Navegando por Assunto "Naftoquinonas"

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Acesso aberto (Open Access)
Antraquinonas e naftoquinonas do caule de um espécime de reflorestamento de Tectona grandi (Verbenaceae)
(2006-09) MOREIRA, Rafael Yasunori Okada; ARRUDA, Mara Silvia Pinheiro; ARRUDA, Alberto Cardoso; SANTOS, Lourivaldo da Silva; MÜLLER, Adolfo Henrique; GUILHON, Giselle Maria Skelding Pinheiro; SANTOS, Alberdan Silva; TEREZO, Evaristo
The hexane extract of the bark of Tectona grandis (Verbenaceae) afforded two anthraquinones and two naphtoquinones. Their caracterizations were obtained through NMR spectroscopic techniques. This is the first phytochemical study of the bark of Tectona grandis reforestation specimen in Brazil. The main interest in this work is proving the presence of tectoquinone in reforestation specimen.
Acesso aberto (Open Access)
Avaliação da atividade citotóxica e anti-invasiva da biflorina em linhagens de câncer gástrico do tipo intestinal
(Universidade Federal do Pará, 2019-12-03) MOTA, Elizangela Rodrigues da Silva; CALCAGNO, Danielle Queiroz; http://lattes.cnpq.br/1326603355062154; https://orcid.org/0000-0002-4429-2573
Natural products are sources of secondary metabolites with wide pharmacological applicability, including anticancer. Biflorin, a prenylated ortho-naphthoquinone that has been isolated from the roots of the Capraria biflora L. plant, has stood out as a potent prototype antitumor drug. However, despite promising potential, its antineoplastic capacity is incipiently applied to gastric cancer, one of the most incidente, aggressive and lethal cancers, nationally and globally. In this context, this study aimed to analyze the structure-toxicity relationship of biflorin by the redox in silico mechanism, as well as the in vitro cytotoxic and anti-invasive potential, using as a model strains of intestinal-type gastric adenocarcinoma metastatic (AGP01) and isolated from primary tumor (ACP03). In silico analysis showed that biflorin has a differentiated reactivity characteristic and can act as electron donor or acceptor in nucleophilic and electrophilic reactions, respectively. Moreover, when compared to other natural naphthoquinones such as β-lapachone and lapachol, it presented better redox properties and reactivity conditions, but with less toxic effect due to their ability to form more stable intermediates. The molecular simplification of biflorin also allowed to infer that the ortho-naphthoquinone functional group is probably the most related to naphthoquinones toxicity. Additionally, biflorin showed cytotoxic activity at considerably low concentrations for both strains, however, cytotoxicity was more pronounced for AGP01 (IC50 3.1 μM) compared to ACP03 (IC50 4.5 μM) at 48h treatment. Regarding antimetastatic activity, biflorin reduced the cell invasion capacity of the AGP01 strain only (p <0.0001). The results indicate that biflorin has cytotoxic activity for both gastric cancer strains AGP01 and ACP03, as well as anti-invasive specifically for metastatic cells AGP01. In addition, it was possible to clarify the probable selective cytotoxicity of biflorin based on its structural reactivity.
Acesso aberto (Open Access)
Efeitos citotóxicos e mecanismo de ação da eleuterina isolada de Eleutherine plicata em modelo in vitro de células c6
(Universidade Federal do Pará, 2024-05) SHINKAI, Victória Mae Tsuruzaki; NASCIMENTO, José Luiz Martins do; http://lattes.cnpq.br/7216249286784978; https://orcid.org/0000-0003-3647-9124
Glioblastoma multiforme (GBM) is the most prevalent malignant primary tumor of the central nervous system (CNS). GBM cells are characterized by rapid proliferation and aggressive migration. There is growing demand for new therapies to treat this tumor, due to current therapeutic limitations. Quinone derivatives from plants have received increased interest as potential antiglioma drugs due to their diverse pharmacological activities such as inhibition of cell growth, inflammation, tumor invasion and promotion of tumor regression. The herb Eleutherine plicata, popularly known as Marupazinho, is widely used in popular medicine due to its pharmacological properties, containing quinone derivatives, more specifically naphthoquinones. Previous studies have demonstrated the antiglioma activity of Eleutherine plicata, which is related to three main naphthoquinone compounds – eleutherine, isoeleutherine and eleutherol – but mechanism of action remains unclear. Thus, the objective of this study was to investigate the potential cytotoxic and antiproliferative effect of eleutherin in an in vitro model of glioblastoma (C6 lineage). In vitro cytotoxicity was assessed by the MTT assay; Morphological changes were assessed by phase contrast microscopy. Apoptosis was determined by the annexin V-FITCpropidium iodide assay, and antiproliferative effects were assessed by the colony formation assay. Protein kinase B (AKT/pAKT) expression was measured by western blot, and telomerase reverse transcriptase mRNA was measured by quantitative real-time polymerase chain reaction (qRT-PCR). The results obtained indicated that eleutherin, isolated from the Hexanic fraction, had a cytotoxic effect on the C6 lineage. Structural changes were observed by image capture, with a significant reduction in colony formation, induction of apoptosis, inhibition of pAKT and reduction in telomerase expression after treatment. Thus, our study showed that the eleuterin molecule has cytotoxic activity in C6 lineage glioma.
