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1.
Toxicol Appl Pharmacol ; 486: 116937, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38643950

RESUMO

Selective Serotonin Reuptake Inhibitors (SSRIs) are widely used medications for the treatment of major depressive disorder. However, long-term SSRI use has been associated with weight gain and altered lipid profiles. These findings suggest that SSRIs may have negative effects on metabolism. Exposure to certain chemicals called 'obesogens' is known to promote lipid accumulation and obesity by modulating adipogenesis. Here, we investigated whether citalopram (CIT) and sertraline (SER) interfere with the process of adipogenesis, using human mesenchymal stem cells (MSCs) in a 2D and a 3D model. Assessment of intracellular lipid accumulation by fluorescence staining was used as a measure for enhanced adipogenesis. To explore possible mechanisms behind SSRIs' effects, receptor mediated activity was studied using responsive cell lines for various nuclear receptors. Furthermore, RNA sequencing was performed in the 3D model, followed by differential gene expression and pathway analysis. A dose dependent increase in lipid accumulation was observed in both models with CIT and SER. For the 3D model, the effect was seen in a range close to reported steady-state plasma concentrations (0.065-0.65 µM for SER and 0.12-0.92 µM for CIT). Pathway analysis revealed unexpected results of downregulation in adipogenesis-related pathways and upregulation in phospholipids and lysosomal pathways. This was confirmed by an observed increase in lysosomes in the 2D model. Our findings suggest lysosomal dysfunction and disrupted lipid metabolism in mature adipocytes, leading to excessive phospholipid synthesis. Moreover, important adipogenic processes are inhibited, potentially leading to dysfunctional adipocytes, which might have implications in the maintenance of a healthy metabolic balance.


Assuntos
Adipogenia , Antidepressivos , Citalopram , Metabolismo dos Lipídeos , Células-Tronco Mesenquimais , Inibidores Seletivos de Recaptação de Serotonina , Sertralina , Adipogenia/efeitos dos fármacos , Sertralina/farmacologia , Sertralina/toxicidade , Humanos , Citalopram/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Inibidores Seletivos de Recaptação de Serotonina/toxicidade , Antidepressivos/farmacologia , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Células Cultivadas , Relação Dose-Resposta a Droga
2.
Molecules ; 26(7)2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33805996

RESUMO

Oxidative stress is defined as a disturbance in the prooxidant/antioxidant balance in favor of the former and a loss of control over redox signaling processes, leading to potential biomolecular damage. It is involved in the etiology of many diseases, varying from diabetes to neurodegenerative diseases and cancer. Nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor and reported as one of the most important oxidative stress regulators. Due to its regulatory role in the expression of numerous cytoprotective genes involved in the antioxidant and anti-inflammatory responses, the modulation of NRF2 seems to be a promising approach in the prevention and treatment of cancer. Breast cancer is the prevalent type of tumor in women and is the leading cause of death among female cancers. Oxidative stress-related mechanisms are known to be involved in breast cancer, and therefore, NRF2 is considered to be beneficial in its prevention. However, its overactivation may lead to a negative clinical impact on breast cancer therapy by causing chemoresistance. Some known "oxidative stress modulators", such as melatonin and polyphenols, are suggested to play an important role in the prevention and treatment of cancer, where the activation of NRF2 is reported as a possible underlying mechanism. In the present review, the potential involvement of oxidative stress and NRF2 in breast cancer will be reviewed, and the role of the NRF2 modulators-namely, polyphenols and melatonin-in the treatment of breast cancer will be discussed.


Assuntos
Neoplasias da Mama , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Melatonina/uso terapêutico , Fator 2 Relacionado a NF-E2/metabolismo , Proteínas de Neoplasias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Polifenóis/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Feminino , Humanos
3.
Bioorg Chem ; 104: 104219, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32916391

