Hippocampal pituitary adenylate cyclase-activating polypeptide mediates rapid antidepressant-like effects of Yueju pill.

Yueju pill, a classic Chinese Medicine formulated, was recently found to produce rapid antidepressant-like effects in a PKA-CREB signaling-dependent manner. In our study, we found that the Yueju pill induced a remarkable increase in PACAP. The intracerebroventricular injection of PACAP agonist induced a rapid antidepressant-like effect; conversely, the intrahippocampal infusion of a PACAP antagonist reversed the antidepressant response of the Yueju pill. Mice with hippocampal PACAP knockdown via viral-mediated RNAi displayed depression-like behavior. PACAP knockdown also blunted the antidepressant effect of the Yueju pill. PACAP knockdown resulted in down-regulated CREB and expression of the synaptic protein PSD95 at both baselines and after administration of the Yueju pill. However, administration of the Yueju pill in the knockdown mice promoted PACAP and PKA levels. Chronically stressed mice showed deficient hippocampal PACAP-PKA-CREB signaling and depression-like behavior, which were reversed by a single dose of the Yueju pill. In this study, we demonstrated that the up-regulation of PACAP induced activating of PKA-CREB signaling would play a part in the rapid antidepressant-like effects of the Yueju pill. We also identified iridoids fraction of Gardenia jasminoides Ellis (GJ-IF), a vital component of the Yueju pill, was identified to recapitulate rapid antidepressant-like behavior through increased hippocampal PACAP expression of the Yueju pill. The promotion of hippocampal PACAP may collectively represent a novel mechanism of rapid antidepressant-like effect.

Synergistic effects of two naturally occurring iridoids in eliciting a rapid antidepressant action by up-regulating hippocampal PACAP signalling.

BACKGROUND AND PURPOSE: Current mainstream antidepressants have limited efficacy with a delayed onset of action. Yueju, a herbal medicine, has a rapid antidepressant action. Identification of the active ingredients in Yueju and the mechanism/s involved was carried out. EXPERIMENTAL APPROACH: Key molecule/s and compounds involved in this antidepressant action was identified by transcriptomic and HPLC analysis, respectively. Antidepressant effects were evaluated using various behavioural experiments. The signalling involved was assessed using site-directed pharmacological intervention or optogenetic manipulation. KEY RESULTS: Transcriptomic analysis showed that Yueju up-regulated pituitary adenylate cyclase activating polypeptide (PACAP) expression in the hippocampus. Two iridoids, geniposide and shanzhiside methyl ester, were identified and quantified from Yueju. Only co-treatment with both, at an equivalent concentrations found in Yueju, increased PACAP expression and elicited a rapid antidepressant action, which were blocked by intra-dentate gyrus infusion of a PACAP antagonist or optogenetic inactivation of PACAP expressing neurons. Geniposide and shanzhiside methyl ester co-treatment rapidly inhibited CaMKII phosphorylation and enhanced mTOR/4EBP1/P70S6k/BDNF ignalling, while intra-dentate gyrus infusions of a CaMKII activator blunted the rapid antidepressant action and BDNF expression up-regulation induced by the co-treatment. A single co-treatment of them rapidly improved depression-like behaviours and up-regulated hippocampal PACAP signalling in the repeated corticosterone-induced depression model, further confirming the involvement of PACAP. CONCLUSION AND IMPLICATIONS: Geniposide and shanzhiside methyl ester co-treatment had a synergistic rapid onset antidepressant action by triggering hippocampal PACAP activity and associated CaMKII-BDNF signalling. This mechanism could be targeted for development of fast onset antidepressants.

Involvement of NMDA-AKT-mTOR Signaling in Rapid Antidepressant-Like Activity of Chaihu-jia-Longgu-Muli-tang on Olfactory Bulbectomized Mice.

