EIF2AK3 and chronic obstructive pulmonary disease: The results were further confirmed through in vitro cellular assays.<h4>Results</h4>The study found that BFNSP improved pulmonary ventilation, reduced lung tissue damage, decreased inflammatory factor secretion, and alleviated oxidative and endoplasmic reticulum stress in COPD rats by inhibiting the PERK/eIF2α signaling pathway, potentially slowing COPD progression.<h4>Conclusion</h4>BFNSP mitigates COPD progression by regulating endoplasmic reticulum stress via the suppression of the PERK/eIF2α signaling pathway.