Plumbagin alleviates obesity‐related asthma: Targeting inflammation, oxidative stress, and the AMPK pathway

BACKGROUND: Obesity‐related asthma, a specific type of asthma, tends to have more severe symptoms and more frequent exacerbations, and it is insensitive to standard medications. Plumbagin (PLB) has many positive effects on human health. However, it remains unclear whether PLB protects against obesity‐related asthma. The study investigated the effect of PLB on obesity‐related asthma. METHODS: Four‐week‐old male C57BL6/J mice were fed either standard‐chow diet or high‐fat diet (HFD). The mice were sensitized to 100 μg ovalbumin (OVA) once a week and intraperitoneally injected with 1 mg/kg PLB once daily from Week 10 to 11 and then challenged with 10 μg OVA twice a day on Week 12. The lung tissue and bronchoalveolar lavage fluid (BALF) were collected 48 h after the first OVA challenge. RESULTS: HFD enhanced inflammatory cell infiltration within the airways and increased total inflammatory cell and eosinophil counts, levels of eosinophil‐related inflammatory cytokines, including interleukin‐4 (IL‐4), IL‐5, and eotaxin in BALF, and oxidative stress in the lung tissues of asthmatic mice. PLB reduced inflammatory cell infiltration in the airway walls, levels of eosinophil‐related inflammatory cytokines in BALF, and oxidative stress in lung tissues of obese asthmatic mice. In addition, PLB restored HFD‐induced decreases in adenosine monophosphate‐activated protein kinase (AMPK) phosphorylation. CONCLUSION: The study suggested that HFD exacerbated inflammation and oxidative stress, while PLB probably alleviated inflammation and oxidative stress and activated AMPK pathway to attenuate obesity‐associated asthma. Thus, PLB likely had the potential to treat obesity‐related asthma.