Lancao decoction alleviates cognitive dysfunction: A new therapeutic drug and its therapeutic mechanism.

BACKGROUND: Cognitive dysfunction (CD) is a neurodegenerative disease characterized primarily by the decline of learning and memory abilities. The physiological and pathological mechanisms of CD are very complex, which is mainly related to normal function of the hippocampus. Lancao decoction (LC) is a Chinese medicine formula, which has been used to treat neurodegenerative disorders. However, the potential of LC for the treatment of CD, as well as its underlying mechanisms, is unclear. PURPOSE: In the study, we aimed to reveal the functional and neuronal mechanisms of LC's treatments for CD in scopolamine-induced mice. METHODS: Gas chromatography (GC) was used to determine the stability of LC's extraction. CD model was established by the chronic induction of scopolamine (Scop, 1 mg/kg/day) for 1 week. Behavioral tests including morris water maze (MWM) and y-maze were used to evaluate learning and memory abilities of mice after LC's treatments. Immunofluorescence was used to detected the expressions of cFOS, Brdu and Ki67 after LC's treatments. Pharmacological blockade experiments explored the role of α-Amino-3­hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) in LC's treatments for CD and its relationships with regeneration, activities and differentiation of neurons. RESULTS: The results showed that LC was capable of improving spatial learning and memory and spontaneous alternating abilities in Scop-induced mice, which was similar to donepezil. LC could increase the number of cFOS positive cells, which was used as a marker of neuronal activity to upregulate by neuronal activities in hippocampus, but donepezil did not. Moreover, LC could strengthen neurogenesis and neuro-differentiation by increasing the number of Brdu and Ki67 positive cells in hippocampal dentate gyrus (DG), meanwhile, donepezil could only enhance the number of Ki67 positive cells. Transient inhibition of AMPAR by NBQX blunted the function of LC's treatment for CD and inhibited the enhanced effect of LC on Scop-induced hippocampal neuronal excitability and neurogenesis in mice. CONCLUSION: To sum up, our study demonstrated that LC had the function of treating CD by enhancing content of acetylcholine (ACh) to activate AMPAR, which further up-regulated neurogenesis and neuronal differentiation to strengthen neuroactivities in hippocampus.

ZeXieYin formula alleviates atherosclerosis by inhibiting the MAPK/NF-κB signaling pathway in APOE-/- mice to attenuate vascular inflammation and increase plaque stability.

