Liuweidihuang Pill ameliorates Pulmonary Fibrosis through anti-inflammation and modulating gut microbiome in mice

Background: Pulmonary fibrosis is a chronic lung disease. Liuweidihuang pill is a TCM prescription primarily indicated for a range of disorders related to kidney-yin deficiency. Emerging pharmacological evidence indicates LD also has anti-inflammatory and antioxidant properties, suggesting its potential in attenuating inflammatory diseases, including PF. However, the efficacy and mechanism of LD in PF therapy is unclear.

Purpose: This study aimed to investigate the effects and mechanisms of LD on bleomycin-induced PF in mice, and elucidate the underlying mechanism.

Methods: Mice were intratracheally administered bleomycin and simultaneously treated with LD. Pathological changes in lung tissue were evaluated with HE and Masson staining. Levels of pro-inflammatory factors and hydroxyproline content were assessed in lung tissue and serum using ELISA. The chemical components of LD were analyzed using UPLC-MS/MS. Gut microbiome in mice was examined using 16S ribosomal DNA sequencing. To investigate the contributions of gut microbiota and LD's absorbed components, we employed fecal microbiota transplantation, probiotic VSL#3 treatment, and in vitro assays with drug-containing serum.

Results: Our findings demonstrated that LD treatment reduced the lung index, alleviated inflammation and decreased interstitial fibrosis in PF mice. The expression of inflammatory cytokines, α-smooth muscle actin protein expression and hydroxyproline content were reduced in LD-treated mice compared to PF group. The study also revealed alterations in gut microbiota following LD treatment. Meanwhile, VSL#3 partially improved lung pathology, while FMT and drug-containing serum showed limited efficacy in both in vivo and in vitro tests.

Conclusion: Taken together, LD shows promise in delaying bleomycin-induced PF progression by modulating gut microbiota and inhibiting inflammatory factors. This study highlights LD's potential as a therapeutic agent for PF.