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1.
Mol Med Rep ; 10(1): 405-10, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24756411

RESUMO

Naphthoquinones interact with biological systems by generating reactive oxygen species (ROS) that can damage cancer cells. The cytotoxicity and the antitumor activity of 3­acyl­2­phenylamino­1,4­naphthoquinones (DPB1­DPB9) were evaluated in the MCF7 human breast cancer cell line and in male Ehrlich tumor­bearing Balb/c mice. DPB4 was the most cytotoxic derivative against MCF7 cells (EC50 15 µM) and DPB6 was the least cytotoxic one (EC50 56 µM). The 1,4­naphthoquinone derivatives were able to cause DNA damage and promote DNA fragmentation as shown by the plasmid DNA cleavage assay (FII form). In addition, 1,4­naphthoquinone derivatives possibly interacted with DNA as intercalating agents, which was demonstrated by the changes caused in the fluorescence of the DNA­ethidium bromide complexes. Cell death of MCF7 cells induced by 3­acyl­2­phenylamino­1,4­naphthoquinones was mostly due to apoptosis. The DNA fragmentation and subsequent apoptosis may be correlated to the redox potential of the 1,4­naphthoquinone derivatives that, once present in the cell nucleus, led to the increased generation of ROS. Finally, certain 1,4­naphthoquinone derivatives and particularly DPB4 significantly inhibited the growth of Ehrlich ascites tumors in mice (73%).


Assuntos
Antineoplásicos/toxicidade , Apoptose/efeitos dos fármacos , DNA/metabolismo , Substâncias Intercalantes/toxicidade , Naftoquinonas/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Animais , Antineoplásicos/química , Carcinoma de Ehrlich/tratamento farmacológico , DNA/química , Dano ao DNA/efeitos dos fármacos , Humanos , Substâncias Intercalantes/química , Substâncias Intercalantes/uso terapêutico , Células MCF-7 , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Naftoquinonas/química , Naftoquinonas/uso terapêutico , Transplante Heterólogo
2.
Rev Soc Bras Med Trop ; 46(4): 411-9, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23970310

RESUMO

INTRODUCTION: In vitro bioassays were performed to access the larvicidal activity of crude extracts from the endophytic fungus Pestalotiopsis virgulata (Melanconiales, Amphisphaeriaceae) and the saprophytic fungus Pycnoporus sanguineus (Basidiomycetes, Polyporaceae) against the mosquitoes Aedes aegypti and Anopheles nuneztovari. METHODS: The extracts were tested at concentrations of 100, 200, 300, 400 and 500ppm. Ethyl acetate mycelia (EAM) extracts and liquid culture media (LCM) from Pe. virgulata and Py. sanguineus were tested against third instar larvae of Ae. aegypti and An. nuneztovari. RESULTS: The larvicidal activity of the EAM extracts from Pe. virgulata against Ae. aegypti had an LC50=101.8ppm, and the extract from the basidiomycete fungus Py. sanguineus had an LC50=156.8ppm against the Ae. aegypti larvae. The Pe. virgulata extract had an LC50=16.3ppm against the An. nuneztovari larvae, and the Py. sanguineus extract had an LC50=87.2ppm against these larvae. CONCLUSIONS: These results highlight the larvicidal effect of EAM extracts from the endophyte Pe. virgulata against the two larval mosquitoes tested. Thus, Pe. virgulata and Py. sanguineus have the potential for the production of bioactive substances against larvae of these two tropical disease vectors, with An. nuneztovari being more susceptible to these extracts.


