3,5-Dimethoxy-4-hydroxy myricanol attenuated oxidative stress-induced toxicity on cardiomyoblast cells

Myricanol attenuates sepsis-induced inflammatory responses by nuclear factor erythroid 2-related factor 2 signaling and nuclear factor kappa B/mitogen-activated protein kinase pathway via upregulating Sirtuin 1

Sepsis, a life-threatening condition characterized by dysregulated immune responses, remains a significant clinical challenge. Myricanol, a natural compound, plays a variety of roles in regulating lipid metabolism, anti-cancer, anti-neurodegeneration, and it could act as an Sirtuin 1 (SIRT1) activator. This study aimed to explore the therapeutic potential and underlying mechanism of myricanol in the lipopolysaccharide (LPS)-induced sepsis model. In vivo studies revealed that myricanol administration significantly improved the survival rate of LPS-treated mice, effectively mitigating LPS-induced inflammatory responses in lung tissue. Furthermore, in vitro studies demonstrated that myricanol treatment inhibited the expression of pro-inflammatory cytokines, attenuated signal pathway activation, and reduced oxidative stress in macrophages. In addition, we demonstrated that myricanol selectively enhances SIRT1 activation in LPS-stimulated macrophages, and all of the protective effect of myricanol were reversed through SIRT1 silencing. Remarkably, the beneficial effects of myricanol against LPS-induced sepsis were abolished in SIRT1 myeloid-specific knockout mice, underpinning the critical role of SIRT1 in mediating myricanol's therapeutic efficacy. In summary, this study provides significant evidence that myricanol acts as a potent SIRT1 activator, targeting inflammatory signal pathways and oxidative stress to suppress excessive inflammatory responses. Our findings highlight the potential of myricanol as a novel therapeutic agent for the treatment of LPS-induced sepsis.

Arsenic trioxide-induced cardiotoxicity triggers ferroptosis in cardiomyoblast cells

Arsenic trioxide (ATO) has been found to be effective in acute promyelocytic leukemia. However, ATO-induced severe cardiotoxicity limits its clinical application. To date, the mechanisms of ATO-induced cardiotoxicity remain unclear. It is hypothesized that ferroptosis may trigger ATO-induced cardiotoxicity; however, this has not yet been investigated. To clarify this hypothesis, rat cardiomyocyte H9c2 cells were treated with ATO with or without ferrostain-1 (Fer-1). The results indicated that ATO exposure induced H9c2 cell death and apoptosis, and the ferroptosis inhibitor Fer-1, administered for 24 h before ATO exposure, suppressed ATO-induced cell death, and apoptosis, as determined by Annexin V-APC/7-AAD apoptosis assay. Furthermore, Fer-1 displayed a cardioprotective effect through inhibiting the ATO-induced production of intracellular reactive oxygen species, improving the ATO-induced loss of the mitochondrial membrane potential, alleviating hyperactive endoplasmic reticulum stress, and alleviating the ATO-induced impairment in autophagy in H9c2 cells. Overall, the cardioprotective effect of Fer-1 against ATO-induced cell injury implies that ATO may trigger ferroptosis to induce cardiotoxicity. These findings lay the foundation for exploring the potential value of ferroptosis inhibitors against ATO-induced cardiotoxicity in the future.