Background: Fast-onset antidepressants are urgently needed. Chaihu-jia-Longgu-Muli-tang (CLM), a classic Chinese herbal medicine, has been used for antidepressant treatment with long history. Olfactory bulbectomization (OB) model is validated for identification of rapid antidepressant efficacy. Here we used OB model for investigating the rapid onset activity of CLM in mice, and also tested the involvement of prefrontal Akt-mTOR and associated AMPA/NMDA receptors as well as hippocampal BDNF in the rapid antidepressant-like effect of CLM. Methods: The OB model was first characterized with depression-like behaviors and the time course changes of the behaviors. The fast onset of antidepressant effect of CLM was evaluated using sucrose preference test, tail suspension test and forced swim test in OB mice after a single administration. The expression of synaptic proteins of AMPA and NMDA subunits as well as Akt/mTOR signaling in the prefrontal cortex, and hippocampal BDNF was evaluated with the immunoblotting method. Results: A single dose of CLM significantly improved the deficiency in the sucrose preference and decreased the immobility time in the tail suspension test in OB mice. In the prefrontal cortex (PFC) in OB mice, there was lower expression level of the AMPA receptor subunit GluR1, rescued by a single dose of CLM. Additionally, the expression of NMDA subunit NR1 was up-regulated in OB mice, whereas mTOR and its upstream Akt signalings were both down-regulated. These deficiencies were reversed by a single dose of CLM. The CLM treatment also attenuated the expressions of NMDA receptor subunits NR2A and NR2B, which did not change in OB mice. In the hippocampus, expressions of GluR1 and brain derived neurotrophic factor (BDNF) were both up-regulated in OB mice, although CLM increased GluR1, but not BDNF. Conclusion: CLM elicited rapid antidepressant-like effects in the OB model mice, and CLM reversal of the abnormality in PFC expression of AMPA and NMDA receptors and associated Akt-mTOR signaling may underlie the effects.

Neurobiology of Chinese Herbal Medicine on Major Depressive Disorder.

Major depressive disorder, or depression, becomes a serious public health problem globally. As current mainstream conventional antidepressants have limitations in unsatisfied response and remission rate, late onset of efficacy and side effects, increasing attention has been drawn to traditional Chinese medicine (TCM), in which mixture of herbs is commonly prescribed after the clinicians make pattern identification for diagnosis. Here, the principle of herbal formulation for TCM (Chinese herbal medicine, CHM) on depression as well as some clinical outcome research is briefly introduced. The neurobiological mechanisms underlying antidepressant effects of CHM, including enhancement of monoamine, dehyperactivation of hypothalamic-pituitary-adrenal axis, neuroimmune response, and neurotrophic factors are discussed. Additionally, the results from emerging research into rapid antidepressant efficacy using CHM formula Yueju, as well as the associated neuroplastical mechanisms, are summarized. The in-depth study of the antidepressant efficacy, and underlying chemical substrates, as well as the molecular and systems neurobiological mechanisms may shed new lights for better understanding the mechanisms of CHM and improving the therapy.

Rapid antidepressant effects of Yueju: A new look at the function and mechanism of an old herbal medicine.

ETHNOPHARMACOLOGICAL RELEVANCE: Yueju is a traditional herbal medicine which consists of five herbs and formulated to treat depression-related syndromes 800 years ago. Yueju is still widely prescribed to treat conditions which include digestive dysfunction and depression. Recently, Yueju has been shown to promote a fast-onset antidepressant effect clinically and in preclinical studies. Because conventional antidepressants have a delayed onset in treating depression, the novelty of Yueju's rapid antidepressant effect and its underlying mechanism are of great significance both clinically and scientifically. AIM OF THE STUDY: To review the use of Yueju for treatment of mood-related syndromes, and particularly its use in depression. To evaluate recent evidence of Yueju rapid antidepressant actions, based on new findings at behavioral and molecular levels. To suggest direction for future studies to address further scientific issues. MATERIALS AND METHODS: Reports regarding to the history and current use of Yueju are summarized. Recent progress on rapid antidepressant effects of Yueju, the crucial constituent, Gardenia jasminoides J.Ellis (GJ) and other herbs, are reviewed. RESULTS: The medical need for rapid antidepressant actions, as well as breakthrough findings using ketamine and its limitations are introduced. Studies with Yueju using a number of acute, subacute and chronic behavioral paradigms are compared with ketamine. Findings from clinical reports also support the rapid action of Yueju. Studies examine the contribution of the constituent herb GJ, in rapid antidepressant effects. Importantly, research into the mechanism of Yueju or GJ's antidepressant response indicate the importance of up-regulation in the neural circuit responsible for antidepressant activity, and highlight common and specific molecular signaling by Yueju that may explain why this herb formula has unique antidepressant activity. CONCLUSION: Preclinical and clinical studies demonstrate that Yueju confers rapid antidepressant effects. The common mechanisms shared both for ketamine and Yueju, as well as the novel mechanism specific to Yueju are examined. Yueju and GJ may have great clinic applicability and further more detailed studies are warranted.