RESUMO

Over the last decade, there has been substantial interest in the use of melatonin (MLT) and MLT-like compounds in the treatment of several diseases. MLT can scavenge different reactive oxygen species and can also stimulate the synthesis of antioxidant enzymes. Our ongoing study relies on changing the groups in the different modifiable sites of the indole ring to increase the antioxidant activity. In this study a new approach for substitution of indole ring as indole based MLT analogue was proposed. We report the synthesis and characterization of a series of new indole-7-aldehyde hydrazide/hydrazone derivatives as indole-based MLT analogues. Anticancer potential of the compounds were evaluated both by their antioxidant and CYP1 inhibitory activities. In vitro antioxidant capacity of the compounds was investigated both in a cell-based (DCFH assay) and a cell-free (DPPH assay) assay. Potential inhibitory effects of the compounds on CYP1 catalytic activity were investigated via EROD assay. Cytotoxic activity of the compounds was further evaluated by the MTT assay in CHO-K1 cells. MLT analogues having an o-halogenated aromatic moiety exhibited effective antioxidant properties without having any cytotoxic effect. In conclusion, MLT derivatives represent promising scaffolds for discovery of effective antioxidant agents.


Assuntos
Aldeídos/farmacologia , Antioxidantes/farmacologia , Indóis/farmacologia , Melatonina/farmacologia , Aldeídos/síntese química , Aldeídos/química , Animais , Antioxidantes/síntese química , Antioxidantes/química , Compostos de Bifenilo/antagonistas & inibidores , Células CHO , Células Cultivadas , Cricetulus , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Indóis/síntese química , Indóis/química , Melatonina/síntese química , Melatonina/química , Estrutura Molecular , Picratos/antagonistas & inibidores , Relação Estrutura-Atividade
4.
Xenobiotica ; 49(5): 549-556, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-29804490

RESUMO

A causal association is reported between prolonged exposures to elevated levels of estrogen and breast cancer. Therefore inhibiting aromatase (CYP19A), which catalyses the conversion of androgens to estrogens, is an important approach in prevention and treatment of estrogen receptor positive (ER+) breast cancer. Melatonin, a natural indolic hormone, is reported to prevent free radical induced carcinogenesis and block local estrogen synthesis in breast tissue via aromatase inhibition. However several features of melatonin limit its therapeutic use. In the present study aromatase inhibiting potential of 2-methyl indole hydrazones are investigated, and compared with melatonin, by two in vitro models; a cell-free assay using a fluorescence substrate and a cell-based assay where cell proliferation was determined in ER + human breast cancer cells (MCF-7 BUS) in the absence of estrogen and the presence of testosterone. Aromatase inhibitory effect is also explored by molecular modelling studies. In biological activity assays monochloro substituted indole hydrazones were found to have stronger aromatase inhibitory activity among all tested derivatives and were more active than melatonin. This finding is further confirmed by molecular modelling. These results may be useful in the design and synthesis of novel melatonin analogues with higher inhibitory potency against aromatase.


Assuntos
Inibidores da Aromatase/química , Aromatase/química , Hidrazonas/química , Indóis/química , Simulação de Acoplamento Molecular , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/química , Aromatase/metabolismo , Inibidores da Aromatase/farmacologia , Neoplasias da Mama/enzimologia , Proliferação de Células/efeitos dos fármacos , Humanos , Hidrazonas/farmacologia , Indóis/farmacologia , Células MCF-7 , Melatonina/análogos & derivados , Melatonina/química , Melatonina/farmacologia , Proteínas de Neoplasias/metabolismo
5.
Molecules ; 22(1)2017 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-28117726

RESUMO

During the last decade there has been growing interest in physical-chemical oxidation processes and the behavior of free radicals in living systems. Radicals are known as intermediate species in a variety of biochemical reactions. Numerous techniques, assays and biomarkers have been used to measure reactive oxygen and nitrogen species (ROS and RNS), and to examine oxidative stress. However, many of these assays are not entirely satisfactory or are used inappropriately. The purpose of this chapter is to review current EPR (Electron Paramagnetic Resonance) spectroscopy methods for measuring ROS, RNS, and their secondary products, and to discuss the strengths and limitations of specific methodological approaches.