ETHNOPHARMACOLOGICAL RELEVANCE: Zexieyin formula (ZXYF), a traditional Chinese herbal formula recorded in the Huangdi Neijing to have efficacy in relieving spleen dampness and heat accumulation syndrome, which is also the key pathogenesis of atherosclerosis (AS). The efficacy has demonstrated by our previous studies. However, the intrinsic mechanism of ZXYF for treating vascular inflammation and the effect of inflammatory response on plaque are not known. Currently, plaque stabilization is crucial for the prognosis of AS. AIM OF THE STUDY: Our study mainly focused on the therapeutic effects of ZXYF on high-fat diet (HFD)-induced vascular inflammation and vulnerable plaques (VP) in mice and explored its underlying mechanism. METHODS AND MATERIALS: Male apolipoprotein E knockout (APOE-/-) mice were fed HFD for 8 weeks to establish a VP model. During this period, the mice were also administered ZXYF, while atorvastatin (ATO) was used as a positive control. Aortic plaque area and morphology were detected by oil red staining and HE staining. Aortic plaque collagen content was detected by Masson staining. M1/M2 type macrophages were detected using immunofluorescence (IF). The study analyzed the levels of inflammation-related cytokines (IL-1ß, IL-10, IL-6), MAPK/NF-κB pathway proteins, and NLRP3 inflammasomes (NLRP3, Caspase-1) using Western blot. Additionally, the levels of matrix metalloproteinase (MMP)-2 and MMP-9 and α-smooth muscle actin (α-SMA) in the aorta were analyzed using immunohistochemistry (IHC). The plaque instability index was calculated for each group using the vulnerable plaque formula. RESULTS: In this study, APOE-/- mice were fed high-fat diet for 8 weeks. The results of oil-red and HE staining indicated a significant increase in the aortic plaque area of the mice, which exhibited a typical VP phenotype. ZXYF and ATO significantly improved AS plaques and prevented plaque rupture. HFD exacerbated vascular inflammation, stimulated macrophage conversion to M1-type through the MAPK/NF-κB signaling pathway, and released pro-inflammatory factors such as interleukin (IL)-1ß, IL-1α, and IL-6. These factors activated NLRP3 inflammasome, leading to cellular death. However, ZXYF could reverse this trend and promote the conversion of macrophages to the anti-inflammatory M2 type. The anti-inflammatory effect of ATO was not significant. Moreover, HFD promoted the release of MMP-2 and MMP-9 from macrophages, which degraded plaque collagen, and induced a decrease in plaque SMC content, resulting in a thinning of the plaque fibrous cap. In contrast, ZXYF inhibited the decomposition of plaque collagen and increased the content of plaque smooth muscle cells (SMC) by reducing macrophage secretion of MMPs, thereby stabilizing plaques. Although ATO could reverse the decrease in plaque collagen and SMC content, its effect on MMPs was not significant. Finally, we calculated the vulnerability index to assess the overall risk of the plaque vulnerability phenotype. In line with these findings, ZXYF and ATO were able to effectively reverse the increase in the vulnerability index caused by HFD and lower the risk of adverse cardiovascular events. CONCLUSION: Our results suggested that ZXYF could reduce inflammation and increase plaque stability by inhibiting the MAPK/NF-κB signaling pathway, which provided a theoretical basis for clinical application and subsequent research.

Zexieyin formula alleviates atherosclerosis with cognitive impairment: A novel role in the treatment of comorbidities and its underlying mechanisms.

ETHNOPHARMACOLOGICAL RELEVANCY: Zexieyin formula (ZXYF) has been identified to have therapeutic actions of atherosclerosis (AS). It's unknown that whether ZXYF has therapeutic potential of atherosclerosis (AS) with cognitive impairment (CI) and its underlying mechanisms. AIM OF THE STUDY: To elucidate therapeutic effect of ZXYF for AS with CI as well as its underlying mechanisms in AS with CI mice model. METHODS AND MATERIALS: To establish AS with CI model, we fed ApoE-/- mice with high-fat diet (HFD) for 8 weeks. Oil red O staining (ORO) and Hematoxylin-eosin staining (HE) were used to detect aortic plaque area. Morris water maze (MWM) and Y-maze were used to measure cognitive function and cognitive improvement after administration of ZXYF and atorvastatin (ATO). Network pharmacology was used to screen for potential mechanisms for improving cognitive function. Western blot was used to detect expressions of MAPK, Aß and synaptic proteins in hippocampus. RESULTS: HFD caused and accelerated the AS in ApoE-/- mice, while it was easier able to produce CI than normal mice. Administration of ZXYF or ATO for 8 weeks significantly reduced aortic plaque area in ORO and HE tests, and improved cognitive abilities in MWM and Y-maze tests. Network pharmacology results showed that MAPK or synaptic proteins were highly associated with CI. HFD contributed to abnormal expressions of MAPK (pERK, pP38, pJNK), NF-kB, synaptic proteins (PSD95, synapsin1) and ß-amyloid (Aß) in hippocampus, which were all reversed by ZXYF. However, ERK and PSD95 expressions were not reversed by ATO in hippocampus. CONCLUSIONS: ZXYF mitigated AS, further alleviating CI by modulating MAPK signaling, relating to synaptic proteins enhancing and Aß protein decreasing in the hippocampus. This study firstly lit up the new clinical application of ZXYF, which might promote the use of ZXYF in AS and CI patients.

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.

The Rapid and Long-Lasting Antidepressant Effects of Iridoid Fraction in Gardenia Jasminoides J.Ellis Are Dependent on Activating PKA-CREB Signaling Pathway.

