Artemisia argyi H.Lév. & Vaniot essential oil induces ferroptosis in pancreatic cancer cells via up-regulation of TFR1 and depletion of γ-glutamyl cycle

Artemisia argyi H.Lév. & Vaniot, a traditional Chinese medicine with a history spanning over two millennia, has been extensively used in folk medicine to treat dysmenorrhea, uterine bleeding and inflammation. Recent studies have demonstrated that the essential oil extracted from Artemisia argyi H.Lév. & Vaniot, known as AAEO, exhibits significant anti-tumor properties against liver and lung cancers. There is a scarcity of research on the potential impact of AAEO on pancreatic cancer (PC) cells. In this study, UPLC-MS/MS-based metabolomics method was established to evaluate the effect of AAEO on the proliferation of PC cells. The differential compounds included 5-oxoproline, glutamate, γ-glutamylcysteine, glutathione, arachidonic acid, adrenal acid and linoleic acid were detected by metabolomics, enriching in the γ-glutamyl cycle and polyunsaturated fatty acid metabolism, which were closely related to ferroptosis. Meanwhile, AAEO dramatically increased the levels of intracellular iron ion via up-regulation of TFR1, augmented reactive oxygen species and malondialdehyde in a dose-dependent manner by down-regulation of γ-glutamyl cycle through decreasing expressions of SLC7A11. Additionally, β-caryophyllene oxide, one of the main components of AAEO, could covalently bind to Cys in SW1990 cells to form a conjugate Cpo-Cys, resulting in the inhibition of glutathione synthesis. Importantly, the ferroptosis inhibitor deferoxamine significantly blocked the inhibitory effect of AAEO on SW1990 cells. Meanwhile, β-caryophyllene oxide, dihydro-β-ionone and α-bisabolol had strong binding force with GPX4, SLC7A11 and TFR1, respectively. These findings showed that AAEO induced ferroptosis via regulation of γ-glutamyl cycle by SLC7A11 and iron disorders by TFR1. Our study discovered AAEO as a potential therapeutic approach to induce ferroptosis to prevent or treat PC.