Therapeutic effects of tilorone on mammary carcinogenesis through downregulation of pro-inflammatory cytokines and oxidative stress

Abstract

Tilorone dihydrochloride (tilorone) is an orally active interferon inducer with anticancer effects. The present study aimed to evaluate the anticancer effects of tilorone in breast cancer. MTT assay was done to measure the proliferation of MCF-7 and MDA-MB-231 breast cancer cells after treatment with tilorone. Mammary carcinogenesis was induced by subcutaneous injection (35 mg/kg, 0.5 mL) of dimethylbenz[a]anthracene (DMBA) in mammary pads of Sprague Dawley (SD) rats. Tumors were allowed to grow for 16 weeks till their sizes reached to 550–700 mm³, and then treated with 10 and 20 mg/kg of tilorone and standard drug doxorubicin (4 mg/kg) twice a week for 3 weeks. Normal and disease-control animals received normal saline. Tumor volumes and body weights were measured. Tumors were isolated to measure the levels of interferon-β (IFN-β), vascular endothelial growth factor-A (VEGF-A), P53 and inflammatory markers by enzyme-linked immunosorbent assay (ELISA). Serum biochemistry, lipid peroxidation (LPO) and antioxidant enzymes were measured by standard methods. Histopathology and immunohistochemistry (IHC) of P53 was done in tumor sections. Tilorone reduced the proliferation of MCF-7 and MDA-MB-231 cells with IC₅₀ concentrations at 34.08 µM and 14.27 µM, respectively. Tilorone treatment showed reduced tumor volume, and increased survival with no significant changes in the body weights. Tilorone treatment also decreased levels of inflammatory markers and VEGF-A and increased IFN-β and P53 levels. Further, treatment with tilorone also decreased LPO and increased antioxidants levels. Histopathology of tumor sections showed normalizing morphology of treated animals. IHC of tumor sections showed increased levels of P53. In conclusion, tilorone has potential anticancer effects against breast cancer.