Lag periods of therapeutic efficacy cause poor compliance of patients, which has made solutions for rapid antidepressants the most urgent need in the depression study field at present. We have identified through our previous studies the rapid antidepressant effects of the traditional herb Gardenia jasminoides J.Ellis [Rubiaceae] (GJ) and its standardized fractions. Through screening different fractions of GJ, we decided to place our focus on the iridoid fraction of GJ (GJ-IF). Methods: 1. Tail suspension test (TST), forced swimming test (FST), and novelty suppressed-feeding test (NSFT) were performed in sequence on mice after GJ-IF administration. 2. Mice in the model group were under chronic unpredictable mild stress (CUMS) for 3 w. After GJ-IF treatment, mice were placed in an open field test (OFT), Sucrose preference test (SPT), NSFT, TST, and FST. 3. Western Blot was performed to examine the expression of brain-derived neurotrophic factor (BDNF), Synapsin 1, cyclic-AMP dependent protein kinase A (PKA), phosphorylated cyclic-AMP responsive element-binding protein (p-CREB), and cAMP response element-binding protein (CREB). 4. Mice in the test group were administrated with GJ-IF after intraperitoneal injection of PKA blocker H89. Results: 1. GJ-IF treatment significantly reduced the immobility time of TST at 1 d and FST at 26 h. 2. GJ-IF reversed the deficits induced by 3 w CUMS in SPT, TST, FST, and NSFT at 1 d and 26 h. The antidepressant effects of a single dose of iridoid fraction could also last for at least 14 d. 3. The results of molecule studies suggested that a single dose of GJ-IF activated p-CREB at 2 h and the PKA-CREB pathway at 1 d. The expression of BDNF did not significantly change from 30 min to 1 d after GJ-IF administration. 4. Blockade of PKA-CREB signaling pathway reversed the antidepressant effects of GJ-IF at 1 d, but not 30 min and 2 h. Conclusion: GJ-IF is the crucial component in the rapid antidepressant of GJ. Rapid and sustained antidepressant effects of GJ-IF were dependent on activating the PKA-CREB signaling pathway.

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.

Quercitrin Rapidly Alleviated Depression-like Behaviors in Lipopolysaccharide-Treated Mice: The Involvement of PI3K/AKT/NF-κB Signaling Suppression and CREB/BDNF Signaling Restoration in the Hippocampus.

Quercitrin (Qc) is a well-known flavonoid compound that exerts anti-inflammation effects on various diseases. The present study aimed to investigate the antidepressant-like response of Qc and its underlying mechanisms concerning neuroinflammation and neuroplasticity in mice with lipopolysaccharide (LPS)-induced depression-like behaviors. The results showed a single dose of Qc (10 mg/kg) produced an antidepressant-like effect at 2 h postadministration and lasted for at least 3 days. The expressions of neuroplasticity signaling molecules of pCREB/BDNF/PSD95/Synapsin1 were upregulated at 2 h, and ERK signaling was upregulated for 3 days in the hippocampus after a single administration of Oc or ketamine. A 5-day treatment of LPS led to depression-like behaviors, including reduced sucrose preference and increased immobility in the tail suspension test or forced swim test, which were all reversed by a single dose of Qc. In LPS-treated mice, Qc reduced the levels of inflammation-related factors including IL-10, IL-1ß, and TNF-α in serum, as well as the activations of PI3K/AKT/NF-κB and MEK/ERK pathways in the hippocampus. Moreover, Qc restored the expressions of pCREB/BDNF/PSD95/Synapsin1 signaling in the hippocampus that were impaired by LPS. LY294002, a PI3K inhibitor, but not PD98059, a MEK inhibitor, produced effects similar to Qc. LY294002 also restored the expressions of pCREB/BDNF/PSD95/Synapsin1 signaling in the hippocampus impaired by LPS. Additionally, subeffective doses of Qc and LY294002 induced behavioral and molecular synergism. Together, the depression-like behaviors in LPS-treated mice were alleviated by a single dose of Qc likely via inhibition of the activations PI3K/AKT/NF-κB inflammation signaling and subsequent improvement of neuroplasticity.

