Improvement of Number 2 Feibi Recipe on pulmonary fibrosis in mice by inhibiting the level of miR-199a-5p and activating autophagy

This study explored the therapeutic potential of Number 2 Feibi Recipe (FBR2), a traditional Chinese medicine prescription, in the treatment of idiopathic pulmonary fibrosis (IPF). Specifically, it investigated whether FBR2 mediated its effects by modulating miR-199a-5p expression, activating the SIRT1/AMPK/mTOR pathway and then promoting autophagy. Eighty-four mice were divided into seven groups: Control, bleomycin (BLM), FBR2, self-complementary adeno-associated virus expressing miR-199a-5p (scAAV-miR-199a-5p), scAAV-negative control (scAAV-NC), FBR2 + BLM + scAAV-miR-199a-5p, and FBR2 + BLM + scAAV-NC. Fluorescence staining, miR-199a-5p expression levels, histopathological changes, protein expression and autophagy activity were assessed using various techniques, including RT-qPCR, histopathological staining, Western blotting, Elisa and transmission electron microscopy (TEM). FBR2 treatment significantly reduced miR-199a-5p expression elevated by BLM and improved histopathology, reduced levels of α-smooth muscle actin (α-SMA) and collagen-III, and increased E-cadherin expression. FBR2 also enhanced autophagy, as evidenced by elevated LC3-II and Beclin-1 levels and reduced p62 expression. Additionally, it activated the SIRT1/AMPK/mTOR pathway. Finally, network pharmacology identified 227 compounds in FBR2, among which Kaempferol and Quercetin (two major shared constituents) showed strong binding to miR-199a-5p in molecular docking, suggesting their potential as key active components. This study showed FBR2 attenuated BLM-induced pulmonary fibrosis in mice by reducing miR-199a-5p expression and promoting autophagy which may be achieved by modulating the SIRT1/AMPK/mTOR pathway. These findings provide novel insights into the mechanism of FBR2 and its potential as a therapeutic approach for IPF.