Kamila Castro

Effects of an H3R Antagonist on the Animal Model of Autism Induced by Prenatal Exposure to Valproic Acid

Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders primarily characterized by impaired social interaction and communication, and by restricted repetitive behaviors and interests. Ligands of histamine receptor 3 (H3R) are considered potential therapeutic agents for the treatment of different brain disorders and cognitive impairments. Considering this, the aim of the present study is to evaluate the actions of ciproxifan (CPX), an H3R antagonist, on the animal model of autism induced by prenatal exposure to valproic acid (VPA). Swiss mice were prenatally exposed to VPA on embryonic day 11 and assessed for social behavior, nociceptive threshold and repetitive behavior at 50 days of life. The treatment with CPX (3 mg/kg) or saline was administered 30 minutes before each behavioral test. The VPA group presented lower sociability index compared to VPA animals that were treated with CPX. Compared to the Control group, VPA animals presented a significantly higher nociceptive threshold, and treatment with CPX was not able to modify this parameter. In the marble burying test, the number of marbles buried by VPA animals was consistent with markedly repetitive behavior. VPA animals that received CPX buried a reduced amount of marbles. In summary, we report that an acute dose of CPX is able to attenuate sociability deficits and stereotypies present in the VPA model of autism. Our findings have the potential to help the investigations of both the molecular underpinnings of ASD and of possible treatments to ameliorate the ASD symptomatology, although more research is still necessary to corroborate and expand this initial data.

Perceived migraine triggers: do dietary factors play a role?

The present cross-sectional study was designed to assess the frequency of 36 possible triggering factors precipitating a migraine crisis (hormonal, environmental, and dietary) in adult outpatients suffering from migraine attacks. A group of 123 migraine sufferers, aged 43.2 ± 13.9 (mean ± SD) years, including 114 (92.7%) women, 68.3% having migraine without aura, 68.3% reporting pain severe enough to require drug prophylaxis, and 29.3% presenting with hypertension, were evaluated. The most common triggers were stress and fasting, and environmental and hormonal factors were frequently found to precipitate a crisis. More than 90% of the patients reported susceptibility to 5 or more factors, and only 2.4% did not complain about any dietary factor. The large number of triggers detected in the present study emphasises the importance of awareness and avoidance of these factors in the management of patients with migraine.

Folic acid and autism: What do we know?

Autism spectrum disorders (ASD) consist in a range of neurodevelopmental conditions that share common features with autism, such as impairments in communication and social interaction, repetitive behaviors, stereotypies, and a limited repertoire of interests and activities. Some studies have reported that folic acid supplementation could be associated with a higher incidence of autism, and therefore, we aimed to conduct a systematic review of studies involving relationships between this molecule and ASD. The MEDLINE database was searched for studies written in English which evaluated the relationship between autism and folate. The initial search yielded 60 potentially relevant articles, of which 11 met the inclusion criteria. The agreement between reviewers was κ = 0.808. The articles included in the present study addressed topics related to the prescription of vitamins, the association between folic acid intake/supplementation during pregnancy and the incidence of autism, food intake, and/or nutrient supplementation in children/adolescents with autism, the evaluation of serum nutrient levels, and nutritional interventions targeting ASD. Regarding our main issue, namely the effect of folic acid supplementation, especially in pregnancy, the few and contradictory studies present inconsistent conclusions. Epidemiological associations are not reproduced in most of the other types of studies. Although some studies have reported lower folate levels in patients with ASD, the effects of folate-enhancing interventions on the clinical symptoms have yet to be confirmed.

Dietary aspects of migraine trigger factors.

The significance of dietary factors as triggers for migraines is controversial, and the assessment of this topic is complex and inconclusive. In order to evaluate the published evidence on dietary triggers, a critical review of the literature was performed by conducting a search for food item descriptors linked to migraines in the PubMed and SciELO databases. Reviews and relevant references cited within the articles that resulted from the search were also included. Of the 45 studies reviewed, 16 were population studies that involved the association between migraines and eating habits or the prevalence of related dietary factors; 12 involved interventions or analyzed observational prospective cohorts; and 17 were retrospective studies. Approximately 30 dietary triggers were explored in total, although only seven of these were addressed experimentally. In the prospective studies, patients were instructed to keep a diary; two of these studies involved dietary interventions. Conclusions that are based on nonpharmacological prophylactic strategies with a scientific basis and that show an association between certain dietary factors and the triggering of migraines are limited by the lack of prospective studies with clear experimental designs. Nevertheless, the high frequency of possible specific dietary triggers validates efforts to elucidate the involvement of food-related factors in precipitating migraines.