Jianpi Jieyu Decoction, An Empirical Herbal Formula, Exerts Psychotropic Effects in Association With Modulation of Gut Microbial Diversity and GABA Activity.

Background: Recent studies suggest that gut microbiota was associated with the bidirectional gut-brain axis which could modulate neuropsychological functions of the central nervous system. Gut microbiota could produce gamma aminobutyric acid (GABA) that could modulate the gut-brain axis response. Jianpi Jieyu (JPJY) decoction, a traditional Chinese formula, is mainly composed of Astragalus membranaxeus and Radix Pseudostellariae. Although the JPJY decoction has been used to treat the depression in China, the potential action of its antidepressant has not been well understood. Thus this study was aim to investigate the role of JPJY improve gut microbiota homeostasis in the chronic stress induced depressive mice. Methods: The antidepressant effect of JPJY on chronic unpredictable mild stress (CUMS) mice was evaluated by using sucrose preference test, tail suspension test and forced swim test. Fatigue-like behaviors were evaluated using degree of redness, grip strength test, and exhaustive swimming test. The new object recognition test was used to evaluate cognition performance. Fecal samples were collected and taxonomical analysis of intestinal microbial distribution was conducted with 16S rDNA. Serum level of GABA was measured using high performance liquid chromatography (HPLC). The expression of GluR1 and p-Tau protein in the hippocampus was determined using Western blotting. Results: The dose of 9.2 g/kg JPJY produced antidepressant-like effects. JPJY and its major components also modulated gut microbiota diversity in the CUMS mice. Serum level of GABA and the expressions of hippocampal GluR1 and p-Tau were reversed after the administration of JPJY in CUMS mice. Conclusion: JPJY regulates gut microbiota to produce antidepressant-like effect and improve cognition deficit in depressive mice while its molecular mechanism possibly be enhanced NR1 and Tau expression in hippocampus and increased GABA in serum.

Yueju-Ganmaidazao Decoction confers rapid antidepressant-like effects and the involvement of suppression of NMDA/NO/cGMP signaling.

ETHNOPHARMACOLOGICAL RELEVANCE: Yueju-Ganmaidazao Decoction (YG) is a multiherbal medicine prescribed for treatment of mood disorder, consisting of two classical traditional Chinese herbal medicine Yueju and Ganmaidazao. Yueju and Ganmaidazao both are used for depression treatment. The combined decoction of Yueju and Ganmaidazao is prescribed to achieve optimal clinical outcomes by dealing with different symptoms of depression. Recent studies indicated ethanol extract of Yueju was capable to confer rapid antidepressant-like response. The antidepressant activity of YG decoction with fast-onset feature remains to be investigated. AIM OF THE STUDY: Rapid and safe antidepressant treatment is urgently needed. This study aimed to assess the rapid antidepressant-like activity of YG and the underlying mechanism, focusing on NMDA/NO/cGMP signaling. MATERIALS AND METHODS: The optimal doses for immediate and persistent antidepressant-like response were first screened using tail suspension test (TST) and forced swimming test (FST) post a single administration of YG. The rapid action was further confirmed by using the chronic mild stress (CMS) and learned helplessness (LH) paradigms. The expressions of NMDA receptor subunits were evaluated post stress and YG. The contributions of NMDA, NO, and cGMP signaling to the antidepressant effect of YG were investigated systematically using pharmacological interventions. RESULTS: The optimal dose for immediate and persistent antidepressant potential, evidenced with reduced immobility times in TST or FST from 30 min to 7 days, was determined. The rapid antidepressant-like effect was confirmed in CMS and LH paradigms, including instant normalization of sucrose preference behavior. The expression of NMDA subunit NR1 in the hippocampus was reduced from 30 min to 5 days post YG. In animals subjected to CMS and LH, hippocampal NR1 expression increased, reversed by YG. YG's antidepressant-like effect was blunted by pretreatment with the agonists along the signalings including NMDA (75 mg/kg), L-arginine (750 mg/kg) and sildenafil (5 mg/kg) in TST or FST. Conversely, administration of subeffective dose of individual antagonists, including MK-801 (0.05 mg/kg), 7-nitroindazole (30 mg/kg), methylene blue (10 mg/kg), in combination with a subeffective dose of YG, elicited antidepressant effects. CONCLUSION: YG conferred rapid antidepressant-like effects, and the antidepressant response was essentially dependent on suppression of NMDA/NO/cGMP signaling.

