Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
J Toxicol Environ Health A ; 87(12): 516-531, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38619152

RESUMO

The bark extract from Endopleura uchi has been widely used in traditional medicine to treat gynecological-related disorders, diabetes, and dyslipidemias albeit without scientific proof. In addition, E. uchi bark extract safety, especially regarding mutagenic activities, is not known. The aim of this study was to determine the chemical composition, antitumor, and toxicological parameters attributed to an E. uchi bark aqueous extract. The phytochemical constitution was assessed by colorimetric and chromatographic analyzes. The antiproliferative effect was determined using sulforhodamine B (SRB) assay using 4 cancer cell lines. Cytotoxic and genotoxic activities were assessed utilizing MTT and comet assays, respectively, while mutagenicity was determined through micronucleus and Salmonella/microsome assays. The chromatographic analysis detected predominantly the presence of gallic acid and isoquercitrin. The antiproliferative effect was more pronounced in human colon adenocarcinoma (HT-29) and human breast cancer (MCF-7) cell lines. In the MTT assay, the extract presented an IC50 = 39.1 µg/ml and exhibited genotoxic (comet assay) and mutagenic (micronucleus test) activities at 20 and 40 µg/ml in mouse fibroblast cell line (L929) and mutagenicity in the TA102 and TA97a strains in the absence of S9 mix. Data demonstrated that E. uchi bark possesses bioactive compounds which exert cytotoxic and genotoxic effects that might be associated with its antitumor potential. Therefore, E. uchi bark aqueous extract consumption needs to be approached with caution in therapeutic applications.


Assuntos
Adenocarcinoma , Antineoplásicos , Neoplasias do Colo , Humanos , Camundongos , Animais , Extratos Vegetais/química , Casca de Planta/química , Dano ao DNA , Água , Mutagênicos , Células MCF-7
2.
J Ethnopharmacol ; 314: 116614, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37164253

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Aloysia gratissima leaves are popularly used to treat respiratory, digestive, and nervous system disorders. Several studies have been carried out to determine the biological activity of A. gratissima, such as its antibacterial and anti-edematogenic activities, but despite the beneficial uses of A. gratissima, few studies have examined the toxicological profile of this plant. AIM OF THE STUDY: This study aimed to determine the chemical composition, cytotoxic, genotoxic, mutagenic potential, and antioxidant activity of an aqueous extract of A. gratissima leaves (AG-AEL). MATERIAL AND METHODS: The phytochemical constitution of AG-AEL was assessed by colorimetric analyses and High-performance liquid chromatography (HPLC). The inorganic elements were detected by Particle-Induced X-ray Emission (PIXE). The antioxidant, cytotoxicity, genotoxic, and mutagenic activities were evaluated in vitro by Di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH), Sulforhodamine B (SRB) assay, comet assay, and Salmonella/microsome assays. RESULTS: AG-AEL indicated the presence of terpenoids, flavonoids, and phenolic acids. HPLC detected rutin at 2.41 ± 0.33 mg/100 mg. PIXE analysis indicated the presence of Mg, Si, P, S, K, Ca, Mn, and Zn. The 50% inhibitory concentration was 84.17 ± 3.17 µg/mL in the DPPH assay. Genotoxic effects were observed using the Comet assay in neuroblastoma (SH-SY5Y) cells and mutations were observed in TA102 and TA97a strains. The extract showed cytotoxic activities against ovarian (OVCAR-3), glioblastoma (U87MG), and colon (HT-29) cancer cell lines. CONCLUSIONS: In conclusion, AG-AEL increased DNA damage, induced frameshift, and oxidative mutations, and showed cytotoxic activities against different cancer cells. The in vitro toxicological effects observed suggest that this plant preparation should be used with caution, despite its pharmacological potential.


Assuntos
Neuroblastoma , Neoplasias Ovarianas , Humanos , Feminino , Apoptose , Extratos Vegetais/toxicidade , Extratos Vegetais/química , Linhagem Celular Tumoral , Mutagênicos/farmacologia , Antioxidantes/toxicidade
3.
Basic Clin Pharmacol Toxicol ; 130(1): 20-27, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34605186

