Effects of omega-3 supplementation on anxiety-like behaviors and neuroinflammation in Wistar rats following cafeteria diet-induced obesity

• Published in: Nutritional neuroscience Vol. ahead-of-print; no. ahead-of-print; pp. 1 - 12
• Main Authors: González, Lucía Paola Facciola, Rodrigues, Fernanda da Silva, Jantsch, Jeferson, Fraga, Gabriel de Farias, Squizani, Samia, Castro, Luis Felipe dos Santos, Correia, Lídia Luz, Neto, João Pereira, Giovenardi, Márcia, Porawski, Marilene, Guedes, Renata Padilha
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 01-02-2024
• Subjects: Animals; Anxiety - etiology; Anxiety - prevention & control; contextual aversive conditioning; Diet; Dietary Supplements; Fatty Acids, Omega-3 - pharmacology; GFAP; light-dark box; Male; Neuroinflammatory Diseases; Obesity - etiology; Obesity - metabolism; Open field; polyunsaturated fatty acids (PUFAs); Rats; Rats, Wistar; TLR-4; Toll-Like Receptor 4; TLR-4; contextual aversive conditioning; light–dark box; Open field; polyunsaturated fatty acids (PUFAs); GFAP
• ISSN: 1028-415X; 1476-8305
• DOI: 10.1080/1028415X.2023.2168229

Objetives: Omega-3 (n3) fatty acids have been studied as an option to alleviate the harmful effects of obesity. However, its role in obesity-related behavioral changes is still controversial. This study aimed to evaluate the effects of n3 on behavior and neuroinflammation in obese animals. Methods: Male Wistar rats were divided into four groups: control diet (CT), CT+n3, cafeteria diet (CAF), and CAF+n3. Diet was administered for 13 weeks, and n3 was supplemented during the last 5 weeks. Metabolic and biochemical parameters were evaluated, as well as anxiety-like behaviors. Immunoblots were conducted in the animals' cerebral cortex and hippocampus to assess changes in neuroinflammatory markers.
Results: CAF-fed animals showed higher weight gain, visceral adiposity, fasting glucose, total cholesterol, triglycerides, and insulin levels, and n3 improved the lipid profile and restored insulin sensitivity. CAF-fed rats showed anxiety-like behaviors in the open field and light-dark box tasks but not in the contextual aversive conditioning. Omega-3 did not exert any effect on these behaviors. Regarding neuroinflammation, diet and supplementation acted in a region-specific manner. In the hippocampus, CAF reduced claudin-5 expression with no effect of n3, indicating a brain-blood barrier disruption following CAF. Furthermore, in the hippocampus, the glial fibrillary acidic protein (GFAP) and toll-like receptor 4 (TLR-4) were reduced in treated obese animals. However, n3 could not reverse the TLR-4 expression increase in the cerebral cortex.
Discussion: Although n3 may protect against some neuroinflammatory manifestations in the hippocampus, it does not seem sufficient to reverse the increase in anxiolytic manifestations caused by CAF.