NMDA receptors and L-arginine/nitric oxide/cyclic guanosine monophosphate pathway contribute to the antidepressant-like effect of Yueju pill in mice.

The present study aims to evaluate the involvement of N-methyl-d-aspartate receptor and nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) system in antidepressant-like effects of Yueju pill (YJ), a Chinese herbal medicine. The immobility time in tail suspension test (TST) and forced swim test (FST) was used to assess the antidepressant effects. Prior administration of L-arginine (750 mg/kg, intraperitoneal [i.p.]), a NO synthase substrate that enhances NO signaling or sildenafil (5 mg/kg, i.p.), a phosphodiesterase 5 inhibitor that enhances cGMP, blunted the antidepressant-like activity of YJ (2.7 g/kg, i.g.). Co-treatment of ineffective dose of YJ (1.35 g/kg, i.g.) with one of the reagents that suppress the NO/cGMP signaling, including methylene blue (10 mg/kg, i.p.), an inhibitor of NO synthase; 7-NI (7-nitroinidazole, 30 mg/kg, i.p.), an nNOS specific inhibitor; L-NAME (10 mg/kg, i.p.), a non-specific inhibitor of NO synthase; and MK-801 (0.05 mg/kg, i.p.), an NMDA receptor antagonist, reduced the immobility time in TST and FST, compared with those in vehicle or single drug treatment groups. Neither above drugs alone or co-administrated with YJ affected locomotor activity or anxiety behavior in open field test. Thus, our results suggest that the antidepressant-like action of YJ may depend on the inhibition of NMDA/NO/cGMP pathway.

Immediate and persistent antidepressant-like effects of Chaihu-jia-Longgu-Muli-tang are associated with instantly up-regulated BDNF in the hippocampus of mice.

Conventional antidepressants have a disadvantage in delayed onset of efficacy. Here, we aimed to evaluate the immediate and persistent antidepressant-like action of a classic herbal medicine Chaihu-jia-Longgu-Muli decoction (CLM) as well as the action of CLM on hippocampal brain-derived neurotrophic factor (BDNF) over time. CLM consists of Xiaochaihu decoction (XchD), Longgu-Muli (LM) and several other herbs. The contribution of constituent herbal formula XchD and other parts of CLM was also assessed. Following a single dose of CLM, tail suspension test (TST), forced swim test (FST), and novelty-suppressed feeding test (NSF) were performed. The antidepressant activity of XchD, its interaction with LM or remaining parts of CLM was also examined after a single administration. BDNF expression in the hippocampus was examined at 30 min and 24 hr post a single CLM. A single administration of half of clinical dose of CLM elicited antidepressant effects at TST 30 min post administration, and lasted for 72 hr. Furthermore, CLM also reduced the latency to eat in NSF test. A single proportional dose of XchD induced antidepressant effects at 30 min and lasted for 48 hr, whereas the effect lasted for 72 hr when combined with either LM or the remaining parts of CLM. BDNF expression increased at 30 min and persisted at least for 24 hr after a single dose of CLM. The results support that Chaihu-jia-Longgu-Muli decoction was capable to immediately and enduringly elicit antidepressant activity via enhancement of hippocampal BDNF expression, in which the constituent Xiaochaihu decoction played the primary role.

Expression of Disrupted-in-schizophrenia 1 in Hippocampus in Postpartum Depression Animal Models Induced by Pre-pregnancy Stress.

