Role of emodin and aloe-emodin againnst cancer chemotherapy resistance

Cancer is a major health concern characterized by uncontrolled cell proliferation and loss of differentiation, associated with high morbidity and mortality. Osteosarcoma, predominantly observed in children and adolescents, has a poor prognosis due to its rapid metastatic potential. Although chemotherapy and radiotherapy remain the primary treatment approaches, therapeutic resistance often limits their effectiveness. Natural compounds have attracted attention due to their potential anticancer properties. Emodin and aloe-emodin, anthraquinone derivatives isolated from Rheum ribes, are known for their antiproliferative and pro-apoptotic effects. In this study, the effects of these compounds were investigated in the PARP inhibitor-resistant osteosarcoma cell line (U2OS/PIR). WST-1 assays demonstrated a significant reduction in cell viability following treatment with both compounds. Colony formation assays revealed marked inhibition of the cells' clonogenic capacity. ROS and VEGF analyses indicated increased oxidative stress and suppressed angiogenesis, respectively. Furthermore, alterations in apoptosisrelated protein levels confirmed the activation of apoptotic pathways. In conclusion, emodin and aloe-emodin exhibited anticancer effects in osteosarcoma cells, and their combination with PARP inhibitors enhanced therapeutic efficacy, suggesting a potential strategy to overcome drug resistance.