RESUMO

Plants of the Calea genus have been reported to contain lipophilic compounds, such as sesquiterpene lactones, with cytotoxic effect against different cancer cell lines. The aim of this manuscript was to investigate the chemical profile and cytotoxic activity of different fractions from Calea phylolepis leaves on different human cancer cell lines. The fractions were prepared using solvent extraction of increasing polarity, yielding hexane, ethyl acetate and methanolic fractions. All fractions were chemically analysed by thin layer chromatography (TLC), and their cytotoxic activity against HT-29 (colon adenocarcinoma), MCF-7 (breast cancer), U-251MG (malignant glioblastoma) and L929 (mouse fibroblast) cell lines was investigated. Among these, the hexane and ethyl acetate fractions showed higher cytotoxic effects, while the methanolic fraction did not show any cytotoxic effects. The major bioactive compound from the hexane fraction (12.15%) was isolated using chromatographic methods and was identified by nuclear magnetic resonance spectroscopy (NMR) and gas chromatography-mass spectrometry (GC-MS) analysis as 6-epi-ß-verbesinol coumarate. This compound showed activity against breast cancer cells (IC50 = 5.8 ± 1.0 µg/ml), similar to etoposide. Furthermore, 6-epi-ß-verbesinol coumarate showed low cytotoxicity to normal fibroblast cells, suggesting a high selectivity index (SI = 7.39) against breast cancer cells.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Asteraceae/química , Neoplasias da Mama/tratamento farmacológico , Extratos Vegetais/farmacologia , Animais , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/toxicidade , Linhagem Celular , Linhagem Celular Tumoral , Feminino , Fibroblastos/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Células HT29 , Humanos , Concentração Inibidora 50 , Células MCF-7 , Espectroscopia de Ressonância Magnética , Camundongos , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Extratos Vegetais/administração & dosagem , Extratos Vegetais/toxicidade , Folhas de Planta
4.
J Toxicol Environ Health A ; 84(8): 345-355, 2021 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-33435828

RESUMO

Sida planicaulis is a weed thought to have originated in Brazil, where it is present in abundant quantities, but also this plant is also found in south-central Florida, Indian Ocean Islands, and the Pacific Islands. Sida planicaulis produces neurotoxicity that adversely affects livestock breeding with heavy animal losses and consequent negative impact on Brazil's economy. The aim of this study was to determine the chemical profile, cytotoxic and genotoxic effects of ethanolic extracts of S. planicaulis collected in winter (leaf extract) and summer (leaf extract and leaf + flower extract) using an in vitro model of human neuroblastoma cell line SH-SY5Y. Phytochemical screening demonstrated the presence of alkaloids, flavonoids, and apolar compounds. Rutin, quercetin, and swainsonine were detected by HPLC and GC/MS, respectively. Phosphorus, potassium, iron, and zinc were the inorganic elements found. Extracts produced cytotoxicity at all concentrations tested (7-4,000 µg/ml) as evidenced by the colorimetric assay [3-(4,5-dimethyl-thiazol-2-yl) -2,5-diphenyl-tetrazolium bromide (MTT)]. Based upon the alkaline comet assay extracts were found to induce genotoxicity at concentrations ranging from 0.437 to 7 µg/ml. DNA damage produced by extracts was affirmed using a modified comet assay with the enzymes Endo III and FPG in a concentration dependent manner. Further, enzyme-modified comet assay showed both oxidized purines and pyrimidines, and consequently oxidative stress was related to genomic instability and cell death. Data suggest that low concentrations of ethanolic extracts of S. planicaulis (different seasons) induced increased DNA damage related to oxidative stress and chemical composition.


Assuntos
Citotoxinas/farmacologia , Mutagênicos/farmacologia , Extratos Vegetais/farmacologia , Sida (Planta)/química , Linhagem Celular Tumoral , Citotoxinas/química , Humanos , Mutagênicos/química , Extratos Vegetais/química , Estações do Ano
5.
J Toxicol Environ Health A ; 83(19-20): 659-671, 2020 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-32865139

