The cytotoxic effects of some selected gold(III) complexes on 4T1 cells and their role in the prevention of breast tumor growth in BALB/c mice.

PURPOSE: to investigate the cytotoxic activity of newly synthesized gold(III) complexes [AuCl(2)(en)](+), [AuCl(2) (SMC)](+), [AuCl(2)(DMSO)(2)(+) (en: ethylenediamine, SMC: S-methyl- L-cysteine and DMSO: for dimethylsulfoxide) in 4T1 mouse breast cancer cell line in vitro and in vivo and to compare their antitumor characteristics with cisplatin complex [PtCl(2)(NH(3))(2)]. METHODS: the in vitro, effects of the tested complexes on 4T1 cell viability were determined using MTT colorimetric technique. In vivo, progression of mouse breast tumor growth in BALB/c mice was measured by using external caliper. RESULTS: among the tested gold(III) complexes, [AuCl(2) (en)](+) showed best cytotoxic effects in vitro. The cytotoxic effects of [AuCl(2)(en)](+) and [PtCl(2)(NH(3))(2)] were similar at all concentrations. The data from the in vivo experiment showed that among the tested gold(III) complexes only [AuCl(2)(en)](+) can prevent the primary breast tumor growth. [AuCl(2)(en)](+) was tolerated well and much better than [AuCl(2)(DMSO)(2)(+), [AuCl(2)(SMC)](+) and [PtCl(2)(NH(3))(2)] complex which was confirmed by weight gain in mice that received [AuCl(2)(en)](+). In addition, mice that received [AuCl(2)(en)](+) showed better survival time in comparison with mice that received [PtCl(2) (NH(3))(2)] complex. CONCLUSION: [AuCl(2) (en)](+) complex seems to be good candidate for future pharmacological evaluation in breast cancer research.

Binding of Platinum(II) to Some Biologicaly Important Thiols.

The reactions between [Pt(terpy)Cl(+) and thiols, such as glutathione, L-cysteine, D-penicillamine and thioglycolic acid have been Studied by conventional UV-VIS spectrophotometry and H NMR spectroscopy. The second-ordero rate constants, K(2), are similar for these four thiols, varying between 1.06 x 10(-2) and 6.10 x 10(+3) M(-1) s(-1) at 25( degrees )C. The activation entropies have large negative values between -100 and -200 J mol(-1) which are compatible with an associative A mechanism. However, L-methionine, as thioether ligand, is unreactive under the same experimental conditions. The obtained results have been analyzed in relation to the antitumor activity and toxicity of platinum(II) complexes.