RESUMO
The bioassay-guided fractionation of the ethyl acetate extract of the fungus Cochliobolus sp. highlighted leishmanicidal activity and allowed for anhydrocochlioquinone A (ANDC-A) isolation. MS, 1D and 2D NMR spectra of this compound were in agreement with those published in the literature. ANDC-A exhibited leishmanicidal activity with EC 50 value of 22.4 microgram/mL (44 mu M) and, when submitted to the microdilution assay against Gram-ositive and Gram-negative bacteria, showed a minimal inhibitory concentration against Staphylococcus aureus ATCC 25295 of 128 microgram/mL (248.7 mu M). It was also active against five human cancer cell lines, showing IC50 values from 5.4 to 20.3 mu M. ANDC-A demonstrated a differential selectivity for HL-60 (SI 5.5) and THP-1 (SI 4.3) cell lines in comparison with Vero cells and was more selective than cisplatin and doxorubicin against MCF-7 cell line in comparison with human peripheral blood mononuclear cells. ANDC-A was able to eradicate clonogenic tumour cells at concentrations of 20 and 50 mu M and induced apoptosis in all tumour cell lines at 20 mu M. These results suggest that ANDC-A might be used as a biochemical tool in the study of tumour cells biochemistry as well as an anticancer agent with durable effects on tumours.
Assuntos
Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Antiprotozoários/farmacologia , Ascomicetos/química , Benzoquinonas/farmacologia , Animais , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Antiprotozoários/química , Antiprotozoários/isolamento & purificação , Ascomicetos/metabolismo , Benzoquinonas/química , Benzoquinonas/isolamento & purificação , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Células HCT116 , Células HL-60 , Humanos , Células Jurkat , Klebsiella oxytoca/efeitos dos fármacos , Klebsiella oxytoca/crescimento & desenvolvimento , Leishmania mexicana/efeitos dos fármacos , Leishmania mexicana/crescimento & desenvolvimento , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento , Células MCF-7 , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/crescimento & desenvolvimento , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Células THP-1 , Células VeroRESUMO
Old yellow enzyme (OYE) is a NAD(P)H flavin oxidoreductase that in Trypanosoma cruzi (TcOYE) catalyzes prostaglandin PGF2alpha synthesis and reduction of some trypanocidal drugs. We performed DNA microarray analysis and it revealed that the levels of transcription of the TcOYE gene were six-fold lower in a T. cruzi population with in vitro-induced resistance to benznidazole (BZ) (17LER) than in the wild-type (17WTS). Further we investigated the TcOYE levels in 15 T. cruzi strains and clones that were either susceptible or naturally resistant to BZ and nifurtimox, or had in vivo-selected resistance to BZ. Northern blot and real-time RT-PCR analyses confirmed our finding that TcOYE transcription levels were lower in 17LER than in 17WTS. In contrast, we detected no differences in TcOYE transcription levels between other T. cruzi samples. All T. cruzi strains contained four copies of TcOYE gene, except 17LER that contained only one. A 42kDa TcOYE protein was detected in all T. cruzi strains tested. The expression of this protein was similar for all samples, with the exception of 17LER for which the protein was nearly seven-fold less expressed. The chromosomal location of the TcOYE gene and the polymorphisms detected in TcOYE nucleotide and amino acid sequences of the T. cruzi strains are associated with the zymodeme but not with drug-resistance phenotype. Our data show that one of the mechanisms conferring in vitro-induced BZ resistance to T. cruzi correlates with deletion of copies of the TcOYE gene. In contrast, the in vivo and natural resistance to BZ are mediated by different mechanisms.