Anxiolytic-like efects of Pseudospondias microcarpa hydroethanolic leaf extract in zebrafsh: Possible involvement of GABAergic and serotonergic pathways

Abstract

Pseudospondias microcarpa is used in ethnomedicine to manage central nervous system diseases. The hydroethanolic extract (PME) from the leaves of the plant has shown anxiolytic-like properties in mice anxiety models. However, its efects in chronic anxiety models and possible mechanism(s) of action were not studied. Therefore, the current study evaluated the anxiolytic-like mechanisms of PME in zebrafsh models of anxiety. The zebrafsh light dark test (LDT) and novel tank test (NTT) were employed to assess the anxiolytic-like efects of PME (0.1, 0.3, 1.0 mg mL−1), fuox etine (3× 10−5 mg mL−1) and diazepam (1.5× 10−7 mg mL−1). The chronic unpredictable stress (CUS) test was used to further evaluate the extract’s anxiolytic-like properties. The potential mechanisms of anxiolytic action of the extract was evaluated after pre-treated with fumazenil, granisetron, methysergide, or pizotifen, all at 1× 10−3 mg mL−1. The extract signifcantly decreased anxiety behaviours in the NT and LD tests. These observed efects of the extract were however counteracted by fumazenil, granisetron, methysergide and pizotifen pre-treatment. In addition, PME treat ment signifcantly reversed CUS-induced anxiety behaviours in zebrafsh. Results show that PME possesses anxiolytic like efects possibly through interaction with serotonergic and gamma-aminobutyric acid mediated pathways