Objective To establish a postpartum depression animal model induced by pre-pregnancy stress,assess abnormal maternal depressive-like behavior,observe the expression of disrupted-in-schizophrenia 1 (DISC1) in the hippocampus,and detect serum estradiol and corticosterone.Methods A total of 32 female Balb/c were assigned to two groups using random number table:the control group and the pre-pregnancy stressed group(model group),and the model group was subjected to 3 weeks of chronic restraint stress. After the last stressor,the control group and the model group were housed with a male. About 4 weeks later,the mice gave birth to pups. Then at 3 weeks postpartum,open field test,tail suspension test,and sucrose preference test were carried out. The expressions of DISC1 mRNA and protein of hippocampus were detected by real-time quantitative polymerase chain reaction and Western blot,respectively. The serum levels of estradiol and corticosterone were detected with enzyme linked immunosorbent assay. Results After 3 weeks of postpartum,the model mice showed depression-like behaviors. In the open field test,there was no effect on the total distance moved or time spent in the center field (P>0.05). Immobility in tail suspension test was significantly increased (t=-4.950,P<0.001) and sucrose preference was significantly reduced in model group (t=2.475,P<0.05). There was significant statistical difference between control and model group on the expression of DISC1 mRNA (t=-8.915,P<0.001) and protein (t=-5.004,P<0.01) in hippocampus. There was no significant statistical difference on estradiol and corticosterone between two groups (P>0.05). Conclusion Chronic pre-pregnancy stress can induce dams into postpartum depression.The pathogenesis of postpartum depression may be related to the regulation of DISC1 in the hippocampus.

Transgenerational impairment of hippocampal Akt-mTOR signaling and behavioral deficits in the offspring of mice that experience postpartum depression-like illness.

Postpartum depression (PPD) has adverse effects on offspring and increases their vulnerability to psychiatric disorders such as depression. Akt-mTOR signaling in the hippocampus is implicated in depression but its role in the behavioral deficits in PPD offspring remains unknown. By using a prepregnancy stress model of PPD in which Balb/c females that experience chronic stress before pregnancy show long-lasting PPD-like behaviors, we tested depression-like behaviors in PPD offspring (PPD-F1) at juvenile and adult ages as well as in the second generation (PPD-F2) produced by cross of male PPD-F1 with naïve females. Hippocampal Akt-mTOR signaling was examined in the F1 and F2 generations of PPD, as well as in PPD-F1 mice treated with a single dose of the antidepressant ketamine. PPD-F1 showed depression-like behaviors at juvenile and adult stages, evidenced by reduced sucrose preference (SP), increased immobility time in the forced swim test (FST), and a longer latency to feed and reduced food consumption in the novelty suppressed feeding (NSF) test. PPD-F1 mice showed Akt-mTOR signaling deficiency in the hippocampus, with down-regulated expression of p-Akt, p-mTOR and p-p70S6K. A single dose of ketamine reversed the behavior deficits and the impairment in Akt-mTOR signaling in PPD-F1. Furthermore, the PPD-F2 mice remained deficient in the SP and NSF test and hippocampal Akt-mTOR signaling, although the performance in FST was normal. The present study demonstrated both long-term and transgenerational effects of PPD on the depression-like behaviors of offspring, and suggested impaired Akt-mTOR signaling may play a part.

Chronic stress prior to pregnancy potentiated long-lasting postpartum depressive-like behavior, regulated by Akt-mTOR signaling in the hippocampus.

Postpartum depression (PPD) affects over 10% of new mothers and adversely impacts the health of offspring. One of the greatest risk factors for PPD is prepregnancy stress but the underlying biological mechanism is unknown. Here we constructed an animal model which recapitulated prepregnancy stress induced PPD and tested the role of Akt-mTOR signaling in the hippocampus. Female virgin Balb/c mice received chronic restraint stress, followed by co-housing with a normal male mouse. We found that the chronic stress led to a transient depressive-like condition that disappeared within two weeks. However, prepregnantly stressed females developed long-term postpartum depressive-like (PPD-like) symptoms as indicated by deficient performance in tests of sucrose preference, forced swim, and novelty-suppressed feeding. Chronic stress induced transient decrease in Akt-mTOR signaling and altered expressions of glutamate receptor subunits NR1 and GluR1, in contrast to long-term deficits in Akt-mTOR signaling, GluR1/NR1 ratio, and hippocampal neurogenesis in PPD-like mice. Acute ketamine improved the molecular signaling abnormality, and reversed the behavioral deficits in PPD-like mice in a rapid and persistent manner, in contrast to ineffectiveness by chronic fluoxetine treatment. Taken together, we find that chronic prepregnancy stress potentiates a long-term PPD, in which Akt-mTOR signaling may play a crucial role.

