Antidepressant effects of ginseng total saponins in the forced swimming test and chronic mild stress models of depression

Efficacy and safety of YOXINTINE for depression: A double-blinded, randomized, placebo-controlled, phase 2 clinical trial

BACKGROUND

YOXINTINE contains >98 % of 20(S)-protopanaxadial (PPD), a metabolic product of ginsenosides with pre-clinical neuroprotective activity. Animal experiments and previous studies have shown that PPD has good antidepressant effect and safety.

PURPOSE

To evaluate YOXINTINE in treating depression compared with a placebo in Chinese patients.

STUDY DESIGN

This was a multicenter, double-blinded, randomized, placebo-controlled, phase 2 clinical trial.

METHODS

The study included 178 randomized (1:1:1) Chinese patients with depression. Patients were randomly assigned to receive oral YOXINTINE at doses of 200 or 400 mg or a placebo administered twice daily for 8 weeks. The primary outcome was assessed by measuring changes in the Montgomery-Asberg Depression Rating Scale (MADRS) total score. All adverse reactions were recorded. All demographic and baseline characteristics were comparable.

RESULTS

The changes in MADRS total scores from baseline were -10.43 for the placebo group, -16.24 for the 200 mg YOXINTINE group, and -13.60 for the 400 mg YOXINTINE group. The differences in MADRS total score changes compared with the placebo were -5.81 (95 % CI: -7.69, -3.92; P < 0.0001) and -3.17 (95 % CI: -5.08, -1.25; P = 0.0013) for the 200 mg and 400 mg groups, respectively. The results indicated a significantly greater MADRS score reduction in the 200 mg group (P = 0.0058, 95 % CI: 0.78, 4.51). Adverse event incidence was comparable among all groups.

CONCLUSION

Oral YOXINTINE is safe and significantly improves depressive symptoms. PPD may exhibit antidepressant properties through mechanisms distinct from monoamine reuptake inhibition.

REGISTRATION NUMBER

ChiCTR2300070568.

Ginsenoside Rg1 protects the blood-brain barrier and myelin sheath to prevent postoperative cognitive dysfunction in aged mice

In this study, the postoperative cognitive dysfunction (POCD) mouse model was established to observe the changes in inflammation, blood-brain barrier permeability, and myelin sheath, and we explore the effect of ginsenoside Rg1 pretreatment on improving POCD syndrome. The POCD model of 15- to 18-month-old mice was carried out with internal fixation of tibial fractures under isoflurane anesthesia. Pretreatment was performed by continuous intraperitoneal injection of ginsenoside Rg1(40 mg/kg/day) for 14 days before surgery. The cognitive function was detected by the Morris water maze. The contents of interleukin-1β and tumor necrosis factor-α in the hippocampus, cortex, and serum were detected by ELISA. The permeability of blood-brain barrier was observed by Evans blue. The mRNA levels and protein expression levels of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase), myelin basic protein (MBP), beta-catenin, and cyclin D1 in the hippocampus were analyzed by quantitative PCR and western blotting. The protein expression levels of ZO-1 and Wnt1 in the hippocampus were analyzed by western blotting. Finally, the localizations of CNPase and MBP in the hippocampus were detected by immunofluorescence. Ginsenoside Rg1 can prevent POCD, peripheral and central inflammation, and blood-brain barrier leakage, and reverse the downregulation of ZO-1, CNPase, MBP, and Wnt pathway-related molecules in aged mice. Preclinical studies suggest that ginsenoside Rg1 improves postoperative cognitive function in aged mice by protecting the blood-brain barrier and myelin sheath, and its specific mechanism may be related to the Wnt/β-catenin pathway.

Antidepressant Effects of Ginsenoside Rc on L-Alpha-Aminoadipic Acid-Induced Astrocytic Ablation and Neuroinflammation in Mice

Depression is a prevalent and debilitating mental disorder that affects millions worldwide. Current treatments, such as antidepressants targeting the serotonergic system, have limitations, including delayed onset of action and high rates of treatment resistance, necessitating novel therapeutic strategies. Ginsenoside Rc (G-Rc) has shown potential anti-inflammatory and neuroprotective effects, but its antidepressant properties remain unexplored. This study investigated the antidepressant effects of G-Rc in an L-alpha-aminoadipic acid (L-AAA)-induced mouse model of depression, which mimics the astrocytic pathology and neuroinflammation observed in major depressive disorder. Mice were administered G-Rc, vehicle, or imipramine orally after L-AAA injection into the prefrontal cortex. G-Rc significantly reduced the immobility time in forced swimming and tail suspension tests compared to vehicle treatment, with more pronounced effects than imipramine. It also attenuated the expression of pro-inflammatory cytokines (TNF-α, IL-6, TGF-β, lipocalin-2) and alleviated astrocytic degeneration, as indicated by increased GFAP and decreased IBA-1 levels. Additionally, G-Rc modulated apoptosis-related proteins, decreasing caspase-3 and increasing Bcl-2 levels compared to the L-AAA-treated group. These findings suggest that G-Rc exerts antidepressant effects by regulating neuroinflammation, astrocyte-microglia crosstalk, and apoptotic pathways in the prefrontal cortex, highlighting its potential as a novel therapeutic agent for depression.

Korean Red Ginseng and Rb1 restore altered social interaction, gene expressions in the medial prefrontal cortex, and gut metabolites under post-weaning social isolation in mice

Background

Post-weaning social isolation (SI) reduces sociability, gene expressions including myelin genes in the medial prefrontal cortex (mPFC), and alters microbiome compositions in rodent models. Korean Red Ginseng (KRG) and its major ginsenoside Rb1 have been reported to affect myelin formation and gut metabolites. However, their effects under post-weaning SI have not been investigated. This study investigated the effects of KRG and Rb1 on sociability, gene expressions in the mPFC, and gut metabolites under post-weaning SI.

Methods

C57BL/6J mice were administered with water or KRG (150, 400 mg/kg) or Rb1 (0.1 mg/kg) under SI or regular environment (RE) for 2 weeks during the post-weaning period (P21-P35). After this period, mice underwent a sociability test, and then brains and ceca were collected for qPCR/immunohistochemistry and non-targeted metabolomics, respectively.

Results

SI reduced sociability compared to RE; however, KRG (400 mg/kg) and Rb1 significantly restored sociability under SI. In the mPFC, expressions of genes related to myelin, neurotransmitter, and oxidative stress were significantly reduced in mice under SI compared to RE conditions. Under SI, KRG and Rb1 recovered the altered expressions of several genes in the mPFC. In gut metabolomics, 313 metabolites were identified as significant among 3027 detected metabolites. Among the significantly changed metabolites in SI, some were recovered by KRG or Rb1, including metabolites related to stress axis, inflammation, and DNA damage.

Conclusion

Altered sociability, gene expression levels in the mPFC, and gut metabolites induced by two weeks of post-weaning SI were at least partially recovered by KRG and Rb1.

Effect of ginseng and ginsenosides on attention deficit hyperactivity disorder: A systematic review

Attention deficit hyperactivity disorder (ADHD) is a rapidly increasing neurodevelopmental disorder but currently available treatments are associated with abuse risk, side effects, and incomplete symptom relief. There is growing interest in exploring complementary options, and ginseng has gained attention for its therapeutic potential. This systematic review aimed to assess current evidence on the efficacy of ginseng and its active components, ginsenosides, for ADHD. Eligible studies were identified through searches of PubMed, Embase, Cochrane Library, and Web of Science, up to June 2023. The inclusion criteria included both human and animal studies that investigated the effects of ginseng or ginsenosides on ADHD. The risk of bias was assessed according to study type. Six human studies and three animal studies met the inclusion criteria. The results suggest that ginseng and ginsenosides may have beneficial effects on ADHD symptoms, particularly inattention, through dopaminergic/norepinephrinergicmodulation and BDNF/TrkB signaling. Ginseng and ginsenosides have promising potential for ADHD treatment. Due to limitations in evidence quality, such as the risk of bias and variability in study designs, larger controlled studies are essential. Integrating ginseng into ADHD management may have valuable implications for individuals seeking well-tolerated alternatives or adjunctive therapies.

Brain plasticity and ginseng

Brain plasticity refers to the brain's ability to modify its structure, accompanied by its functional changes. It is influenced by learning, experiences, and dietary factors, even in later life. Accumulated researches have indicated that ginseng may protect the brain and enhance its function in pathological conditions. There is a compelling need for a more comprehensive understanding of ginseng's role in the physiological condition because many individuals without specific diseases seek to improve their health by incorporating ginseng into their routines. This review aims to deepen our understanding of how ginseng affects brain plasticity of people undergoing normal aging process. We provided a summary of studies that reported the impact of ginseng on brain plasticity and related factors in human clinical studies. Furthermore, we explored researches focused on the molecular mechanisms underpinning the influence of ginseng on brain plasticity and factors contributing to brain plasticity. Evidences indicate that ginseng has the potential to enhance brain plasticity in the context of normal aging by mediating both central and peripheral systems, thereby expecting to improve age-related declines in brain function. Moreover, given modern western diet can damage neuroplasticity in the long term, ginseng can be a beneficial supplement for better brain health.

