Introduction
Pomegranate (Punica granatum) is rich in phenolic compounds, such as flavonoids and tannins, which possess potent antioxidant properties that neutralize reactive species and protect neural cells from oxidative stress, a factor associated with neurodegenerative diseases. Its anti-inflammatory properties reduce pro-inflammatory cytokines and preserve the integrity of the blood-brain barrier, generating interest in exploring its effects on the central nervous system. Zebrafish (Danio rerio), a widely used animal model in neuropharmacological research, allows for the precise and reproducible evaluation of these effects. This study aimed to evaluate the anxiolytic and antidepressant-like effects of the aqueous extract of pomegranate fruit (Punica granatum) in adult zebrafish.
Methods
The study was approved by the Ethics Committee on Animal Use (CEUA-UECE #04009489/2023), and registered in the National System for the Management of Genetic Heritage (SisGen #A4A0900). Zebrafish were allocated to groups (n = 8/group) and treated orally (p.o.; 20 μL) with the aqueous extract of pomegranate fruit (100% - 1 g/mL or 50% - 0.5 g/mL), or distilled water (control group). An additional naïve (untreated) group (n = 8) was included for comparison. Behavioral tests were conducted 1 h after treatment. Initially, locomotor activity was assessed using the open field test. The animals were placed in Petri dishes divided into quadrants, and the number of times they crossed from one quadrant to another was recorded for 5 min. To assess anxiety-like behavior, the animals were placed in a glass aquarium (30 × 15 × 20 cm) containing a light and a dark zone. The time (s) that the zebrafish spent in the clear zone over a 5 min period was recorded. For the evaluation of depressive-like behavior, the fish were immersed in 1% ethanol for 30 min and then suspended vertically, with the caudal half of their bodies immobilized. The mobility time (s) was recorded over a 5 min period.
Results and Discussion
Pretreatment with the extract did not affect the locomotor activity of the animals but increased the time the zebrafish spent in the clear zone of the aquarium (p < 0.0001 vs. control and naïve) and enhanced mobility time (p < 0.01 vs. control - 50% extract and p < 0.001 vs. control -100% extract). The results show that pomegranate extract induces anxiolytic and antidepressant-like behaviors in adult zebrafish without affecting locomotion, highlighting its potential as a natural therapy for psychiatric disorders. These effects may modulate neural circuits involved in emotional regulation via antioxidant and anti-inflammatory actions. The zebrafish model, with conserved neurochemical pathways, offers translational value. Effects may involve serotonergic and GABAergic systems implicated in anxiety and depression.
Conclusions
These findings open new avenues for the development of effective and safe phytotherapeutics, reinforcing pomegranate as a promising source of neuroprotection. The aqueous extract of pomegranate fruit (Punica granatum) demonstrated anxiolytic and antidepressant-like effects in adult zebrafish, highlighting its neuroprotective effect.
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