Doxorubicin, a potent anticancer drug, is effective against a wide range of human neoplasms. However, the clinical uses of doxorubicin have been limited due to its serious cardiotoxic effects, which are likely the result of generation of free radicals and lipid peroxidation. S-Allylcysteine (SAC), an organosulfur compound purified from garlic, has been reported to have antioxidant and radical scavenging effects. Thus, we examined the effect of SAC on doxorubicin toxicity in mice. Severe doxorubicin toxicity was induced in mice by a single intraperitoneal injection (15 mg/kg body weight). SAC (30 mg/kg) was injected intraperitoneally daily for 5 days, starting two days prior to the administration of doxorubicin. Body weight was measured every alternate day. A measurement of serum creatine phosphokinase (CPK) and a histopathological analysis of the heart and liver was performed 6 days after the administration of doxorubicin. Death of any of the animals was recorded during the observation period. Doxorubicin injection induced a mortality rate of 58%, with SAC treatment reducing the doxorubicin-induced mortality rate to 30%. The severe body weight loss caused by doxorubicin (13%) was also significantly attenuated by SAC treatment (9%). Although an elevation of the level of serum CPK was observed following doxorubicin injection (5472 +/- 570 i.u./L), treatment with SAC significantly reduced the level of CPK (1923 +/- 635 i.u./L). Histological analysis demonstrated that heart and liver damage was significantly less severe in SAC treated mice than in mice receiving only doxorubicin. These results suggest that SAC research may ultimately lead to a resolution of the adverse effects of doxorubicin treatment in cancer chemotherapy.