Anethole as a promising antidepressant for maternal separation stress in mice by modulating oxidative stress and nitrite imbalance

The occurrence of major depressive disorder is widespread and can be observed in individuals belonging to all societies. It has been suggested that changes in the NO pathway and heightened oxidative stress may play a role in developing this condition. Anethole is a diterpene aromatic compound found in the Umbelliferae, Apiaceae, and Schisandraceae families. It has potential pharmacological effects like antioxidant, anxiolytic, analgesic, anti-inflammatory, antidiabetic, gastroprotective, anticancer, estrogenic, and antimicrobial activities. This study aimed to investigate the potential antidepressant properties of Anethole in a mouse model experiencing maternal separation stress while also examining its impact on oxidative stress and nitrite levels. The research involved the participation of 40 male NMRI mice, separated into five distinct groups to conduct the study. The control group was administered 1 ml/kg of normal saline, while the MS groups were given normal saline and Anethole at 10, 50, and 100 mg/kg doses. The study comprised various behavioural tests, including the open field test (OFT), forced swimming test (FST), and splash test, to assess the effects of Anethole on the mice. In addition to the behavioural tests, measurements were taken to evaluate the total antioxidant capacity (TAC), malondialdehyde (MDA), and nitrite levels in the hippocampus of the mice. According to the findings, maternal separation stress (MS) led to depressive-like conduct in mice, including a rise in immobility duration during the FST and a reduction in the duration of grooming behaviour in the splash test. Additionally, the results indicated that MS correlated with an increase in the levels of MDA and nitrite and a reduction in the TAC in the hippocampus. However, the administration of Anethole resulted in an increase in grooming activity time during the splash test and a decrease in immobility time during the FST. Anethole also exhibited antioxidant characteristics, as demonstrated by its ability to lower MDA and nitrite levels while increasing the TAC in the hippocampus. The results suggest that Anethole may have an antidepressant-like impact on mice separated from their mothers, likely partly due to its antioxidant properties in the hippocampus.

Wenyang-Tianjing-Jieyu Decoction Improves Depression Rats of Kidney Yang Deficiency Pattern by Regulating T Cell Homeostasis and Inflammation Level

Purpose

Chronic inflammation is one of the key mechanisms of depression. Wenyang-Tianjin-Jie Decoction (WTJD) is an effective antidepressant found in the course of diagnosis and treatment, but the mechanism of therapeutic effect is not clear. The study aimed to evaluate the efficacy of WTJD in the kidney yang deficiency (KYD) type of depression rats and reveal its mechanisms.

Materials and Methods

We selected forty 6-week-old male Sprague-Dawley rats for the study. We established a KYD [Phellodendron amurense Rupr (Huangbai) solution oral gavage and 4°C environments; 8 weeks] type of depression (chronic unpredictable mild stimulus; 6 weeks) rat model first. After successful modeling, we used WTJD or fluoxetine on rats for 3 weeks. Then we evaluated the depression and KYD behavior. Finally, we observed the expression of key inflammatory factors and proteins in peripheral blood and hippocampus, and further investigated the immune balance of Th17/Treg and Th1/Th2 cells and the activity of their main regulatory pathways JAK2/STAT3 and TLR4/TRAF6/NF-κB.

Results

The imbalance of Th17/Treg and Th1/Th2 cells in rats were related to KYD and depressive symptoms. Through this study, we found that WTJD can inhibit the activity of JAK2/STAT3 and TLR4/TRAF6/NF-κB pathways, balance Th17/Treg and Th1/Th2 cell homeostasis, regulate the levels of inflammatory factors in the hippocampus and peripheral blood, and reverse KYD and depression.

Conclusion

This study confirmed that WTJD had a reliable effect on depression rats with KYD, and its mechanism was to regulate the immune homeostasis of hippocampal T cells and related inflammatory factors to improve KYD and depression symptoms in rats.

Effects of Chaihu Shugan San on Brain Functional Network Connectivity in the Hippocampus of a Perimenopausal Depression Rat Model

In this study, we used Chaihu Shugan San (CSS), a traditional Chinese herbal formula, as a probe to investigate the involvement of brain functional network connectivity and hippocampus energy metabolism in perimenopausal depression. A network pharmacology approach was performed to discover the underlying mechanisms of CSS in improving perimenopausal depression, which were verified in perimenopausal depression rat models. Network pharmacology analysis indicated that complex mechanisms of energy metabolism, neurotransmitter metabolism, inflammation, and hormone metabolic processes were closely associated with the anti-depressive effects of CSS. Thus, the serum concentrations of estradiol (E2), glutamate (Glu), and 5-hydroxytryptamine (5-HT) were detected by ELISA. The brain functional network connectivity between the hippocampus and adjacent brain regions was evaluated using resting-state functional magnetic resonance imaging (fMRI). A targeted metabolomic analysis of the hippocampal tricarboxylic acid cycle was also performed to measure the changes in hippocampal energy metabolism using liquid chromatography-tandem mass spectrometry (LC-MS/MS). CSS treatment significantly improved the behavioral performance, decreased the serum Glu levels, and increased the serum 5-HT levels of PMS + CUMS rats. The brain functional connectivity between the hippocampus and other brain regions was significantly changed by PMS + CUMS processes but improved by CSS treatment. Moreover, among the metabolites in the hippocampal tricarboxylic acid cycle, the concentrations of citrate and the upregulation of isocitrate and downregulation of guanosine triphosphate (GTP) in PMS + CUMS rats could be significantly improved by CSS treatment. A brain functional network connectivity mechanism may be involved in perimenopausal depression, wherein the hippocampal tricarboxylic acid cycle plays a vital role.

The effects of Korean Red Ginseng on stress-related neurotransmitters and gene expression: A randomized, double-blind, placebo-controlled trial

Background

Korean Red Ginseng (KRG) is an effective anti-stress treatment. In this study, we investigated the therapeutic potential effects of KRG on relieving stress in a general population using transcriptome analysis.

Methods

We conducted an 8-week clinical pilot study on 90 healthy men who reported stress. The study was completed by 43 participants in the KRG group and 44 participants in the placebo group. Participants were randomized 1:1 to the KRG and placebo groups. We evaluated the stress by stress response inventory (SRI) at baseline and 8 weeks. The main outcomes were changes in the levels of neurotransmitters (NTs) and NT-related gene expression. NTs were analyzed using automated (GC) content, and levels of gene expression were measured by reads per kilobase of transcript per million mapped reads (RPKM).

Results

The KRG group showed significantly preserved epinephrine decrease compared with placebo group at 8 weeks (changes in epinephrine, KRG vs. placebo; -1623.2 ± 46101.5 vs. -35116.3 ± 86288.2, p = 0012). Among subjects who higher SRI score, meaning stress increased compared to baseline, the KRG group showed a smaller decrease in serotonin than the placebo group (changes in serotonin, KRG vs. placebo; -2627.5 ± 5859.1 vs, -8087.4 ± 7162.4, p = 0.005) and a smaller increase in cortisol than the placebo group (changes in cortisol, KRG vs. placebo; 1912.7 ± 10097.75 vs. 8046.2 ± 8050.6 , p = 0.019) in subgroup analysis. Transcriptome findings indicated that KRG intake affects gene expression related with metabolism of choline, adrenalin, and monoamine.

Conclusion

These findings suggest that KRG has beneficial effects on the amelioration of stress response in NTs, and this effect is more prominent in stressful situations. Further clinical studies are required to confirm the anti-stress effect of KRG.

Pharmacokinetic analysis for simultaneous quantification of Saikosaponin A- paeoniflorin in normal and poststroke depression rats: A comparative study

Bupleurum and Paeonia are common compatibilities for the treatment of depression, most of which are used in classical prescriptions. The main active ingredients saikosaponin A (SSA) and paeoniflorin (PF) have significant therapeutic effects on poststroke depression (PSD). However, the pharmacokinetic (PK) behavior based on the combination of the two components has not been reported in rats. The aim of this study was to compare the pharmacokinetic characteristics of combined administration of SSA and PF in normal and PSD rats. Plasma samples were collected after SSA and PF were injected into the rat tail vein, and plasma pretreatments were analyzed by HPLC. Based on the concentration levels of SSA and PF in plasma, Drug and Statistics 3.2.6 (DAS 3.2.6) software was used to establish the blood drug concentration model. PK data showed that compared with the normal rats, the values of related parameters t_1/2α, AUC_(0-t), AUC_(0-∞) were decreased in diseased rats, while the values of CL₁ was increased. These findings suggest that PSD can significantly affect the PK parameters of SSA-PF. This study established a PK model to explore the time-effect relationship, in order to provide experimental and theoretical support for clinical application.

Total saponins of panax ginseng via the CX3CL1/CX3CR1 axis attenuates neuroinflammation and exerted antidepressant-like effects in chronic unpredictable mild stress in rats

Total saponins of Panax ginseng (TSPG) have antidepressant effects. However, the underlying antidepressant mechanism of TSPG remains not clear. This study aimed to predict the mechanism of TSPG by bioinformatics analysis and to verify it experimentally. Bioinformatics analysis showed that the antidepressant effects of TSPG may be related to inflammation, and CX3CL1/CX3CR1 may play a key mediating role. Wistar rats were exposed to chronic unpredictable mild stress (CUMS) for 6 weeks, and TSPG (50 mg/kg/d, 100 mg/kg/d) was administered throughout the modeling period. It was found that TSPG improves depressive behavior and reduces neuropathic damage in the hippocampus in rats. Meanwhile, TSPG decreased mRNA and protein expression of pro-inflammatory cytokines and CX3CL1/CX3CR1 and inhibited P38 and JNK protein phosphorylation in the hippocampus. Rat astrocytes were employed to explore further the potential mechanism of TSPG in regulating CX3CL1/CX3CR1. The results showed that CX3CL1 small interfering RNA (siRNA-CX3CL1) and CX3CR1 inhibitor (JMS-17-2) had similar effects to TSPG, that is, reduced inflammatory response, reactive oxygen species (ROS), and phosphorylation of P38 and JNK proteins, while overexpression of CX3CL1 (pcDNA-CX3CL1) counteracted the above effects of TSPG. It is suggested that the antidepressant effect of TSPG may be achieved through inhibition of CX3CL1/CX3CR1.

