👤 Arezo Nahavandi

Stress plays a pivotal role in anxiety-like disorders and cognitive decline. The present study investigated the potential effects of prior royal jelly supplementation and environmental enrichment against stress-induced anxiety-like behaviors, serum corticosterone, hippocampal brain-derived neurotrophic factor (BDNF) levels, and cognitive performance deficits in stressed rats. Male Wistar rats were randomly devised into 8 experimental groups. Rats were subjected to royal jelly (200 mg/kg) via oral gavage, standard environmental enrichment, or combination all for 14 days and control rats received saline in the same period of time. Stress induction was done on the 7th day of treatments by exposure to the restrainer under 10°C. Then open field, elevated plus maze, and inhibitory passive avoidance memory tests were used to explore emotional-cognitive behaviour. Also, corticosterone levels, and hippocampal BDNF expression were measured. Stress resulted in an increase in the serum corticosterone levels, anxiety-like behaviors, and decreased hippocampal BDNF expression which reversed by environmental enrichment and royal jelly treatments. Remarkably, the combined treatment exerts a more pronounced effect on the aforementioned outcomes. Our study strongly proposes a novel emerging therapeutic approach through nutritional interventions, emphasizing the potential of these treatments to mitigate stress-induced anxiety and memory impairments prior to stress exposure. Show less

Anhedonia or inability to experience pleasure is the sign of various neuropsychiatric conditions. Current treatment options do not provide adequate control of anhedonia. The present study was conducted to evaluate the protective effects of valproic acid (VPA) as a nonspecific histone deacetylase (HDAC) inhibitor to reverse the effects of stress on induction of anhedonia and explore possible mechanisms. To induce anhedonia, a rat model of chronic unpredictable mild stress (CUMS) was established. Animals were assigned into no stress, stress (6 weeks of CUMS) and two treatment groups. VPA treatment was carried out for 4 continuous weeks (200 mg/kg/day). Behavioral assessments were performed using sucrose consumption (SCT) and new object recognition (NOR) tests. The expression of genes was evaluated using qRT-PCR. The cell density was determined using Nissl staining. Rats with CUMS showed depressive-like behaviors and impaired memory performance compared with the non-stressed group (p < 0.01). Moreover, they had significantly higher levels of HDAC3 and MC4R expression in the nucleus accumbens (NAc) compared to the non-stressed group (p < 0.01). The NAc cell density was significantly higher in the non-stressed rats (p < 0.05). Corticosterone plasma level was increased in the CUMS compared to the non-stressed group (p < 0.05). In the CUMS + VPA subgroup, the corticosterone (CORT) plasma level was lower compared with the CUMS + Saline and/or the CUMS groups (p < 0.05). These findings suggest that VPA can improve anhedonia and stress. Although the protective effect of VPA might link to decreasing HDAC3 and MC4R genes expression in NAc. Show less