Effects of cholecalciferol on behavior and production of reactive oxygen species in female mice subjected to corticosterone-induced model of depression.

Major depressive disorder (or depression) is one of the most frequent psychiatric illnesses in the population, with chronic stress being one of the main etiological factors. Studies have shown that cholecalciferol supplementation can lead to attenuation of the depressive state; however, the biochemical mechanisms involved in the relationship between cholecalciferol and depression are not very well known. The objective of this study was to investigate the effects of the administration of cholecalciferol on behavioral parameters (tail suspension test (TST), open field test (OFT), splash test (ST)) and redox state (dichlorofluorescein (DCF)) in adult female Swiss mice subjected to a model of depression induced by chronic corticosterone treatment. Corticosterone (20 mg/kg, p.o.) was administered once a day for 21 days. For investigation of the antidepressant-like effect, cholecalciferol (100 IU/kg) or fluoxetine (10 mg/kg, positive control) was administered p.o. within the last 7 days of corticosterone administration. After the treatments, the behavioral tests and biochemical analyses in the hippocampus and prefrontal cortex of the rodent samples were performed. Animals submitted to repeated corticosterone administration showed a depressive-like behavior, evidenced by a significant increase in the immobility time in the TST, which was significantly reduced by the administration of cholecalciferol or fluoxetine. In addition, the groups treated with cholecalciferol and fluoxetine showed a significant decrease in the production of reactive oxygen species (ROS) in the hippocampus. These results show that cholecalciferol, similar to fluoxetine, has a potential antidepressant-like effect, which may be related to the lower ROS production.

A single coadministration of subeffective doses of ascorbic acid and ketamine reverses the depressive-like behavior induced by chronic unpredictable stress in mice.

In this study, we investigated the ability of a single coadministration of subeffective doses of ascorbic acid and ketamine to reverse the depressive-like behavior induced by chronic unpredictable stress (CUS) in mice. Moreover, we examined the effect of combined administration of ascorbic acid and ketamine on hippocampal phosphorylation of p70S6K and immunocontents of GLUA1 and PSD-95 in mice submitted to the CUS procedure. CUS procedure was applied for 21 days. Animals received a single coadministration of subeffective doses of ascorbic acid (0.1 mg/kg) and ketamine (0.1 mg/kg) and were subjected to behavioral evaluation 24 h after the treatments. Immediately after the behavioral observations the hippocampi were dissected for Western blotting analyses. Our results revealed that a single administration of subeffective doses of ascorbic acid and ketamine completely reversed the depressive-like behavior induced by CUS, however, this effect was not accompanied by changes in the phosphorylation of p70S6K and immunocontent of GLUA1 or PSD95 in the hippocampus. These findings point to a synergistic antidepressant-like effect of ascorbic acid and ketamine, paving the way for additional studies on the combined use of these compounds for the management of major depressive disorder (MDD).