Assuntos
Espectroscopia de Ressonância de Spin Eletrônica/métodos , Espécies Reativas de Nitrogênio/química , Espécies Reativas de Oxigênio/química , Animais , Radicais Livres/química , Humanos , Estresse Oxidativo
6.
Bioorg Med Chem ; 24(8): 1658-64, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-26970662

RESUMO

Oxidative stress has been recognized as a contributing factor in ageing and various diseases including cancer and neuropathological disorders. Indole derivatives such as the neurohormone melatonin (MLT) constitute an important class of therapeutic agent in medicinal chemistry. MLT can scavenge different reactive oxygen species and can also stimulate the synthesis of antioxidant enzymes. As a part of our ongoing studies, a series of new indole-based hydrazide/hydrazone derivatives were synthesized as MLT analogues. Their antioxidant activity was investigated in human erythrocytes by evaluating their reducing effect against oxidation of a redox-sensitive fluorescent probe. Possible inherent cytotoxicity of the compounds was investigated in CHO-K1 cells by lactate dehydrogenase leakage test. Protection of neuronal PC12 cells against amyloid ß-induced damage was examined by MTT assay and their ability in reduction of ROS generation induced by amyloid ß was tested. MLT analogues having an o-halogenated aromatic moiety exhibited effective antioxidant properties without having any membrane-damaging effect. Moreover, derivatives having o-halogenated and dihalogenated aromatic side chain significantly protected neuronal cells at concentrations of 10 and 100 µM. In conclusion, MLT derivatives represent promising scaffolds for discovery of effective antioxidant and neuroprotective agents.


Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Antioxidantes/química , Antioxidantes/farmacologia , Indóis/farmacologia , Melatonina/análogos & derivados , Melatonina/farmacologia , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/antagonistas & inibidores , Peptídeos beta-Amiloides/metabolismo , Animais , Antioxidantes/síntese química , Células CHO , Sobrevivência Celular/efeitos dos fármacos , Cricetulus , Relação Dose-Resposta a Droga , Humanos , Indóis/química , Melatonina/química , Estrutura Molecular , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/química , Células PC12 , Fragmentos de Peptídeos/metabolismo , Ratos , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Relação Estrutura-Atividade
7.
J Enzyme Inhib Med Chem ; 31(6): 1312-21, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26745200

RESUMO

Melatonin (MLT) is a well-known free-radical scavenger, involving in the prevention of cellular damage that can lead to cancer, ageing and a variety of neurodegenerative diseases. Research on MLT-related compounds has been required to optimise the maximum pharmaceutical activity with the lowest side effects. In our ongoing research, we have synthesized new indole-based MLT analogues as potential antioxidant agents by modifying the MLT molecule. In this study, we build on previous findings, through the synthesis, characterization and in vitro antioxidant profiling of a series of new indole-based MLT analogues which possess triazole, thiadiazole and carbothioamides on the third position on the indole ring. In vitro antioxidant activity was investigated by evaluating their reducing effect against oxidation of a redox sensitive fluorescent probe and their radical scavenging activity was assessed via the DPPH assay. In addition, in vitro cytotoxic effects of newly synthesized compounds were investigated in CHO-K1 cells using the MTT assay.


Assuntos
Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Indóis/química , Melatonina/análogos & derivados , Tiadiazóis/química , Tioamidas/química , Triazóis/química , Animais , Células CHO , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Quimioprevenção , Cricetinae , Cricetulus , Melatonina/química , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray
8.
J Enzyme Inhib Med Chem ; 31(1): 121-5, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-25942363

RESUMO

Overproduction of reactive oxygen species results in oxidative stress that can cause fatal damage to vital cell structures. It is known that the use of antioxidants could be beneficial in the prevention or delay of numerous diseases associated with oxidative stress. Melatonin (MLT) is known as a powerful free-radical scavenger and antioxidant. It was found that indole ring of MLT can be employed by bioisosteric replacement by other aromatic rings. Quinoline derivatives constitute an important class of compounds for new drug development. Owing to quinoline and hydrazones appealing physiological properties and are mostly found in numerous biologically active compounds a series of quinoline-2-carbaldehyde hydrazone derivatives were synthesized as bioisosteric analogues of MLT, characterized and in vitro antioxidant activity was investigated by evaluating their reducing effect against oxidation of a redox-sensitive fluorescent probe. Cytotoxicity potential of all compounds was investigated both by lactate dehydrogenase leakage assay and by MTT assay.


