Lipoic acid prevents mirtazapine-induced weight gain in mice without impairs its antidepressant-like action in a neuroendocrine model of depression.

Mirtazapine (MIRT) is a multi-target antidepressant used in treatment of severe depression with promising efficacy, but also with important side effects, mainly sedation and weight gain. Thus, the present study aimed to test the effects of the neuroprotective antioxidant lipoic acid (ALA) in the reversal of weight and metabolic changes induced by MIRT in corticosterone-induced depression model in mice, as well as proposed mechanisms for their association antidepressant and pro-cognitive effects. To do these male Swiss mice received Tween 80 (control), corticosterone (CORT 20 mg / kg), MIRT (3 mg / kg) and ALA (100 or 200 mg / kg), alone or associated for 21 days. After this, the animals were subjected to behavioral tests for affective and cognitive domains. Daily weight changes, blood cholesterol fractions and corticosterone were measured. Also, hippocampus (HC) protein expression of the serotonin transporter (SERT), synaptophysin, protein kinase B-Akt (total and phosphorylated) and the cytokines IL-4 and IL-6 were investigated. CORT induced a marked depression-like behavior, memory deficits, metabolic changes (total cholesterol and LDL) and increased serum corticosterone. Also, CORT increased SERT expression in the HC. MIRT alone or combined with ALA sustained its antidepressant-like effect, as well as reversed CORT-induced impairment in spatial recognition memory. Additionally, the association MIRT+ALA200 reversed the weight gain induced by the former antidepressant, as well as reduced serum corticosterone levels and SERT expression in the HC. ALA alone induced significant weight loss and reduced total cholesterol and HDL fraction. Our findings provide promising evidence about the ALA potential to prevent metabolic and weight changes associated to MIRT, without impair its antidepressant and pro-cognition actions. Therefore, ALA+MIRT combination could represent a new therapeutic strategy for treating depression with less side effects.

Sex influences in the preventive effects of peripubertal supplementation with N-3 polyunsaturated fatty acids in mice exposed to the two-hit model of schizophrenia.

Schizophrenia is a devastating neurodevelopmental disorder. The animal model based on perinatal immune activation, as first-hit, combined with peripubertal stress, as a second hit, has gained evidence in recent years. Omega-3 polyunsaturated fatty acids (n3-PUFAs) is being a promise for schizophrenia prevention. Nevertheless, the influence of sex in schizophrenia neurobiology and prevention has been neglected. Thus, the present study evaluates the preventive effects of n3-PUFAs in both sexes' mice submitted to the two-hit model and the participation of oxidative changes in this mechanism. The two-hit consisted of polyI:C administration from postnatal days (PNs) 5-7, and unpredictable stress from PNs35-43. n3-PUFAs were administered from PNs30-60. Prepulse inhibition of the startle reflex (PPI), social interaction, and Y-maze tests were conducted between PNs70-72 to evaluate positive-, negative-, and cognitive-like schizophrenia symptoms. We assessed brain oxidative changes in brain areas and plasma. Both sexes' two-hit mice presented deficits in PPI, social interaction, and working memory that were prevented by n3-PUFAs. In two-hit females, n3-PUFAs prevented increments in nitrite levels in the prefrontal cortex (PFC), hippocampus, striatum, and plasma TBARS levels. In two-hit males, n3-PUFAs prevented the increase in TBARS in the PFC, hippocampus, and striatum. Notably, male mice that received only n3-PUFAs without hit exposure presented impairments in working memory and social interaction. These results add further preclinical evidence for n3-PUFAs as an accessible and effective alternative in preventing behavioral and oxidative changes related to schizophrenia but call attention to the need for precaution in this indication due to hit- and sex-sensitive issues.