Behavioral effects of Chaenomeles maulei fruit juice in rats with impaired circadian rhythm

Abstract

Introduction: Impaired circadian rhythm (ICR) is a commonly used model of mild stress. The fruit juice of Chaenomeles japonica var. maulei (Mast.) Lavall‚e (CMFJ) is rich in polyphenols known for their anti-inflammatory, antioxidant, and neuroprotective properties.  Aim: The aim of this study was to investigate the effects of CMFJ on the behavior of rats subjected to ICR. Materials and methods: Male Wistar rats were divided into five groups of 10 animals each: control group (without ICR), the ICR, ICR+CMFJ2.5, ICR+CMFJ5, and ICR+CMFJ10 groups. ICR was induced by exposing rats to 14 days of constant light. Over these days, oral treatment was administered with distilled water (the control and ICR groups) and CMFJ at doses 2.5, 5, and 10 ml/kg for the respective groups. Then we performed the open field test, the social interaction test (SIT), and the forced swim test (FST) to assess rats’ locomotion, anxiety, and the depressive-like behavior, respectively. Results: The ICR animals increased their horizontal and vertical locomotion when compared to the controls. The ICR rats did not change significantly the social interaction time in the SIT test and immobility time in the FST. The horizontal and vertical activity of the ICR+CMFJ10 rats was reduced in comparison with ICR animals. Compared to ICR rats, the animals treated with CMFJ at doses of 2.5 and 10 ml/kg demonstrated an improved social interaction and decreased immobility time in the FST.  ]Conclusions: CMFJ prevented the development of ICR-induced hyperactivity and showed an anxiolytic-like and antidepressant-like effect, probably due to its high polyphenol content.