*Rosmarinus o*ffi*cinalis* **Essential Oil Improves Scopolamine-Induced Neurobehavioral Changes via Restoration of Cholinergic Function and Brain Antioxidant Status in Zebrafish (***Danio rerio***)**

**Luminita Capatina 1, Razvan Stefan Boiangiu 1, Gabriela Dumitru 1, Edoardo Marco Napoli 2, Giuseppe Ruberto 2, Lucian Hritcu 1,\* and Elena Todirascu-Ciornea 1**


Received: 10 December 2019; Accepted: 8 January 2020; Published: 10 January 2020

**Abstract:** *Rosmarinus o*ffi*cinalis* L. is a traditional herb with various therapeutic applications such as antibacterial, antioxidant, anti-inflammatory, antidepressant, and anticholinesterase activities, and can be used for the prevention or treatment of dementia. In the present study, we tested whether *Rosmarinus o*ffi*cinalis* L. could counteract scopolamine-induced anxiety, dementia, and brain oxidative stress in the zebrafish model and tried to find the underlying mechanism. *Rosmarinus o*ffi*cinalis* L. essential oil (REO: 25, 150, and 300 μL/L) was administered by immersion to zebrafish (*Danio rerio*) once daily for eight days while scopolamine (100 μM) treatment was delivered 30 min before behavioral tests. The antidepressant and cognitive-enhancing actions of the essential oil in the scopolamine zebrafish model was measured in the novel tank diving test (NTT) and Y-maze test. The chemical composition was identified by Gas chromatograph–Mass spectrometry (GC-MS) analysis. The brain oxidative status and acetylcholinesterase (AChE) activity was also determined. REO reversed scopolamine-induced anxiety, memory impairment, and brain oxidative stress. In addition, a reduced brain AChE activity following the administration of REO in scopolamine-treated fish was observed. In conclusion, REO exerted antidepressant-like e ffect and cognitive-enhancing action and was able to abolish AChE alteration and brain oxidative stress induced by scopolamine.

**Keywords:** *Rosmarinus o*ffi*cinalis*; essential oil; scopolamine; anxiety; memory; oxidative stress
