Complexos de cobre com análogos de produtos naturais encontrados em organismos marinhos com atividade antitumoral / Copper complexes with analogues of natural products found in marine organisms with antitumor activity

Neste trabalho foram sintetizados complexos de cobre(II) com derivados imínicos da isatina, incluindo isatinas bromadas semelhantes a compostos encontrados em gastrópodes, a fim de compará-los com o composto já produzido e investigado [Cu(isaepy)], complexo de cobre(II) com base de Schiff feita a partir da isatina e 2-aminoetilpiridina. A isatina é um oxindol produzido em algumas plantas, também encontrado no tecido de mamíferos, com propriedades antitumorais naturais. Isatinas bromadas foram previamente constatadas como mais citotóxicas frente a células tumorais do que a isatina sem substituições. O objetivo principal foi verificar se a presença de bromo nos compostos análogos ao [Cu(isaepy)] levaria a um aumento da atividade antitumoral, assim como maior interação com DNA, alvo usual de metalofármacos. Depois de sintetizados, os compostos foram caracterizados por análise elementar (CHN), espectroscopia no infravermelho, espectroscopia UV/Vis e EPR. Foram feitos testes de citotoxicidade pelo método MTT com células de sarcoma uterino (MES-SA e MES-AS/Dx5, esta última resistente a doxorrubicina), adenocarcinoma cervical (HeLa) e células não cancerosas de fibroblasto humano P4. Adicionalmente, foram feitos testes de interação com DNA por UV/Vis e dicroísmo circular, além de testes de clivagem de DNA plasmidial. De modo geral, foi demonstrado que a simetria tetragonal em torno do cobre, determinada pelo EPR, é importante para a citotoxicidade dos complexos, que dessa forma podem se intercalar ao DNA e impedir sua replicação, por acabar distorcendo a hélice, e pela habilidade de realizarem clivagem oxidativa das fitas. [Cu(isaepy)] e seus análogos bromados demonstraram uma atividade citotóxica muito parecida, assim como grau de interação e clivagem com DNA. Conclui-se que, embora a presença de bromo nos análogos de [Cu(isaepy)] não levem a um aumento de atividade antitumoral, como observado em ligantes correlatos livres, nossos estudos apontam para diferentes fontes naturais (animal ou vegetal) para obtenção de precursores de novos compostos antitumorais

In the present work, copper(II) complexes were synthesized with isatin derived imine ligands, including brominated oxindoles similar to compounds found in gastropods, in order to compare their reactivity with that of [Cu(isaepy)], a Schiff base-copper(II) complex already investigated, obtained with the precursors isatin and 2-aminoethylpyridine. Isatin is a natural oxindole extracted from plants, and also found in mammal tissue, with antitumor properties. Brominated isatins were previously described as much more cytotoxic, towards tumor cells, than unsubstituted isatin. The aim of this work was to verify if the presence of brome in analogue [Cu(isaepy)] compounds would increase their antitumor activity, along with higher DNA interaction, an usual target for metallodrugs. The copper(II) complexes were synthesized and then characterized through elemental analyses (CHN), infrared, UV/Vis and EPR spectroscopies. Cytotoxicity tests were carried out using MTT assay with cells lines MES-SA e MES-SA/Dx5 (uterine sarcome, sensitive and resistent to doxorubicin), HeLa (cervical adenocarcinoma) and non-tumor cells, human fibroblast P4. Additionally, DNA interaction experiments were carried out through UV/Vis spectroscopy and circular dichroism, and at last, DNA cleavage experiments with the studied complexes. In general, it was shown that a tetragonal symmetry around copper, shown by EPR, is very important to the complexes toxicity, since in that way they are able to intercalate DNA, and prevent its replication, as a consequence of double helix distortion, and eventual oxidative cleavage. [Cu(isaepy)] and its brominated analogues demonstrated a very similar cytotoxicity towards cancer cells, as well as quite same level of DNA interaction and cleavage. Although the presence of brome did not increase significantly their antitumor activity, as verified with the free isatin derivatives, our studies pointed to different natural sources to obtain precursors for such new antitumor compounds

Research of anti-tumor effect of PHⅡ-7 to K562/A02 cells / 中国药理学通报

Aim To study the mechanism of anti-tumor effect of PHⅡ-7 to K562 and K562/A02 cells.Methods The effects of individual and combined doxorubicin on K562 and K562/A02 cells were observed by MTT assay.The coefficient of drug interaction was used to analyse the synergistic effect of PHⅡ-7,obtaining the RNA from the cells stimulated by PHⅡ-7 with different doses to analyse the MDR1 gene expression level.Finally,the cumulation of doxorubicin was observed in K562 and K562/A02 cells after being coped with PHⅡ-7.Results PH Ⅱ-7 had anti-tumor effect with IC50 of (1.37?0.37) ?mol?L-1;(1.48?0.34) ?mol?L-1 for K562 and K562/A02,respectively.It could potentiate the anti-tumor effect of dororubicin with CDI of 0.22 and 0.09 for K562 and K562/A02,respectively.PHⅡ-7 could synergistically inhibit the proliferation of K562 and K562/A02 cells.The decrease of MDR1 expression level depended on the increase of dose of PHⅡ-7 acting on cells.PHⅡ-7 could also develop the cumulation of doxorubicin in cells.Conclusion PHⅡ-7 is not only a Cytotoxinic drug but also can synergistically inhibit the proliferation of K562 and K562/A02 cells with the decrease of MDR1 expression level,especially in K562/A02 cells.