Nobiletin ameliorates heatstroke-induced acute lung injury by inhibiting ferroptosis via p53/SLC7A11 pathway

Abstract

The molecular mechanism for nobiletin’s protective effect against heatstroke-induced acute lung injury (HS-ALI) remains largely unknown. Previous research has demonstrated that ferroptosis is an important pathogenic event in HS-ALI. Nobiletin is a natural polymethoxylated flavonoid. Herein, we investigated the potential contribution of nobiletin to HS-ALI by inhibiting ferroptosis. Heat stress was used to induce HS-ALI in mice, and MLE-12 cells were stimulated by heat stress in vitro. Nobiletin was administrated by gavage for 2 hours before HS induction. Biochemical kits, immunofluorescence staining, and western blotting were performed on the markers of ferroptosis. Our results showed that nobiletin administration significantly attenuated HS-induced lung injury and ferroptosis. Moreover, nobiletin pretreatment significantly reversed HS-induced p53 upregulation in vivo and in vitro. Pretreatment with a p53 agonist, Tenovin-6 partly abolished the protective effect of nobiletin in mice with HS-ALI. Meanwhile, p53 knockdown significantly increased GPX4 and SLC7A11 expression levels compared to the HS group in HS-induced MLE-12 cells. Subsequently, nobiletin ameliorated HS-induced MLE-12 cells ferroptosis by activating the SLC7A11/GPX4 pathway, while p53 overexpression effectively abolished the protective effect of nobiletin. Taken together, our findings reveal that nobiletin attenuates HS-ALI by inhibiting ferroptosis through the p53/SLC7A11 pathway, indicating it to be a potential therapeutic agent for HS-ALI prevention and treatment.