Assuntos
Antioxidantes/síntese química , Antioxidantes/farmacologia , Hidrazonas/farmacologia , Melatonina/análogos & derivados , Melatonina/farmacologia , Quinolinas/farmacologia , Animais , Antioxidantes/química , Células CHO , Sobrevivência Celular/efeitos dos fármacos , Cricetulus , Relação Dose-Resposta a Droga , Corantes Fluorescentes/química , Corantes Fluorescentes/metabolismo , Hidrazonas/síntese química , Hidrazonas/química , Melatonina/química , Estrutura Molecular , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Quinolinas/síntese química , Quinolinas/química , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Relação Estrutura-Atividade
9.
Toxicol In Vitro ; 100: 105895, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39004236

RESUMO

Endocrine disruptors are suggested to act as potential "obesogens" by interacting with various metabolic processes in adipose tissue. Besides industrial chemicals that are blamed for acting as endocrine disruptors as well as obesogens, pharmaceuticals can also cause obesogenic effects as unintended adverse effects. However, limited studies evaluated the obesogenic adverse effects of pharmaceuticals. Based on this information, the present study aimed to investigate the possible in vitro adipogenic/lipogenic potential of indomethacin and pantoprazole that are prescribed during pregnancy. Their effects on lipid accumulation, adiponectin level, glycerol-3-phosphate dehydrogenase (G3PDH) activity, and expression of adipogenic genes and proteins were investigated in 3 T3-L1 cell line. The range of concentrations of the pharmaceuticals was selected according to their Cmax values. Lipid accumulation was increased dependently with indomethacin dose and with pantoprazole at its highest concentration. Both pharmaceuticals also increased adiponectin levels, which was thought to play a role in stimulating the adipogenesis pathway. Moreover, both pharmaceuticals altered the gene and/or protein expression of some adipogenic/lipogenic transcriptional factors, which may lead to disruption of metabolic pathways during the fetal period. In conclusion, indomethacin and pantoprazole may have obesogenic effects through different mechanisms and their potential to cause obesity should be investigated by further in vivo and epidemiological studies.


Assuntos
Células 3T3-L1 , Adipogenia , Indometacina , Lipogênese , Pantoprazol , Pantoprazol/toxicidade , Indometacina/toxicidade , Animais , Adipogenia/efeitos dos fármacos , Camundongos , Lipogênese/efeitos dos fármacos , Adiponectina/metabolismo , Glicerolfosfato Desidrogenase/metabolismo , Glicerolfosfato Desidrogenase/genética
10.
J Enzyme Inhib Med Chem ; 28(6): 1143-55, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22994658

RESUMO

Melatonin (MLT) is a strong free-radical scavenger, which protects the body from the effects of oxidants. In recent years, MLT have been described resulting in much attention in the development of synthetic compounds possessing. As a part of our ongoing study a series of indole-based MLT analogue hydrazide/hydrazone derivatives were synthesized, characterized and in vitro antioxidant activity was investigated by evaluating their reducing effect against oxidation of a redox sensitive fluorescent probe. Membrane stabilizing effect of all compounds was also investigated by lactate dehydrogenase leakage assay. Furthermore voltammetric methods have been applied to the synthesized compounds to characterize oxidation potentials to get insight into their metabolism owing to the oxidation mechanisms taking place at the electrode and in the body share similar principles.


Assuntos
Antioxidantes/química , Antioxidantes/metabolismo , Técnicas Eletroquímicas , Eritrócitos/química , Indóis/química , Melatonina/análogos & derivados , Melatonina/metabolismo , Antioxidantes/síntese química , Eletrodos , Eritrócitos/metabolismo , Corantes Fluorescentes , Humanos , Hidroliases/metabolismo , Melatonina/síntese química , Melatonina/química , Estrutura Molecular
11.
Artigo em Inglês | MEDLINE | ID: mdl-36843259