Research Progress on Rapid Antidepressant of Traditional Chinese Medicine / 世界科学技术-中医药现代化

Major depression is a public health problem that seriously harms individuals and the society.But one of the major shortcomings of mainstream antidepressant is the delayed onset.Recent series of studies demonstrated that,from a variety of animal models and clinical studies,classic stagnation-removing formula Yue-Ju (Y J) pill has the advantage in rapid antidepressant efficacy,which is similar to the prototype drug ketamine.It has the mechanism of rapid and sustained enhancement of neural plasticity and individual difference in response to YJ pill.The evidence of Gardenia jasminoides (Zhi-Zi) as the monarch component of YJ pill's rapid antidepressant action has also been revealed.The further in-depth research on rapid antidepressant traditional Chinese medicine (TCM) is important for providing the scientific and reliable TCM strategies to treat depression.

Two standardized fractions of Gardenia jasminoides Ellis with rapid antidepressant effects are differentially associated with BDNF up-regulation in the hippocampus.

ETHNOPHARMACOLOGICAL RELEVANCE: Gardenia jasminoides Ellis (GJ) is one of the five constituents of Yueju pill, a Traditional Chinese Medicine for treatment of syndromes associated with mood disorders. Recently, preclinical and clinical studies suggest that Yueju pill confers rapid antidepressant effects. GJ is identified as the constituent primary for Yueju pill's rapid antidepressant effects. GJ's antidepressant action is temporally associated with up-regulated expression of brain-derived neurotrophic factor (BDNF) in the hippocampus. The present study aimed to identify chemical fractions responsible for the rapid antidepressant efficacy of GJ and its association with BDNF signaling. MATERIALS AND METHODS: Four fractions of GJ were extracted using standardized procedure. The four fractions were screened for rapid antidepressant potential, using the behavioral paradigm of forced swimming test (FST) and tail suspension test (TST) assessed at 24h post a single administration. A single dose of the putatively effective fractions was further tested in mice exposed to chronic mild stress (CMS), followed with a comprehensive behavioral testing including TST, FST, sucrose preference test (SPT), and novelty suppressed-feeding (NSF). To test the association of BDNF signaling with rapid antidepressant effects of effective factions, the expressions of BDNF and its receptor tropomyosin receptor kinase B (TrkB) in the hippocampus were assessed at different times post a single administration of effective fractions. RESULTS: Both petroleum ether (GJ-PE) and n-butyl alcohol fraction (GJ-BO) fractions of GJ displayed rapid antidepressant potential in the FST. In the TST, the antidepressant effects of GJ-PE lasted for a longer time than GJ-BO. Acute administration of either GJ-PE or GJ-BO significantly reversed the behavioral deficits in the tests of TST, FST, SPT and NSF in chronically stressed mice, confirming both fractions conferred rapid antidepressant efficacy. Interestingly, GJ-PE, but not GJ-BO, increased the expression of BDNF and TrkB in the hippocampus post a single administration. CONCLUSION: Two standardized fractions GJ-PE and GJ-BO exhibited comparable rapid antidepressant-like effects on the CMS mice. However, only the effects of GJ-PE was associated with BDNF signaling.

Rapid mood-elevating effects of low field magnetic stimulation in depression.

BACKGROUND: We previously reported rapid mood elevation following an experimental magnetic resonance imaging procedure in depressed patients with bipolar disorder (BPD). This prompted the design, construction, and testing of a portable electromagnetic device that reproduces only the rapidly oscillating (1 kHz, <1 V/m) electromagnetic field of the experimental procedure, called low field magnetic stimulation (LFMS). METHODS: We used a randomized, double blind, sham controlled treatment protocol to study the effects of LFMS in a large group of stably medicated, depressed patients with either BPD (n = 41) or major depressive disorder (n = 22). Subjects received a single, 20-minute treatment. Change in mood was assessed immediately afterward using a visual analog scale (VAS), the 17-item Hamilton Depression Rating Scale (HDRS-17), and the Positive and Negative Affect Schedule scales. RESULTS: Substantial improvement (>10% of baseline) in mood was observed following LFMS treatment relative to sham treatment for both diagnostic subgroups for our primary outcomes, the VAS and the HDRS-17. These differences were not statistically significant in primary analyses stratifying by diagnosis but were significant in secondary analyses combining data across the two diagnostic groups (p = .01 VAS, p = .02 HDRS-17). Rapid improvement in mood was also observed using the Positive and Negative Affect Schedule scales as secondary measures (positive affect scale p = .02 BPD, p = .002 combined group). A finite element method calculation indicates a broad penetration of the LFMS electric field throughout the cerebral cortex. CONCLUSIONS: Low field magnetic stimulation may produce rapid changes in mood using a previously unexplored range of electromagnetic fields.