Anemoside B4 prevents chronic obstructive pulmonary disease through alleviating cigarette smoke-induced inflammatory response and airway epithelial hyperplasia

Background: Cigarette smoke (CS) is one of the major risk factors for chronic obstructive pulmonary disease (COPD) and increases the risk of lung cancer (LC). Anemoside B4 (B4) is the main bioactive ingredient in Pul-satilla chinensis (P. chinensis), a traditional medicinal herb for various diseases. It has a wide range of anti-inflammatory, anti-oxidation and anti-cancer activities. However, in recent years, there is no relevant litera-ture report on the therapeutic effect of B4 on COPD, and the anti-inflammatory and inhibitory effects of ane-moside B4 on basal cell hyperplasia in CS-induced COPD have not been clearly established. Purpose: In the present study, we investigated whether anemoside B4 could alleviate CS or cigarette smoke extract (CSE) induced inflammation of COPD and further prevent basal cell hyperplasia, hoping to find its possible mechanism. Methods: In this study, a COPD mouse model was established in C57BL mice by CS exposure 3 months. Bronchial pathology and basal cell hyperplasia were observed by HE staining and immunostaining. The contents of glutathione peroxidase catalase (GSH-PX), malondialdehyde (MDA) and superoxide dismutase (MPO) were determined by GSH-PX, MDA and SOD assay kits, respectively. 16HBE cells were cultured with 5% CSE with or without treatment with B4 (1, 10, 100 mu M) or DEX (20 mu M) in vitro. Cell viability was assessed by a cell counting kit 8 (CCK-8). Reactive oxygen species (ROS) generation was tested by DCFH-DA. Moreover, anti-inflammatory mechanism of anemoside B4 was further determined by pro-inflammatory cytokines production using RT-PCR. Protein expression levels of MAPK/AP-1/TGF-beta signaling pathway were measured by western blot. Results: Anemoside B4 improved the lung function of mice, relieved lung inflammation and reduced the MDA, MPO and GSH-Px in the plasma. At the same time, B4 repressed the oxidative stress response and played a role in balancing the levels of protease and anti-protease. During the process of bronchial basal cell hyperplasia, B4 alleviated the degree of cell hyperplasia, and prevented further deterioration of hyperplasia through increased P53 and inhibited FHIT protein. In addition, B4 reduced ROS levels in human bronchial epithelial cells stimu-lated by CSE in vitro study. Meanwhile, B4 treatment also significantly attenuated increased IL-1 beta, TGF-beta, IL-8 and TNF-alpha from CSE treated human bronchial epithelial cells. The expression of p-P38, AP-1(c-fos, and c -Jun), TGF-beta proteins in MAPK/AP-1/TGF-beta signaling pathway were decreased and the signal cascade reaction was blocked. Conclusion: Anemoside B4 protects against CS-induced COPD. These findings indicated that B4 may have ther-apeutic potential for the prevention and treatment of COPD.

Automated summary

Anemoside B4 can alleviate CS-induced inflammation in COPD and prevent basal cell hyperplasia. It exerts its anti-inflammatory effects by inhibiting oxidative stress response, reducing the production of inflammatory cytokines, and regulating protein expression in the MAPK/AP-1/TGF-β signaling pathway.