Anxiolytic-like effects of Pseudospondias microcarpa hydroethanolic leaf extract in zebrafish: 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 effects 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 zebrafish models of anxiety. The zebrafish light dark test (LDT) and novel tank test (NTT) were employed to assess the anxiolytic-like effects of PME (0.1, 0.3, 1.0 mg mL−1), fluoxetine (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 flumazenil, granisetron, methysergide, or pizotifen, all at 1 × 10−3 mg mL−1. The extract significantly decreased anxiety behaviours in the NT and LD tests. These observed effects of the extract were however counteracted by flumazenil, granisetron, methysergide and pizotifen pre-treatment. In addition, PME treatment significantly reversed CUS-induced anxiety behaviours in zebrafish. Results show that PME possesses anxiolytic-like effects possibly through interaction with serotonergic and gamma-aminobutyric acid mediated pathways. Graphical abstract

Benincasa hispida Alleviates Stress and Anxiety in a Zebrafish (Danio rerio) Model

“…Research on medicinal plants can lead to the identification and development of new treatments for stress and anxiety disorders [ 48 ]. To the best of our knowledge, this is the first study to show that B. hispida fruit extract prevents zebrafish stress and anxiety reactions.…”