β-Carotene-15,15ʹ-epoxide acts as an XIAP antagonist with pro-apoptotic (Apoptosis) and anti-tumor properties, found in the leaves of Spondias mombin. In rat models of DMBA-induced breast cancer, it induces tumor cell apoptosis by binding to the BIR3 domain of the XIAP protein, thereby inhibiting its interaction with caspase-9. Additionally, β-carotene-15,15ʹ-epoxide significantly reduces BCL-2, COX-2, and TNF-α expression in tumor tissue, decreases MDA levels, enhances catalase activity, and modulates biochemical markers in serum such as LDH, ALP, and ALT, indicating its antioxidant, anti-inflammatory, and metabolic protective effects. This compound is useful for researching inflammation-related diseases and tumors such as breast cancer.