Ginseng total saponins and Fuzi total alkaloids exert antidepressant-like effects in ovariectomized mice through BDNF-mTORC1, autophagy and peripheral metabolic pathways

BACKGROUND

Shenfu decoction (SFD) is a classic Chinese medicine prescription that has a strong cardiotonic effect. The combination of ginseng (the dried root of Panax ginseng C. A. Meyer) and Fuzi (processed product of sub-root of Aconitum carmichaeli Debx), the main constituents of SFD, has been reported to improve the pharmacological effect of each other. Moreover, research has shown that the main active components of SFD, ginseng total saponins (GTS) and Fuzi total alkaloids (FTA), have antidepressant activity. However, the effects of these ingredients on depressive-like behavior induced by ovariectomy, a model of menopausal depression, have not been studied.

PURPOSE

Our research aims to elucidate the antidepressant-like effects of GTS and FTA compatibility (GF) in ovariectomized mice and the potential mechanisms.

METHODS

To elucidate the antidepressant-like effects of GF in mice in ovariectomy condition, behavioral tests were performed after 7 days of intragastric administration of different doses of GF. Underlying molecular mechanisms of CREB-BDNF, BDNF-mTORC1 and autophagy signaling were detected by western blotting, serum metabolites were examined by UPLC-QE plus-MS and dendritic spine density was determined by Golgi-Cox staining.

RESULTS

GF remarkably decreased the immobility time in the forced swim test. GF also increased levels of pCREB/CREB, BDNF, Akt, mTORC1 and p62 in the prefrontal cortex and hippocampus, as well as decreased LC3-II/LC3-I in the prefrontal cortex and hippocampus of ovariectomized mice. Furthermore, 15 serum differential metabolites (9 of which are lipids and lipid molecules) were identified by metabonomics. Next, the antidepressant-like effects of GF was blocked by rapamycin, an inhibitor of mTORC1. The antidepressant actions of GF on levels of pCREB, mTORC1, LC3-Ⅱ/LC3-Ⅰ and p62 in the prefrontal cortex and the levels of BDNF, Akt, mTORC1 and p62 in the hippocampus were inhibited by rapamycin, and the dendritic spines density was also regulated.

CONCLUSION

GF has antidepressant effects in ovariectomized mice, and like other antidepressants, these effects involve activation of BDNF-mTORC1, autophagy regulation and consequent effects on hippocampal synaptic plasticity. Moreover, metabolomic results suggest that GF also has effects on peripheral lipid profiles that may provide potential biomarkers for these antidepressant-like effects. These results indicate that GF is worthy of further exploration as a promising pharmaceutical treatment for depression. This study provides a new direction for the development of new indications for traditional Chinese medicine compounds.

Natural product-based pharmacological studies for neurological disorders

Central nervous system (CNS) disorders and diseases are expected to rise sharply in the coming years, partly because of the world's aging population. Medicines for the treatment of the CNS have not been successfully made. Inadequate knowledge about the brain, pharmacokinetic and dynamic errors in preclinical studies, challenges with clinical trial design, complexity and variety of human brain illnesses, and variations in species are some potential scenarios. Neurodegenerative diseases (NDDs) are multifaceted and lack identifiable etiological components, and the drugs developed to treat them did not meet the requirements of those who anticipated treatments. Therefore, there is a great demand for safe and effective natural therapeutic adjuvants. For the treatment of NDDs and other memory-related problems, many herbal and natural items have been used in the Ayurvedic medical system. Anxiety, depression, Parkinson's, and Alzheimer's diseases (AD), as well as a plethora of other neuropsychiatric disorders, may benefit from the use of plant and food-derived chemicals that have antidepressant or antiepileptic properties. We have summarized the present level of knowledge about natural products based on topological evidence, bioinformatics analysis, and translational research in this review. We have also highlighted some clinical research or investigation that will help us select natural products for the treatment of neurological conditions. In the present review, we have explored the potential efficacy of phytoconstituents against neurological diseases. Various evidence-based studies and extensive recent investigations have been included, which will help pharmacologists reduce the progression of neuronal disease.

Review of Herbal Medicines for the Treatment of Depression

Depression, a mental illness that is receiving increasing attention, is caused by multiple factors and genes and adversely affects social life and health. Several hypotheses have been proposed to clarify the pathogenesis of depression, and various synthetic antidepressants have been introduced to treat patients with depression. However, these drugs are effective only in a proportion of patients and fail to achieve complete remission. Recently, herbal medicines have received much attention as alternative treatments for depression because of their fewer side effects and lower costs. In this review, we have mainly focused on the herbal medicines that have been proven in clinical studies (especially randomized controlled trials and preclinical studies) to have antidepressant effects; we also describe the potential mechanisms of the antidepressant effects of those herbal medicines; the cellular and animal model of depression; and the development of novel drug delivery systems for herbal antidepressants. Finally, we objectively elaborate on the challenges of using herbal medicines as antidepressants and describe the benefits, adverse effects, and toxicity of these medicines.

Norlignans and phenolics from genus Curculigo protect corticosterone-injured neuroblastoma cells SH-SY5Y by inhibiting endoplasmic reticulum stress-mitochondria pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The plants of genus Curculigo are divided into the Section Curculigo and the Section Capitulata, which are mainly distributed in southeastern and southwestern China. Various ancient chinese books record that these plants were used as an important herb for tonifying kidney yang. Traditional Chinese medicine often draws on this property to treat depression syndrome. Thus genus Curculigo has potential for the treatment of neurodegenerative diseases (ND). The study showed that phenolics were the main characteristic components of plants in the Section Curculigo, represented by orcinol glucoside and curculigoside; the norlignans, with Ph-C5-Ph as the basic backbone, were the main characteristic components of the Section Capitulata. However, there is a lack of sufficient scientific evidence as to whether these two types of ingredients have neuroprotective effects.

AIM OF THE STUDY

To determine the neuroprotective effects of phenolics and norlignans in genus Curculigo on human neuroblastoma cells SH-SY5Y. To discuss their structure-activity relationship and screen for compounds with high activity and neuroprotective effects. To reveal that the amelioration of endoplasmic reticulum (ER) stress by two classes of compounds is mediated by the PERK/eIF2α/ATF4 pathway.

MATERIALS AND METHODS

The cytotoxicity of 17 compounds was assayed by MTT. SH-SY5Y cells were damaged by corticosterone (Cort) (200 μM) for 24 h and then co-administered with 17 compounds (0.1-100 μM) and Cort (200 μM) for 24 h. Cell survival was determined by MTT assay. Apoptosis rate, mitochondrial membrane potential (MMP) and intracellular reactive oxygen species (ROS) levels were detected using flow cytometry. Intracellular Ca²⁺ levels were detected using a fluorescent probe. Cellular mitochondrial and ER damage was observed using transmission electron microscopy (TEM). ER stress and apoptotic pathway-related proteins (BiP, CHOP, cleaved caspase-3, cleaved caspase-9, Bax/Bcl-2), and the expression level of PERK/eIF2α/ATF4 pathway was measured via western blot (WB).

RESULTS

The experimental data showed that Cort treatment of SH-SY5Y cells resulted in decreased cell survival and increased apoptosis, mitochondrial depolarization, ROS, and intracellular Ca²⁺ levels. The co-action of 17 compounds and Cort for a period of time significantly increased cell survival. Compounds 3, 7, 12, 13 also reduced apoptosis rate, mitochondrial depolarization, ROS and intracellular Ca²⁺ levels in the subsequent experiments. In addition, TEM observed that Cort caused mitochondrial and ER damage, and the damage was improved after treatment. WB analysis obtained that Cort increased the expression of apoptotic and ER stress-related proteins and activated pathway expression. However, in the presence of compounds 3, 7, 12, 13, the expression of BiP, CHOP, cleaved caspase-3, cleaved caspase-9, and Bax/Bcl-2 was significantly reduced, and the phosphorylation of PERK and eIF2α and the expression of ATF4 were inhibited.

CONCLUSION

This study found that one phenolic (3) and three norlignans (7, 12, 13) from genus Curculigo have significant neuroprotective effects. The results of the structure-activity relationship indicated that the glucosyl polymeric norlignans and the phenolics with benzoic acid as the parent nucleus were more active. The neuroprotective effect of three norlignans is the latest discovery. This finding has important research value in the field of prevention and treatment of neurodegenerative diseases.