RESUMO

BACKGROUND: Prenatal period is a critical developmental phase that is sensitive to hormonal disruption by natural and/or exogenous hormones. Some pharmaceuticals frequently prescribed and used safely during pregnancy are shown to interact with the developmental programming of fetus, resulting in endocrine-related adverse effects. OBJECTIVE: In this research, we aimed to determine the endocrine disrupting potential of paracetamol, indomethacin, alpha-methyldopa and pantoprazole which are frequently prescribed pharmaceuticals during pregnancy. METHODS: In vitro aromatase inhibitory, estrogen receptor (ER) agonist/antagonist (E-Screen assay) and hormone biosynthesis modulatory effects (H295R steroidogenesis assay) of the selected pharmaceuticals were evaluated. Furthermore, their effects on viability of MCF-7/BUS and H295R cells were also evaluated by MTT assay. RESULTS: None of the pharmaceuticals affected H295R cell viability. Only indomethacin reduced MCF-7/BUS cell viability at 100µM and 300µM. Among the tested pharmaceuticals, only paracetamol and indomethacin showed aromatase inhibitory activity with IC 50 values of 14.7 x 10 -5 M and 57.6 x 10 -5 M, respectively. Moreover, indomethacin displayed a biphasic ER agonist effect. ER antagonist effects of indomethacin and pantoprazole were confirmed by performing two stepped E-Screen assay. After the partial validation of the H295R steroidogenesis assay with forskolin and prochloraz, the effects of pharmaceuticals on synthesis of testosterone (T) and estradiol (E2) levels were tested. Alpha-methyldopa increased E2 at all tested concentrations and T at 1.48 and 4.4µM. Contrarily other tested pharmaceuticals did not affect steroidogenesis. CONCLUSION: Present data suggest that all tested pharmaceuticals may have potential endocrine disrupting effect, which should be considered when used in pregnancy.

12.
Turk J Pharm Sci ; 19(6): 626-629, 2022 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-36544280

RESUMO

Objectives: Aromatase is an enzyme that catalyzes the conversion of androgens to estrogens. While inhibition of aromatase is a useful approach for treating breast cancer, it may also have toxicological consequences due to its endocrine disrupting/modulating effect. In this study, sensitivity and performance of two in vitro assays -a cell free and a cell-based- for evaluating aromatase activity were investigated by testing known aromatase inhibitors and partial validation of the methods was performed. Advantages and disadvantages of these methods are also discussed. Materials and Methods: Aromatase activity was evaluated via two in vitro models; direct measurement with a cell-free assay using a fluorescent substrate and recombinant human enzyme and indirect evaluation with a cell-based assay where cell proliferation was determined in estrogen receptor positive human breast cancer cells (MCF-7 BUS) in the absence of estrogen and the presence of testosterone. Results: In the cell-free direct measurement assay, reference compounds ketoconazole and aminoglutethimide have been shown to inhibit the aromatase enzyme with half-maximal inhibitory concentration (IC50) values concordant with literature. In cell-based indirect measurement assay, only ketoconazole dose-dependently inhibited cell proliferation with 3.47 x 10-7 M IC50. Inter-assay and intra-assay reproducibility of both methods was found to be within acceptable deviation levels. Conclusion: Both methods can be successfully applied. However, to evaluate the potential aromatase activity of the novel compounds in vitro, it seems better to perform both the cell-based and the cell-free assays that allows low-moderate biotransformation and eliminate cytotoxicity potential, respectively.

13.
Curr Drug Metab ; 22(8): 628-644, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34082678

RESUMO

An "endocrine disruptor" has been broadly defined as an exogenous chemical that interferes with the production, release, transportation, metabolism, binding, action, or the elimination of endogenous hormones, which are responsible for homeostasis, reproduction, development or behaviour. Diverse groups of chemicals such as pharmaceuticals, phytoestrogens, natural hormones, and synthetic chemicals such as pesticides, plasticizers, phthalates, parabens, polychlorinated/polybrominated biphenyls, bisphenols are shown to interfere with the endocrine system, and they have been defined as EDs in the last three decades. As for all chemicals, the biotransformation of EDs has a decisive role in their potential toxic effects. Humans are exposed to vast amounts of diverse chemicals throughout their lives. Fortunately, most of the chemicals are converted via biotransformation reactions catalyzed by the enzymes, into more hydrophilic metabolites, which are readily excreted in urine or bile. Biotransformation reactions resulting in less toxic metabolites are known as detoxification. However, some biotransformation reactions are called bioactivation, in which more toxic metabolites are formed. In the case of EDs, metabolites formed via bioactivation usually have a higher affinity for a hormone receptor or induce/inhibit an enzyme involved in the synthesis or catabolism of an endogenous hormone more dramatically compared to their parent compound. In the present review, the role of bioactivation in endocrine modulating effects of chemicals from all groups of EDs, namely endogenous estrogens, phytoestrogens, synthetic/industrial chemicals, and pharmaceuticals it can be were discussed.