RESUMO

CECROPIA PACHYSTACHYA: leaves are popularly used to treat asthma and diabetes. Despite the widespread consumption of this plant, there are few scientific studies regarding its toxicological potential. In order to conduct a thorough study concerning the potential adverse effects, the aim of this study was to assess acute and subacute toxicity tests of crude aqueous extract from C. pachystachya leaves (CAE-Cp) using in vivomodel, as well as in vitro cytotoxicity, genotoxicity and antioxidant activity. In addition, genotoxicity, and cytotoxicity of chlorogenic acid (CGA) and cytotoxicity of isoorientin (ISOO) were also evaluated. The antioxidant activity was verified by DPPH, cytotoxicity using sulforhodamine B (SRB) assay and genotoxicity by comet assay on V79 cells. The phytochemical analysis of CAE-Cp detected flavonoids and tannins, CGA and ISOO as the major compounds utilizing HPLC. The total flavonoid content (6.52 mg/g EQ) and antioxidant activity (EC50 = 62.15 µg/ml) of CAE-Cp were determined. In vitro evaluations with CAE-Cp showed genotoxic effects at 0.31 to 2.5 mg/ml and an expressive cytotoxicity on HT-29 (IC50 = 4.43 µg/ml) cells. CGA was genotoxic against V79 cells at 0.07 mg/ml and cytotoxic against to HT-29 (IC50 = 71.70 µg/ml), OVCAR-3 (IC50 = 80.07 µg/ml), MCF-7 (IC50 = 45.58 µg/ml) and, NCI-H460 (IC50 = 71.89 µg/ml) cancer cell lines. Wistar rats treated with a single dose (2,000 mg/kg) CAE-Cp decreased hemoglobin levels after 14 days, although no significant toxicity was observed in animals after 28 days. In view of the in vitro cytotoxicity and genotoxicity detected, further studies are necessary to establish the safe use of CAE-Cp.


Assuntos
Antioxidantes/toxicidade , Cecropia/química , Ácido Clorogênico/toxicidade , Citotoxinas/toxicidade , Luteolina/toxicidade , Mutagênicos/toxicidade , Extratos Vegetais/toxicidade , Animais , Masculino , Extratos Vegetais/química , Folhas de Planta/química , Ratos , Ratos Wistar , Testes de Toxicidade Aguda , Testes de Toxicidade Subaguda
6.
J Lasers Med Sci ; 11(3): 262-267, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32802285

RESUMO

Introduction: This experimental study investigated the mRNA expression of aquaporins (AQPs) 1 and 5 in the parotid glands of rats irradiated with volumetric modulated arc therapy (VMAT) and subjected to low-level laser therapy (LLLT) at different time points. Methods: The sample consisted of 30 Wistar rats (Rattus norvegicus) divided into the following groups: control, LLLT alone (LG), radiotherapy alone (RG), and experimental groups that received LLLT at 24 hours (early experimental group [EEG], n=12) and 120 hours (late experimental group [LEG], n=12) after radiotherapy. VMAT was delivered at a single dose (12 Gy) and LLLT was performed with an aluminium-gallium-arsenide diode laser (660 nm, 100 mW), spot area of 0.0028 cm2, energy of 2 J/cm2 applied to 3 spots in the region corresponding to the right parotid gland, for 10 consecutive days. The right parotid gland was resected and prepared for RNA extraction. The gene expression of AQPs was evaluated by quantitative polymerase chain reaction (qPCR) using specific TaqMan probes, with the HPRT gene as an internal control. Results: The lowest AQP1 gene expression was 0.83 (0.27) with the use of LLLT 24 hours after radiotherapy (EEG), and the highest was 1.56 (0.80) with the use of LLLT alone (LG). Likewise, the lowest AQP5 gene expression was found in the EEG (mean = 0.88; SD = 0.49) and the highest in the LG (mean = 1.29; SD = 0.33). Conclusion: The use of LLLT after radiotherapy may contribute to the maintenance and an increase of these proteins, even when used at a later time point after radiotherapy.

7.
Oxid Med Cell Longev ; 2018: 7804135, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30210656

RESUMO

The use in folk medicine of Baccharis trimera and recent studies on DNA damage by oxidative stress mechanisms have motivated this study. We investigated the biotoxicological effects of trimeroside from this plant. Aqueous extract from aerial parts of B. trimera was fractioned by flash chromatography for further isolation by thin-layer chromatography. The novel nor-monoterpene glycoside, trimeroside, and three flavonoids, cirsimaritin, luteolin and quercetin, were isolated. The genotoxic and mutagenic potential of trimeroside was determined by Salmonella/microsome (TA98 and TA100), comet assay, and cytokinesis-block micronucleus cytome assay (CBMN-cyt) in HepG2 cells. We also screened trimeroside into different human tumoral cell lines by sulforhodamine B (SRB) assay. Mutagenicity was detected in TA100 strain with metabolic activation. Genotoxic effects were not observed in HepG2 by comet assay. However, a decrease in the nuclear index division in the 2.0 mg·mL-1 concentration and an increase of nucleoplasmic bridges in the 1.5 mg·mL-1 concentration were detected by CBMN-cyt assay indicating cytotoxic and mutagenic effects. In SRB assay, trimeroside showed weak antiproliferative activity against the cell lines.


