Folic Acid Improves Abnormal Behavior Via Mitigation of Oxidative Stress, Inflammation, and Ferroptosis in the BTBR T+Tf/J Mouse Model of Autism

Background: Autism spectrum disorder (ASD) is a group of pervasive heterogeneous neurodevelopmental disorders that is characterized by lasting impairments in restricted interests; stereotyped, repetitive behaviors; and social interaction and communication deficits. The etiology of this disorder is not well understood. Recent research has also reported that folic acid (FA) notably impacts cognitive function and autistic-like behaviors. However, the underlying mechanisms of FA are rarely studied, and the signal transduction pathways affected by FA remain elusive.

Objectives: The aim of his study were to examine the effects of FA on the autistic phenotypes in BTBR T+ Itpr3tf/J (BTBR) mice, and to investigate the possible underlying mechanisms.

Methods: Mice received 0.2 mg/kg FA orally daily from postnatal days 14 to 35. Mice were tested for stereotyped and repetitive behaviors, social interaction, and spatial learning and memory at the end of FA supplementation. Oxidative stress, neuroinflammatory responses, and ferroptosis-related proteins in the brain were evaluated.

Results: FA supplementation in BTBR mice (1) reduced repetitive and stereotyped behavior, improved social communication, and enhanced memory and spatial learning. (2) FA supplementation reduced neuronal loss in hippocampal CA1 regions of the brain, and (3) decreased the levels of the pro-inflammatory cytokines interleukin-1β (IL- 1β), Iba- 1, IL- 18, TNF- а, and IL- 6 and glial fibrillary acidic protein (GFAP) in the hippocampus. (4) FA supplementation changed the malondialdehyde (MDA) and glutathione (GSH) levels and superoxide dismutase (SOD) and glutathione peroxidase (GSH- Px) activities in the hippocampus. (6) FA supplementation inhibited the elevation of the SOD1 and TFR protein levels and enhanced the relative expression levels of GPx4 and Fpn1 in the hippocampus and (7) increased the relative levels of phospho- Ca²+/calmodulin-dependent protein kinase II (p- CaMKII) and phospho- cAMP-response element binding protein (p- CREB) in the hippocampus.

Conclusions: FA oral supplementation to BTBR mice rescued stereotyped and repetitive behaviors, social deficit, and spatial learning and memory impairments, likely by improving the oxidative-stress and inflammatory responses and altering the ferroptosis signaling pathways.