Assuntos
Disruptores Endócrinos/farmacocinética , Poluentes Ambientais/farmacocinética , Animais , Biotransformação , Estrogênios/metabolismo , Humanos
14.
Molecules ; 15(4): 2187-202, 2010 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-20428037

RESUMO

The aim of this study was to synthesize and examine possible in vitro antioxidant effects of indole-based melatonin analogue compounds. As a part of our ongoing study nineteen indole hydrazide/hydrazone derivatives were synthesized, characterized and their in vitro antioxidant activity was investigated by three different assays: by evaluating their reducing effect against oxidation of a redox sensitive fluorescent probe, by examining their protective effect against H2O2-induced membrane lipid peroxidation and by determining their inhibitory effect on AAPH-induced hemolysis of human erythrocytes. The results indicated significant strong antioxidant activity for most of the compounds, when compared to melatonin.


Assuntos
Antioxidantes/síntese química , Antioxidantes/farmacologia , Indóis/química , Melatonina/análogos & derivados , Melatonina/farmacologia , Eritrócitos/efeitos dos fármacos , Humanos , Hidrazonas/síntese química , Hidrazonas/farmacologia
15.
Antioxidants (Basel) ; 9(8)2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32722041

RESUMO

Oxidative stress is represented as an imbalance between reactive oxygen species (ROS) production and the response of antioxidant proteins [...].

16.
Curr Med Chem ; 25(33): 4084-4101, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-28699501

RESUMO

BACKGROUND: Latest data from International Agency for Cancer Research shows that breast cancer is the leading cancer site in women and is the leading cause of death among female cancers. Induction of reactive oxygen species (ROS) and oxidative stress as a consequence of impaired balance between prooxidants and antioxidants are suggested to be involved in induction and progression of breast cancer. Cancer cells are found to exhibit higher levels of ROS compared to normal cells. However increased antioxidant defence which balances the oxidative status within the cancer cells suggests that high ROS levels may prevent tumorigenesis via various mechanisms. These contradictory roles of ROS and oxidative stress in breast cancer let scientists investigate potential oxidative stress modulators as anticancer strategies. CONCLUSIONS: In the present review we address the mechanisms of ROS production in breast cancer cells, the role of impaired oxidative status as well as the benefits of introducing oxidative stress modulators in therapeutic strategies in breast cancer. This review is focusing more on melatonin which we have been working on during the last decade. Our data, in accordance with the literature, suggest an important role for melatonin in breast cancer prevention and adjuvant therapy.


Assuntos
Neoplasias da Mama/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Animais , Ácido Ascórbico/farmacologia , Carotenoides/farmacologia , Feminino , Humanos , Melatonina/farmacologia , Resveratrol , Estilbenos/farmacologia , Tocoferóis/farmacologia
17.
Biochem J ; 395(2): 277-84, 2006 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-16363993