Instant and Persistent Antidepressant Response of Gardenia Yellow Pigment Is Associated with Acute Protein Synthesis and Delayed Upregulation of BDNF Expression in the Hippocampus.

Gardenia yellow pigment (GYP) is a collection of compounds with shared structure of crocin, which confers antidepressant activity. GYP is remarkably enriched in Gardenia jasminoides Ellis, implicated in rapid antidepressant effects that are exerted through enhanced neuroplasticity. This study aims to investigate the rapid antidepressant-like activity of GYP and its underlying mechanism. After the optimal dose was determined, antidepressant responses in tail suspension test or forced swim test were monitored at 30 min, 1 day, 3 days, and 7 days post a single GYP administration. Rapid antidepressant potential was tested using learned helplessness paradigm. The expression of proteins involved in hippocampal neuroplasticity was determined. The effect of blockade of protein synthesis on GYP's antidepressant response was examined. Antidepressant response was detected at 30 min, and lasted for at least 3 days post a single administration of GYP. A single administration of GYP also reversed the deficits in learned helplessness test. Thirty minutes post GYP administration, ERK signaling was activated, and its downstream effector phosphorylated eukaryotic elongation factor 2 was inhibited, contributing to increased protein translation. Expression of synaptic proteins GluR1 and synapsin 1 was upregulated. Blockade of protein synthesis with anisomycin blunted the immediate antidepressant response of GYP. CREB signaling and BDNF expression were upregulated at 24 h, but not at 30 min. In conclusion, GYP-induced immediate antidepressant response was dependent on synthesis of proteins, including synaptic proteins. This was followed by enhanced expression of CREB and BDNF, which likely mediated the persistent antidepressant responses.

PKA-CREB-BDNF signaling regulated long lasting antidepressant activities of Yueju but not ketamine.

Yueju confers antidepressant effects in a rapid and long-lasting manner, similar to ketamine. CREB (cAMP-response element binding protein) signaling is implicated in depression pathology and antidepressant responses. However, the role of CREB and associated brain derived neurotrophic factor (BDNF) signaling in rapid and long-lasting antidepressant effects remains unclear. Here, we demonstrated that ICR and Kunming strain mice conferred antidepressant responses lasting for 1 and 5 days, respectively, following a single dose of Yueju. One day post Yueju in Kunming but not ICR strain mice, expression of total and phosphorylated CREB, as well as the CREB signaling activator, PKA (protein kinase A) was up-regulated in the hippocampus. Although BDNF gene expression increased at 3 hours in both strains, it remained up-regulated at 1 day only in Kunming mice. Ketamine showed similar strain-dependent behavioral effects. However, blockade of PKA/CREB signaling blunted the antidepressant effects and reversed the up-regulation of BDNF gene expression by Yueju, but not ketamine. Conversely, blockade of mammalian target of rapamycin signaling led to opposite effects. Taken altogether, prolonged transcriptional up-regulation of hippocampal BDNF may account for the stain-dependent enduring antidepressant responses to Yueju and ketamine, but it was mediated via PKA/CREB pathway only for Yueju.

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.

Instant and Lasting Down-Regulation of NR1 Expression in the Hippocampus is Associated Temporally with Antidepressant Activity After Acute Yueju.