Fluoxetine improves bone microarchitecture and mechanical properties in rodents undergoing chronic mild stress - an animal model of depression

Depression is one of the most prevalent mental disorders associated with reductions in bone mineral density and increased fracture risk. Fluoxetine is a highly prescribed selective serotonin reuptake inhibitor (SSRI) in the treatment of depression and is reported to be a risk factor for fractures. The present study examined the effect of fluoxetine on bone microarchitecture and the mechanical properties under chronic mild stress (CMS), a rodent model of depression. Thirty-one 6-9 week-old rats were allocated to 4 groups: 1) CMS + fluoxetine group (n = 10), 2) fluoxetine-only group (n = 5), 3) CMS + placebo group (n = 10) and 4) control group (no CMS and treatment) (n = 6). After 16 weeks, bone microarchitecture of the distal femur was analyzed by µCT. Mechanical properties were assessed by the three-point bending test, and antidepressant efficacy was determined by sucrose preference and forced swimming tests. Significant correlations were found between volume of sucrose intake and bone volume/tissue volume (BV/TV) (p = 0.019) and elastic absorption energy (p = 0.001) in the fluoxetine only group. The fluoxetine-only group showed significantly higher in the second moment of area in y-direction (p = 0.0298), horizontal outer diameter (mm) (p = 0.0488) and average midshaft thickness (mm) (p = 0.00047) than control group. Comparing with the control group, there was a significant reduction in trabecular number (Tb.N) in the CMS + fluoxetine group (p = 0.026) but not the fluoxetine-only group (p > 0.05). Significant increases in trabecular separation were observed in the metaphysis of CMS + placebo (p = 0.003) and CMS + fluoxetine (p = 0.004) groups when compared to the control group but not in the fluoxetine-only group (p > 0.05). During the three-point bending test, the fluoxetine-only group demonstrated significantly higher structural strength than controls (p = 0.04). Micro computed tomography (µCT) slices showed loss of trabecular bone in the metaphysis region of the CMS + fluoxetine and CMS + placebo groups but not the fluoxetine-only and control groups. In an animal model of depression, the adverse effect on the bone microarchitecture was caused by CMS but not by fluoxetine. Without exposure to CMS, fluoxetine significantly increased the cross-sectional area, trabecular bone area, structural strength and osteoblasts / bone area as compared to control condition.

Antidepressant Active Ingredients From Chinese Traditional Herb Panax Notoginseng: A Pharmacological Mechanism Review

Depression is one of the most common mental illnesses in the world and is highly disabling, lethal, and seriously endangers social stability. The side effects of clinical drugs used to treat depression are obvious, and the onset time is longer. Therefore, there is a great demand for antidepressant drugs with better curative effects, fewer side effects, and shorter onset time. Panax notoginseng, a Chinese herbal medication, has been used to treat depression for thousands of years and shown to have a therapeutic effect on depression. This review surveyed PubMed’s most recent 20 years of research on Panax notoginseng’s use for treating depression. We mainly highlight animal model research and outlined the pathways influenced by medicines. We provide a narrative review of recent empirical evidence of the anti-depressive effects of Panax Notoginseng and novel ideas for developing innovative clinical antidepressants with fewer side effects.

Trehalose ameliorates prodromal non-motor deficits and aberrant protein accumulation in a rotenone-induced mouse model of Parkinson's disease

Trehalose has been recently revealed as an attractive candidate to prevent and modify Parkinson's disease (PD) progression by regulating autophagy; however, studies have only focused on the reduction of motor symptoms rather than the modulation of disease course from prodromal stage. This study aimed to evaluate whether trehalose has a disease-modifying effect at the prodromal stage before the onset of a motor deficit in 8-week-old male C57BL/6 mice exposed to rotenone. We found significant decrease in tyrosine hydroxylase immunoreactivity in the substantia nigra and motor dysfunction after 2 weeks rotenone treatment. Mice exposed to rotenone for a week showed an accumulation of protein aggregates in the brain and prodromal non-motor deficits, such as depression and olfactory dysfunction, prior to motor deficits. Trehalose significantly improved olfactory dysfunction and depressive-like behaviors and markedly reduced α-synuclein and p62 deposition in the brain. Trehalose further ameliorated motor impairment and loss of nigral tyrosine hydroxylase-positive cells in rotenone-treated mice. We demonstrated that prodromal non-motor signs in a rotenone-induced PD mouse model are associated with protein aggregate accumulation in the brain and that an autophagy inducer could be valuable to prevent PD progression from prodromal stage by regulating abnormal protein accumulation.

Antidepressant-Like Effect and Mechanism of Ginsenoside Rd on Rodent Models of Depression

Background

There is growing evidence to suggest that ginsenoside Rd (GRd) has a therapeutic effect on depression, but the specific mechanisms behind its activity require further study.

Objective

This study is designed to investigate the antidepressant-like effect and underlying mechanisms of GRd.

Methods

In this study, the behavioral despair mouse model of depression and chronic unpredictable mild stress (CUMS) rat model of depression were established to explore the effects of GRd on depression-like behavior and its underlying mechanisms. Behavioral tests were used to evaluate the replication of animal models and depression-like behaviors. The hypoxia-inducible factor-1α (HIF-1α) blocker 2-methoxyestradiol (2-ME) was injected to determine the role of HIF-1α in the antidepressant-like effect of GRd. In addition, molecular biology techniques were used to determine the mRNA and protein expression of HIF-1ɑ signaling pathway and synaptic plasticity-related regulators, that is synapsin 1 (SYN 1) and postsynaptic density protein 95 (PSD 95). In silico binding interaction studies of GRd with focused target proteins were performed using molecular docking to predict the affinity and optimal binding mode between ligands and receptors.

Results

Our data show that GRd significantly reversed depression-like behavior and promoted mRNA and protein expression of HIF-1ɑ signaling pathway and synaptic plasticity-related regulators. However, the antidepressant-like effect of GRd disappeared upon inhibition of HIF-1α expression following administration of 2-ME. Furthermore, molecular docking results showed that GRd possessed significant binding affinity for HIF-1α, VEGF, and VEGFR-2.

Conclusion

Our results show that GRd exhibits significant antidepressant-like effect and that HIF-1α signaling pathway is a promising target for the treatment of depression.

Behavioral tests for evaluating the characteristics of brain diseases in rodent models: Optimal choices for improved outcomes (Review)

Behavioral assessment is the dominant approach for evaluating whether animal models of brain diseases can successfully mimic the clinical characteristics of diseases. At present, most research regarding brain diseases involves the use of rodent models. While studies have reported numerous methods of behavioral assessments in rodent models of brain diseases, each with different principles, procedures, and assessment criteria, only few reviews have focused on characterizing and differentiating these methods based on applications for which they are most appropriate. Therefore, in the present review, the representative behavioral tests in rodent models of brain diseases were compared and differentiated, aiming to provide convenience for researchers in selecting the optimal methods for their studies.

Epigenetic Mechanism of 5-HT/NE/DA Triple Reuptake Inhibitor on Adult Depression Susceptibility in Early Stress Mice

Major depressive disorder (MDD) is a chronic, remitting and debilitating disease and the etiology of MDD is highly complicated that involves genetic and environmental interactions. Despite many pharmacotherapeutic options, many patients remain poorly treated and the development of effective treatments remains a high priority in the field. LPM570065 is a potent 5-hydroxytryptamine (5-HT), norepinephrine (NE) and dopamine (DA) triple reuptake inhibitor and both preclinical and clinical results demonstrate significant efficacy against MDD. This study extends previous findings to examine the effects and underlying mechanisms of LPM570065 on stress vulnerability using a "two-hit" stress mouse model. The "two-hit" stress model used adult mice that had experienced early life maternal separation (MS) stress for social defeat stress (SDS) and then they were evaluated in three behavioral assays: sucrose preference test, tail suspension test and forced swimming test. For the mechanistic studies, methylation-specific differentially expressed genes in mouse hippocampal tissue and ventral tegmental area (VTA) were analyzed by whole-genome transcriptome analysis along with next-generation bisulfite sequencing analysis, followed by RT-PCR and pyrophosphate sequencing to confirm gene expression and methylation. LPM570065 significantly reversed depressive-like behaviors in the mice in the sucrose preference test, the tail suspension test, and the forced swimming test. Morphologically, LPM570065 increased the density of dendritic spines in hippocampal CA1 neurons. Hypermethylation and downregulation of oxytocin receptor (Oxtr) in the hippocampal tissues along with increased protein expression of Dnmt1 and Dnmt3a in mice that experienced the "two-hit" stress compared to those that only experienced adulthood social defeat stress, and LPM570065 could reverse these changes. Combined, these results suggest that methylation specificity of the gene Oxtr in the hippocampus may play an important role in early life stress-induced susceptibility to depression and that the5-HT/NE/DA triple reuptake inhibitor LPM570065 may reduce depression susceptibility via the reversal of the methylation of the gene Oxtr.

Complex Effects of Sertraline and Citalopram on In Vitro Murine Breast Cancer Proliferation and on In Vivo Progression and Anxiety Level

Some selective serotonin reuptake inhibitors (SSRIs), primarily sertraline, demonstrate anti-proliferative activity in malignant cell-lines and in xenografted mouse models of colorectal tumor. There is, however, a paucity of comparative studies on the anti-tumor effects of SSRIs. We compared the in vitro and in vivo effects of sertraline and citalopram on murine 4T1 breast cancer. Grafted mice were used to determine the rate of tumor growth and survival as well as the impact of stress and antidepressant treatment on tumor progression and mortality and on pro-inflammatory cytokines. Sertraline, in the micromolar range, but not citalopram, induced a significant in vitro concentration-dependent inhibition of murine 4T1 cell proliferation and splenocyte viability. In contrast, sertraline (10 mg/kg/d), enhanced in vivo tumor growth. Contrary to the study's hypothesis, chronic mild stress did not modify tumor growth in grafted mice. The in vitro effects of sertraline on tumor growth seem to be the opposite of its in vivo effects. The impact of sertraline treatment on humans with breast cancer should be further investigated.

