Tilianin obtained from Agastache mexicana inhibits monoamine oxidase and modifies depressive behavior in rats.

Background: Agastache mexicana is used in traditional medicine to treat anxiety, insomnia, pain, among others. In a previous study, the methanolic extract exerted anxiolytic and sedative effects, as observed behaviorally, associated with one of its major components, tilianin.

Objective: To assess the effect produced by the extracts and tilianin obtained from Agastache mexicana on depressive-induced behavior model and on the activity of monoamine oxidases (MAOs).

Methods: The depression experimental model consisted of the forced swimming test in rats. MAOs activity was evaluated in cortex and hippocampus from the tilianin and Agastache extracts treated rats using specific inhibitors for each isoform. The quantification of monoamines was carried out using an High Performance Liquid Chromatography method.

Results: An increase in the swimming time was observed in rodents treated with doses of 16 (226.6 ± 5.5 seconds) and 50 mg/kg (237.8 ± 5.7 seconds) of tilianin, methanolic (260.4 ± 3 seconds), and hydroalcoholic extracts (249.6 ± 2.6 seconds) at 100 mg/kg. MAOs activity was significantly decreased in brain tissue from animals treated with 16 and 50 mg/kg of tilianin, methanolic, and hydroalcoholic extracts at 100 mg/kg.

Conclusions: The tilianin effect on monoamine oxidases inhibition is confirmed, suggesting its potential use in the treatment of certain neurological disorders.