Eleutheroside B ameliorated high altitude pulmonary edema by attenuating ferroptosis and necroptosis through Nrf2-antioxidant response signaling

High altitude pulmonary edema (HAPE) is a potentially fatal condition induced by exposure to high-altitude environment. Eleutheroside B is a naturally active polyphenolic substance that has previously demonstrated anti-inflammatory, antioxidant and antidepressant properties. However, the effects of eleutheroside B on HPAE are unknown. Here, eleutheroside B (50 mg/kg and 100 mg/kg) was applied to HAPE rats. Eleutheroside B alleviated lung edema and decreased levels of tumor necrosis factor-α, interleukin-1β, vascular endothelial growth factor, and total proteins in the bronchoalveolar lavage fluid. Eleutheroside B reversed the acid-base disturbances by HAPE. In addition, eleutheroside B reversed the oxidative stress. Eleutheroside B pretreatment facilitated the translocation of nuclear factor E2-related factor 2 (Nrf2) into the nucleus, contributing to the inhibition of ferroptosis and necroptosis. ML385 confirmed the role of Nrf2 in ferroptosis and necroptosis. Collectively, the beneficial effects of eleutheroside B against HAPE were associated with the inhibition of ferroptosis and necroptosis through Nrf2-antioxidant response signaling.