Protective effect of grape seed extract against chronic physical stress‐induced zona fasciculata injury in male rats: Functional, immunohistochemical and electron microscopic study

Abstract

In the present study, we investigated the antioxidant effect of grape seed extract (GSE) against chronic immobilization stress-induced zona fasciculata injury in Wistar male rats. Thirty male rats were divided into three groups: Non-stress group: rats were not subjected to stress protocol and received distilled water orally for 30 days. Stress group: rats received distilled water orally for 15 consecutive days before the induction of chronic immobilization stress experiment (repeated stress for 15 consecutive days), distilled water was continued along with the constant stress experiment. GSEstress group: rats treated with oral GSE (300 mg/kg), administered orally for 15 consecutive days before the induction of chronic immobilization stress experiment (repeated stress for 15 consecutive days), GSE was continued along with the stress exposure. Chronic stress was induced by placing each animal in a restrainer for 2 h daily for 15 consecutive days in both Stress and GSE-stress groups. The serum corticosterone and adrenal cortex malondialdehyde (MDA) levels were measured as indices of stress. Immunohistochemistry of the inducible nitric oxide synthase (iNOS) as a nitrosative stress marker beside the adrenal cortex's ultrastructure, particularly zona fasciculata, was assessed. Chronic restraint stress significantly elevated the serum corticosterone and adrenal cortex MDA levels, while oral administration of GSE reduced the serum corticosterone level, adrenal cortex MDA levels, and iNOS immunoreactivity in zona fasciculata. Besides, adrenocortical ultrastructure significantly improved. These results suggested that GSE enhanced the antioxidant defense against reactive oxygen species produced under chronic stress conditions, protecting the adrenal cortex.

Physiological Changes Caused by Dietary Proanthocyanidin Supplementation at Varying Doses in Laying Hens

“…Proanthocyanidin lowers corticosterone secretion [9] by regulating the hyperactivity of the hypothalamic-pituitaryadrenal cortical axis. According to [19], grape seed extract is useful because it includes Proanthocyanidins, a molecule that controls corticosterone release. The hormone corticosterone prevents the protein from being catabolized in the blood serum after it has been released from adrenal cortex cells by inhibiting cytochrome P450c21-hydroxylase in adrenal cortex cells, thereby regulating the activity of the hypothalamic-pituitary-adrenal cortex axis.…”