Can Ocimum basilicum relieve chronic unpredictable mild stress-induced depression in mice?

Abstract

BackgroundDepression is one of the important world-wide health problems. ObjectivesThis study aimed to assess the ameliorative effect of Ocimum basilicum (OB) essential oil on the behavioral, biochemical and histopathological changes resulted from exposure to chronic unpredictable mild stress (CUMS). It also aimed to investigate the underlying mechanism in an animal model of depression. Materials and methodsForty male Swiss albino mice were divided into four groups (n=10): control, CUMS (exposed to CUMS for 4weeks), CUMS plus fluoxetine, and CUMS plus OB. At the end of the experiment, behavioral changes, serum corticosterone level, protein and gene expressions of brain derived neurotropic factor (BDNF) and glucocorticoid receptors (GR) in the hippocampus was all assessed. Immunoexpression of surface makers of glial fibrillary acidic protein (GFAP), Ki67, Caspase-3, BDNF and GR in the hippocampus were estimated. Data were analyzed by using the statistical package for the social sciences (SPSS). ResultsOB alleviated both behavioral and biochemical changes recorded in mice after exposure to CUMS. It also reduced neuronal atrophy observed in the hippocampal region III cornu ammonis (CA3) and dentate gyrus and restored back astrocyte number. OB decreased apoptosis in both neurons and glial cells and increased neurogenesis in the dentate gyrus in a pattern comparable to that of fluoxetine. Increased BDNF and GR gene and protein expressions seems to be behind the antidepressant-like effect of OB. ConclusionOcimum basilicum ameliorates the changes induced after exposure to the chronic stress. Assessing Ocimum basilicum efficacy on human as antidepressant is recommended in further studies.