Antidepressant-like effect of ethanol extract fromPaeonia lactiflorain mice

A review of the ethnopharmacology, phytochemistry, pharmacology, pharmacokinetics and quality control of Paeonia lactiflora Pall

ETHNOPHARMACOLOGICAL RELEVANCE

Paeonia lactiflora Pall. (called Shaoyao in China) is a common herb cultivated all over the world. In some Asian and European countries, such as China, Japan, South Korea and Britain, P. lactiflora has a long history of ethnomedical uses, which is widely used to relieve pain, treat gynecological diseases, anti-infection and so on. It is attributed to the extensive pharmacological activities of total glucosides of P. lactiflora. Up to now, it is still commonly used in clinical medicine.

THE AIM OF THE REVIEW

The paper aims to make a comprehensive review on the botanical characterization and distribution, ethnopharmacology, phytochemistry, biosynthesis pathway, pharmacology, pharmacokinetics and quality control of P. lactiflora, so as to provide new insights and scientific evidence for the subsequent research.

MATERIALS AND METHODS

The information of P. lactiflora was obtained from books related to traditional Chinese medicine and electronic databases, including Scifinder, PubMed, Web of Science, CNKI and Google Scholar.

RESULTS

P. lactiflora is a kind of herb with a long history and it is used for medicine, food and ornamental, and shows high utilization value. There are 200 compounds have been identified from it, including terpenoids, flavonoids, polyphenols, organic acids and others, among those paeoniflorin, a monoterpenoid glycoside, has multiple activities and is currently the focus of pharmacological research. A great deal of pharmacological experiments supported the anti-inflammatory, anti-oxidant, hepatoprotective, neuroprotective, antibacterial, antitumor, dermatosis treating and other effects of P. lactiflora. In addition, evaluating the quality of P. lactiflora is essential to safe use of drug in humans.

CONCLUSIONS

The chemical components of P. lactiflora are diverse and have a wide range of activities. Modern pharmacological studies have provided reliable evidence for the traditional efficacy, such as suppressing liver yang, regulating menstruation and relieving pain. However, there are still some problems to be solved, such as part of the pharmacological mechanism has not been clarified and the biosynthetic pathway of cage-like monoterpenoids remains poorly defined. In addition, further studies on compounds other than paeoniflorin are clearly warranted. It is hoped that P. lactiflora will serve the clinic better in the future.

Efficacy of a mixed extract of Salvia miltiorrhiza and Paeonia lactiflora in inhibiting the aging of vascular wall through in vitro and in vivo experiments

Vascular wall aging has been strongly associated with cardiovascular diseases. Thus, this study aimed to investigate the efficacy of USCP-GVH-014, a mixed extract of Salvia miltiorrhiza Bunge and Paeonia lactiflora Pall., in inhibiting vascular wall aging through in vitro and in vivo experiments. The results revealed that USCP-GVH-014 inhibited abnormal cell proliferation, collagen overproduction, and MMP-2 and MMP-9 overexpression caused by various stimuli and recovered the antioxidant enzyme superoxide dismutase on human aortic smooth muscle cells. In addition, it inhibited the increase in ICAM-1 and VCAM-1 expression induced by tumor necrosis factor alpha on human aortic endothelial cells and prevented the aging of the vascular wall by regulating related proteins such as epidermal growth factor and interleukin-1ß. Furthermore, it reduced vascular aging in in vivo studies. These results demonstrate that USCP-GVH-014 effectively reduces vascular aging, thereby rendering it a potential therapeutic candidate for cardiovascular diseases.

Polyphenols in edible herbal medicine: targeting gut-brain interactions in depression-associated neuroinflammation

Supplementing with edible herbal medicine is an important strategy because of its role in nutrition. Many polyphenols, which are universal components in edible herbal medicines, have low bioavailability. Therefore, gut microbiota is a key determinant of polyphenol bioactivity. Polyphenols can alter the abundance of flora associated with neuroinflammation by reversing intestinal microbiota dysbiosis. Intestinal flora-mediated chemical modification of polyphenols can result in their conversion into active secondary metabolites. The current review summarizes the main edible medicines used in anti-depression and details the interactions between polyphenols and gut microbiota; in addition, it provides insights into the mechanisms underlying the possible suppression of neuroinflammation associated with depression, by polyphenols in edible herbal medicine. A better understanding of polyphenols with bioactivities that are crucial in edible herbal medicine may facilitate their use in the prevention and treatment of neuroinflammation associated with depression.