Acesso aberto (Open Access)
Estudos de citotoxicidade e genotoxicidade de Eleutherine plicata Herb
(Universidade Federal do Pará, 2014-09-30) GALUCIO, Natasha Costa da Rocha; BAHIA, Marcelo de Oliveira; http://lattes.cnpq.br/3219037174956649; DOLABELA, Maria Fâni; http://lattes.cnpq.br/0458080121943649
The purpose of this study was phytochemical studies of E. plicata, and to evaluate the cytotoxicity, the role of oxidative stress and genotoxicity. The powder of E. plicata bulbs underwent maceration with ethanol, the solution concentrated to residue in rotaevaporator. The ethanol extract was subjected to fractionation by open column chromatography over silica gel, being used as the mobile phase solvents of increasing polarity. The dichloromethane fraction was subjected to fractionation by preparative layer chromatography using dichloromethane as mobile phase, and 3 subfractions obtained. The ethanol extract, fractions and subfractions were subjected to chromatographic and spectrophotometric analysis. All samples were subjected to the tests: cellular viability (MTT), the antioxidant capacity (DPPH), comet and micronucleus assays. From the ethanol extract obtained a rich fraction naphthoquinone (dichloromethane fraction). Fractionation of this led to the isolation of: S1, S2 (major fraction), and fraction of minority S3 (unidentified, not tested). Chromatographic studies and spectrophotometric allowed the identification of S2 (isoeleuterin). Fractionation contributed positively to cytotoxicity on VERO cells, the sample being more cytotoxic to S1. The cytotoxicity in HepG2 cells was concentration dependent, being the fractionation did not contribute positively to this. Also, over time, the longer the exposure time, the lower the cytotoxicity to HepG2 cells. The maximum antioxidant activity was observed for subfraction S1, and this low genotoxicity possessed by both methods and it was the most cytotoxic. The dichloromethane fraction has an intermediate antioxidant capacity, but had a high genotoxicity in micronucleus assay. The isoeleuterin (S2) was lower antioxidant capacity, lower cytotoxicity and genotoxicity conflicting results. The ethanol extract possessed the lowest antioxidant capacity, moderate genotoxicity and lower cytotoxicity. When analyzing the results occur that: a subfraction S1 is the most promising candidate as the antimalarial drug, as have cytotoxicity and genotoxicity rates at acceptable levels. The isoeleuterin needs additional research on 11 genotoxicity. Regarding the dichloromethane fraction was not advisable to use for the development of an antimalarial drug, since it is more genotoxic.
Acesso aberto (Open Access)
Estudos químico-farmacêuticos, atividade antitumoral e mutagênica de Eleutherine plicata. Herb.
(Universidade Federal do Pará, 2020-11-03) CASTRO, Ana Laura Gadelha; MONTEIRO, Marta Chagas; http://lattes.cnpq.br/6710783324317390; https://orcid.org/ 0000-0002-3328-5650; DOLABELA, Maria Fâni; http://lattes.cnpq.br/0458080121943649; https://orcid.org/ 0000-0003-0804-5804
Naphthoquinones have been linked to antitumor activity; however, they can cause DNA damage and be mutagenic. Some of these as the isoeleutherine and eleutherine, present in Eleutherine plicata Herb., do not have studies of mutagenicity and antitumor activity. This study evaluated the antitumor potential of the ethanolic extracts of E. plicata (EEEP), the fraction in which the quinones were found (Fraction dichloromethane-FDEP) and the genotoxic potential related to these substances. For understanding whether fractionation influences antitumor activity, EEEP was obtained by macerating the bulbs, it was fractionated under reflux and FDEP was obtained and fractionated in an open chromatographic column, resulting in the isolatation of eleutherine, isoeleutherine and eleutherol. Chemical-pharmaceutical studies were carried out: silica toxicity and pharmacokinetics (PreADMET), docking and dynamics. The antitumor activity was evaluated through the cytotoxicity in tumor cell line (oral cancer-SCC-9) and normal cell line (human keratinocytes-HaCaT), three-dimensional assay in spheroid model and cell migration in the same lines. Genotoxicity and mutagenicity were evaluated in Allium cepa model, the results of the isolated compounds were similar to those obtained in silico studies. In addition to the isoeleutherine and eleutherine, eleuterol was isolated from FDEP, the silica evaluation demonstrated similar pharmacokinetic profiles between these compounds. In the evaluation of anti-tumor activities, the EEEP fractionation contributed negatively to the activity, with EEEP (SCC09: IC50 = 12.87 ± 0.86 and HaCaT: 28.81 ± 1.82µg/mL) being the most promising with higher selectivity index for the tumor cell, interfering in the speed and directionality of tumor migration. Trying to understand this result, the capacity of naphthoquinones bind to Topoisomerase II (TOPII) was evaluated, confirming that they bind in its pouch, stabilizing the DNA-TOP II complex. In contrast, eleutherine proved to be more genotoxic, increasing the rate of mitosis, of aberrations, with micronucleus, bud and bridge being observed in the metaphase phase. However, it was not possible to differentiate the toxicity of eleutherine and isoleutherine in silico studies (Algae, Daphinia, fish and mutagenicity), obtaining similar results. In summary, EEEP is promising as a cytotoxic agent in tumor cells, and in the prevention of squamous cancer of the mouth. In relation to naphthoquinones, isoleutherine, due to its lower toxic potential and stabilization capacity of the DNA-TOP II complex, needs to be evaluated in other tumor strains.