Pt(IV), Pd(II), and Rh(III) complexes induced oxidative stress and cytotoxicity in the HCT-116 colon cancer cell line

The use of transition metal complexes as appropriate analogues to cisplatin and similar anticancer drugs nowadays is of utmost importance. The inertness of Pt(IV), Pd(II), and Rh(III) complexes and the choosing of convenient ligands could offer a possible advantage in comparison to Pt(II) complexes. These advantages could be attributed to the better anticancer activity and fewer possible side effects. In this paper, we have chosen three complexes of different transition metal ions, [(TLtBu)PdIICl]ClO4, [RhIII(LH2tBu)Cl3], and [PtIV(LH2tBu)Cl3]Cl (where TLtBu is 2,6-bis[(1,3-di-tert-butylimidazolin-2-imino)methyl]pyridine and LH2tBu is 2,6-bis(5-tert-butyl-1H-pyrazol-3-yl)pyridine), for biological tests. All three complexes exerted strong prooxidative and cytotoxic effects on the human colorectal colon cancer HCT-116 cell line. The Pd(II) complex showed the most significant effect, while the Rh(III) complex showed the least effect.