Study of the Central Injection Effects of Chrysin on Behavioral and Intra Hypothalamic Gene Expression Levels of CRH and CGRP in Male Rats

Background: Chrysin is a natural flavonoid with several demonstrated neuro-pharmacological effects in brain areas related to anxiety. However, the intra-hypothalamic molecular mechanisms underlying the anxiolytic effects of chrysin remain unclear. Objectives: The current study revealed the effects of chrysin on hypothalamic corticotrophin-releasing hormone ( CRH) and calcitonin gene-related peptide ( CGRP) gene expression levels in a rat model of stress. Methods: Thirty male Wistar rats weighing 200 ± 10 g were divided into six groups for this investigation. Acute restraint stress was induced in the animals for 2 hours. Intact or stress-induced rats received 20 or 40 µg of chrysin via the third cerebral ventricle, respectively. Open-field and forced swimming tests were performed to evaluate stress-related behaviors. Hypothalamic samples were then removed, and real-time polymerase chain reaction (PCR) was used to measure relative gene expression. Results: The results showed that in the rats receiving chrysin, CRHand CGRPgene expression levels were significantly decreased compared to the stress group. Additionally, chrysin injection reduced anxiogenic behaviors. Conclusions: Chrysin decreased the expression of hypothalamic CRHand CGRPgenes in stressed rats.