RESUMO

In vitro studies demonstrate that the hydroxyl radical converts L-phenylalanine into m-tyrosine, an unnatural isomer of L-tyrosine. Quantification of m-tyrosine has been widely used as an index of oxidative damage in tissue proteins. However, the possibility that m-tyrosine might be generated oxidatively from free L-phenylalanine that could subsequently be incorporated into proteins as an L-tyrosine analogue has received little attention. In the present study, we demonstrate that free m-tyrosine is toxic to cultured CHO (Chinese-hamster ovary) cells. We readily detected radiolabelled material in proteins isolated from CHO cells that had been incubated with m-[14C]tyrosine, suggesting that the oxygenated amino acid was taken up and incorporated into cellular proteins. m-Tyrosine was detected by co-elution with authentic material on HPLC and by tandem mass spectrometric analysis in acid hydrolysates of proteins isolated from CHO cells exposed to m-tyrosine, indicating that free m-tyrosine was incorporated intact rather than being metabolized to other products that were subsequently incorporated into proteins. Incorporation of m-tyrosine into cellular proteins was sensitive to inhibition by cycloheximide, suggesting that protein synthesis was involved. Protein synthesis using a cell-free transcription/translation system showed that m-tyrosine was incorporated into proteins in vitro by a mechanism that may involve L-phenylalanine-tRNA synthetase. Collectively, these observations indicate that m-tyrosine is toxic to cells by a pathway that may involve incorporation of the oxidized amino acid into proteins. Thus misincorporation of free oxidized amino acids during protein synthesis may represent an alternative mechanism for oxidative stress and tissue injury during aging and disease.


Assuntos
Proteínas/química , Proteínas/metabolismo , Tirosina/metabolismo , Tirosina/toxicidade , Animais , Células CHO , Radioisótopos de Carbono , Morte Celular/efeitos dos fármacos , Células Cultivadas , Cricetinae , Cicloeximida/farmacologia , Oxirredução , Fenilalanina/farmacologia , Biossíntese de Proteínas , Análise Espectral , Transcrição Gênica , Tirosina/antagonistas & inibidores
18.
Comb Chem High Throughput Screen ; 9(6): 449-54, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16842226

RESUMO

The present study was designed to investigate the potential of reactive oxygen species (ROS) generating and subsequent ROS-mediated lipid peroxidation (LPO) inducing effect of several mono- and di-halogenated biphenyls and biphenyl ethers in rat hepatocytes in vitro. For this aim, 4-chloro- and 4-bromo biphenyl (4-CB and 4-BB), 4-OH, 4'-BB, 4-bromo diphenylether (4-BDE), 4,4'-dichlorobiphenyl (4,4'-DCB), 4,4'-dibromobiphenyl (4,4'-DBB), and 3,4-dichlorobiphenyl (3,4-DCB) were incubated with freshly isolated rat hepatocytes. Their oxidative potential was evaluated by detecting the intracellular ROS formation by oxidant-sensing fluorescent probes (2',7'-dichlorofluorescein diacetate and C(11)-BODIPY(581/591)) using a multiplate reader and determining the levels of eight LPO products (formaldehyde, malondialdehyde, propanal, butanal, pentanal, hexanal, octanal, and nonanal) by a gas chromatography-electron capture detection. 4-BDE was found to be active both in cytoplasm and in the cell membrane in terms of inducing the formation of ROS. Another important finding was the increase in ROS-inducing potential of 4-BB when the same concentration of the hydroxylated derivative, 4-OH,4'-BB, was incubated with hepatocytes. 4-BDE was also found to be the most effective among all tested compounds in inducing LPO where 4-OH, 4'-BB was again more potent than its unmetabolized form, 4-BB. Lactate dehydrogenase leakage analyses indicated that all tested compounds are cytotoxic; 4-BDE caused the highest LDH leakage compared to other mono-halogenated biphenyls tested. Our results suggest that ROS formation by chlorinated biphenyls and mono-hydroxylated bromobiphenyls, and concomitant induction of LPO might be involved in the cytotoxic effects of these industrial pollutants. Similar effects of mono-BDE are also reported, which is a novel observation.


Assuntos
Éteres/farmacologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Bifenil Polibromatos/farmacologia , Bifenilos Policlorados/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Animais , Avaliação Pré-Clínica de Medicamentos , Éteres/química , L-Lactato Desidrogenase/efeitos dos fármacos , L-Lactato Desidrogenase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Bifenil Polibromatos/química , Bifenilos Policlorados/química , Ratos , Ratos Wistar
19.
Int J Nanomedicine ; 11: 2641-53, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27358561