Histaminergic system in brain disorders: lessons from the translational approach and future perspectives

Histamine and its receptors were first described as part of immune and gastrointestinal systems, but their presence in the central nervous system and importance in behavior are gaining more attention. The histaminergic system modulates different processes including wakefulness, feeding, and learning and memory consolidation. Histamine receptors (H1R, H2R, H3R, and H4R) belong to the rhodopsin-like family of G protein-coupled receptors, present constitutive activity, and are subjected to inverse agonist action. The involvement of the histaminergic system in brain disorders, such as Alzheimer’s disease, schizophrenia, sleep disorders, drug dependence, and Parkinson’s disease, is largely studied. Data obtained from preclinical studies point antagonists of histamine receptors as promising alternatives to treat brain disorders. Thus, clinical trials are currently ongoing to assess the effects of these drugs on humans. This review summarizes the role of histaminergic system in brain disorders, as well as the effects of different histamine antagonists on animal models and humans.

The effect of ketogenic diet in an animal model of autism induced by prenatal exposure to valproic acid

Objectives: Autism spectrum disorder (ASD) is characterized by impairments in social interaction and communication, and by restricted repetitive behaviors and interests. Its etiology is still unknown, but different environmental factors during pregnancy, such as exposure to valproic acid (VPA), are associated with high incidence of ASD in children. In this context, prenatal exposure to VPA in rodents has been used as a reliable model of ASD. Ketogenic diet (KD) is an alternative therapeutic option for refractory epilepsy; however, the effects of this approach in ASD-like behavior need to be evaluated. We conducted a behavioral assessment of the effects of KD in the VPA model of autism. Methods: Pregnant animals received a single-intraperitoneal injection of 600 mg/kg VPA, and their offspring were separated into four groups: (1) control group with standard diet (C-SD), (2) control group with ketogenic diet (C-KD), (3) VPA group with standard diet (VPA-SD), and (4) VPA group with ketogenic diet (VPA-KD). Results: When compared with the control group, VPA animals presented increased social impairment, repetitive behavior and higher nociceptive threshold. Interestingly, the VPA group fed with KD presented improvements in social behavior. These mice displayed higher scores in sociability index and social novelty index when compared with the SD-fed VPA mice. Discussion: VPA mice chronically exposed to a KD presented behavioral improvements; however, the mechanism by which KD improves ASD-like features needs to be further investigated. In conclusion, the present study reinforces the potential use of KD as a treatment for the core deficits of ASD.

Body mass index, abdominal obesity, body fat and migraine features in women

BACKGROUND Studies seeking to establish an association between migraine and anthropometric parameters have thus far been inconclusive. Furthermore, drugs used for migraine prophylaxis may be associated with changes in body weight. OBJECTIVE To investigate the potential association of anthropometric parameters and body fat percentage with attack patterns and use of prophylactic medication in migraineurs. METHODS Cross-sectional study that assessed the body mass index, waist circumference, body fat percentage and related clinical variables (characteristics of attacks and the use of prophylactic medication) in female outpatients with migraine. RESULTS 166 female migraineurs aged ≥18 years (mean age, 45 ± 14 years) were included in the study. Migraine without aura was most prevalent (71.7%). Mean body mass index and body fat percentage were 27.8±6.0 kg/m² and 36.4 ± 8.3% respectively. Body mass index and waist circumference were weakly correlated with frequency of attacks over 6 months (rs = 0.162, p < 0.05 and rs = 0.187, p < 0.05 respectively). These correlations remains weak considering only premenopausal women, but disappear in the older women. Stratification of analysis by migraine type field shows a moderate correlation between migraine with aura and frequency of attacks over 6 months and body mass index (rs = 0.369, p < 0.05), as well as waist circumference (rs = 0.423, p < 0.01). Patients who were on prophylactic medication had higher body mass index, waist circumference, and body fat percentage values (p < 0.01, Student t-test). CONCLUSION This study revealed a potential, though tenuous association between migraine and anthropometric parameters and frequency of attacks, which does not reflect on the duration, severity, and disability of attacks, with patterns differing by migraine type, reproductive age and prophylactic medication.

