Neuromodulatory and possible anxiolytic-like effects of a spice functional food ingredient in a pig model of psychosocial chronic stress

Psychological chronic stress is associated with the development of mood disorders, and spices have shown protective properties in this context. This research investigated the effects of a supplementation with a functional food ingredient containing spice extracts in a pig model of psychosocial chronic stress. Its impact on behavior, neurophysiology, immune system and gastrointestinal tract were evaluated. Almost no significant results were found at the gut and immune levels. An increased expression of 5-HT1AR and BDNF in the hippocampus and prefrontal cortex, respectively, and blood perfusion changes in several brain regions including the olfactory bulb, hippocampus, dorsolateral prefrontal cortex and dorsal anterior cingulate cortex were observed. Also, slight anxiolytic-like effects were observed in the Open-field and Novelty-Suppressed Feeding tests. These modulations of brain regions associated with the regulation of emotions and cognition as well as the potential effects on anxiety might come from the repeated stimulation of the olfactory system.