Assessment of the Effect of Melissa Officinalis L. Hydro Alcoholic Extract on Anxiety and Depressive-Like Behaviors in a Mice Model of Chronic Restraint Stress

Abstract

Background, the prevalence of mood disorders is increasing gradually. At the same time, physicians are increasingly interested in using herbal medicines based on patients' beliefs. Since lemon balm (Melissa officinalis L.) is one of the famous medicines in traditional Iranian medicine for the treatment of mood disorders, it led us to evaluate the effects of lemon balm on depression and anxiety. Aim, this study evaluated the effects of a hydro-alcoholic extract of Melissa officinalis (HAEMO) on anxiety- and depressive-like behaviors, oxidative stress and apoptosis markers in restraint stress-exposed mice. Methods: First, we prepared the hydro-alcoholic extract of lemon balm in vitro and then assayed the amounts of phytochemical compounds of total phenols, flavonoids, antioxidant activity and the active ingredient of rosmarinic acid in the extract. in order to induce a depression-like model, mice were subjected to restraint stress (3 h/day) and received normal saline or HAEMO (50, 75 and 150 mg/kg/day) for 14 days. The behavioral changes in an open field task, elevated plus maze, tail suspension and forced swimming tests were evaluated. Also, malondialdehyde (MDA) levels and enzyme activities of superoxide dismutase and glutathione peroxidase, and total antioxidant capacity were assessed in the prefrontal cortex and hippocampus. Moreover, levels of Bcl-2, Bax and caspase 3 in the brain as well as serum concentration of corticosterone were evaluated. Results: HAEMO (75 and 150 mg/kg) significantly reversed anxiety- and depressive-like behaviors. Also, HAEMO reduced MDA levels, enhanced enzymatic antioxidant activities and restored serum levels of corticosterone. An immunoblotting analysis also demonstrated that HAEMO decreased levels of pro-apoptotic markers and increased anti-apoptotic protein levels in the prefrontal cortex and hippocampus of restraint stress-exposed mice. Conclusion: Our findings suggested that HAEMO reduced inflammation and had anxiolytic and anti-depressant effects in mice.