Assuntos
Baccharis/química , Cicloexenos/toxicidade , Glicosídeos/toxicidade , Animais , Ensaio Cometa , Cicloexenos/química , Cicloexenos/isolamento & purificação , Dano ao DNA , Glicosídeos/química , Glicosídeos/isolamento & purificação , Células HT29 , Células Hep G2 , Humanos , Células KB , Camundongos , Testes para Micronúcleos , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/toxicidade , Testes de Toxicidade
8.
Photomed Laser Surg ; 36(10): 536-540, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30251923

RESUMO

BACKGROUND: Photobiomodulation (PBM) has been studied mainly for its effects on the repair, regeneration, and healing of tissue due to its direct and indirect actions on cell proliferation. However, it is necessary to consider the way in which laser acts, that is, whether it affects the rates of spontaneous mutation and mitotic recombination of cells. OBJECTIVE: This study investigated the genotoxic potential of PBM (904 nm) based on an in vivo bioassay that concomitantly evaluates mitotic recombination and point and chromosomal mutations. METHODS: Strains of Drosophila melanogaster that carry specific marker genes were used to detect the induction of mutation and somatic recombination when exposed to different fluences (3, 5, 10, and 20 J/cm2). DNA damage was measured using the somatic mutation and recombination test (SMART), which is based on the identification of wing hair with mutant phenotypes that express lesions at DNA level. RESULTS: The doses 5, 10, and 20 J/cm2 induced significant increase in the total number of spots compared with the negative control. The highest frequency of spots was caused by the 10 J/cm2. CONCLUSIONS: Besides recombination events, the quantitative and qualitative analysis of mutant hairs revealed the occurrence of mutagenic events, both punctual and chromosomal. In addition, the results point to a dose-dependent response.


Assuntos
Dano ao DNA/efeitos da radiação , Terapia com Luz de Baixa Intensidade/efeitos adversos , Mutação/efeitos da radiação , Recombinação Genética/efeitos da radiação , Animais , Drosophila melanogaster , Testes de Mutagenicidade
9.
Dig Dis ; 36(5): 377-384, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30007984

RESUMO

INTRODUCTION: Sorafenib (SOR) has proved to be effective in patients with advanced hepatocellular carcinoma (HCC), since overall survival was higher in phase III clinical trials; however, disease progression can occur. OBJECTIVES: The study aimed to describe real-life experience in advanced HCC treatment with SOR at a university hospital in Brazil and to estimate the number of patients with indication of second-line therapy. METHODS: This is a retrospective study that included cases of HCC with prescription of SOR based on real-life practice between 2011 and 2016. Demographic, clinical, and laboratory data were collected. RESULTS: From 572 patients with HCC, SOR was prescribed in 103 cases. From them, 62.1% were classified as Child-Pugh (CP)-A, 54.4% as Barcelona Clinic Liver Cancer (BCLC)-C, and 74 (71.8%) started treatment. Overall survival was 25.5 (95% CI 17.0-34.1) months and 1-year survival was greater in patients who received SOR than in non-treated (88.7 vs. 44.4%, p < 0.001). There was no difference in survival between BCLC-B and C (p = 0.405), as well as CP-A and B (p = 0.919). In 21.6% of the patients, a second-line therapy with regorafenib was indicated. CONCLUSION: In this real-life study, SOR significantly increased the survival rate by 1 year in patients with advanced HCC regardless of BCLC staging and CP score. Second-line therapy would be indicated in 21.6% of cases.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Niacinamida/análogos & derivados , Compostos de Fenilureia/uso terapêutico , Idoso , Antineoplásicos/uso terapêutico , Carcinoma Hepatocelular/patologia , Feminino , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Niacinamida/administração & dosagem , Niacinamida/farmacologia , Niacinamida/uso terapêutico , Compostos de Fenilureia/administração & dosagem , Compostos de Fenilureia/farmacologia , Probabilidade , Piridinas/uso terapêutico , Estudos Retrospectivos , Sorafenibe , Resultado do Tratamento
10.
J Pharm Biomed Anal ; 129: 427-432, 2016 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-27475406

