BACKGROUND:Previous research indicated that iron-fluorouracil-phenanthroline complex has good antitumor activity in vitro, which can inhibit the proliferation of human cancer cels. OBJECTIVE:To detect the antitumor activity and toxicity of iron-fluouracil-phenanthroline complex, [Fe(5-Fu)2(Phen)SO4],in vivo. METHODS:A total of 40 Kunming mice were randomly divided into four groups, which were intraperitoneally injected with 72, 102.9, 147, 210 mg/kg [Fe(5-Fu)2(Phen)SO4] and the half lethal dose of the complex was detected. One day after the establishment of mouse S180 sarcoma models, the model mice were randomly divided into eight groups, and administered with the intraperitoneal injection of 15 mg/kg (low dose group), 30 mg/kg (middle dose group), 60 mg/kg (high dose group) [Fe(5-Fu)2(Phen)SO4], normal saline (negative control group), cisplatin (positive control group), 5-fluorouracil, iron-salt and phenanthroline, respectively. The injection was done once a day, lasting for 7 days. The weight of sarcomas, body weight, the main organ coefficient and histopathological changes of the main organs were detected. RESULTS AND CONCLUSION: The half lethal dose of [Fe(5-Fu)2(Phen)SO4] was 103.9 mg/kg. Compared with the negative control group, high dose group, positive control group and 5-fluorouracil could significantly inhibit the growth of the tumor (P< 0.05 orP< 0.01), and the effect of high dose group was the most obvious (P < 0.01). Compared with cisplatin, 60mg/kg [Fe(5-Fu)2(Phen)SO4] had a weaker inhibitory effect on the kidney, but higher inhibitory effect on the liver, spleen and thymus, indicating the complex has a lower nephrotoxicity, but stronger immunotoxicity and hepatotoxicity than cisplatin.