the IL-17/NF-κB p65 signaling pathway. This pathway inhibition led to a significant decrease in the production of pro-inflammatory cytokines, such as TNF-α, IL-6, and IL-1β, thus mitigated silicosis.

Conclusion

TP demonstrates efficacy in alleviating silica particle-induced lung injury by suppressing inflammation through the IL-17/NF-κB p65 signaling pathway, underscoring its potential as a valuable natural compound for silicosis management.