Cytotoxic properties of two families of benzaldehyde thiosemicarbazone complexes of palladium

Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata-700 032, India E-mail : samaresh _ b@hotmal.J. com Department of Anticancer Drug Development, Chittaranjan National Cancer Institute, Kolkata-700 026, India Manuscript received online 16 July 2012. accepted 20 July 2012 Reaction of 4-R-benzaldehy thiosermicarbazones (HL-R, where H stands for the dissociable hydrazinic proton- and R (R = OCH3, CH3, H, Cl and NO2) for the substituent) with trans-[Pd(PPh3)2CI2] and Na2[PdCI4] afford complexes of type [Pd(PPh3)(L-R)CI] and [Pd(L-R)2] respectively. In vitro cytotoxicity screenings of these complexes along with four human clinical drugs, viz. cisplatin, BCNU, 5-fluorouracil (5-FU) and hydtoxyurea, have been carried out in two human tumor cell lines, viz. pro myelocytic leukemia HL-60 and histiocytic lymphoma U-937. Majority of these complexes show remarkably low IC50 value and are found to be much more cytotoxic than the reference anticancer drugs in both the cell lines. Apoptosis study in HL-60 with two selected complexes from each group shows that at 5 and 10 µM concentration they induce apoptosis to a greater extent than cisplatin and camptothecin