The effect of Wogonoside on the expression of TGF-β1/Smad3 in Mycoplasma pneumoniae pneumonia

Screening active compounds from complex herbal extracts is an important part of the drug mechanism research. The present study describes the establishment and application of a sensitive, convenient and efficient method for screening active ingredients targeting pulmonary fibrosis factor TGF-β1 from Radix Scutellariae extracts based on the surface plasmon resonance (SPR) biosensors. Previous studies have proved that Qin bai qing fei pellet (Qin bai) can inhibit the expression of TGF-β1 in Mycoplasma pneumoniae pneumonia (MPP). Radix Scutellariae is the main component of Qin bai. However, the mechanism of Radix Scutellariae inhibiting TGF-β1 expression remains unexplained. The study investigated the active compound in Radix Scutellariae which was bound with TGF-β1 by SPR and UPLC-Q-TOF-MS techonology. As a result, Radix Scutellariae extracts showed a good combination with the TGF-β1 in vitro. Wogonoside was identified as a bioactive ingredient by UPLC-Q-TOF-MS. The affinity constant of Wogonoside to TGF-β1 was determined by SPR affinity analysis (KD=21.7 μm). Pharmacology assays revealed that Wogonoside strongly inhibited the expression of TGF-β1 and Smad3 in A549 cells infected by Mycoplasma pneumoniae(M.pneumoniae). Wogonoside prevented Mycoplasma pneumoniae infection by inhibiting the expression of TGF-β1, which might be one of the mechanisms for the anti-MPP properties of Qin bai. These results provided a foundation to further explore the mechanisms of Qin bai.