In recent decades, phytochemicals have been the object of extensive research for their ability to improve or prevent cognitive decline. Tanacetum vulgare L. (common tansy) is a rich source of various secondary metabolites (essential oil, sesquiterpenoids, and phenolic compounds) with anti-inflammatory, antioxidant, and antimicrobial activity. However, research data about its cognitive effects are scarce. The present study investigated the effect of two doses of T. vulgare hydroalcoholic extract (TVE) on learning and memory in an experimental model of scopolamine-induced amnesia in rats.

The experiment was conducted using a Shuttle box apparatus for active and passive avoidance. Fifty male Wistar rats were divided randomly into five groups (n=10) as follows: placebo (C-veh), scopolamine (C-Scop), glycerin+scopolamine (Gly-Scop), scopolamine+200 mg/kg TVE (T.vulgare-Scop 200), and scopolamine+1000 mg/kg TVE (T.vulgare-Scop 1000). The measured behavioral parameters were the number of avoidances, the number of escapes, and thr number of inter-trial crossings. Statistical evaluation was carried out using one-way ANOVA and Tukey's post hoc test, at a level of significance p<0.05.

We found that both groups with scopolamine-induced amnesia (C-Scop and Gly-Scop) had impaired learning and memory compared to the C-veh animals (p<0.05). Both doses of TVE increased the number of avoidances compared to the C-Scop and Gly-Scop groups during the learning session on days 4 and 5 (p<0.05), as well as on the re-test on day 12 (p<0.001). An increased number of escapes was observed on day 5 in animals treated with 200 mg/kg TVE, and on the re-test, in those treated with 1000 mg/kg TVE, compared to the C-Scop and Gly-Scop groups (p<0.05). T.vulgare 200 mg/kg increased the number of inter-trial crossings on the re-test, compared to the C-Scop rats (p<0.01).

These results reveal the beneficial effect of TVE on cognitive function in rats with scopolamine-impaired memory. Further research is needed to explore the plant's potential as a nutrient supplement with cognitive-function-enhancing properties.