Turmeric Extract Rescues Ethanol-Induced Developmental Defect in the Zebrafish Model for Fetal Alcohol Spectrum Disorder (FASD)

Effect of curcumin on the embryotoxic effect of ethanol in a zebrafish model

Curcumin, a natural polyphenol found in the turmeric plant, has been shown to have anti-inflammatory and antioxidant properties. It has been widely studied for its potential protective effect against various health conditions, including ethanol-induced malformation. Ethanol exposure during pregnancy can lead to various developmental abnormalities, known as fetal alcohol syndrome (FAS) and fetal alcohol spectrum disorders (FASD). Due to the high prevalence of FASD and FAS and no effective treatment, it is essential to develop preventive strategies. Recent studies have investigated the potential protective effect of curcumin against ethanol-induced malformation in animal models. This study aimed to examine whether curcumin can reduce the toxic effects of ethanol in zebrafish embryos. The present study showed that pure curcumin applied together with 1.5 % ethanol (v/v) did not lead to a protective effect on ethanol-induced malformations such as disturbances of body length and width or pericardia oedema in growing zebrafish embryos. Moreover, curcumin extract showed a pro-oxidant effect in the Fenton reaction in the presence of ethanol.

The Fetal Alcohol Spectrum Disorders-An Overview of Experimental Models, Therapeutic Strategies, and Future Research Directions

Since the establishment of a clear link between maternal alcohol consumption during pregnancy and certain birth defects, the research into the treatment of FASD has become increasingly sophisticated. The field has begun to explore the possibility of intervening at different levels, and animal studies have provided valuable insights into the pathophysiology of the disease, forming the basis for implementing potential therapies with increasingly precise mechanisms. The recent reports suggest that compounds that reduce the severity of neurodevelopmental deficits, including glial cell function and myelination, and/or target oxidative stress and inflammation may be effective in treating FASD. Our goal in writing this article was to analyze and synthesize current experimental therapeutic interventions for FASD, elucidating their potential mechanisms of action, translational relevance, and implications for clinical application. This review exclusively focuses on animal models and the interventions used in these models to outline the current direction of research. We conclude that given the complexity of the underlying mechanisms, a multifactorial approach combining nutritional supplementation, pharmacotherapy, and behavioral techniques tailored to the stage and severity of the disease may be a promising avenue for further research in humans.

Curcumin treatment attenuates alcohol-induced alterations in a mouse model of foetal alcohol spectrum disorders

Alcohol exposure during development produces physical and mental abnormalities in the foetus that result in long-term molecular adjustments in the brain, which could underlie the neurobehavioural deficits observed in individuals suffering from foetal alcohol spectrum disorders. In this study, we assessed the effects of curcumin on cognitive impairments caused by prenatal and lactational alcohol exposure (PLAE). Furthermore, we examined whether curcumin could counteract the molecular alterations that may underlie these behavioural impairments. We focused on inflammatory and epigenetic mechanisms by analysing the expression of pro-inflammatory mediators, such as IL-6, TNF-α, and NF-κB, in the hippocampus and prefrontal cortex, as well as microglia and astrocyte activation in the dentate gyrus. We also assessed the activity of histone acetyltransferase in these brain areas. To model binge alcohol drinking, we exposed pregnant C57BL/6 mice to a 20% v/v alcohol solution during gestation and lactation, with limited access periods. We treated male offspring with curcumin during postnatal days (PD28-35) and then evaluated their behaviour in adulthood (PD60). Our results showed that curcumin treatment during the peri-adolescence period improved the anxiety and memory deficits observed in PLAE mice. At the molecular level, we found enhanced histone acetyltransferase activity in mice subjected to PLAE that curcumin treatment could not reverse to baseline levels. These mice also showed increased expression of pro-inflammatory mediators, which could be rescued by curcumin treatment. They also displayed astrogliosis and microglia activation. Our study provides further evidence to support the use of curcumin as a therapeutic agent for counteracting behavioural and molecular alterations induced by PLAE.

Short Exposure to Moderate Concentration of Alcohol During Embryonic Development Does Not Alter Gross Morphology in Zebrafish

Several studies have demonstrated translational potential of the zebrafish in modeling fetal alcohol spectrum disorders (FASDs), including the less severe forms of this disease. Short exposure to even low doses of alcohol during embryonic development has been shown to disrupt behavior, alter neurochemistry, and expression of neuronal markers and glial cell phenotypes in zebrafish. However, no study to date has systematically analyzed the potential morphological effects of the short- and low-dose embryonic alcohol exposure regimen used before with zebrafish to model milder forms of human FASD. In this study, we use this previously used embryonic alcohol exposure regimen. We immerse intact zebrafish eggs of AB strain and of a genetically variable wild-type population for 2 h into 1% or 0% (vol/vol) ethanol bath at one of five developmental stages (8, 16, 24, 32, or 40 h postfertilization). At 8 days postfertilization, we quantify body length and width and eye diameter of the larvae. We report nonsignificant effects of embryonic alcohol exposure used at all developmental stages in both populations of zebrafish. Our results confirm that visual perception or motor function is unlikely to have contributed to previously reported behavioral abnormalities resulting from embryonic alcohol exposure in zebrafish.

Persistent increase in ecto‑5'‑nucleotidase activity from encephala of adult zebrafish exposed to ethanol during early development

Prenatal alcohol exposure causes alterations to the brain and can lead to numerous cognitive and behavioral outcomes. Long-lasting effects of early ethanol exposure have been registered in glutamatergic and dopaminergic systems. The purinergic system has been registered as an additional target of ethanol exposure. The objective of this research was to evaluate if the ecto‑5'‑nucleotidase and adenosine deaminase activities and gene expression of adult zebrafish exposed to 1% ethanol during early development could be part of the long-lasting targets of ethanol. Zebrafish embryos were exposed to 1% ethanol in two distinct developmental phases: gastrula/segmentation (5-24 h post-fertilization) or pharyngula (24-48 h post-fertilization). At the end of three months, after checking for morphological outcomes, the evaluation of enzymatic activity and gene expression was performed. Exposure to ethanol did not promote gross morphological defects; however, a significant decrease in the body length was observed (17% in the gastrula and 22% in the pharyngula stage, p < 0.0001). Ethanol exposure during the gastrula/segmentation stage promoted an increase in ecto‑5'‑nucleotidase activity (39.5%) when compared to the control/saline group (p < 0.0001). The ecto‑5'‑nucleotidase gene expression and the deamination of adenosine exerted by ecto and cytosolic adenosine deaminase were not affected by exposure to ethanol in both developmental stages. HPLC experiments did not identify differences in adenosine concentration on the whole encephala of adult animals exposed to ethanol during the gastrula stage or on control animals (p > 0.05). Although the mechanism underlying these findings requires further investigation, these results indicate that ethanol exposure during restricted periods of brain development can have long-term consequences on ecto‑5'‑nucleotidase activity, which could have an impact on subtle sequels of ethanol early exposure.