RESUMO

Soybean acid hydrolyzed extracts are raw-materials widely used for manufacturing of pharmaceuticals and cosmetics products due to their high content of isoflavone aglycones. In the present study, the main sugar degradation products 5-hydroxymethyl-2-furfural (HMF) and 5-ethoxymethyl-2-furfural (EMF) were quantitatively determined after acid hydrolysis of extracts from different soybean cultivars by a validated liquid chromatography method. The furanic compounds determined in samples cover the range of 0.16-0.21mg/mL and 0.22-0.33mg/mL for HMF and EMF, respectively. Complementarily, due to the scarce literature regarding the EMF toxicology, this study also assessed the EMF mutagenicity by the Salmonella/microsome test and genotoxicity by the comet assay. The results revealed that EMF did not show mutagenicity at the range of 50-5000µg/plate in S. typhimurium strains TA98, TA97a, TA100, TA102 and TA1535, but induced DNA damage in HepG2 cells at non-cytotoxic doses of 0.1-1.3mg/mL, mainly by oxidative stress mechanisms. Based on literature of HMF genotoxicity, and considering the EMF genotoxicity results herein shown, purification procedures to remove these impurities from extracts are recommended during healthcare products development to ensure the security of the products.


Assuntos
Ácidos/química , Furaldeído/análogos & derivados , Glycine max/química , Mutagênicos/toxicidade , Extratos Vegetais/química , Extratos Vegetais/toxicidade , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Contaminação de Medicamentos , Furaldeído/toxicidade , Células Hep G2 , Humanos , Hidrólise , Testes de Mutagenicidade , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética
11.
Food Chem Toxicol ; 55: 56-9, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23274746

RESUMO

Artichoke leaves are used in traditional medicine as an herbal medicament for the treatment of hepatic related diseases, as well as choleretic and diuretic. The aim of the present study was to evaluate the capacity of Cynara scolymus L. leaves extract (LE) to cause chromosomal instability and cytotoxicity in Chinese hamster ovary cells (CHO) employing the cytokinesis-block micronucleus (CBMN) cytome assay. Cells were treated with four concentrations of C. scolymus for two exposure times: 1h and 24h. Our findings showed that LE did not increase the frequencies of nucleoplasmic bridges (NPBs) and nuclear bud (NBUD). However, all concentrations of the extract produced increments in micronuclei frequencies (MNi) in both exposure times, when compared to the negative control. No significant differences were observed in the nuclear division cytotoxicity index (NDCI), reflecting the absence of cytotoxic effects associated to LE. The results demonstrated the ability of C. scolymus LE to promote chromosomal mutations which are, probably, a result of the pro-oxidant activity of LE constituents such as flavonoids and chlorogenic acids. The data obtained in this study suggests that high concentrations of artichoke can pose a risk associated to its consumption.


Assuntos
Cynara scolymus , Citocinese , Testes para Micronúcleos , Animais , Células CHO , Cricetinae , Cricetulus
12.
J Ethnopharmacol ; 137(1): 926-9, 2011 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-21693176

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Himatanthus articulatus (Vahl) Woodson (Apocynaceae) is a tree occurring in the Amazon region. The local population uses its bark against to external tumors and cancer. AIM OF THE STUDY: Evaluated the antiproliferative activity of the crude extract and their fractions against human tumors cells. MATERIALS AND METHODS: The antiproliferative responses of the crude extract and their fractions were colorimetrically evaluated by sulforhodamine B (SRB) assay against HT-29 (colon adenocarcinoma); NCI-H460 (non-small cell lung carcinoma); MCF-7 (breast cancer); OVCAR-3 (ovarian adenocarcinoma) and RXF-393 (renal cell carcinoma) as well as against NIH-3T3 (mouse embryo fibroblast cell). RESULTS: The cytotoxicity data from the crude extract allowed considering active only in the NCI-H460 cell line. However, the antiproliferative activity was much more pronounced at the chloroformic fraction in all cell lines tested. The butanolic fraction demonstrated activity against to HT-29, MCF-7, RXF-393 and OVCAR-3 cells. The ethyl acetate fraction demonstrated activity only in RXF-393 and the aqueous residue did not present antiproliferative effect. CONCLUSIONS: Through the popular use we find that the crude extracts of Himatanthus articulatus bark displayed weak cytotoxic. However, the butanolic fraction showed to be active only against to tumor cell lines while chloroformic fraction possesses high activity being similar to the positive control. Both fractions have been selected for future bio-guided fractionation and isolation of active compounds.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apocynaceae , Proliferação de Células/efeitos dos fármacos , Neoplasias/patologia , Acetatos/química , Animais , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Apocynaceae/química , Butanóis/química , Fracionamento Químico , Clorofórmio/química , Relação Dose-Resposta a Droga , Fibroblastos/efeitos dos fármacos , Células HT29 , Humanos , Concentração Inibidora 50 , Medicina Tradicional , Camundongos , Estrutura Molecular , Células NIH 3T3 , Casca de Planta , Plantas Medicinais , Solventes/química , Água/química
13.
Phytother Res ; 22(12): 1577-80, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19003947

