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 <i>Atractylodes japonica</i> Koidz. ex Kitam), known as AJ extracts, in mitigating subacute pulmonary injuries caused by particulate matter 2.5 (PM_2.5) 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 (<i>PI3K/Akt</i>) and p38 mitogen-activated protein kinase α (<i>p38 MAPKα</i>) pathways and reducing mucus overproduction. These protective effects were achieved through the downregulation of <i>p38 MAPKα</i> and <i>PI3K/Akt</i> 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 <i>MUC5AC</i> and <i>MUC5B</i>. 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 <i>A. japonica</i> may serve as a potential candidate for creating alternative treatments for respiratory conditions or as an ingredient in functional foods.