Lavandula angustifolia aqueous extract ameliorates anxiety and depressive-like behaviors in chronic mild stress-treated male rats

Abstract

The study aims to show the possible anxiolytic and antidepressant-like properties of an oral lavender’s flower aqueous extract (LAE) in chronic mild stress (CMS) model of rats. Test and control rats received LAE (200 or 400 mg/ kg) and distilled water respectively. Tests of Sucrose preference (SP), elevated plus maze (EPM), and open field (OFT) were used to evaluate rats’ behavioral changes.  The percentage of SP in the CMS group was 2.6 times less than that of the unstressed group (p<0.05). However, administration of LAE (200 and 400 mg / kg) increased SP of CMS rats by 2.0 and 3.01 times respectively in comparison to those of the stressed animals. EPM analysis revealed that 5-week CMS exposure significantly reduced the number of entries in open arm (0.8 times) as compared to unstressed rats (6.6 times). LAE (200 and 400 mg / kg) reversed CMS by increasing both the total time spent (1.73 and 1.23% respectively) and the number of entries in open arm (5 and 5.7 times respectively) compared to those related to unstressed group (p< 0.05). CMS decreased the number of entries and time spent in the central zone of OFT. Administration of LAE (200 and 400 mg/ kg) to stressed rats enhanced the total distance traveled respectively by 3.30 and 2.65% than the control rats. Taken together, oral lavender aqueous extracts showed ameliorating effects on the depression and anxiety-related behaviors in rats. Key words: Depression, lavender, chronic mild stress, anxiety, aqueous extract.