Effects of Radix Polygalae on Cognitive Decline and Depression in Estradiol Depletion Mouse Model of Menopause

Abstract

Postmenopausal syndrome refers to symptoms caused by the gradual decrease in female hormones after mid-40 years. As a target organ of estrogen, decrease in estrogen causes various changes in brain function such as a decrease in choline acetyltransferase and brain-derived neurotrophic factor; thus, postmenopausal women experience cognitive decline and more depressive symptoms than age-matched men. Radix Polygalae has been used for memory boosting and as a mood stabilizer and its components have shown neuroprotective, antidepressant, and stress relief properties. In a mouse model of estrogen depletion induced by 4-vinylcyclohexene diepoxide, Radix Polygalae was orally administered for 3 weeks. In these animals, cognitive and depression-related behaviors and molecular changes related to these behaviors were measured in the prefrontal cortex and hippocampus. Radix Polygalae improved working memory and contextual memory and despair-related behaviors in 4-vinylcyclohexene diepoxide-treated mice without increasing serum estradiol levels in this model. In relation to these behaviors, choline acetyltransferase and brain-derived neurotrophic factor in the prefrontal cortex and hippocampus and bcl-2-associated athanogene expression increased in the hippocampus. These results implicate the possible benefit of Radix Polygalae in use as a supplement of estrogen to prevent conditions such as postmenopausal depression and cognitive decline.

Polygalae Radix: review of metabolites, pharmacological activities and toxicology

“…Also, RP could enhance the expression of LC3-II and Beclin1 in mouse cortex and rat prefrontal cortex (PFC), reduce the level of p62, and regulate the dysfunction of AMPK-mTOR pathway in PFC of CRS rats, thus exhibiting antidepressant effects ( Zhou et al, 2021 ). Another study found that RP significantly improved the working memory, situational memory and despair-related behaviors of estrogen-depleted mice, increased the expression of BDNF in the prefrontal cortex and the expression of BAG1 in the hippocampus, indicating that RP could improve the cognitive and depressive symptoms of postmenopausal women ( Han et al, 2021 ). However, these two studies did not systematically screen out the antidepressant metabolites in PR.…”

Saponin components in Polygala tenuifolia as potential candidate drugs for treating dementia

“…Ancient Chinese medical texts document PT’s efficacy in treating ailments such as insomnia, neurasthenia, excessive cough with phlegm, and palpitations ( Jiang et al, 2021 ; Chen et al, 2023 ). In preclinical research, PT and its extracts have demonstrated neuroprotective properties, as well as potential for dementia prevention and antidepressant effects ( Shin et al, 2018 ; Han et al, 2021 ). Traditional plant-based medicinal combinations containing PT, such as Kaixinsan ( Fu et al, 2019 ), Sagacious Confucius’ Pillow Elixir ( Hou et al, 2019 ), and Buyuan Congnao decoction ( Chen et al, 2012a ), have also exhibited pharmacological actions against AD.…”