Low-dose candesartan prevents schizophrenia-like behavioral alterations in a neurodevelopmental two-hit model of schizophrenia

Schizophrenia is a severe mental disorder with complex etiopathogenesis. Based on its neurodevelopmental features, an animal model induced by "two-hit" based on perinatal immune activation followed by peripubertal unpredictable stress was proposed. Sex influences the immune response, and concerning schizophrenia, it impacts the age of onset and symptoms severity. The neurobiological mechanisms underlying the influence of sex in schizophrenia is poorly understood. Our study aimed to evaluate sex influence on proinflammatory and oxidant alterations in male and female mice exposed to the two-hit model of schizophrenia, and its prevention by candesartan, an angiotensin II type 1 receptor (AT1R) blocker with neuroprotective properties. The two-hit model induced schizophrenia-like behavioral changes in animals of both sexes. Hippocampal microglial activation alongside the increased expression of NF-κB, and proinflammatory cytokines, namely interleukin (IL)-1β and TNF-α, were observed in male animals. Conversely, females presented increased hippocampal and plasma levels of nitrite and plasma lipid peroxidation. Peripubertal administration of low-dose candesartan (0.3 mg/kg PO) prevented behavioral, hippocampal, and systemic changes in male and female mice. While these results indicate the influence of sex on inflammatory and oxidative changes induced by the two-hit model, candesartan was effective in both males and females. The present study advances the neurobiological mechanisms underlying sex influence in schizophrenia and opens new avenues to prevent this devasting mental disorder.

Alpha-lipoic acid in the treatment of psychiatric and neurological disorders: a systematic review

Despite the existence of many preclinical studies, scientific evidence is lacking on the clinical use of alpha-lipoic acid (ALA) for central nervous system disorders. Therefore, we aimed at revising the literature concerning the use of ALA for the treatment of psychiatric and neurological conditions and to point out what is missing for the introduction of this antioxidant to this purpose. For this systematic review we performed a search using PubMed and SCOPUS databases with the following keywords: "alpha-Lipoic Acid AND central nervous system OR psychiatric disorders OR neurological disorders OR mood disorders OR anxiety OR psychosis OR Alzheimer OR Parkinson OR stroke". The total number of references found after automatically and manually excluding duplicates was 1061. After primary and secondary screening 32 articles were selected. Regarding psychiatric disorders, the studies of ALA in schizophrenia are advanced being ALA administration related to the improvement of schizophrenia symptoms and side effects of antipsychotic medication. In neurological disorders, ALA as a supplement was effective in the prevention of Alzheimer disease progression. For stroke, the use of the supplement ALAnerv® (containing 300 mg ALA) presented important results, since it was observed a reversal of clinical parameters and oxidative imbalance in these patients. For other neurological conditions, such as encephalopathy, multiple sclerosis, traumatic brain injury, mitochondrial disorders and migraine, the results are still preliminary. Overall, there is a need of well-designed clinical trials to enhance the clinical evidences of ALA effects for the treatment of neurological and psychiatric conditions.

Brain antioxidant effect of mirtazapine and reversal of sedation by its combination with alpha-lipoic acid in a model of depression induced by corticosterone

BACKGROUND

Depression is accompanied by activated neuro-oxidative and neuro-nitrosative pathways, while targeting these pathways has clinical efficacy in depression. This study aimed to investigate the effects of mirtazapine (MIRT) alone and combined with alpha-lipoic acid (ALA) against corticosterone (CORT) induced behavioral and oxidative alterations.

METHODS

Male mice received vehicle or CORT 20mg/kg during 14 days. From the 15th to 21st days they were divided in groups administered: vehicle, MIRT 3mg/kg or the combinations MIRT+ALA100 or MIRT+ALA200. On the 21st day of treatment, the animals were subjected to behavioral tests. Twenty-four hours after the last drug administration hippocampus (HC) and striatum (ST) were dissected for the determination reduced glutathione (GSH), lipid peroxidation (LP) and nitrite levels.

RESULTS

CORT induced anxiety- and depressive-like behaviors as observed by increased immobility time in the tail suspension test and decreased sucrose consumption. MIRT or MIRT+ALA are effective in reversing anxiety- and depressive-like behaviors induced by CORT. CORT and MIRT alone prolonged sleeping time and this effect was reversed by MIRT+ALA. CORT significantly increased LP, which was reversed by MIRT or MIRT+ALA. Nitrite levels were increased in CORT-treated animals and reversed by MIRT+ALA200 (HC), MIRT or MIRT+ALA (ST).

LIMITATION

A relative small sample size and lack of a washout period between drug administration and behavioral testing.

CONCLUSIONS

MIRT or MIRT+ALA reverse CORT-induced anxiety- and depressive-like behaviors probably via their central antioxidant effects. Augmentation of MIRT with ALA may reverse sedation, an important side effect of MIRT. Randomized controlled studies are needed to examine the clinical efficacy of this combination in human depression.