Mitomycin C-activity effected by vitamins B1, C, E and beta-carotene under irradiation with gamma-rays.
Vitamin B1 (thiamine) can essentially effect the activity of mitomycin C (MMC), added individually or in combination with antioxidant vitamins (C, E-acetate, beta-carotene) as found in experiments in vitro (Escherichia coli bacteria, AB 1157) under irradiation with gamma-rays. The environment plays a crucial role. In airfree media vitamin B1 leads to a 2-fold increase of the MMC-efficiency, but adding vitamin C it decreases. In the presence of all vitamins (B1, C, E-ac., and beta-carotene) the MMC-action increases about 1.8-fold. In aerated media vitamin B1 causes an about 4-times increase of the MMC-efficiency, but by adding vitamin B1 and C the MMC-activity decreases by a factor of two, whereas in the presence of B1, C, E-ac., and beta-carotene it rises again to 2.6-fold. In environment saturated with N2O (conversion of e(-)aq into OH radicals) a different picture is observed. The presence of vitamin B1 or vitamin B1 + C causes a strong decrease of the MMC-efficiency, but the addition of all vitamins (B1, C, E-ac., and beta-car.) leads to a small increase of the cytostatic action. The results demonstrate the influence of vitamin B1 used individually or in combination with other antioxidants on the MMC-efficiency and the strong effect of the environment. The results are of interest for the application of MMC in radiotherapy.
Heinrich
Edith
E
Institute for Theoretical Chemistry and Structural Biology, The University of Vienna, Althanstr.14, A-1090 Vienna, Austria.
Getoff
Nikola
N
D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects* / Q000254:growth & development; D005720:Gamma Rays; D007700:Kinetics; D016685:Mitomycin / Q000494:pharmacology* / Q000528:radiation effects*; D013831:Thiamine / Q000494:pharmacology; D014810:Vitamin E / Q000494:pharmacology; D014815:Vitamins / Q000494:pharmacology* / Q000528:radiation effects; D019207:beta Carotene / Q000494:pharmacology
D000975:Antioxidants; D014815:Vitamins; D019207:beta Carotene; D014810:Vitamin E; D016685:Mitomycin; D001205:Ascorbic Acid; D013831:Thiamine