HMOX1 and adrenal gland pheochromocytoma: The structures of new steroids 41–43 were elucidated by comprehensive spectroscopic analysis and steroid 41 was found to show protection against hydrogen-peroxide (H2O2)-induced oxidative damage in neuron-like PC-12 (rat adrenal gland pheochromocytoma) cells by promoting nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and enhancing the expression of heme oxygenase-1 (HO-1) [60].