Herbal Approaches in the Management of Mental Depression

BACKGROUND

Human's existence has become more stressful these days, most likely for the sake of improving one's lifestyle and fulfilling one's aspirations and needs. Depression is the most frequent neurological disorder, which affects millions of individuals worldwide. In clinical research, depression is the second most frequent chronic disease. A variety of herbal medications thought to have antidepressant-like effects have been reported in ancient pharmacopoeias from around the world. These provide several prospective chemicals that could be developed into modern mental medications while also causing no noticeable negative effects.

OBJECTIVE

The review is written to provide herbal treatment and comprehensive information about depression.

METHODS

Plants and plant formulations that were found effective in the treatment of depression are thoroughly reviewed. The antidepressant efficacies of medicinal plants, as well as their dosages, are investigated using experimental models. The review article contains 140 plants possessing antidepressant properties, 11 commercial formulations, and 25 active/isolated ingredients, as well as their chemical structure, which have been thoroughly reviewed with antidepressant activity after studying 283 references.

RESULTS

Literature revealed that a variety of medicinal plants are effective for the treatment of depression such as Hypericum perforatum, Catha edulis, Tinospora cordifolia, Curcuma longa, Ferula foetida, Rhodio larosea, Glycyrrhiza glabra, Crocus sativus, Ocimumba silicum and Embelica officinalis.

CONCLUSION

Potential compounds isolated from medicinal plants for the treatment of depressive disorders need to be established and herbal plant research could aid in this endeavour.

Quercetin Attenuates Nitroglycerin-Induced Migraine Headaches by Inhibiting Oxidative Stress and Inflammatory Mediators

This study aimed to investigate the antimigraine potential of quercetin in migraine pain induced by nitroglycerin (NTG), 10 mg/kg, intraperitoneal injection in rats. Quercetin was administered orally for 1 week, and behavioral parameters associated with pain were assessed 30 min after NTG injection. At the end of the study, the rats were killed so that immunohistochemical examination of their brains could be performed. The time and frequency of rearing and sniffing in the category of exploratory behavior, walking in the category of locomotor behavior, and total time spent in the light chamber were reduced in the disease control group compared with the normal group during the assessment of behavioral parameters. Pathologic migraine criteria, such as increased levels of calcitonin gene-related peptide and increased release of c-fos cells, were more prominent in the caudal nucleus triceminalis of the NTG control group. In the treatment groups, behavioral and pathological measures were less severe after pretreatment with quercetin at doses of 250 and 500 mg/kg. Therefore, it was concluded that quercetin improved the pain behavior of migraine patients in the NTG-induced migraine rat model. Quercetin is thought to have antimigraine effects due to its antioxidant and anti-inflammatory potential. Quercetin may therefore be a novel agent that can treat or prevent migraine pain and associated avoidance behaviors.

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.

Synergistic neuroprotective effect of saikosaponin A and albiflorin on corticosterone-induced apoptosis in PC12 cells via regulation of metabolic disorders and neuroinflammation

BACKGROUND

Saikosaponin A (SSA) and albiflorin (AF) are major bioactive compounds of Radix Bupleuri and Radix Paeoniae alba respectively, which possess antidepressant effects in pharmacological experiments. However, whether SSA and AF have synergistic neuroprotective effects and the synergistic mechanisms are still unknown.

METHODS AND RESULTS

The corticosterone-induced PC12 cells apoptosis model was employed to assess the neuroprotective effects of SSA and AF, and the synergistic effect was analyzed using three mathematical models. Meanwhile, cell metabolomics was used to detect the effects on metabolite regulation of SSA and AF. Furthermore, the key metabolites, metabolic enzymes, and cellular markers were verified by ELISA and Western blotting. The results showed that the combination of SSA and AF has a synergistic neuroprotective effect. Besides, the combination could regulate more metabolites than a single agent and possessed a stronger adjustment effect on metabolites. The TCA cycle was regulated by SSA and AF via improving mitochondrial function. The purine metabolism was regulated by SSA via inhibition xanthine oxidase activity and the glutamate metabolism was regulated by AF via inhibition glutaminase activity. Moreover, the oxidative stress induced by the purine metabolism was attenuated by SSA via a reduction in the ROS level. Additionally, the inflammation induced by the oxidative stress was attenuated by the SSA and AF via inhibition of the NLRP3 protein expression.