Ginsenosides in central nervous system diseases: Pharmacological actions, mechanisms, and therapeutics

The nervous system is one of the most complex physiological systems, and central nervous system diseases (CNSDs) are serious diseases that affect human health. Ginseng (Panax L.), the root of Panax species, are famous Chinese herbs that have been used for various diseases in China, Japan, and Korea since ancient times, and remain a popular natural medicine used worldwide in modern times. Ginsenosides are the main active components of ginseng, and increasing evidence has demonstrated that ginsenosides can prevent CNSDs, including neurodegenerative diseases, memory and cognitive impairment, cerebral ischemia injury, depression, brain glioma, multiple sclerosis, which has been confirmed in numerous studies. Therefore, this review summarizes the potential pathways by which ginsenosides affect the pathogenesis of CNSDs mainly including antioxidant effects, anti-inflammatory effects, anti-apoptotic effects, and nerve protection, which provides novel ideas for the treatment of CNSDs.

Protective Effect of Total Panax Notoginseng Saponins on Retinal Ganglion Cells of an Optic Nerve Crush Injury Rat Model

Irreversible loss of retinal ganglion cells (RGCs) is a common pathological feature of various optic nerve degenerative diseases such as glaucoma and ischemic optic neuropathy. Effective protection of RGCs is the key to successful treatment of these diseases. Total Panax notoginseng saponins (TPNS) are the main active component of Panax notoginseng, which has an inhibitory effect on the apoptosis pathway. This study is aimed at assessing the protective effect of TPNS on RGCs of the optic nerve crush (ONC) model of rats and exploring the underlying mechanisms. The intraperitoneal or intravitreal injection of TPNS was used based on the establishment of the rat ONC model. Fifteen days after the injury, the cell membrane fluorescent probe (Fluoro-Gold) was applied to retrograde RGCs through the superior colliculus and obtain the number of surviving RGCs. TUNEL assay was also used to detect the number and density of RGC apoptosis after the ONC model. The expression and distribution of Bcl-2/Bax, c-Jun/P-c-Jun, and P-JNK in the retina were demonstrated by Western blot analysis. After the intervention of TPNS, the rate of cell survival increased in different retinal regions (p < 0.05) and the number of apoptosis cells decreased. Regarding the expression of Bcl-2/Bax, c-Jun/P-c-Jun, and P-JNK-related apoptotic proteins, TPNS can reduce the level of apoptosis and play a role in protecting RGCs (p < 0.05). These findings indicate that topical administration of TPNS can inhibit cell apoptosis and promote RGC survival in the crushed optic nerve.

Melatonin Improves Short-Term Spatial Memory in a Mouse Model of Alzheimer's Disease

INTRODUCTION

Alzheimer's disease (AD) is a neurodegenerative disease that has become a leading cause of death in recent years. Impairments in spatial learning and memory are an important clinical feature of AD. Melatonin (MLT), the main product secreted by the pineal gland, showed multiple antioxidant, anti-inflammatory, and neuroprotective properties.

PURPOSE

The present study aimed to explore the possible prophylactic effects of MLT against spatial memory deficits in a sporadic mouse model of AD induced by D-galactose and aluminium chloride (AlCl3).

METHODS

Four groups of mice (n = 10 per group) were prepared: control, AD (the D-galactose and AlCl3 AD model group), AD+MLT (AD mice treated with 80 mg/kg MLT), and AD+DON (AD mice treated with 3 mg/kg donepezil). We then used the object location and Y-maze tests to assess spatial memory in the four groups. Gene expression levels of brain-derived neurotrophic factor (Bdnf) and cAMP-responsive element-binding protein (Creb1) were measured using real-time polymerase chain reaction.

RESULTS

We found that MLT improved spatial memory in the sporadic AD mice. MLT ameliorated Creb1 gene expression and significantly increased Bdnf gene expression in the hippocampus of AD model mice compared with the AD group.

CONCLUSION

MLT could have a substantial potential to alleviate memory impairment in sporadic AD if introduced at early stages.

The effect of ginsenosides on depression in preclinical studies: A systematic review and meta-analysis

BACKGROUND

Many ginsenosides have been shown to be efficacious for major depressive disorder (MDD), which is a highly recurrent disorder, through several preclinical studies. We aimed to review the literature assessing the antidepressant effects of ginsenosides on MDD animal models, to establish systematic scientific evidence in a rigorous manner.

METHODS

We performed a systematic review on the antidepressant effects of ginsenoside evaluated in in vivo studies. We searched for preclinical trials from inception to July 2019 in electronic databases such as Pubmed and Embase. In vivo studies examining the effect of a single ginsenoside on animal models of primary depression were included. Items of each study were evaluated by two independent reviewers. A meta-analysis was conducted to assess behavioral changes induced by ginsenoside Rg1, which was the most studied ginsenoside. Data were pooled using the random-effects models.

RESULTS

A total of 517 studies were identified, and 23 studies were included in the final analysis. They reported on many ginsenosides with different antidepressant effects and biological mechanisms of action. Of the 12 included articles assessing ginsenoside Rg1, pooled results of forced swimming test from 9 articles (mean difference (MD): 20.50, 95% CI: 16.13-24.87), and sucrose preference test from 11 articles (MD: 28.29, 95% CI: 22.90-33.69) showed significant differences compared with vehicle treatment. The risk of bias of each study was moderate, but there was significant heterogeneity across studies.

CONCLUSION

These estimates suggest that ginsenosides, including ginsenoside Rg1, reduces symptoms of depression, modulates underlying mechanisms, and can be a promising antidepressant.

Effectiveness and Tolerability of Korean Red Ginseng Augmentation in Major Depressive Disorder Patients with Difficult-to-treat in Routine Practice

Objective

: To test clinical effectiveness and tolerability of Korean Red Ginseng augmentation (RGA) in major depressive disorder (MDD) patients with difficult-to-treat.

Methods

Thirty six patients were enrolled in this 6 weeks, prospective, clinical trial. Rating scales were MontgomeryÅsberg Depression Rating Scale (MADRS), Patient Health Questionnaire-15, Clinical Global Impression-improvement (CGI-I), and Patient Satisfaction Score. The primary endpoint was a remission rate measured by MADRS score at the end of study (≤ 10). Clinical outcomes and tolerability were assessed at baseline, week 2, and week 6.

Results

Among 36 patients, 26 patients completed the study and 28 patients had post-baseline visit data. The remission rate by MADRS score was 39.3% (11/28) and 57.1% by CGI-I scores of 1 or 2 at the end of the study. The mean change of MADRS score was significantly decreased by 44.4% from baseline to the end of study. The most frequent adverse events were headache (7/28, 25.0%) during the study.

Conclusion

Our study indicates the putative effectiveness and tolerability of RGA for treating MDD with difficult-to-treat in clinical practice. However, adequately powered, randomized, controlled trials will be needed to confirm these results.

Possible Involvement of N-methyl-D-aspartate Receptor (NMDA-R) in the Antidepressant- like Effect of Trigonelline in Male Mice

Background and Aim:

Depression is a mood disorder with high global prevalence. Depression is associated with a reduction in the hippocampal volume and change in its neurotransmitters function. Trigonelline is an alkaloid with neuroprotective activity. The aim of this study was to investigate the possible role of N-methyl-Daspartate (NMDA) receptor in the antidepressant-like effect of trigonelline, considering histopathological modifications of the hippocampus.

Methods:

60 Naval Medical Research Institute (NMRI) male mice were divided into 6 groups including group 1 (normal saline), groups 2, 3 and 4 (trigonelline at doses of 10, 50 and 100 mg/kg), group 5 (effective dose of trigonelline plus NMDA agonist) and group 6 (sub-effective dose of trigonelline plus NMDA antagonist). Forced swimming test (FST) was used to assess depressive-like behavior. Hippocampi were separated under deep anesthesia and used for histopathological evaluation as well as NMDA receptor gene expression assessment.

Results:

Trigonelline at doses of 10, 50 and 100 significantly reduced the immobility time in the FST in comparison to the control group. The administration of the sub-effective dose of trigonelline plus ketamine (an NMDA receptor antagonist) potentiated the effect of the sub-effective dose of trigonelline. In addition, co-treatment of an effective dose of trigonelline with NMDA mitigated the antidepressant-like effect of trigonelline. Trigonelline at doses of 50 and 100 mg/kg significantly increased the diameter of the CA1 area of the hippocampus.

Conclusion:

Trigonelline showed an antidepressant-like effect in mice, probably via attenuation of NMDA receptor activity and an increase in the CA1 region of the hippocampus.

Effect of combined chronic predictable and unpredictable stress on depression-like symptoms in mice

Background

Mental stress mainly induces depression, and predictable stress, as well as a constant bombardment of chronic unpredictable micro-stressors, always coexist in daily life. However, the combined effect of predictable and unpredictable stress on depression is still not fully understood.

Methods

The chronic restraint stress (CRS) is to restrain the mice for 6 h per day for 3 weeks, and the chronic unpredictable mild stress (CUMS) is to stimulate the mice with 7 different stressors for 3 weeks. We evaluated the combined effect of CRS and CUMS on depression-like symptoms using behavioral tests and investigated the action mechanism through analysis of neurotransmitters, brain-derived factors, inflammatory factors, antioxidants, and intestinal microorganisms.

