RESUMO

The aim of the study was to investigate the in vitro and in vivo antitumor activity of leaves ethanol extract from Smilax fluminensis on murine melanoma. The extract was performed by ethylic alcohol and submitted to classical chemical analysis. Cytotoxicity test were performed on neoplastic cells, where antitumor activity was expressed in GI50 (concentration that inhibits 50% of cell growth) and the determination of selectivity index using a normal cell line. In addition, BALB/c mice models were used to evaluate the in vivo antitumor activity of extract in two different concentrations against B16-F10 melanoma cells. The tumor inhibition ratio was determined and the histopathological analyses of nodules and liver were compared. The chemical analysis indicated a major presence of phenolic compounds and flavonoids. Cytotoxicity test results that S. fluminensis extract was active in B16-F10 line (GI50: 4.37 µg/mL), being the extract considered a promising antineoplastic agent. In the experimental model, the inhibition percentage of tumoral growth was between 78.77 and 83.49%. Histopathology analysis of nodules showed necrotic cells reduction, adipocytes presence, melanin deposition, vascularization, and inflammatory process in a concentration-dependent manner. On the liver, the animals treated with the extract on both concentrations showed normal hepatic organization, normal hepatocytes, and absence of inflammatory focus. The results indicate that S. fluminensis extract demonstrated both in vitro and in vivo antitumor activity, reducing the tumoral growth in B16-F10 and could therefore be a promising antineoplastic agent.

Assuntos

Antineoplásicos Fitogênicos/farmacologia , Etanol/química , Melanoma Experimental/tratamento farmacológico , Extratos Vegetais/farmacologia , Smilax/química , Animais , Antineoplásicos Fitogênicos/química , Células HT29 , Humanos , Células MCF-7 , Melanoma Experimental/metabolismo , Camundongos , Células NIH 3T3 , Células PC-3 , Extratos Vegetais/química

RESUMO

The wing Somatic Mutation and Recombination Test (SMART) in D. melanogaster was used to study genotoxicity of the medicinal plant Tabebuia impetiginosa. Lapachol (naphthoquinone) and ß-lapachone (quinone) are the two main chemical constituents of T. impetiginosa. These compounds have several biological properties. They induce apoptosis by generating oxygen-reactive species, thereby inhibiting topoisomerases (I and II) or inducing other enzymes dependent on NAD(P)H:quinone oxidoreductase 1, thus affecting cell cycle checkpoints. The SMART was used in the standard (ST) version, which has normal levels of cytochrome P450 (CYP) enzymes, to check the direct action of this compound, and in the high bioactivation (HB) version, which has a high constitutive level of CYP enzymes, to check for indirect action in three different T. impetiginosa concentrations (10%, 20% or 40% w/w). It was observed that T. impetiginosa alone did not modify the spontaneous frequencies of mutant spots in either cross. The negative results observed prompted us to study this phytotherapeuticum in association with the reference mutagen doxorubicin (DXR). In co-treated series, T. impetiginosa was toxic in both crosses at higher concentration, whereas in the HB cross, it induced a considerable potentiating effect (from ~24.0 to ~95.0%) on DXR genotoxity. Therefore, further research is needed to determine the possible risks associated with the exposure of living organisms to this complex mixture.

RESUMO

The wing Somatic Mutation and Recombination Test (SMART) in D. melanogaster was used to study genotoxicity of the medicinal plant Tabebuia impetiginosa. Lapachol (naphthoquinone) and β-lapachone (quinone) are the two main chemical constituents of T. impetiginosa. These compounds have several biological properties. They induce apoptosis by generating oxygen-reactive species, thereby inhibiting topoisomerases (I and II) or inducing other enzymes dependent on NAD(P)H:quinone oxidoreductase 1, thus affecting cell cycle checkpoints. The SMART was used in the standard (ST) version, which has normal levels of cytochrome P450 (CYP) enzymes, to check the direct action of this compound, and in the high bioactivation (HB) version, which has a high constitutive level of CYP enzymes, to check for indirect action in three different T. impetiginosa concentrations (10 percent, 20 percent or 40 percent w/w). It was observed that T. impetiginosa alone did not modify the spontaneous frequencies of mutant spots in either cross. The negative results observed prompted us to study this phytotherapeuticum in association with the reference mutagen doxorubicin (DXR). In co-treated series, T. impetiginosa was toxic in both crosses at higher concentration, whereas in the HB cross, it induced a considerable potentiating effect (from ~24.0 to ~95.0 percent) on DXR genotoxity. Therefore, further research is needed to determine the possible risks associated with the exposure of living organisms to this complex mixture.