Omega-3 fatty acids' supplementation in Alzheimer's disease: A systematic review

Introduction: Alzheimers disease (AD) is a neurodegeneration disorder characterized by progressive impairments of memory, language, reasoning, and other cognitive functions. Evidence suggests that omega-3 fatty acids may act as a possible protection factor in AD. Objective: To evaluate the results available in the literature involving omega-3 fatty acids supplementation and its effect on cognitive function in AD patients. Methods: A systematic review of MEDLINE (from PubMed), Excerpta Medica Database, and Cochrane Library databases was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Inclusion criteria consisted in original intervention studies, controlled by placebo, that assessed the impact of supplementation or dietary intake of omega-3 fatty acids on cognitive function, in humans with AD, without limitation for prime date of publication. Results: Initial search resulted in 361 articles. Seven studies fully met the inclusion criteria. Most studies did not find statistically significant results for the omega-3 fatty acids supplementation compared to placebo, and those who show some benefit do it only in a few cognitive assessment scales. However, the effects of omega-3 fatty acids appear to be most effectively demonstrated in patients with very mild AD. Conclusion: The effects of omega-3 fatty acids supplementation in mild AD corroborate epidemiological observational studies showing that omega-3 fatty acids may be beneficial in disease onset, when there is slight impairment of brain function. Although some studies have shown changes in scales of cognitive function in more severe cases, they are not enough to support omega-3 fatty acids supplementation in the treatment of AD.

Body composition in patients with classical homocystinuria: body mass relates to homocysteine and choline metabolism

INTRODUCTION Classical homocystinuria is a rare genetic disease caused by cystathionine β-synthase deficiency, resulting in homocysteine accumulation. Growing evidence suggests that reduced fat mass in patients with classical homocystinuria may be associated with alterations in choline and homocysteine pathways. This study aimed to evaluate the body composition of patients with classical homocystinuria, identifying changes in body fat percentage and correlating findings with biochemical markers of homocysteine and choline pathways, lipoprotein levels and bone mineral density (BMD) T-scores. METHODS Nine patients with classical homocystinuria were included in the study. Levels of homocysteine, methionine, cysteine, choline, betaine, dimethylglycine and ethanolamine were determined. Body composition was assessed by bioelectrical impedance analysis (BIA) in patients and in 18 controls. Data on the last BMD measurement and lipoprotein profile were obtained from medical records. RESULTS Of 9 patients, 4 (44%) had a low body fat percentage, but no statistically significant differences were found between patients and controls. Homocysteine and methionine levels were negatively correlated with body mass index (BMI), while cysteine showed a positive correlation with BMI (p<0.05). There was a trend between total choline levels and body fat percentage (r=0.439, p=0.07). HDL cholesterol correlated with choline and ethanolamine levels (r=0.757, p=0.049; r=0.847, p=0.016, respectively), and total cholesterol also correlated with choline levels (r=0.775, p=0.041). There was no association between BMD T-scores and body composition. CONCLUSIONS These results suggest that reduced fat mass is common in patients with classical homocystinuria, and that alterations in homocysteine and choline pathways affect body mass and lipid metabolism.

Dietary Practices of Children and Adolescents with Down Syndrome.

The aim of this study was to assess dietary intake, breastfeeding history, weight at birth and current weight in children and adolescents with Down syndrome (DS). Therefore, a cross-sectional, controlled study with 19 DS participants and 19 controls without DS matched by gender and age was performed. Except for vitamin D, a lower or the same frequency of insufficient intake in other micronutrients was noted in participants compared with controls. The DS group had a reduced exclusive breastfeeding duration and increased carbohydrate and caloric intake. The consumption of micronutrients in both groups reinforced the current trend of excessive sodium consumption and insufficient intake of calcium, some B complex vitamins and water by children and adolescents.