Argan Oil Supplementation Reverses Anxiety and Depressive-Like Behaviors, Neurodegeneration and Oxidative Stress in Amygdala Induced by Chronic Mild Stress in Rats

Abstract

Background: Argan Oil (AO) has been used as a natural remedy in traditional medicine, mainly in Morocco, for several centuries. In this study, we evaluated the beneficial effects of AO dietary on vulnerability of rats to the chronic unpredictable mild stress (UCMS) using behavioral tests, biochemical and histological markers of depression or anxiety. Method: Rats were handled daily (home cage control) or subjected to the UCMS procedure during 6 weeks (i.e., from 43th to 85 Post-natal Day (PND)) (Stress group, n=12). Animals were previously administered orally by NaCl 0.9% (Control group, n=11) or AO (10 ml/kg/day) (AO+Stress group, n=12) for 10 weeks (i.e., from weaning 21th to 93 PND). The efficacy of UCMS or AO dietary on behavioral performances of the animals in the open field, the forced swimming, the light/dark, the novelty suppression of feeding and sucrose preference tests, was measured. Following behavioral assays, oxidative stress in amygdala, histologic semiquantitative analysis of neurodegeneration in the hippocampus, frontal cortex and basolateral amygdala (BLA) subregions, and corticosterone level in plasma was also performed. Results: Our data supports pharmacological and biochemical evidences for the antidepressant and anxiolytic-like effects of AO. Prolonged supplementation with AO reverses all the behavioral changes that occurred due to UCMS and restored corticosterone level in the plasma, oxidative status of amygdala and the neurons level in the CA3 subregion of rats’ hippocampus. Conclusion: This study suggests that antidepressant and anxiolytic like effects of AO in adult rats can be the result of modulation of brain antioxidant enzyme activities, the activation of hippocampal neurogenesis and the modulation of HPA axis activity. However, more experiment and detailed analysis is required for definitive conclusion.