Ginger-processed Magnoliae Officinalis Cortex ameliorates ovalbumin-induced asthma by alleviating inflammation via the gut-lung axis.

BACKGROUND

The complex pathophysiology of asthma and the lack of effective therapies have driven research into natural product remedies. Ginger-processed Magnoliae Officinalis Cortex (GMOC), a traditional Chinese medicine, has been used for asthma treatment, but the lack of its potential mechanism of action limits the clinical application of GMOC.

PURPOSE

To investigate the mechanism of action of GMOC in asthmatic mice based on the gut-lung axis.

METHODS

The anti-asthma effects of GMOC were evaluated in an ovalbumin (OVA)-induced mouse model of asthma. The lung and gut microbiota were analysed via 16S rRNA gene sequencing and short-chain fatty acids (SCFAs) were determined using GC/MS. Protein expression was evaluated by western blotting. Additionally, the chemical profile of GMOC was elucidated using LC/MS. Candidate compounds targeting target proteins were screened using in silico analysis, and an in vitro experiment was used to preliminarily verify the results.

RESULTS

GMOC mitigated lung inflammation, mucus hypersecretion, and airway hyperresponsiveness (AHR) in asthmatic mice. It modulated the lung and gut microbiota and increased the levels of SCFAs in the colon, resulting in a reduction in inflammatory responses. In addition, GMOC downregulated transient receptor potential (TRP) channels and key proteins in the PI3K/AKT pathway in the lung and colon. The communication between TRPs and the PI3K/AKT pathway was further investigated in vitro using honokiol, the main compound in GMOC. Further, GMOC upregulated the expression of junction proteins in the lungs and colon to protect the epithelial barrier.

CONCLUSION

Crosstalk between organs (lung-gut-microbiota) and proteins (TRPs, junction proteins, and proteins in the PI3K/AKT pathway) contributes to the anti-inflammatory activities of GMOC in asthmatic mice.