Assuntos
Aedes/efeitos dos fármacos , Anopheles/efeitos dos fármacos , Basidiomycota/química , Endófitos/química , Insetos Vetores/efeitos dos fármacos , Animais , Bioensaio , Larva/efeitos dos fármacos , Dose Letal Mediana
3.
Rev. Soc. Bras. Med. Trop ; Rev. Soc. Bras. Med. Trop;46(4): 411-419, Jul-Aug/2013. tab, graf
Artigo em Inglês | LILACS | ID: lil-683327

RESUMO

Introduction In vitro bioassays were performed to access the larvicidal activity of crude extracts from the endophytic fungus Pestalotiopsis virgulata (Melanconiales, Amphisphaeriaceae) and the saprophytic fungus Pycnoporus sanguineus (Basidiomycetes, Polyporaceae) against the mosquitoes Aedes aegypti and Anopheles nuneztovari. Methods The extracts were tested at concentrations of 100, 200, 300, 400 and 500ppm. Ethyl acetate mycelia (EAM) extracts and liquid culture media (LCM) from Pe. virgulata and Py. sanguineus were tested against third instar larvae of Ae. aegypti and An. nuneztovari. Results The larvicidal activity of the EAM extracts from Pe. virgulata against Ae. aegypti had an LC50=101.8ppm, and the extract from the basidiomycete fungus Py. sanguineus had an LC50=156.8ppm against the Ae. aegypti larvae. The Pe. virgulata extract had an LC50=16.3ppm against the An. nuneztovari larvae, and the Py. sanguineus extract had an LC50=87.2ppm against these larvae. Conclusions These results highlight the larvicidal effect of EAM extracts from the endophyte Pe. virgulata against the two larval mosquitoes tested. Thus, Pe. virgulata and Py. sanguineus have the potential for the production of bioactive substances against larvae of these two tropical disease vectors, with An. nuneztovari being more susceptible to these extracts. .


Assuntos
Animais , Aedes/efeitos dos fármacos , Anopheles/efeitos dos fármacos , Basidiomycota/química , Endófitos/química , Insetos Vetores/efeitos dos fármacos , Bioensaio , Larva/efeitos dos fármacos
4.
Biochem Biophys Res Commun ; 430(3): 883-8, 2013 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-23261463

RESUMO

Pharmacological doses of ascorbate were evaluated for its ability to potentiate the toxicity of sodium orthovanadate (Na(3)VO(4)) in tumor cells. Cytotoxicity, inhibition of cell proliferation, generation of ROS and DNA fragmentation were assessed in T24 cells. Na(3)VO(4) was cytotoxic against T24 cells (EC(50)=5.8 µM at 24 h), but in the presence of ascorbate (100 µM) the EC(50) fell to 3.3 µM. Na(3)VO(4) plus ascorbate caused a strong inhibition of cell proliferation (up to 20%) and increased the generation of ROS (4-fold). Na(3)VO(4) did not directly cleave plasmid DNA, at this aspect no synergism was found occurring between Na(3)VO(4) and ascorbate once the resulting action of the combination was no greater than that of both substances administered separately. Cells from Ehrlich ascites carcinoma-bearing mice were used to determine the activity of antioxidant enzymes, the extent of the oxidative damage and the type of cell death. Na(3)VO(4) alone, or combined with ascorbate, increased catalase activity, but only Na(3)VO(4) plus ascorbate increased superoxide dismutase activity (up to 4-fold). Oxidative damage on proteins and lipids was higher due to the treatment done with Na(3)VO(4) plus ascorbate (2-3-fold). Ascorbate potentiated apoptosis in tumor cells from mice treated with Na(3)VO(4). The results indicate that pharmacological doses of ascorbate enhance the generation of ROS induced by Na(3)VO(4) in tumor cells causing inhibition of proliferation and apoptosis. Apoptosis induced by orthovanadate and ascorbate is closer related to inhibition on Bcl-xL and activation of Bax. Our data apparently rule out a mechanism of cell demise p53-dependent or related to Cdk2 impairment.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Ácido Ascórbico/farmacologia , Proliferação de Células/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Vanadatos/farmacologia , Animais , Linhagem Celular Tumoral , DNA/efeitos dos fármacos , Fragmentação do DNA , Sinergismo Farmacológico , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Plasmídeos/efeitos dos fármacos , Proteína X Associada a bcl-2/agonistas , Proteína bcl-X/antagonistas & inibidores
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