Introduction: Alzheimer's 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.

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.

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.