Folic acid does not have an anti-manic effect but protect the brain against oxidative stress in an animal model of mania induced by ouabain.

Background: Bipolar disorder (BD) is a complex and severe mental disorder that affects 1-3 % of the world population. Studies have suggested the involvement of oxidative stress in the physiopathology of this psychiatry disorder. Folic acid (FA), a vitamin from the B complex, is a nutraceutical that has recently been researched as a possible treatment for BD since folate is reduced in patients with the disorder. The present study aimed to evaluate the effects of lithium (Li) and FA on behavioral changes and oxidative stress parameters in an animal model of mania induced by ouabain (OUA). Methods: Wistar rats received a single intracerebroventricular (ICV) injection of OUA or artificial cerebrospinal fluid (aCSF). From the day following ICV injection, the rats were treated for seven days with gavage injections of Li (47.5 mg/kg/mL), FA (50 mg/kg/mL), or water (1 mL/kg). On the 7th day after OUA injection, locomotor activity was measured using the open-field test. In addition, the oxidative stress parameters were evaluated in rats' frontal cortex, striatum, and hippocampus. Results: OUA induced mania-like behavior and oxidative stress in rats' brains, but Li could reverse these alterations. FA did not affect behavior parameters; however, it presents an antioxidant effect on the brain structures evaluated. Limitations: The study was only evaluated male rats and ICV injection is an invasive procedure. Conclusion: These results indicate that even though FA has an effect against the oxidative stress induced by OUA, this effect was not strong enough to interfere with behavior parameters.