Woohwangcheongsimwon Prevents High-Fat Diet-Induced Memory Deficits and Induces SIRT1 in Mice.

Woohwangcheongsimwon (WHC) is a mixture of herbal medicines that is widely prescribed in Korean traditional medicine. SIRT1 is known for its regulatory roles in energy metabolism, oxidative stress, and circadian rhythms. This study was designed to determine whether WHC can increase and mimic the biological reactions of SIRT1 activation. Ten-month-old male mice were divided into four groups: nontreated normal diet (ND), nontreated high-fat diet (HFD), WHC-treated ND, and WHC-treated HFD. Body weight and cognitive functions were evaluated after treatment. The hippocampal expressions of SIRT1 and PGC-1α were also measured. The components of WHC were identified by liquid chromatography. High-fat diet-fed mice gained more weight and demonstrated greater deficits in short-term and long-term cognitive functions. WHC suppressed the deleterious effects of a HFD on weight gain and cognitive decline, but showed no prominent effects on animals fed NDs. The herbal treatment also increased the expression of SIRT1 and PGC-1α in the hippocampus. Despite the induction of hippocampal SIRT1 expression by WHC, resveratrol was not present among the natural compounds identified. This expression might have contributed to the suppression of high-fat diet-induced memory deficits in mice treated with the herbal mixture.

Preclinical evidence of rapid-onset antidepressant-like effect in Radix Polygalae extract.

Radix Polygalae (the root of Polygala tenuifolia) is a herb widely used in traditional Asian medicine that is thought to exert a variety of neuropsychiatric effects. Radix Polygalae extract can protect against N-methyl D-aspartate (NMDA) neurotoxicity and induce brain-derived neurotrophic factor (BDNF) expression, suggesting modulatory roles at glutamatergic synapses and possible antidepressant action. In accordance with this hypothesis, Radix Polygalae extract demonstrated antidepressant-like effects in 8-week-old male C57Bl/6 mice by decreasing behavioral despair in the forced swim and tail suspension tasks and increasing hedonic-like behavior in the female urine sniffing test 30 minutes after a single oral administration of 0.1 mg/kg. Reduced latency to acquire a food pellet in the novely suppressed feeding paradigm, without change in anxiety-like behaviors suggested a rapid-onset nature of the antidepressant-like effect. In addition, it decreased the number of failed escapes in the learned helplessness paradigm after two oral administrations 24 hours and 30 minutes before the first test. Finally, it reversed anhedonia as measured by saccharin preference in mice exposed to the chronic stress model after two administrations of 0.1 mg/kg, in contrast to the repeated administration generally needed for similar effect by monoamergic antidepressants. Immobility reduction in tail suspension task was blocked by the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist NBQX, a pattern previously demonstrated by ketamine and other ketamine-like rapid-onset antidepressants. Also similarly to ketamine, Radix Polygalae appeared to acutely decrease phosphorylation of GluR1 serine-845 in the hippocampus while leaving the phosphorylation of hippocampal mTOR serine 2448 unchanged. These findings serve as preclinical evidence that Radix Polygalae extract exerts rapid-onset antidepressant effects by modulating glutamatergic synapses in critical brain circuits of depression and may be worthy of further evaluation as a safe substitute to other rapid-onset antidepressants known to have unacceptable side effects.