RESUMO

This study aimed to develop a suitable buccal mucoadhesive nanoparticle (NP) formulation containing fluconazole for the local treatment of oral candidiasis. The suitability of the prepared formulations was assessed by means of particle size (PS), polydispersity index, and zeta potential measurements, morphology analysis, mucoadhesion studies, drug entrapment efficiency (EE), in vitro drug release, and stability studies. Based on the optimum NP formulation, ex vivo drug diffusion and in vitro cytotoxicity studies were performed. Besides, evaluation of the antifungal effect of the optimum formulation was evaluated using agar diffusion method, fungicidal activity-related in vitro release study, and time-dependent fungicidal activity. The effect of the optimum NP formulation on the healing of oral candidiasis was investigated in an animal model, which was employed for the first time in this study. The zeta potential, mucoadhesion, and in vitro drug release studies of various NP formulations revealed that chitosan-coated NP formulation containing EUDRAGIT(®) RS 2.5% had superior properties than other formulations. Concerning the stability study of the selected formulation, the formulation was found to be stable for 6 months. During the ex vivo drug diffusion study, no drug was found in receptor phase, and this is an indication of local effect. The in vitro antifungal activity studies showed the in vitro efficacy of the NP against Candida albicans for an extended period. Also, the formulation had no cytotoxic effect at the tested concentration. For the in vivo experiments, infected rabbits were successfully treated with local administration of the optimum NP formulation once a day. This study has shown that the mucoadhesive NP formulation containing fluconazole is a promising candidate with once-a-day application for the local treatment of oral candidiasis.


Assuntos
Antifúngicos/farmacologia , Candidíase Bucal/tratamento farmacológico , Fluconazol/farmacologia , Nanopartículas/administração & dosagem , Administração Oral , Animais , Antifúngicos/administração & dosagem , Antifúngicos/farmacocinética , Células CHO/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Bovinos , Quitosana/química , Cricetulus , Sistemas de Liberação de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Estabilidade de Medicamentos , Fluconazol/administração & dosagem , Fluconazol/farmacocinética , Masculino , Mucosa Bucal/efeitos dos fármacos , Nanopartículas/química , Tamanho da Partícula , Ácidos Polimetacrílicos/química , Coelhos
20.
Drug Deliv ; 23(5): 1502-13, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25259424

RESUMO

Atopic dermatitis (AD) is a chronic and relapsing skin disease with severe eczematous lesions. Long-term topical corticosteroid treatment can induce skin atrophy, hypopigmentation and transepidermal water loss (TEWL) increase. A new treatment approach was needed to reduce the risk by dermal targeting. For this purpose, Betamethasone valerate (BMV)/Diflucortolone valerate (DFV)-loaded liposomes (220-350 nm) were prepared and incorporated into chitosan gel to obtain adequate viscosity (∼13 000 cps). Drugs were localized in stratum corneum + epidermis of rat skin in ex-vivo permeation studies. The toxicity was assessed on human fibroblast cells. In point of in-vivo studies, pharmacodynamic responses, treatment efficacy and skin irritation were evaluated and compared with previously prepared nanoparticles. Liposome/nanoparticle in gel formulations produced higher paw edema inhibition in rats with respect to the commercial cream. Similar skin blanching effect with commercial creams was obtained via liposome in gels although they contain 10 times less drug. Dermatological scoring results, prognostic histological parameters and suppression of mast cell numbers showed higher treatment efficiency of liposome/nanoparticle in gel formulations in AD-induced rats. TEWL and erythema measurements confirmed these results. Overview of obtained results showed that liposomes might be an effective and safe carrier for corticosteroids in skin disease treatment.


Assuntos
Corticosteroides/administração & dosagem , Valerato de Betametasona/administração & dosagem , Diflucortolona/análogos & derivados , Portadores de Fármacos/administração & dosagem , Epiderme/química , Lipossomos/administração & dosagem , Nanopartículas/química , Administração Cutânea , Corticosteroides/química , Corticosteroides/farmacologia , Animais , Valerato de Betametasona/química , Valerato de Betametasona/metabolismo , Química Farmacêutica , Diflucortolona/administração & dosagem , Diflucortolona/química , Diflucortolona/metabolismo , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Farmacoeconomia , Epiderme/fisiologia , Humanos , Lipossomos/química , Tamanho da Partícula , Ratos , Absorção Cutânea
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