Comparison of the therapeutic effects of two vanadium complexes administered at low dose on benzo[a]pyrene-induced malignant tumors in rats.
The antitumor effects of low dose administration of the vanadium(III) complexes with L-cysteine (complex 1) and N-(2-mercaptopropionyl)-glycine (complex 2) were compared on benzo[a]pyrene (BaP)-induced tumors in Wistar rats. Male Wistar rats, injected with 10.0 mg of BaP, were divided into one control (C-G) and two treatment (TR-G) groups of 17 animals each. Animals of the first treatment group were administered complex 2 (TR-2 group) and those of the second group were administered complex 1 (TR-1 group) at doses of 100 microg of vanadium per os daily, starting from the day a palpable tumor was developed till their death. BaP injection induced a 100% tumor (leiomyosarcomas) development in the animals of all groups. Administration of complex 1 to the animals resulted in a significant prolongation of the mean survival time, a complete remission of 17.6% of the tumors developed, a significant reduction of the carcinogenic potency (CP) of BaP and of the tumor growth rate (TGR) in TR-1 group animals, compared to the control and the TR-2 group. In marked contrast, complex 2 failed at the doses administered to exert any significant modulation of the above mentioned parameters. Results indicate that at low (100 micro/day) concentrations of vanadium, complex 1 exerts a significant anticarcinogenic effect on experimentally-induced leiomyosarcomas in rats, whereas complex 2 has no effect when administered at the same low concentrations of vanadium.
Evangelou
A
A
Laboratory of Experimental Physiology, Faculty of Medicine, University of Ioannina, Greece.
Karkabounas
S
S
Kalpouzos
G
G
Malamas
M
M
Liasko
R
R
Stefanou
D
D
Vlahos
A T
AT
Kabanos
T A
TA
D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001564:Benzo(a)pyrene; D002273:Carcinogens; D004354:Drug Screening Assays, Antitumor; D007890:Leiomyosarcoma / Q000139:chemically induced / Q000188:drug therapy*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012513:Sarcoma, Experimental / Q000139:chemically induced / Q000188:drug therapy*; D016019:Survival Analysis; D017968:Vanadium Compounds / Q000627:therapeutic use*
D000970:Antineoplastic Agents; D002273:Carcinogens; D017968:Vanadium Compounds; D001564:Benzo(a)pyrene