Clove volatile oil-loaded nanoemulsion reduces the anxious-like behavior in adult zebrafish.

Background: Clove volatile oil (CVO) and its major compound, eugenol (EUG), have anxiolytic effects, but their clinical use has been impaired due to their low bioavailability. Thus, their encapsulation in nanosystems can be an alternative to overcome these limitations.

Objectives: This work aims to prepare, characterize and study the anxiolytic potential of CVO loaded-nanoemulsions (CVO-NE) against anxious-like behavior in adult zebrafish (Danio rerio).

Methods: The CVO-NE was prepared using Agaricus blazei Murill polysaccharides as stabilizing agent. The drug-excipient interactions were performed, as well as colloidal characterization of CVO-NE and empty nanoemulsion (B-NE). The acute toxicity and potential anxiolytic activity of CVO, EUG, CVO-NE and B-NE against adult zebrafish models were determined.

Results: CVO, EUG, CVO-NE and B-NE presented low acute toxicity, reduced the locomotor activity and anxious-like behavior of the zebrafish at 4 - 20 mg kg^-1. CVO-NE reduced the anxious-like behavior of adult zebrafish without affecting their locomotor activity. In addition, it was demonstrated that anxiolytic activity of CVO, EUG and CVO-NE is linked to the involvement of GABAergic pathway.

Conclusion: Therefore, this study demonstrates the anxiolytic effect of CVO, in addition to providing a new nanoformulation for its administration.