Effect of Guben Fangxiao Decoction regulating iron metabolism, inhibiting airway epithelial cells ferroptosis and improving the remission period of asthma

This study aims to observe the effects of Guben Fangxiao Decoction (GBFXD) on inhibit ferroptosis of airway epithelial cells by regulating iron metabolism, thereby playing a role in the prevention and treatment of the asthma remission. The animal experiments have been approved by the Ethics Committee of the Animal Experiment Center of Nanjing University of Chinese Medicine (approval number: 202401A044). Female Balb/c mice were randomly divided into control group, model group, GBFXD low-, medium-, and high-dose groups 12, 24, 36 g·kg^-1 (crude drug), and montelukast sodium group (2.6 mg·kg^-1). Except for the control group, the other groups of mice were used to establish a mouse model of the remission period of asthma with ovalbumin. Hematoxylin-eosin staining (HE) of the lung tissue of mice was observed and the inflammation score was conducted; the levels of interleukin 33 (IL-33), tumor necrosis factor-α (TNF-α), and high mobility histone B1 (HMGB1) in the lung tissue were detected by enzyme-linked immunosorbent assay (ELISA); the expression of solute carrier family 7 member 11 (SLC7A11), glutathione peroxidase 4 (GPX4), and long-chain acyl-CoA synthase 4 (ACSL4) in the lung tissue was observed by immunohistochemistry; the content of lipid peroxides (LPO) and ferrous ions (Fe²⁺) in the lung tissue was detected. The protein expression levels of SLC7A11, GPX4, ACSL4, transferrin receptor 1 (TFR1), ferritin heavy chain 1 (FTH1), nuclear receptor co-activator 4 (NCOA4), and ferroportin 1 (FPN1) in 16HBE of each group were detected by Western blot; the expression of Fe²⁺ in 16HBE of each group was detected. The results of HE staining of lung tissue showed that GBFXD could reduce inflammatory infiltration in the periairway region of mice (P < 0.05). The results of ELISA showed that GBFXD down-regulated the levels of IL-33, TNF-α and HMGB1 in lung tissue of mice (P < 0.05). Immunohistochemical results showed that GBFXD could up-regulate the expression of SLC7A11 and GPX4 in the lung tissue of mice, and down-regulate the expression of ACSL4 (P < 0.05). Biochemical results showed that GBFXD treatment reduced LPO accumulation in lung tissue of mice and Fe²⁺ accumulation in lung tissue and 16HBE cells (P < 0.05). Western blot results showed that GBFXD up-regulated the expressions of SLC7A11, GPX4, FTH1, FPN1 in 16HBE cells, and down-regulated the expressions of ACSL4, TFR1 and NCOA4 in 16HBE cells (P < 0.05). These results suggest that GBFXD can inhibit ferroptosis of airway epithelial cells, reduce airway epithelial damage, alleviate airway inflammation, and prevent and treat the remission period of asthma. Its mechanism of inhibiting ferroptosis may be related to the regulation of iron metabolism-related protein expression and the reduction of Fe²⁺ accumulation.