According to the literature, there is a decrease in glial cell number or hypofunction of glial cells in depression. It was also found that both antidepressants and atypical antipsychotics might target glial cells, and that they increase the release of glial-cell-line-derived neurotrophic factor (GDNF) from C6 rat glioma cells (C6 cells). In this project, C6 cells were used as a model for glial cells to investigate the effects of fluoxetine and quetiapine on proliferation and differentiation, and to investigate their effects on the release of GDNF. A combination of quetiapine and fluoxetine was used to study their potential synergistic effect on the release of GDNF from C6 cells. <p>C6 cells were treated with different concentrations of fluoxetine and quetiapine in both normal and serum starvation culture conditions. Under the serum present condition, fluoxetine (25 mM) decreased the number of C6 cells from 24 to 48 h, while quetiapine (25 mM) decreased the cell number only at 48h. Under serum starvation, it was found that fluoxetine (12.5 mM) increased the number of C6 cells from 24 to 48 h treatment; in contrast, quetiapine (25 mM) decreased the number of C6 cells after 48 h treatment. Both fluoxetine and quetiapine inhibited the proliferation of C6 cells under normal and serum starvation conditions. Fluoxetine (12.5 mM) decreased C6 cell death, while quetiapine had no significant effect. Fluoxetine, but not quetiapine, changed the morphology of C6 cells and increased the level of glial fibrillary acidic protein (GFAP), an astrocyte marker. Both fluoxetine (12.5, 25 mM) and quetiapine (25 mM) increased the release of GDNF from C6 cells, and an apparent additive effect was found between quetiapine and fluoxetine in the modulation of release of GDNF from these cells. <p>It was concluded that:<p>1. High concentration (25 mM) of fluoxetine and quetiapine decreased the number of C6 cells under the serum present condition and both drugs inhibited the proliferation of C6 cells.<p>2. Fluoxetine had a protective effect on the C6 cells under serum starvation, and affected the differentiation of C6 cells; this implies that fluoxetine may protect glial cells in vivo and affect their differentiation. <p>3. A high concentration of quetiapine decreased the number of C6 cells and inhibited the proliferation under serum starvation; even though it increased the release of GDNF from C6 cells as did fluoxetine.<p>4. Both quetiapine and fluoxetine increased the release of GDNF from <p>C6 cells under serum starvation. The combination of quetiapine and fluoxetine had an apparent additive effect in the modulation of GDNF release.<p>5. These effects on proliferation & GDNF release may underlie the benefit observed with these drugs in treating depression and schizophrenia.

According to the literature, there is a decrease in glial cell number or hypofunction of glial cells in depression. It was also found that both antidepressants and atypical antipsychotics might target glial cells, and that they increase the release of glial-cell-line-derived neurotrophic factor (GDNF) from C6 rat glioma cells (C6 cells). In this project, C6 cells were used as a model for glial cells to investigate the effects of fluoxetine and quetiapine on proliferation and differentiation, and to investigate their effects on the release of GDNF. A combination of quetiapine and fluoxetine was used to study their potential synergistic effect on the release of GDNF from C6 cells. <p>C6 cells were treated with different concentrations of fluoxetine and quetiapine in both normal and serum starvation culture conditions. Under the serum present condition, fluoxetine (25 mM) decreased the number of C6 cells from 24 to 48 h, while quetiapine (25 mM) decreased the cell number only at 48h. Under serum starvation, it was found that fluoxetine (12.5 mM) increased the number of C6 cells from 24 to 48 h treatment; in contrast, quetiapine (25 mM) decreased the number of C6 cells after 48 h treatment. Both fluoxetine and quetiapine inhibited the proliferation of C6 cells under normal and serum starvation conditions. Fluoxetine (12.5 mM) decreased C6 cell death, while quetiapine had no significant effect. Fluoxetine, but not quetiapine, changed the morphology of C6 cells and increased the level of glial fibrillary acidic protein (GFAP), an astrocyte marker. Both fluoxetine (12.5, 25 mM) and quetiapine (25 mM) increased the release of GDNF from C6 cells, and an apparent additive effect was found between quetiapine and fluoxetine in the modulation of release of GDNF from these cells. <p>It was concluded that:<p>1. High concentration (25 mM) of fluoxetine and quetiapine decreased the number of C6 cells under the serum present condition and both drugs inhibited the proliferation of C6 cells.<p>2. Fluoxetine had a protective effect on the C6 cells under serum starvation, and affected the differentiation of C6 cells; this implies that fluoxetine may protect glial cells in vivo and affect their differentiation. <p>3. A high concentration of quetiapine decreased the number of C6 cells and inhibited the proliferation under serum starvation; even though it increased the release of GDNF from C6 cells as did fluoxetine.<p>4. Both quetiapine and fluoxetine increased the release of GDNF from <p>C6 cells under serum starvation. The combination of quetiapine and fluoxetine had an apparent additive effect in the modulation of GDNF release.<p>5. These effects on proliferation & GDNF release may underlie the benefit observed with these drugs in treating depression and schizophrenia.

Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2014-02-07T19:19:35Z No. of bitstreams: 1 Lizandra Moreira Góes... Caracterização dos efeitos tóxicos....pdf: 1602592 bytes, checksum: 16b9153b36fb34585abb21b40bd4bdef (MD5) / Made available in DSpace on 2014-02-07T19:19:35Z (GMT). No. of bitstreams: 1 Lizandra Moreira Góes... Caracterização dos efeitos tóxicos....pdf: 1602592 bytes, checksum: 16b9153b36fb34585abb21b40bd4bdef (MD5) Previous issue date: 2013 / Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Faculdade de Medicina. Salvador, BA, Brasil / Catecóis são derivados do benzeno, podendo apresentar citotoxicidade, que pode constituir um modelo experimental útil para o desenvolvimento de novos fármacos. No bioma brasileiro inúmeras plantas produzem metabólitos com atividades diversas, como antioxidantes, ou inibidores do crescimento celular. No Brasil, as neoplasias são a segunda causa de óbito, especialmente aquelas derivadas do sistema nervoso, aumentando o interesse por novos antineoplásicos e agentes neuroprotetores. Este trabalho caracteriza efeitos citotóxicos do 1,2-dihidroxibenzeno (CAT) e discretamina (DSC) em células do sistema nervoso in vitro. Determinou-se a EC50 de CAT e DSC usando brometo de 3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolium (MTT), investigou-se sua auto-oxidação por espectrofotometria, avaliou-se mudanças morfológicas e condensação/fragmentação nuclear por microscopia. Avaliou-se a proteção de DSC e 8-metoxipsoraleno (8-MOP) contra a citotoxicidade do CAT. O padrão de morte celular foi analisado por citometria de fluxo. A espoliação de glutation reduzido (GSH) foi analisada usando monoclorobimano. A toxicidade do CAT para células SH-SY5Y e C6 depende da dose e associa-se à formação de quinonas. Houve mudanças morfológicas, condensação/fragmentação da cromatina e morte apoptótica, não relacionada à espoliação de GSH. DSC não foi tóxica para células SH-SY5Y, porém protegeu contra os efeitos do CAT em baixas concentrações. DSC mostrou-se citotóxica para células de glioma (GL-15 e C6) e potencializou o CAT. Pré-tratamento por 30 minutos com DSC protegeu contra a ação do CAT após 72 horas. 8-MOP potencializou os efeitos do CAT, não revertendo seus efeitos na viabilidade celular, morfologia celular, condensação/fragmentação nuclear, e espoliação de GSH. Esses resultados caracterizam um modelo de citotoxicidade que pode ser aplicado no desenvolvimento de novos agentes farmacológicos. Estudos complementares são necessários para elucidar a proteção da DSC. / Catechols are benzene derivatives, which may exhibit cytotoxic activity that can be employed to develop new drugs. Plants are important sources of metabolites with pharmacological activities such as antioxidants, or cell growth inhibitors. In Brazil, cancer is the second leading cause of death, especially those derived from the nervous system, which increase the interest for new antineoplastic and neuroprotective drugs. The cytotoxic effects promoted by 1,2-dihydroxybenzene (CAT) and discretamine (DSC) in nervous system cells were characterized in vitro. The protective effects of DSC and 8-methoxypsoralen (8-MOP) against CAT-induced cytotoxicity were also evaluated. CAT and DSC EC50 was determined by using 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT). CAT auto-oxidation was investigated by spectrophotometry. Morphological changes and nuclear condensation/ fragmentation were evaluated by microscopy. The pattern of cell death was obtained by flow cytometry. Reduced glutathione (GSH) depletion was analyzed by using monochlorobimane. CAT induced a dose-dependent toxicity to SH-SY5Y and C6 cells, associated with reactive quinones formation. It also induced morphological changes, nuclear condensation/fragmentation, and apoptotic death not caused by GSH depletion. DSC was not toxic to SH-SY5Y cells, but protected against CAT effects at low concentrations. DSC was be cytotoxic to glioma cells (GL-15 and C6) and potentiated CAT effects. However, pretreatment for 30 minutes with DSC protected them against CAT after 72 hours. 8-MOP also potentiated CAT effects instead to protect cells. These results characterize an experimental model useful for studies searching new pharmacological agents. However, further studies are needed to elucidate the DSC protective effects.

Modifying the metabolism of the body’s own endocannabinoids is a novel approach for analgesia. Two key catabolic enzymes are fatty acid amide hydrolase (FAAH) and inflammation-inducible cyclooxygenase 2 (COX-2). The cellular uptake of the key endocannabinoid anandamide (AEA) has been found to be regulated by its FAAH-catalysed intracellular degradation, but COX-2 has not been investigated in this respect. We aimed to find out whether or not COX-2 in an in vitro inflammation setting would be able to gate AEA uptake. To achieve this, C6 cells and Raw 264.7 cells were stimulated with LPS/INF-γ and lysates then analyzed by immunoblot in order to verify COX-2 expression. AEA cellular uptake was quantified using a radioassay with [3H]-AEA. It was found that COX-2 was not inducible in C6 cells using the LPS/INF-γ conditions studied, while it was inducible in Raw 264.7 cells. AEA uptake in the COX-2-induced Raw 264.7 cells was not reduced by inhibitors of this enzyme. FAAH appeared to be down-regulated in the stimulated Raw 264.7 cells, and this was reflected in an overall lower AEA uptake. Our interpretation of the data points to FAAH as gating AEA uptake. Additional experiments are required to validate our findings by verifying significance.