A study of the central injection effects of chrysin on behavioural and intra hypothalamic gene expression levels of CRH and CGRP in male rats

Abstract

Abstract Chrysin is a natural flavonoid, and its several neuro-pharmacological effects have been demonstrated in brain areas related to anxiety. However, the intra-hypothalamic molecular mechanisms underlying the anxiolytic effects of chrysin are unclear. The present study aimed to investigate the effects of chrysin on hypothalamic corticotrophin-releasing hormone (CRH) and calcitonin gene-related peptide (CGRP) gene expression in a rat model of stress. For present study, thirty male Wistar rats (200 ± 10 g) were divided into six groups. Acute restraint stress was induced in the animals for 2 hours. Intact or stress- induced rats received 20 or 40µg chrysin via the third cerebral ventricle respectively. Open field and forced swimming tests were performed to evaluate the stress-related behaviors. The hypothalamic samples were removed. Real-time polymerase chain reaction (PCR) measured relative gene expression. Acute stress significantly increased anxiogenic behaviors, CRH, and CGRP mRNA levels compared to the control group. Chrysin significantly improved the forced swimming and open field test behavioral parameters compared to the stress group. The mRNA levels of CRH and CGRP significantly decreased in intact or stress- induced rats receiving chrysin compared to the control or stress groups. The inhibition of hypothalamic CRH neural circuits may be involved in the preventive effects of chrysin against acute stress.