CONCLUSIONS

This study for the first time demonstrated the synergistic neuroprotective effects of SSA and AF, and the synergistic mechanisms were involved in metabolic disorders regulation and neuroinflammation inhibition.

Natural Products for the Treatment of Post-stroke Depression

Post-stroke depression (PSD) is the most frequent and important neuropsychiatric consequence of stroke. It is strongly associated with exacerbated deterioration of functional recovery, physical and cognitive recoveries, and quality of life. However, its mechanism is remarkably complicated, including the neurotransmitters hypothesis (which consists of a monoaminergic hypothesis and glutamate-mediated excitotoxicity hypothesis), inflammation hypothesis, dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis, and neurotrophic hypothesis and neuroplasticity. So far, the underlying pathogenesis of PSD has not been clearly defined yet. At present, selective serotonin reuptake inhibitors (SSRIs) have been used as the first-line drugs to treat patients with PSD. Additionally, more than SSRIs, a majority of the current antidepressants complied with multiple side effects, which limits their clinical application. Currently, a wide variety of studies revealed the therapeutic potential of natural products in the management of several diseases, especially PSD, with minor side effects. Accordingly, in our present review, we aim to summarize the therapeutic targets of these compounds and their potential role in-clinic therapy for patients with PSD.

Ancestral Food Sources Rich in Polyphenols, Their Metabolism, and the Potential Influence of Gut Microbiota in the Management of Depression and Anxiety

The relationship between a population's diet and the risk of suffering from mental disorders has gained importance in recent years, becoming exacerbated due to the COVID-19 lockdown. This review concentrates relevant literature from Scopus, PubMed, and Google Scholar analyzed with the aim of rescuing knowledge that promotes mental health. In this context, it is important to highlight those flowers, seeds, herbaceous plants, fungi, leaves, and tree barks, among other ancestral matrices, that have been historically part of the eating habits of human beings and have also been a consequence of the adaptation of collectors, consuming the ethnoflora present in different ecosystems. Likewise, it is important to note that this knowledge has been progressively lost in the new generations. Therefore, this review concentrates an important number of matrices used particularly for food and medicinal purposes, recognized for their anxiolytic and antidepressant effects, establishing the importance of metabolism and biotransformation mainly of bioactive compounds such as polyphenols by the action of the gut microbiota.

Translational Informatics for Natural Products as Antidepressant Agents

Depression, a neurological disorder, is a universally common and debilitating illness where social and economic issues could also become one of its etiologic factors. From a global perspective, it is the fourth leading cause of long-term disability in human beings. For centuries, natural products have proven their true potential to combat various diseases and disorders, including depression and its associated ailments. Translational informatics applies informatics models at molecular, imaging, individual, and population levels to promote the translation of basic research to clinical applications. The present review summarizes natural-antidepressant-based translational informatics studies and addresses challenges and opportunities for future research in the field.

Medicinal Plants in the Treatment of Depression: Evidence from Preclinical Studies

Medicinal plants and their extracts are natural remedies with enormous potential for treating various diseases, including depression and anxiety. In the case of depression, hundreds of plants have traditionally been used in folk medicine for generations. Different plant extracts and natural products have been analyzed as potential antidepressant agents with validated models to test for antidepressant-like effects in animals, although other complementary studies have also been employed. Most of these studies focus on the possible mediators implicated in these potential effects, with dopamine, serotonin, and noradrenaline being the principal neurotransmitters implicated, both through interference with receptors and with their metabolism by monoamino oxidases, as well as through neuro-endocrine and neuroprotective effects. There are approximately 650 reports of antidepressant-like medicinal plants in PubMed; 155 of them have been compiled in this review, with a relevant group yielding positive results. Saffron and turmeric are the most relevant species studied in both preclinical and clinical studies; St. John's wort or kava have also been tested extensively. To the best of our knowledge, no review to date has provided a comprehensive understanding of the biomolecular mechanisms of action of these herbs or of whether their potential effects could have real benefits. The purpose of this narrative review is to provide an update regarding medicinal plants from the year 2000 to the present to examine the therapeutic potential of these antidepressant-like plants in order to contribute to the development of new therapeutic methods to alleviate the tremendous burden that depression causes worldwide.

