[Testing antineoplastic activity of new platinum(II) and palladium(II) complex compounds]

A pyrazole system is incorporated in many biological molecules which play an important part in genetic processes. It seems that co-ordinating biological molecules, which would serve as carriers, should contribute to minimising the toxic effects of the potential platinic drugs.

Assessment of in vivo biological activity, and in particular of antineoplastic activity of new platinum(II) and palladium(II) complexes.

The assessment of toxicity of the compounds was made with the Deichmann and Le Blanck method. The antineoplastic activity of the new complex compounds--pyrazole derivatives with Pt(II) and Pd(II) ions was tested on mouse L1210 leukemia cell culture and on lymphatic leukemia P388. BDF1 or CDF1 mice divided into groups of 5-9 animals were subject to the tests.

Complexes 13, 21, 25, 16, 24 and 28 did not reveal any antineoplastic activity to the mouse L1210 leukemia, whereas complexes 13, 21 and 25 revealed in-vivo antineoplastic activity to the P388 leukemia, extending the mouse's survival time by about 50%. The control group consisted of mice which were administered a 14% methylcellulose solution.

As a result of the tests conducted to asses the in-vivo antineoplastic activity it was found that the 25 complex demonstrates the strongest activity to the P388 leukemia. It may be presumed that it is caused by trans configuration of the complex predisposing to the creation of interstrand cross-links. It may be also caused by the presence of the chloromethyl substituents, located on N1 nitrogen atom of the ligand, which increases the capacity of nitrogen N7 guanine alkylation in DNA.