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.

Influence of vitamin B1 on sanazole activity under irradiation. A study in vitro.

The effect of vitamin B1 (thiamine) on sanazole (AK-2123) efficiency was investigated in vitro under irradiation, using E. coli bacteria (AB 1157) as a model. In order to get a deeper insight into the reaction mechanisms, the experiments were performed in media saturated with argon, air or N20. In the first case vitamin B1 acts as a cytostatic, but in the presence of air or N20 it shows strongly pronounced antioxidant action and leads to an essential increase of sanazole efficiency.