Franciane Cabral Pinheiro

7-chloro-4-(phenylselenyl) quinoline prevents dopamine depletion in a Drosophila melanogaster model of Parkinson’s-like disease

Neurodegeneration in Parkinsons disease appears to be caused by multiple factors, including oxidative damage and an increase in acetylcholinesterase expression that can culminate in loss of dopaminergic neurons. A selenium-containing quinoline derivative, 7-chloro-4-(phenylselanyl) quinoline (4-PSQ), shows important pharmacological actions mainly attributed to its antioxidant and anticholinesterase properties. Thus, this study investigated the neuroprotective effect of 4-PSQ in a model of Parkinsons-like disease induced by rotenone (ROT) in Drosophila melanogaster and verified whether these effects are related to selenium levels. Adult flies were divided into: [1] control, [2] 4-PSQ (25 μM), [3] ROT (500 μM), and [4] 4-PSQ (25 μM) + ROT (500 μM) groups and exposed to a diet containing ROT and/or 4-PSQ for 7 days, according to their respective groups. Survival, behavioral, and ex vivo analyses were performed. Dopamine levels, reactive species levels (RS), lipid peroxidation (LPO), superoxide dismutase (SOD) and catalase (CAT) activity, and proteic thiol (PSH) and non-proteic thiol (NPSH) content in the head region were analyzed, while acetylcholinesterase (AChE) activity and selenium levels in the head and body regions were analyzed. 4-PSQ was able to reverse the ROT-induced deficits in flies, reestablish dopamine and selenium levels, reverse cholinergic deficits, improve motor function, and ameliorate mortality. Furthermore, 4-PSQ also reduced RS levels and LPO, and restored the activities of the antioxidant enzymes, SOD and CAT. Interestingly, a positive relationship between dopamine and selenium levels could be seen. Our results demonstrate the neuroprotective effect of 4-PSQ, and we suggest that the compound may act via different mechanisms, such as improving antioxidant defenses and consequently reducing oxidative damages, as well as having an anticholinesterase action, which together can prevent dopamine depletion, as these actions were correlated with the presence of selenium in the 4-PSQ molecule.

Chrysin reverses the depressive-like behavior induced by hypothyroidism in female mice by regulating hippocampal serotonin and dopamine

Abstract Hypothyroidism is often associated with psychiatric disorders such as depression. In this study, we evaluated the effect of chrysin on depressive‐like behavior and monoamine levels in hypothyroid female mice. Hypothyroidism was induced by continuous exposure to 0.1% methimazole (MTZ) in drinking water for 31 days. Exposure to MTZ was associated with low plasma levels of thyroid hormones T3 and T4 compared with the control group. Subsequently, euthyroid and MTZ‐induced hypothyroid mice were intragastrically administered vehicle or chrysin (20 mg/kg) once a day for 28 consecutive days. After treatments, the following behavioral assessments were performed: Open‐Field Test (OFT), Tail suspension test (TST), and Forced Swimming Test (FST). Additionally, T3 and T4 levels were measured again, and serotonin (5HT), dopamine, and noradrenaline levels were analyzed in the prefrontal cortex and the hippocampus. Chrysin treatment could not reverse T3 and T4 levels. Hypothyroid mice showed an increased immobility time in TST and FST; chrysin treatment reversed these effects. Reduced levels of 5HT and dopamine in the prefrontal cortex and the hippocampus were observed in the hypothyroid mice than in the euthyroid mice. Chrysin treatment recovered 5HT content in both structures and dopamine content only in the hippocampus. Noradrenaline content was not altered by treatments. Together, our results have demonstrated that chrysin treatment reverses depressive‐like behaviors in hypothyroid female mice and suggests the involvement of 5HT and dopamine in these effects.

Chronic unpredictable mild stress-induced depressive-like behavior and dysregulation of brain levels of biogenic amines in Drosophila melanogaster

ABSTRACT The etiopathogenesis of depression may involve repeated exposure to several unpredictable stressors. This study was conducted to investigate changes induced by chronic unpredictable mild stress (CUMS) and to assess behavioral and neurochemical changes that predict depressive‐like behavior in Drosophila melanogaster. Male Drosophila melanogaster flies were exposed to CUMS with several stressors (cold, heat, starvation, and sleep deprivation) in an unpredictable and chronic manner for ten days. At the end of treatment, in vivo behavioral tests (open field, aggression, forced swimming, mating, light/dark box, male fertility evaluation, sucrose preference, weight evaluation) and ex vivo analyses (dopamine and serotonin levels) were performed. Using this CUMS model, we obtained results that contribute to the construction of a depressive model in Drosophila, where we reproduce some behavioral phenotypes corresponding to depressive symptoms, such as immobility in the forced swimming test, less exploration in the light/dark test, changes in mating behavior, changes in the aggressiveness test, reduced sucrose preference, and weight‐loss, in addition to a significant reduction in the levels of serotonin and dopamine when compared to the control group. Fluoxetine was used in our study as a positive control to demonstrate that CUMS‐induced depressive‐like behaviors in flies can be reversed by antidepressants. In conclusion, male Drosophila melanogaster exposed to CUMS display a depressive‐like phenotype, and, while this poses some limitations as an animal model for depression, it meets some of the criteria required to be a valid model, such as good face and construct validity. HIGHLIGHTSThe validity of the CUMS paradigm was confirmed in D. melanogaster model.CUMS induced depressive‐like behavior in D. melanogaster.CUMS decreases biogenic amine levels in D. melanogaster.CUMS induces longer immobility time in FST in D. melanogaster.FLX exerts antidepressant effect on the induction of depressive‐like behavior.

DESCONTAMINAÇÃO MICROBIOLÓGICA DE ESPONJAS DE COZINHA UTILIZADAS EM SERVIÇOS DE ALIMENTAÇÃO

A ocorrencia das doencas transmitidas por alimentos pode estar relacionada a praticas inadequadas na manipulacao e preparacao de alimentos e a contaminacao cruzada, que podem envolver esponjas de cozinha. Com base nisso, o objetivo deste estudo foi avaliar a contaminacao microbiologica de esponjas usadas em servicos de alimentacao e verificar a eficacia de um procedimento para sua descontaminacao. As esponjas foram coletadas em nove servicos de alimentacao e substituidas por esponjas novas. Apos uma semana de utilizacao, uma nova amostragem foi realizada e partes das esponjas foram submetidas a um processo de descontaminacao por imersao em agua fervente. Analises microbiologicas incluiram contagens de mesofilos aerobios totais, coliformes totais e termotolerantes, Staphylococcus sp., e presenca de S. aureus. A quantificacao de mesofilos aerobios em esponjas novas (EN) variou de 2,85 a 8,92 logUFC/mL. A quantificacao dos grupos coliformes totais e termotolerantes apresentou valores entre 0,48 a 3,04 logNMP/mL. Para Staphylococcus sp., as contagens foram de 2,65 logUFC/mL a acima de 3 logUFC/mL, demonstrando resultado positivo para S. aureus em amostras de dois dos estabelecimentos. Houve grande variacao nas contagens microbiologicas entre os estabelecimentos e a descontaminacao resultou em reducoes significativas em grande parte dos estabelecimentos, variando de 84,2% a 98%. A partir desses resultados, a descontaminacao de esponjas de cozinha e sua substituicao periodica mostraram-se essenciais para a seguranca do alimento.