Protective Effects of Atractylodis Rhizoma Extracts on Lung Injury Induced by Particulate Matter 2.5 in Mice

This study investigated the lung-protective effects of Atractylodis Rhizoma extracts (the root of Atractylodes japonica Koidz. ex Kitam), known as AJ extracts, in mitigating subacute pulmonary injuries caused by particulate matter 2.5 (PM2.5) exposure in Balb/c mice. AJ was given orally at concentrations of 400, 200, and 100 mg/kg, demonstrating a promising impact by mitigating oxidative stress and inflammation associated with phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) and p38 mitogen-activated protein kinase α (p38 MAPKα) pathways and reducing mucus overproduction. These protective effects were achieved through the downregulation of p38 MAPKα and PI3K/Akt mRNA expressions, enhanced anti-inflammatory and antioxidant activities, and increased mucolytic expectorant effects arbitrated by elevated lung acetylcholine (ACh) and substance P levels, along with decreased mRNA expressions of MUC5AC and MUC5B. Importantly, these outcomes occurred without significant hepatotoxicity. While all AJ dosages provided dose-dependent pulmonary protection, their effects were less pronounced than those of dexamethasone (DEXA) at 0.75 mg/kg. However, AJ uniquely exhibited mucolytic expectorant activities absent in DEXA-treated mice. The results indicate that A. japonica may serve as a potential candidate for creating alternative treatments for respiratory conditions or as an ingredient in functional foods.