Results

Our data suggested the combined stress of CRS and CUMS caused significant weight loss, food intake reduction, depression-like behaviors-including anhedonia, learned helplessness, and reduction in spontaneous activity-and even atrophy and severe structural damage to the hippocampus in mice. Our pathogenesis study showed that combined stress-induced the reduction of glucocorticoid receptor (GR) levels, loss of oligodendrocytes (NG2 and Olig2 cells), and inhibition of neuron proliferation in the CA1, CA3, and DG regions of the hippocampus, decreased the contents of monoamine neurotransmitters (5-HT and NE) and BDNF in the cerebral cortex, caused hyperactivity of the HPA system, led to immune dysfunction, aggravated oxidative stress, and weakened the capacity of antioxidants in mice. Compared with single stress, combined stress gave rise to a more significant diversity change of the gut microbiota.

Conclusions

Combined stress caused significant depression-like behaviors, atrophy, and severe structural damage to the hippocampus in mice via monoamine neurotransmitter, BDNF, HPA axis, neurogenesis, and neurodegenerative, immune, oxidative stress and gut-brain axis action pathways.

Korean Red Ginseng prevents posttraumatic stress disorder-triggered depression-like behaviors in rats via activation of the serotonergic system

Background

Posttraumatic stress disorder (PTSD), a mental disorder induced by traumatic stress and often accompanied by depression and/or anxiety, may involve an imbalance in the neurotransmitters associated with the fear response. Korean Red Ginseng (KRG) has long been used as a traditional medicine and is known to be involved in a variety of pharmacological activities. We used the open field test and forced swimming test to examine the effects of KRG on the depression-like response of rats after exposure to single prolonged stress (SPS), leading to activation of the serotonergic system.

Methods

Male rats received KRG (30, 50, and 100 mg/kg, intraperitoneal injection) once daily for 14 days after exposure to SPS.

Results

Daily KRG administration significantly improved depression-like behaviors in the forced swimming test, increased the number of lines crossed and time spent in the central zone in the open field test, and decreased freezing behavior in contextual and cued fear conditioning. KRG treatment attenuated SPS-induced decreases in serotonin (5-HT) tissue concentrations in the hippocampus and medial prefrontal cortex. The increased 5-HT concentration during KRG treatment may be partially attributable to the 5-hydroxyindoleacetic acid/5-HT ratio in the hippocampus of rats with PTSD. These effects may be caused by the activation of hippocampal genes encoding tryptophan hydroxylase-1 and 2 mRNA levels.

Conclusion

Our findings suggest that KRG has an antidepressant effect in rats subjected to SPS and may represent an effective use of traditional medicine for the treatment of PTSD.

Rutin via Increase in the CA3 Diameter of the Hippocampus Exerted Antidepressant-Like Effect in Mouse Model of Maternal Separation Stress: Possible Involvement of NMDA Receptors

Methods

Mouse neonates were exposed to MS paradigm 3 hours daily from postnatal days (PND) 2 to 14. The control and MS mice were divided separately into 16 groups (n = 8) (8 groups for each set) including mice that received normal saline, mice that received rutin at doses of 10, 50, and 100 mg/kg, mice that received NMDA at a dose of 150 mg/kg, mice that received ketamine (NMDA antagonist) at a dose of 0.25 mg/kg, mice that received NMDA antagonist plus a subeffective dose of rutin, and mice that received NMDA plus an effective dose of rutin. Forced swimming test (FST) was performed. Afterwards, the hippocampus was evaluated in cases of histopathological changes as well as expression of NR2A and NR2B genes.

Results

Rutin significantly reduced immobility time in the FST. The expression of NR2A and NR2B subunits of NMDA receptor in MS mice was significantly higher than that in the control group. Rutin significantly decreased the expression of NR2B and NR2A subunits in the hippocampus. The CA3 diameter and percentage of dark neurons in the hippocampus of MS mice significantly decreased and increased, respectively, which partially reversed following rutin administration.

Conclusion

Rutin, partially, through a neuroprotective effect on the hippocampus exerted antidepressant-like effect. We concluded that NMDA receptors, at least in part, mediated the beneficial effect of rutin.

Potency of Selected Berries, Grapes, and Citrus Fruit as Neuroprotective Agents

A healthy diet should nourish the brain with essential nutrients, including bioactive compounds, for normal brain functioning and to protect it from the negative effects of inflammation and oxidative stress. In this review, a concise summation of the protective effects of selected fruits, namely, berries, grapes, and citrus fruits, against neurological disorder is presented. The focus is on the neuroprotective potential of these fruits against neurodegenerative and mental disorders. The fruits selection was based on the vast reported pharmacological studies on their neuroprotection efficacies. Hence, the respective knowledge and limitations are discussed based on the biological and pharmacological evidence compiled from the previously reported laboratory, epidemiology, and intervention trials.

Constitutive and Stress-Induced Psychomotor Cortical Responses to Compound K Supplementation

Isolated ginsenoside metabolites such as Compound K (CK) are of increasing interest to consumer and clinical populations as safe and non-pharmacological means to enhance psychomotor performance constitutively and in response to physical or cognitive stress. Nevertheless, the influence of CK on behavioral performance and EEG measures of cortical activity in humans is undetermined. In this double-blinded, placebo-controlled, counterbalanced within-group study, dose-dependent responses to CK (placebo, 160 and 960 mg) were assessed after 2 weeks of supplementation in nineteen healthy men and women (age: 39.9 ± 7.9 year, height 170.2 ± 8.6 cm, weight 79.7 ± 11.9 kg). Performance on upper- and lower-body choice reaction tests (CRTs) was tested before and after intense lower-body anaerobic exercise. Treatment- and stress-related changes in brain activity were measured with high-density EEG based on event-related potentials, oscillations, and source activity. Upper- (−12.3 ± 3.5 ms, p = 0.002) and lower-body (−12.3 ± 4.9 ms, p = 0.021) response times improved after exercise, with no difference between treatments (upper: p = 0.354; lower: p = 0.926). Analysis of cortical activity in sensor and source space revealed global increases in cortical arousal after exercise. CK increased activity in cortical regions responsible for sustained attention and mitigated exercise-induced increases in arousal. Responses to exercise varied depending on task, but CK appeared to reduce sensory interference from lower-body exercise during an upper-body CRT and improve the general maintenance of task-relevant sensory processes.

Garlic essential oil mediates acute and chronic mild stress-induced depression in rats via modulation of monoaminergic neurotransmission and brain-derived neurotrophic factor levels

Garlic essential oil (GEO) and its major organosulfur component (diallyl disulfide, DADS) possess diverse biological properties; however, limited information on their antidepressant-like effects is available. This study is the first to investigate these effects of GEO using the forced swimming test (FST) and unpredictable chronic mild stress (UCMS) induced depression in rats. After oral administration for 28 consecutive days, GEO (25 and 50 mg per kg bw) significantly reduced the immobility time in the FST. Additionally, GEO and DADS significantly reversed the sucrose preference index decrease induced by 5 weeks of UCMS. GEO (25 mg per kg bw) effectively decreased the frontal cortex turnover ratio of serotonin (5-HT) and dopamine (DA), thus increasing the 5-HT and DA levels, with no hippocampal effects. Chronic GEO treatment increased hippocampal brain-derived neurotrophic factor (BDNF), c-AMP response element binding protein (CREB), and protein kinase B (AKT) expression, exhibiting its effects via monoamine neurotransmitter modulation and the BDNF-related signaling pathway.

Insights into gastrointestinal microbiota-generated ginsenoside metabolites and their bioactivities

The gastrointestinal microbiota and host co-evolve into a complex 'super-organism,' and this relationship plays a vital role in many physiological processes, such as drug metabolism. Ginseng is an important medicinal resource and the main ingredients are ginsenosides, which are less polar, difficult to absorb, and have low bioavailability. However, studies have shown that the biological activity of ginsenosides such as compound K (CK), ginsenoside Rg3 (Rg3), ginsenoside Rh2 (Rh2), 20(S)-protopanaxatriol (20(S)-PPT), and 20(S)-protopanaxadiol (20(S)-PPD) is closely related to the gastrointestinal microbiota. In this paper, the metabolic pathway of gastrointestinal microbiota-generated ginsenosides and the main pharmacological effects of these metabolites are discussed. Furthermore, our study provides a new insight into the discovery of novel drugs. Specifically, in new drug screening process, candidates with low biological activity and bioavailability should not be excluded. Because their metabolites may exhibit good pharmacological effects due to the involvement of the gastrointestinal microbiota. In addition, in further research studies to develop probiotics, a combination of agents could exert greater efficacy than single agents. Moreover, differences in lifestyle and diet lead to differences in the gastrointestinal microbiota in the human body. Therefore, administration of the same drug dose to different individuals could elicit different therapeutic effects, owing to the involvement of the gastrointestinal microbiota. Thus, treatment accuracy could be achieved by detecting the gastrointestinal microbiota before drug treatment.HighlightsGastrointestinal microbiota plays a decisive role in bioactivities of ginsenosides.The metabolic pathway and main pharmacological effects of ginsenoside metabolites are discussed.It provides new insights into novel drug discovery and further research to find probiotic, combinations to exert greater efficacy.Differences in lifestyle and diet, varies the gastrointestinal microbiota in the human body. However, the same dose of a drug producing different therapeutic effects may involve gastrointestinal microbiota.

