Reduced Consolidation, Reinstatement, and Renewal of Conditioned Fear Memory by Repetitive Treatment of Radix Polygalae in Mice

Abstract

The therapeutic goal for the treatment of posttraumatic stress disorder (PTSD) is to promote extinction and to prevent the relapse of fearful memories. Research has identified pharmacological treatments that may regulate the formation and extinction of fear memories, but not many reagents that block the relapse of extinguished fear are known. Radix Polygalae (RP) is an Asian herb used for sedation, and its ingredients have anxiolytic and antidepressant properties. As various neurological effects have been identified, we tested whether RP affects the relapse of fear. Freezing in response to a conditioned context and cues was used to measure the effects of RP in mice. In cohort 1 (n = 30), consolidation, extinction, and reinstatement were tested during the course of 18 days of treatment. In cohort 2 (n = 30), consolidation, extinction, and renewal were tested during 10 days of treatment. The consolidation, extinction, reinstatement, and possibly the renewal of context-induced freezing were inhibited due to the administration of RP in animal subjects. However, the effects of RP on the freezing responses of subjects elicited by conditioned auditory cues were less obvious. Because it effectively suppresses the consolidation of fear memories, RP may be used for primary and secondary prevention of symptoms in PTSD patients. Additionally, because it effectively suppresses the reinstatement and renewal of fear memories, RP may be applied for the prevention of fear relapse in PTSD patients who have undergone exposure therapy.

Therapeutic Candidates for Alzheimer’s Disease: Saponins

“…In both Aβ-induced PC12 cells and AD rats, LSS can reduce the expression of homocysteine-3 and Bax, while increasing the expression of Bcl-2 and the ratio of Bcl-2/Bax, reversing apoptosis, and, ultimately, alleviating cognitive dysfunction in AD rats [ 234 ]. Polygalasaponin F (PGSF), a triterpenoid saponin monomer isolated from P. japonica, has been shown to improve hippocampal-dependent learning memory capacity [ 235 ]. Furthermore, it has also been reported to reduce the number of caspase3-positive cells, thereby reversing glutamate-induced apoptosis in primary hippocampal neurons [ 236 ].…”

Integrated Lipidomics and Network Pharmacology Reveal Mechanism of Memory Impairment Improvement by Yuanzhi San

“…Polygalae Radix extract is used in Japanese medicine to treat memory loss in patients with AD [16] . In Korean medical research, Polygalae Radix was shown to effectively inhibit memory consolidation of post‐traumatic stress disorder for primary and secondary prevention [17] . Codonopsis polysaccharide in Codonopsis improved MI in mice by increasing the level of acetylcholine, clearing free radicals, and upregulating the expression of α7‐nAChR and CaMKII protein [18] .…”

“…[16] In Korean medical research, Polygalae Radix was shown to effectively inhibit memory consolidation of post-traumatic stress disorder for primary and secondary prevention. [17] Codonopsis polysaccharide in Codonopsis improved MI in mice by increasing the level of acetylcholine, clearing free radicals, and upregulating the expression of α7-nAChR and CaMKII protein. [18] In the early stage of our research, we used D-galactose combined with aluminum chloride to establish a rat model of MI.…”

A microemulsion high-performance liquid chromatography (MELC) method for the separation and determination of hydrolyzed tenuifolin in Radix Polygalae

“…or Polygala sibirica L 1 . Modern pharmacological studies indicate that Radix Polygalae possesses various biological activities against certain ailments, such as cerebrovascular diseases, senile dementia and depression 2–4 . Moreover, some researchers found that Radix Polygalae could effectively suppress the consolidation and reinstatement of fear memories 5 .…”