spergualin and pimagedine

The amine oxidase activities contained in calf serum and human serum were detected at levels of 90.8 and less than 0.1 nmol O2/minute/ml serum, respectively, by measuring oxygen consumption coupled with spermidine oxidation. Deoxyspergualin (NKT-01) and spergualin (SGL) containing spermidine in their structure were also oxidized in calf serum at the rate of 3.6 and 11.6 nmol O2/minute/ml serum, respectively. To investigate whether amine oxidase is essential for NKT-01 and SGL to exhibit their antiproliferative activities or not, the in vitro activities of NKT-01, SGL and polyamines against L1210 cells were examined in the presence of calf or human serum. Polyamines exhibited antiproliferative activity only in the presence of calf serum, while NKT-01 and SGL inhibited cell growth in the presence of both calf and human serum. In the presence of calf serum the activity of NKT-01 was inhibited by aminoguanidine, an amine oxidase inhibitor. Aminoguanidine did not inhibit the activity of NKT-01 in the presence of human serum. The activity of NKT-01 was shown at much lower concentrations in the presence of human serum than that in the presence of calf serum, and was strongly dependent on incubation time. The in vivo activities of NKT-01, SGL and SGL derivatives correlated with their in vitro activities in the presence of human serum. These results suggest that the in vivo antitumor activities of NKT-01, SGL and SGL derivatives may be attributed to a mechanism different from those of amine oxidase-oxidized product and represent a novel growth inhibitory action.

Topics: Amine Oxidase (Copper-Containing); Animals; Cell Line; Cell Survival; Guanidines; Leukemia L1210; Mice; Mice, Inbred DBA; Oxidoreductases Acting on CH-NH Group Donors; Oxygen Consumption; Species Specificity

The cytotoxicity of spergualin on cultured L5178Y cells is dependent on the kind of serum contained in culture media. Spergualin has stronger cytotoxicity to L5178Y cells in calf serum (IC50 = 2 micrograms/ml) than in horse serum (IC50 = 60 micrograms/ml). This was thought to be caused by amine oxidase in sera. Because calf serum was rich in amine oxidase and horse serum was very poor. Spergualin was found to be oxidized by either calf serum or amine oxidase purified from beef plasma. Aminoguanidine, an amine oxidase inhibitor suppressed the spergualin effect to inhibit the growth of L5178Y cells in calf serum to the level in horse serum. On the other hand, in horse serum the spergualin cytotoxicity was enhanced by addition of amine oxidase. These results suggested to us that spergualin might be inactive in itself and that the amine oxidase-oxidized product might play an essential role in inhibiting the growth of cells.

Topics: Amine Oxidase (Copper-Containing); Animals; Antibiotics, Antineoplastic; Cells, Cultured; Culture Media; Drug Evaluation, Preclinical; Drug Synergism; Guanidines; Mice; Oxidoreductases Acting on CH-NH Group Donors