A Novel Therapeutic Approach for IPF: Based on the "Autophagy - Apoptosis" Balance Regulation of Zukamu Granules in Alveolar Macrophages

Ethnopharmacological Relevance: Zukamu Granules (ZKMG) is one of the representative Uygur patent drugs widely used in China, which is included in the National Essential Drugs List (2018 edition). As the first choice for common cold treatment in Uygur medicine theory, it has unique anti-inflammatory and antitussive efficacy.

Aim Of The Study: According to the recent inflammatory hypothesis, the abnormal proliferation, autophagy and apoptosis process of lung cells especially alveolar macrophages (AMs) may play an important role in the progress of idiopathic pulmonary fibrosis (IPF). Therefore, we came up with a novel treatment approach for IPF by regulating the balance of AMs "autophagy - apoptosis", and took ZKMG as the sample drug for our research.

Materials And Methods: Network pharmacology approach was conducted to predict the active components and intersected targets between ZKMG and inflammation. PPI network, GO and KEGG enrichment analysis were screened and analyzed to predict the anti-inflammatory mechanism of ZKMG. Biological experiment adopted from 128 rats, and hematoxylin-eosin staining, flow cytometry and RT-PCR were performed to examine the pathological morphology, HYP contents in lung tissue, AMs counting, AMs apoptosis, AMs phagocytosis rate, mRNA relative quantity determination of 3 key factors associated with AMs "autophagy - apoptosis" and mRNA relative quantity determination of AMs surface receptor signaling pathway.

Results: The predicted results showed that the mechanism of ZKMG in anti-inflammatory was related to the response and elimination of inflammatory stimuli, the intervention of apoptosis and surface receptor signaling pathways of cells. The verification experiments showed that excessive apoptosis and insufficient autophagy of AMs always existed in the progression of IPF. ZKMG could inhibit AMs proliferation, significantly reduce AMs apoptosis rate, intervene the binding of the Bcl-2 to Beclin 1, inhibit the Caspase 3 activation, stimulate the enhancement of AMs phagocytosis, and inhibit the high expression of TLR4/MyD88/NF-κB surface receptor signaling pathway, which may partly retard the fibrosis process.

Conclusion: By inhibiting proliferation, enhancing phagocytosis, inhibiting the formation of Bcl-2 complex, and inhibiting the high expression of MYD88-dependent TLR4 signaling pathway, ZKMG can regulate the balance of AMs "autophagy - apoptosis" in the alveolitis stage to retard the fibrosis process partly. With a comprehensive strategy of "target prediction - experimental verification", we have demonstrated that inhibiting the apoptosis and promoting autophagy activity of AMs may suggest a new perspective for IPF treatment, which would provide reference for the subsequent development.