Investigation Of Dipfluzine's Mutagenic Toxicity

Dipfluzine(Dip), a novel calcium antagonist of diphenylpiperazines, was firstly sythensized by Institute of Pharmaceutic in Hebei Medical Univercity. Previous researches revealed that Dip selectively dilated vertebral artery,basilar artery and coronary artery. And the effects of Dip were more potent than those of flunarizine. In addition, Dip increased brain blood and improved brain ischemia as well as brain hypooxygen. It also inhibited thrombus formation and the platelet aggregation. Thus Dip is well likely to be a promising calcium antagonist to treat brain vascular diseases. At present, there is still no report about special toxicity of Dip. This experiment investigated the mutagenic toxicity of Dip in vivo and in vitro, which provided genetic data for the further study of Dip. Aim: To investigate the mutagenic toxicity of Dip. Method: salmonella typhimurium mutagenicity test (Ames test), chromosome aberration (CA) test of cultivated cells of mammalian, micronucleus test in mice and mammalian bone marrow CA test were used. Result: 1 The revertant effect of Dip on Ames tester strains: TA97, TA98, TA100 and TA102 were used. At the concentrations of Dip 2000, 1000, 100, 10 and 1μg/plate, revertant number of four tester strains,were not up to or over the double number of spontaneous reversion in control group with or without mixture S9. Also,there was no dose-dependence in the number of revertants induced by Dip. So the effect of Dip on the number of revertants was qualified to be negative,indicating that Dip dose not genetic mutagenicity including base-pair substitutions and frameshift in vitro. 2 Mutagenetic effect of Dip on CHL cells: Dip,at the concentration of 125μg/ml, 62.5μg/ml and 31.3μg/ml, was incubated with CHL cells for 24h and 48h with or without mixture S9. CHL cells were respectively harvested at the time 24h and 48h without S9 or 24h with S9 , and the CA was observed . It was found that CA rates in CHL cells incubated with Dip were less than 4%, which was qualified to be negative. The result indicates that Dip dose not induce chromosome aberration in vitro. 3 Micronucleus test in mice: The mice were treated with Dip p.o. at the doses of 2.8g/kg, 1.4g/kg and 0.7g/kg, the bone marrow of mice was taken out at 24h after Dip treatment. MNPCE were counted and MNPCE rates were calculated. MNPCE rates in Dip groups had no significant difference from those in control group, and Dip has noeffect on MNPCE rates in a dose-dependent way. Thus the effect of Dip on MNPCE was qualified to be negative, indicating that Dip has no mutagenicity in vivo. 4 CA test of mouse marrow cells: The mice were treated with Dip p.o. at the doses of 2.8g/kg, 1.4g/kg and 0.7g/kg, the bone marrow of mice was taken out at 12h, 24h and 48h respectively after Dip treatment. There was no significant difference in CA rate between Dip and control groups. Also, there was no dose-dependence in CA rate induced by Dip. Thus the effect of Dip on CA rate was qualified to be negative, indicating that Dip has no mutagenicity in vivo. Conclusion: Dip has no mutagenic toxicity on prokaryocyte and eukaryocyte in vitro or in vivo.