Ginsenoside Rg1 ameliorates the cognitive deficits in D-galactose and AlCl3-induced aging mice by restoring FGF2-Akt and BDNF-TrkB signaling axis to inhibit apoptosis

Ginsenoside Rg1 is the main active ingredient of Panax ginseng with the activity of neuroprotective, antioxidant and strengthening the immune system. Therefore, we hypothesized that Rg1 may afford anti-aging effects although the mechanism remains to be elucidated. In this study, chemically induced aging mice were established by consecutive administration of D-galactose and AlCl₃. We found that Rg1 effectively ameliorates spatial learning and memory deficits in aging mice demonstrated by their improved performance in step down avoidance tests and Morris water maze experiments. Rg1 restored aging-induced decline of FGF2 and BDNF, reactivated TrkB/Akt signaling pathways in the hippocampus and prefrontal cortex to inhibit apoptosis, for the expression of anti-apoptotic protein Bcl-2 and apoptosis promoting enzyme cleaved-Caspase3 were antagonistically restored. Therefore, these results established the anti-aging effects of Rg1, and FGF2, BDNF and associated signaling pathways might be promising targets. Our data may provide a new avenue to the pharmacological research and diet therapeutic role of ethnic products such as Rg1 in anti-aging and aging associated diseases.

Mental energy: plausible neurological mechanisms and emerging research on the effects of natural dietary compounds

Objective: Lack of mental energy is one of the leading reasons adults turn to dietary supplements, with three out of ten supplement users hoping to improve their energy level; even more consume caffeine-containing products for the same reason. Despite this interest from consumers, there is no consensus scientific definition of mental energy or sole validated instrument for measuring it. We performed this review to summarize main findings from research regarding the influence of natural dietary compounds on three aspects of mental energy: cognition (vigilance), motivation (to do mental work), and mood (feelings of energy and/or absence of feelings of fatigue).Methods: A narrative review of key papers.Results: In addition to caffeine, a number of other compounds, including the polyphenols, which are found in all plant-derived products, and the phytochemicals in culinary herbs and herbal products such as Panax ginseng and Ginkgo biloba, have been shown in animal models to modulate neurotransmitter activity potentially relevant to mental energy. Inadequate intake of B vitamins could also potentially have a negative effect on mental energy due to their role in overall energy production, as precursors of key cofactors in the citric acid cycle, as well as their role in brain function and neurotransmitter synthesis. Consumption of some of these products may have direct or indirect effects on one or more elements of mental energy.Conclusion: Large, prospective clinical trials of these products using appropriate, validated instruments designed to measure mental energy may be worthwhile if sufficient evidence exists to justify such trials.

Mechanisms of Panax ginseng action as an antidepressant

OBJECTIVES

Panax ginseng, a well-known traditional Chinese medicine with multiple pharmacological activities, plays a crucial role in modulating mood disorders. Several recent studies have identified an underlying role of Panax ginseng in the prevention and treatment of depression. However, the cellular and molecular mechanisms remain unclear.

MATERIALS AND METHODS

In this review, we summarized the recent progress of antidepressant effects and underlying mechanisms of Panax ginseng and its representative herbal formulae.

RESULTS

The molecular and cellular mechanisms of Panax ginseng and its herbal formulae include modulating monoamine neurotransmitter system, upregulating the expression of neurotrophic factors, regulating the function of HPA axis, and anti-inflammatory action.

CONCLUSIONS

Therefore, this review may provide theoretical bases and clinical applications for the treatment of depression by Panax ginseng and its representative herbal formulae.

Genetically modified rice produces ginsenoside aglycone (protopanaxadiol)

MAIN CONCLUSION

Protopanaxadiol is dammarane-type tetracyclic triterpene sapogenin found in ginseng and has a high medicinal values. We successfully constructed transgenic rice producing protopanaxadiol by introducing the ginseng PgDDS and CYP716A47 genes in this crop plant. Protopanaxadiol (PPD), an aglycone of ginsenosides, possesses pleiotropic anticarcinogenesis activities in many cancers. Here, we constructed transgenic rice overexpressing the Panax ginseng dammarenediol-II synthase gene (PgDDS) and protopanaxadiol synthase gene (CYP716A47) driven by a rice endosperm-specific α-globulin promoter. Among more than 50 independent lines, five transgenic lines were selected. The introduction of the genes in the T1 generation of the transgenic lines was confirmed by genomic PCR. The expression of the introduced genes in T2 seeds was confirmed by qPCR. Methanol extracts of transgenic rice grains were analyzed by LC/MS to detect the production of PPD and dammarenediol-II (DD). The production of both PPD and DD was identified not only by comparing the retention times but also mass fraction patterns of authentic PPD and DD standards. The mean concentrations of PPD and DD in rice grains were 16.4 and 4.5 µg/g dry weight, respectively. The invention of genetically engineered rice grains producing PPD and DD can be applied to rice breeding to reinforce new medicinal values.

Antidepressant effects of ginsenoside Rf on behavioral change in the glial degeneration model of depression by reversing glial loss

Background

Depression is a common neuropsychiatric disease that shows astrocyte pathology. Ginsenoside Rf (G-Rf) is a saponin found in Panax ginseng which has been used to treat neuropsychiatric diseases. We aimed to investigate antidepressant properties of G-Rf when introduced into the L-alpha-aminoadipic acid (L-AAA)–infused mice model which is representative of a major depressive disorder that features diminished astrocytes in the brain.

Methods

L-AAA was infused into the prefrontal cortex (PFC) of mice to induce decrease of astrocytes. Mice were orally administered G-Rf (20 mg/kg) as well as vehicle only or imipramine (20 mg/kg) as controls. Depression-like behavior of mice was evaluated using forced swimming test (FST) and tail suspension test (TST). We observed recovery of astroglial impairment and increased proliferative cells in the PFC and its accompanied change in the hippocampus by Western blot and immunohistochemistry to assess the effect of G-Rf.

Results

After injection of L-AAA into the PFC, mice showed increased immobility time in FST and TST and loss of astrocytes without significant neuronal change in the PFC. G-Rf–treated mice displayed significantly more decreased immobility time in FST and TST than did vehicle-treated mice, and their immobility time almost recovered to those of the sham mice and imipramine-treated mice. G-Rf upregulated glial fibrillary acidic protein (GFAP) expression and Ki-67 expression in the PFC reduced by L-AAA and also alleviated astroglial change in the hippocampus.

Conclusion

G-Rf markedly reversed depression-like behavioral changes and exhibited protective effect against the astrocyte ablation in the PFC induced by L-AAA. These protective properties suggest that G-Rf might be a therapeutic agent for major depressive disorders.

Social isolation and social support at adulthood affect epigenetic mechanisms, brain-derived neurotrophic factor levels and behavior of chronically stressed rats

Epigenetic modulation of brain-derived neurotrophic factor (BDNF) provides one possible explanation for the dysfunctions induced by stress, such as psychiatric disorders and cognitive decline. Interestingly, social support can be protective against some of these effects, but the mechanisms of social buffering are poorly understood. Conversely, early isolation exacerbates the responses to stressors, although its effects in adulthood remain unclear. This study investigated the effects of social isolation and social buffering on hippocampal epigenetic mechanisms, BDNF levels and behavioral responses of chronically stressed young adult rats. Male Wistar rats (3 months) were assigned to accompanied (paired) or isolated housing. After one-month half of each group was submitted to a chronic unpredictable stress (CUS) protocol for 18 days. Among accompanied animals, only one was exposed to stress. Behavioral analysis encompassed the Open field, plus maze and inhibitory avoidance tasks. Hippocampal H3K9 and H4K12 acetylation, HDAC5 expression and BDNF levels were evaluated. Isolated housing increased HDAC5 expression, decreased H3K9 and H4K12 acetylation, reduced BDNF levels, and impaired long-term memory. Stress affected weight gain, induced anxiety-like behavior and decreased AcK9H3 levels. Interactions between housing conditions and social stress were seen only for HDAC5 expression, which showed a further increase in the isolated + CUS group but remained constant in accompanied animals. In conclusion, social isolation at adulthood induced epigenetic alterations and exacerbated the effects of chronic stress on HDAC5. Notwithstanding, social support counteracted the adverse effects of stress on HDAC5 expression.

LC-MS/MS-based quantification of tryptophan metabolites and neurotransmitters in the serum and brain of mice

l-Tryptophan (Trp) metabolites and related neurotransmitters play crucial roles in physiological functions, and their imbalances are implicated in the pathology of depression, Alzheimer's disease and other diseases. Measurement of Trp metabolites and related neurotransmitters possesses a great potential to elucidate the disease mechanisms and evaluate the outcomes of therapeutic interventions. A simple, rapid, sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous determination of Trp, l-kynurenine (Kyn), kynurenic acid (Kyna), 3-hydroxykynurenine (3-HK), 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), norepinephrine (NE), l-glutamic acid (Glu), γ-aminobutyric acid (GABA) and acetylcholine (ACh) in mice serum and the brain tissues in a single chromatographic run. Samples were spiked with the internal standard, mixed with trifluoroacetic acid to precipitate protein and analyzed by LC-MS/MS. Chromatographic separation was achieved using a Restek Ultra Aqueous C18 column in combination with a gradient elution within 8 min. Mass spectrometric detection was performed using multiple reaction monitoring with electrospray ionization source in positive mode. The method exhibited good selectivity and correlation coefficient values for the calibration curves of each analyte were >0.99. The limit of detection and quantification ranged from 0.96 to 24.48 nmol/L and 3.42 to 244.82 nmol/L, respectively. The intra- and inter-day precision were ≤13.92%. All analytes were stable in prepared samples at room temperature in the autosampler for 24 h. This method was successfully applied to the analysis of biological samples from control and chronic mild stress (CMS) induced depression mice. It was found that Kyn and 3-HK pathways were enhanced by CMS, while the levels of Trp, Kyna, 5-HIAA, Glu, GABA and ACh were significantly reduced. The changes in 5-HT and NE levels were not uniform in the periphery and the brain. This method can therefore be applied to analyze Trp metabolites and related neurotransmitters levels to monitor disease states, study the mechanisms and outcomes of therapeutic interventions.