Activation of monoaminergic system contributes to the antidepressant- and anxiolytic-like effects of J147

Major depressive disorder (MDD) is a severe mental disorder, which is closely related to the deficiency of monoamine neurotransmitters. Our previous study suggested that acute treatment with J147, a novel curcumin derivative, produced antidepressant-like effects in mouse model of depression by regulation of 5-HT receptor subtypes. However, it is still unknown whether the antidepressant-like effects of J147 are involved in activation of central monoaminergic system. In this study, a series of classical behavior tests were employed to assess the involvement of monoaminergic system in antidepressant- and anxiolytic-like effects after sub-acute treatment of mice with J147 for 3 days. The results suggested that J147 at 10 mg/kg significantly reduced the immobility time in both the tail suspension and forced swimming tests, but didn't show effects in the sucrose preference test. Similarly, sub-acute treatment of J147 did not induce amelioration in novelty suppressed feeding test. J147 increased duration and crossing time in the central area, but did not show significant change in rearing counts in the open field test. In neurochemical assays, studies suggested that serotonin and noradrenaline levels were significantly increased in the frontal cortex and hippocampus after treatment of J147 by the high-performance liquid chromatography (HPLC) with an electrochemical detector. Moreover, J147-induced significant inhibition of monoamine oxidase A activity. These findings suggest that the antidepressant- and anxiolytic-like effects of J147 might be related to the monoaminergic system by the evidence that high dose of J147 inhibits monoamine oxidase (MAO)-A activity and increases synaptic monoamines in the mouse brain.

Potential effect of herbal antidepressants on cognitive deficit: Pharmacological activity and possible molecular mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

Cognitive symptom is a "core" symptom of major depressive disorder (MDD) patients with clear deficit in memory, social and occupational function, and may persist during the remitting phase. Therefore, the remission of cognitive symptom has been considered as one of the main objectives in the treatment of MDD. Herbal antidepressants have been used to treat MDD, and there has been great advances in the understanding of the ability of these herbs to improve cognitive deficit linked to brain injury and various diseases including depression, Alzheimer disease, diabetes and age-related disorders. This systematic review summarizes the evidence from preclinical studies and clinical trials of herbal antidepressants with positive effects on cognitive deficit. The potential mechanisms by which herbal antidepressants prevent cognitive deficit are also reviewed. This review will facilitate further research and applications.

MATERIALS AND METHODS

We conducted an open-ended, English restricted search of MEDLINE (PubMed), Web of Science and Scopus for all available articles published or online before 31 December 2019, using terms pertaining to medical herb/phytomedicine/phytochemical/Chinese medicine and depression/major depressive disorder/antidepressant and/or cognitive impairment/cognitive deficit/cognitive dysfunction.

RESULTS

7 prescriptions, more than 30 individual herbs and 50 phytochemicals from China, Japan, Korea and India with positive effects on the depressive state and cognitive deficit are reviewed herein. The evidence from preclinical studies and clinical trials proves that these herbal antidepressants exhibit positive effects on one or more aspects of cognitive defect including spatial, episodic, aversive, and short- and long-term memory. The action mode of the improvement of cognitive deficit by these herbal antidepressants is mediated mainly through two pathways. One pathway is to promote hippocampal neurogenesis through activating brain derived neurotrophic factor-tropomyosin-related kinase B signaling. The other pathway is to prevent neuronal apoptosis through the inhibition of neuro-inflammation and neuro-oxidation.

CONCLUSION

These herbal antidepressants, having potential therapy for cognitive deficit, may prevent pathological processes of neurodegenerative diseases. Furthermore, these herbal medicines should provide a treasure trove, which will accelerate the development of new antidepressants that can effectively improve cognitive symptom in MDD. Studies on their molecular mechanisms may provide more potential targets and therapeutic approaches for new drug discovery.