RESUMO

The antiproliferative activity of three benzopyrans isolated from the chloroform extract of the aerial parts of Hypericum polyanthemum was analysed in order to determine their effect on the growth and cell cycle in the U-373 MG glioblastoma cell line. Compound 1 was less cytotoxic than compounds 2 and 3. A synergistic effect was noticed when the three benzopyrans were used simultaneously. The cytotoxicity noted could be related to an arrest in G2/M phase, leading to apoptosis in the U-373 MG glioblastoma cell line.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Benzopiranos/farmacologia , Ciclo Celular/efeitos dos fármacos , Hypericum/química , Análise de Variância , Linhagem Celular Tumoral , Proliferação de Células , Sinergismo Farmacológico , Humanos , Componentes Aéreos da Planta/química , Extratos Vegetais/farmacologia
14.
Toxicol In Vitro ; 22(4): 873-8, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18282684

RESUMO

Multidrug resistance (MDR) is the major obstacle to cancer chemotherapy. MDR phenotype is mainly related to the over-expression of MDR1 gene, being responsible for tumor resistance to several chemotherapeutic drugs. It has been suggested that MDR1 expression is redox-regulated and we have recently described a pro-oxidative effect of retinol. Here we tested the therapeutic use of retinol as a modulator of MDR1 gene expression in tumor cell lines, and verified in situ the enhancement of anticancer drug efficacy. Two human colorectal adenocarcinoma cell lines (HT29, SW620) with different degrees of MDR1 expression were used. Cells were pre-treated with a sublethal dose of retinol and then challenged with the etoposide (VP16) drug. The drug GI50 was assessed by SRB method and levels of MDR1 expression were determined by semi-quantitative rtPCR. Retinol treatment caused a 40% decrease in MDR1 expression and increased VP16 toxicity. MDR1 expression and drug sensitivity were restored to control values when mannitol (a hydroxyl radical scavenger) was co-administrated. Our data point a role to the use of retinol as an adjuvant in the treatment of tumors with MDR phenotype.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/efeitos dos fármacos , Antineoplásicos Fitogênicos/farmacologia , Etoposídeo/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Vitamina A/farmacologia , Subfamília B de Transportador de Cassetes de Ligação de ATP , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/patologia , Linhagem Celular Tumoral , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Células HT29 , Humanos , Reação em Cadeia da Polimerase
15.
Fitoterapia ; 76(2): 210-5, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15752632

RESUMO

In the present study we have investigated the in vitro antitumor effects of three benzopyrans, 6-isobutyryl-5,7-dimethoxy-2,2-dimethylbenzopyran (1), 7-hydroxy-6-isobutyryl-5-methoxy-2,2-dimethylbenzopyran (2) and 5-hydroxy-6-isobutyryl-7-methoxy-2,2-dimethylbenzopyran (3) isolated from Hypericum polyanthemum. The three compounds tested demonstrated potent growth inhibitory activity at 40 microg/ml (<25% control growth) in the NCI-H460, HT-29 and U-373MG human cell lines. Determination of cell cycle distribution demonstrated that the antiproliferative effect of the three benzopyrans could be associated to alterations in the cell cycle phase distribution. Treatment with the IC50 of the three compounds induced an arrested in S phase. Only in cells treated with compound 3 did the percentage of sub-G1 population increase up to 9%, suggesting that this compound induced more cell death than the others. Consistent with sub-G1 analysis, appreciable oligonucleosomal DNA fragmentation was only observed in the NCI-H460 cell line treated with compound 3. From these results it can be suggested that despite no differences among the cytotoxicity of the three compounds, it was observed that the mechanism of their antiproliferative effects appears to be different.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Hypericum , Fitoterapia , Extratos Vegetais/farmacologia , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/uso terapêutico , Benzopiranos/administração & dosagem , Benzopiranos/farmacologia , Benzopiranos/uso terapêutico , Linhagem Celular Tumoral/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Fragmentação do DNA/efeitos dos fármacos , Citometria de Fluxo , Humanos , Concentração Inibidora 50 , Componentes Aéreos da Planta , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA