Allicin enhances chemotherapeutic response and ameliorates tamoxifen-induced liver injury in experimental animals

Context: Tamoxifen (TAM) is widely used for treatment of hormone-dependent breast cancer; however, it may be accompanied with hepatic injury. Allicin is the most abundant thiosulfinate molecule from garlic with the potential to provide beneficial effects on various diseases.

Objective: To elucidate the effect of commercially available allicin on both antitumor activity and liver injury of TAM.

Materials and methods: The cytotoxicity of TAM and/or allicin was evaluated in vitro using cultured Ehrlich ascites carcinoma (EAC) cells and in vivo against murine tumor (solid) model of EAC. TAM induced liver injury in rats by intraperitoneally (i.p.) injection at a dose of 45?mg/kg, for 7 successive days.

Results: TAM at a dose of 3?µM (IC₅₀) significantly decreased percent survival of EAC to 52%. TAM combination with allicin (5 or 10?µM) showed a significant cytotoxic effect compared with the TAM-treated group as manifested by a decrease in percent survival of EAC to 35% and 29%, respectively. Allicin (10?mg/kg, orally) enhanced the efficacy of TAM (1?mg/kg, i.p.) in mice as manifested by a significant increase in solid tumor growth inhibition by 82% compared with 70% in the TAM group. In rats, TAM intoxication resulted in a significant decline in SOD, GSH, and total protein with significant elevation in TBARS, ALT and AST, ALP, LDH, total bilirubin, γGT, and TNF-α levels. These changes are abrogated by allicin treatment.

Discussion and conclusion: The results suggest the beneficial role of allicin as an adjuvant to TAM in cancer treatment by alleviating liver injury.