Neuroprotective effect of Kojic acid in Rotenone - induced Parkinsonism in a Zebrafish Model

Abstract

Parkinson’s disease is a progressive neurodegenerative disorder characterized by the degeneration of dopaminergic neurons in the substantia nigra, resulting in motor impairments such as bradykinesia, tremors, and postural instability. The zebrafish (Danio rerio), with 87% genetic closeness to humans, serves as an exemplary model for investigating neurodegeneration. Kojic acid is a natural metabolite produced by fungi Aspergillus oryzae and has been reported for antimicrobial, antioxidant, anti-inflammatory and anticonvulsant properties. The present study investigates the neuroprotective effect of Kojic acid in a zebrafish model of Parkinson’s disease. Zebrafishes were divided into six experimental groups namely Normal, Positive control, Standard, and Kojic acid treated group. Parkinsonian symptoms were induced in the zebrafish using the neurotoxin rotenone (5 μg/L). Following induction, the fishes were treated with standard (Kapikacchu, Mucuna prunens extract, 20 mg/L) and kojic acid (5, 10, and 20 mg/L) for 28 days, with the medium being changed every 48 hours to maintain the concentrations. Behavioural analysis was conducted using ANY-MAZE software. On the 29th day, the zebrafishes were euthanized and their brains were extracted for the assessment of biochemical parameters and histopathology. The study revealed that zebrafish exposed to 10 mg/L of Kojic acid exhibited a notable enhancement in locomotor activity relative to the positive control group, indicating Kojic acid as a potential option in the treatment of Parkinson’s disease.