Background: Alzheimer's disease (AD) is a neurodegenerative disease characterized by the
progressive and incapacitating decay of cognitive, neuropsychiatric, and behavioral manifestations.
L-tryptophan is the precursor amino acid of serotonin, which is a neurotransmitter responsible for
mood balance and the sense of well-being and can be administered in the form of nanoparticles. Objective:
This study analyzed the effectiveness of L-tryptophan nanoparticles and L-tryptophan on
behavioral physiological alterations resulting from AD in animal models.
Method: The sample consisted of 50 Rattus norvegicus rats, divided in 10 groups with 5 animals each:
one negative control (NC), three positive control groups (C3, C7, and C21), three groups treated with
L-tryptophan nanoparticles (T3N, T7N, and T21N) at the concentration of 1.5 mg, and three groups
treated with L-tryptophan (T3L, T7L, and T21L) at the concentration of 1.5 mg. The rats underwent
stereotactic surgery to induce AD through the injection of amyloid beta-amyloid peptide1-42 in the intracerebroventricular
region. All rats were submitted to pre- and post-surgery and post-treatment motor
behavior evaluation through the Later Water Maze (LWM) and elevated cross-labyrinth (ECL). Histological
analysis was performed to verify the presence of senile plaques, and the statistical analysis
used the unpaired T-test.
Results: Significant intergroup differences were observed in some of the evaluated parameters between
treated and untreated groups.
Conclusion: It was concluded that the treatment with L-tryptophan nanoparticles was beneficial to
improve behavioral reactions in the Alzheimer's model.