Anxiolytic-like effect of the aqueous extract of Justicia spicigera leaves on female rats: A comparison to diazepam.

Background: In Mexico, an infusion made from muicle (Justicia spicigera, Mexican honeysuckle) is used to treat menstrual problems and soothe people's "nerves" (i.e., anxiety and/or depression). However, no studies have yet substantiated these affects. Anxiety currently ranks as the seventh most common cause of disability worldwide, a fact that has intensified the search for new treatments with fewer adverse effects and better therapeutic efficacy.

Objective: The anxiolytic-like effect of the aqueous extract of muicle leaves (AEML) was analyzed, and the influence of the estrous cycle on its pharmacological effect in rats was explored.

Methods: Female Wistar rats were subjected to the elevated plus maze test to evaluate the anxiolytic effect, followed by an assessment of locomotor activity using the open field test. Diazepam was the reference drug used. Preliminary phytochemical tests were performed.

Results: The dose of 12  mg/kg of AEML increased the time to first entry, and the frequency of entries into, the open arms in the proestrus-estrus (P-E) and metestrus-diestrus phases (M-D), while also reducing the anxiety index in the P-E phases. These effects are similar to those observed with diazepam on the elevated plus maze test. None of the treatments showed effects on locomotor activity. The presence of flavonoids, sterols and terpenes in the AEML was confirmed.

Conclusion: The anxiolytic-like effect of the dose of 12  mg/kg of AEML in the P-E phases could be due to the presence of the metabolites identified; i.e., flavonoids, sterols and/or terpenes.