Antidepressant-like activities of live and heat-killed Lactobacillus paracasei PS23 in chronic corticosterone-treated mice and possible mechanisms

Emerging evidence indicates that ingestion of specific probiotics, known as "psychobiotics", confer beneficial effects on mental health. This study investigated antidepressant-like effects and possible underlying mechanisms of Lactobacillus paracasei PS23 (PS23), live or heat-killed, in a mouse model of corticosterone-induced depression using fluoxetine as standard drug. PS23 were orally gavaged to mice from day 1 to 41 or fluoxetine from day 17 to 41 and injected with corticosterone from day 17 to 37. After the last corticosterone treatment, anxiety- and depression-like behaviors were tested within 4 days. On day 42, serum and brain tissue were collected 24 min after forced swim stress. Abnormal behavioral changes induced by corticosterone were ameliorated by treatment with live PS23 in open field and sucrose preference tests, with heat-killed PS23 in open field, forced swim and sucrose preference tests, and with fluoxetine in open field and forced swim tests. Furthermore, both live and heat-killed PS23 and fluoxetine reversed corticosterone-reduced protein levels of brain-derived neurotropic factor, mineralocorticoid, and glucocorticoid receptors in the hippocampus. In addition, live PS23 also reverses corticosterone-reduced serotonin levels in hippocampus, prefrontal cortex and striatum; whereas heat-killed PS23 reverses corticosterone-reduced dopamine levels in hippocampus and prefrontal cortex. And fluoxetine normalized reduced corticosterone level in serum. These studies showed that both live and heat-killed PS23 can reverse chronic corticosterone-induced anxiety- and depression-like behaviors and that may provide insights into the mechanism and a potential psychobiotic for depression management.

The Effect of Traditional Chinese Medicine Zhike-Houpu Herbal Pair on Depressive Behaviors and Hippocampal Serotonin 1A Receptors in Rats After Chronic Unpredictable Mild Stress

OBJECTIVE

Zhike-Houpu herbal pair (ZKHPHP) is a well-known Chinese medicine to treat gastrointestinal motility dysfunction. Recently, many researchers have found that some of the compounds of ZKHPHP such as meranzin hydrate and magnolol have antidepressant effects. However, little is known about the antidepressant mechanism of ZKHPHP. Therefore, the main aim of the study is to evaluate the antidepressant-like effects of ZKHPHP and its possible mechanism of action on 5-hydroxytryptamine receptor 1A (HTR1A) in the hippocampus CA1 region in rats exposed to chronic unpredictable mild stress.

METHODS

Male Sprague Dawley rats were randomly divided into the following six groups: normal, model, ZKHPHP (3 g/kg), ZKHPHP (10 g/kg), ZKHPHP (20 g/kg), and ZKHPHP (30 g/kg); n = 8 per group. We exposed the rats to chronic unpredictable mild stress and then assessed antidepressant-like effects of ZKHPHP by measuring weight change, observing the open-field test, and measuring sucrose water consumption. The antidepressant mechanism was examined by measuring the effect of ZKHPHP on HTR1A protein expression and HTR1A mRNA expression in the hippocampus CA1 region by using immunohistochemistry analysis, Western blotting, and real-time reverse transcription-polymerase chain reaction.

RESULTS

ZKHPHP (10 or 20 g/kg) reduced the incidence of depressive-like behaviors and increased HTR1A protein and HTR1A mRNA expression in the hippocampus CA1 in rats displaying depressive behavior, whereas ZKHPHP (3 or 30 g/kg) had no obvious effect on the measured depression indicators.

CONCLUSIONS

These data show that ZKHPHP has antidepressant-like effects based on a chronic unpredictable mild stress-induced depression model in rats. ZKHPHP may be attractive as an antidepressant because of its beneficial effects on depression and the absence of gastrointestinal dysregulation, which is a frequently observed unintended effect of many commonly used antidepressive medications.

Total saponins from the leaves of Panax notoginseng inhibit depression on mouse chronic unpredictable mild stress model by regulating circRNA expression

OBJECTIVES

Total saponins from the leaves of Panax notoginseng saponins (SLPN) could inhibit development of depression, but the underlying mechanisms remains unclear. This study aimed to address the roles of circular RNAs in depression inhibition by SLPN.

METHODS

The mouse chronic unpredictable mild stress (CUMS) model was established, which were confirmed by mouse weight, forced swimming test (FST) and tail suspension test (TST). Effects of SLPN on depression were evaluated in CUMS through these same assays. Circular RNA profiles in mouse ventral medial prefrontal cortex (VMPC) and hippocampus of CUMS mice were determined by high-through sequencing, followed by confirmation via qRT-PCR. Overexpression of mmu_circ_0001223 was done by transfection of PC12 cell through lentiviral system. Protein abundances of cAMP response element binding protein 1(CREB1) and brain-derived neurotrophic factor (BDNF) were evaluated by western blotting.

RESULTS

Mouse body weight, immobility time in FST and immobility time in TST of CUMS mice were significantly recovered by SLPN treatment. A large number of circular RNAs were differentially expressed in the ventral medial prefrontal cortex (VMPC) and hippocampus tissues of CUMS mice. Among them, mmu_circ_0001223 expression was greatly decreased in CUMS mice, but significantly elevated by SLPN treatment. The protein levels of CREB1 and BDNF were also remarkably promoted in CUMS mice by treatment of SLPN. Overexpression of mmu_circ_0001223 enhanced CREB1 and BDNF protein levels in PC12 cells.

CONCLUSION

SLPN regulate the expression of large number circular RNAs in CUMS mice, which might be important mediators of SLPN's anti-depression effects.

Differences in the dopaminergic reward system in rats that passively and actively behave in the Porsolt test

The aim of the study was to assess appetitive responses and central dopaminergic neurotransmission in passive and active rats divided according to their immobility time in the Porsolt swim test and exposed to restraint stress. Passive rats had more episodes of appetitive 50-kHz ultrasonic vocalization (USV) during rat encounter after social isolation and spent significantly more time in the amphetamine-associated context in conditioned place preference test, compared to active rats. Restraint stress decreased sucrose preference, but increased appetitive vocalization and reinforced the conditioned place preference only in passive animals that was associated with increased dopamine concentration in the amygdala. Restraint stress increased also the level of Cocaine- and Amphetamine Regulated Transcript (CART) peptide, a neuromodulator linked to dopamine neurotransmission, in the central nucleus of amygdala, while decreasing it the nucleus accumbens shell in passive rats. In the parvocellular region of paraventricular nucleus of the hypothalamus passive animals had a higher expression of CART compared to passive restraint rats and active control rats. The obtained results show that active and passive rats in the Porsolt test differ significantly in response to appetitive stimuli, which can be additionally changed under stress conditions. The underlying mechanisms are probably associated with differences in dopaminergic activity and CART signaling in reward system.

Genistein Ameliorates Scopolamine-Induced Amnesia in Mice Through the Regulation of the Cholinergic Neurotransmission, Antioxidant System and the ERK/CREB/BDNF Signaling

Genistein (GE) was reported to exert a wide spectrum of biological activities, including antioxidant, anti-inflammatory, anti-mutagenic, anticancer, and cardio-protective effects. In addition, both clinical and preclinical studies have recently suggested GE a potential neuroprotective and memory-enhancing drug against neurodegenerative diseases. The animal model of scopolamine (Scop)-induced amnesia is widely used to study underlying mechanisms and treatment of cognitive impairment in neurodegenerative diseases. However, there is no report about the effects of GE on Scop-induced amnesia in mice. Therefore, the present study was carried out to investigate the beneficial effects and potential mechanism of GE against Scop-induced deficits in mice. The mice were orally pretreated with either GE (10, 20, and 40 mg/kg) or donepezil (1.60 mg/kg) for 14 days. After the pretreatment, the open field test was conducted to assess the effect of GE on the locomotor activity of mice. Thereafter, mice were daily injected with Scop (0.75 mg/kg) intraperitoneally to induce memory deficits and subjected to the cognitive behavioral tests including the Object Location Recognition (OLR) experiment and Morris Water Maze (MWM) task. After the behavioral tests, biochemical parameter assay and western blot analysis were used to examine the underlying mechanisms of its action. The results showed that GE administration significantly improved the cognitive performance of Scop-treated mice in OLR and Morris water maze tests, exerting the memory-enhancing effects. Additionally, GE remarkably promoted the cholinergic neurotransmission and protected against the oxidative stress damage in the hippocampus of Scop-treated mice, as indicated by decreasing AChE activity, elevating ChAT activity and Ach level, increasing SOD activity, lowering the level of MDA and increasing GSH content. Furthermore, GE was found to significantly upregulate the expression levels of p-ERK, p-CREB and BDNF proteins in the hippocampus of Scop-treated mice. Taken together, these results for the first time found that GE exerts cognitive-improving effects in Scop-induced amnesia and suggested it may be a potential candidate compound for the treatment of some neurodegenerative diseases such as Alzheimer's Disease (AD).