Accumulating evidence indicated that N-methyl-D-aspartate (NMDA) receptors are involved in the pathophysiology of depression and implicated in therapeutic targets. NMDA antagonists, such as ketamine, displayed fast-onset and long-lasting antidepressant activity in preclinical and clinical studies. Previous studies showed that Yueju pill exerts antidepressant effects similar to ketamine. Here, we focused on investigating the association of acute and lasting antidepressant responses of Yueju with time course changes of NMDA receptor subunits NR1, NR2A, and NR2B expressions in the hippocampus, a key region regulating depression response. As a result, Yueju reduced immobility time in the forced swimming test from 30 min to 5 days post a single administration. Yueju acutely decreased NR1 and NR2B protein expression in the hippocampus, with NR2A expression unaltered. NR1 expression remained down-regulated 5 days post Yueju administration, whereas NR2B returned to normal level in 24 h. Yueju and ketamine similarly ameliorated the depression-like symptoms at least for 72 h in learned helplessness test. They both reversed the up-regulated expression of NR1 in the learned helpless mice 1 or 3 days post administration. Different from ketamine, the antidepressant effects of Yueju were not influenced by blockade of amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor. These findings served as preclinical evidence that Yueju may confer acute and long-lasting antidepressant effects by favorably modulating NMDA function in the hippocampus.

Involvement of normalized NMDA receptor and mTOR-related signaling in rapid antidepressant effects of Yueju and ketamine on chronically stressed mice.

Yueju, a Traditional Chinese Medicine formula, exhibited fast-onset antidepressant responses similar to ketamine. This study focused on assessing the rapid and persistent antidepressant efficacy of Yueju and ketamine in chronically stressed mice and its association with alternations in prefrontal N-methyl-D-aspartate (NMDA) receptor and mammalian target of rapamycin (mTOR)-related activity. Chronic mild stress (CMS) led to deficits in sucrose preference test (SPT), forced swim test, tail suspension test, and novelty-suppressed feeding test, which were improved differently by acute Yueju or ketamine administration. The improvement in SPT started as soon as 2 hours post Yueju and ketamine but lasted for 6 days only by Yueju. Body weight was regained by Yueju more than ketamine at post-drug administration day (PAD) 6. CMS decreased phosphorylation of the mTOR effectors 4E-BP1 and p70S6K, their upstream regulators ERK and Akt, and downstream targets including synaptic protein GluR1. Yueju or ketamine reversed these changes at PAD 2, but only Yueju reversed phosphor-Akt at PAD 6. CMS selectively and lastingly increased NMDA receptor subunit NR1 expression, which was reversed by ketamine or Yueju at PAD 2 but only by Yueju at PAD 6. These findings suggest that NR1 and Akt/mTOR signaling are important therapeutic targets for depression.

Rapid Antidepressant Activity of Ethanol Extract of Gardenia jasminoides Ellis Is Associated with Upregulation of BDNF Expression in the Hippocampus.

Ethanol extract of Yueju pill, a Traditional Chinese Medicine herbal formula widely used to treat mood disorders, demonstrates rapid antidepressant effects similar to ketamine, likely via instant enhancement of brain-derived neurotrophic factor (BDNF) expression in the hippocampus. Here we investigated ethanol extracts of the constituent herbs of Yueju responsible for rapid antidepressant effects. Screening with tail suspension test in Kunming mice at 24 hours after a single administration of five individual constituent herbs of Yueju, we found that only Gardenia jasminoides Ellis (GJ) showed a significant effect. The antidepressant response started at 2 hours after GJ administration. Similar to Yueju and ketamine, a single administration of GJ significantly reduced the number of escape failures in the learned helplessness test. Furthermore, GJ decreased latency of food consumption in the novelty suppressed-feeding test. Additionally, starting from 2 hours and continuing for over 20 hours after GJ administration, BDNF expression in the hippocampus was upregulated, temporally linked with the antidepressant response. These findings suggest that GJ has rapid antidepressant effects, which are associated with the elevated expression of BDNF in the hippocampus. In Yueju formula, Yue represents GJ, as thus our study demonstrates the primary role of GJ in rapid antidepressant efficacy of Yueju.