Antidepressant and Anti-Neuroinflammatory Effects of Bangpungtongsung-San

Bangpungtongsung-san (BTS) is a traditional Korean medicine consisting of 18 herbs, some which have antidepressant effects. Here, we used an animal model of reserpine-induced depression and lipopolysaccharide (LPS)-stimulated BV2 microglia to assess the antidepressant and anti-neuroinflammatory effects of BTS. Aside from a control group, C57BL/6 mice were administered reserpine (0.5 mg/kg) daily for 10 days via intraperitoneal injection. BTS (100, 300, or 500 mg/kg), vehicle (PBS), or fluoxetine (FXT, 20 mg/kg) was administered orally 1 h before reserpine treatment. Following treatment, a forced swimming test (FST), tail suspension test (TST), and open field test (OFT) were performed, and immobility time and total travel distance were measured. Administration of BTS not only reduced immobility time in the FST and TST but also significantly increased the total travel distance in the OFT. Furthermore, reserpine-treated mice showed significantly elevated serum levels of corticosterone, a stress hormone; however, treatment with BTS significantly reduced corticosterone levels, similar to FXT treatment. Serotonin in reserpine-treated mice was significantly reduced compared to that in control mice, while BTS mice exhibited increased serotonin levels. BTS mice showed increased expression of brain-derived neurotrophic factor (BDNF) and a higher ratio of phosphorylated cAMP response element-binding protein (p-CREB) to CREB (p-CREB/CREB) in the hippocampus. Additionally, reserpine-treated mice exhibited significantly elevated mRNA levels of pro-inflammatory cytokines, but BTS mice showed reduced mRNA levels of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α in the hippocampus. To further demonstrate the anti-neuroinflammatory effects of BTS in vitro, we examined its anti-neuroinflammatory and neuroprotective effects in lipopolysaccharide (LPS)-stimulated BV2 microglia. BTS significantly reduced the levels of NO, inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, TNF-α, IL-1β, and IL-6 in a dose-dependent manner via a decrease in the expression of nuclear factor (NF)-κB p65. Furthermore, the neuroprotective factor heme oxygenase-1 (HO-1) was upregulated via the nuclear factor-E2-related factor 2 (NRF2)/CREB pathway. Taken together, our data suggest that BTS has considerable potential as an anti-neuroinflammation and antidepressant agent, as it has clear effects on depressive behaviors and associated factors caused by reserpine-induced depression.

Gut Microbiota: A Pivotal Hub for Polyphenols as Antidepressants

Polyphenols, present in a broad range of plants, have been thought to be responsible for many beneficial health effects, such as an antidepressant. Despite that polyphenols can be absorbed in the small intestine directly, most of them have low bioavailability and reach the large intestine without any modifications due to their complex structures. The interaction between microbial communities and polyphenols in the intestine is important for the latter to exert antidepressant effects. Gut microbiota can improve the bioavailability of polyphenols; in turn, polyphenols can maintain the intestinal barrier as well as the community of the gut microbiota in normal status. Furthermore, gut microbita catabolize polyphenols to more active, better-absorbed metabolites, further ameliorating depression through the microbial-gut-brain (MGB) axis. Based on this evidence, the review illustrates the potential role of gut microbiota in the processes of polyphenols or their metabolites acting as antidepressants and further envisions the gut microbiota as therapeutic targets for depression.

Total glucosides of paeony (TGP) extracted from Radix Paeoniae Alba exerts neuroprotective effects in MPTP-induced experimental parkinsonism by regulating the cAMP/PKA/CREB signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The totally-amounted glucosides of paeony (TGP), which are made up of paeoniflorin, albiflorin, oxypaeoniflorin as well as benzoylpaeoniflorin, constitute the Baishao' actively-working component extracted from Radix Paeonia alba employed in conventional oriental medicine aiming to treat cerebrovascular disorders, such as Parkinson's disease. However, its pharmacologic mechanism is not clear.

AIM OF THE STUDY

The initial investigation was made on TGP's neuroprotective effects on PD of the mouse model based on 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) as well as the identification of potential involvement of a molecular signaling pathway.

MATERIALS AND METHODS

The evaluation of the behavioral damage as well as neurotoxicity in mice was made through MPTP. Spontaneous motor activity test, as well as a test of Rota-rod on mice was employed for the measurement of bradykinesia symptom. Additionally, liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS-MS) works as the determiner of the main monoamine neurotransmitters dopamine (DA) along with its metabolites 3, 4-dihydroxyphenylacetic acid (DOPAC) as well as homovanillic acid (HVA) based on mouse hippocampus connected with the anti-Parkinson's disease like effect of TGP. Besides, the measurement of the effects of TGP treatment on the expressions level of TH, DAT, a-synuclein, p-CREBS¹³³ as well as apoptosis influence was made with the help of western-blot assay with apoptosis-related markers such as Bax and Bcl-2.

RESULTS

The results showed that TGP treatment lessened the behavior-based loss shown "in the spontaneous motor activity as well as the potential of falling to rotarod test". In addition, we found that pretreatment with TGP markedly improved motor coordination, striatal dopamine and its metabolite levels. Furthermore, pretreatment of TGP conducted the protection for dopaminergic neurons with the prevented MPTP-induced reductions within the tyrosine hydroxylase (TH), substantia nigra dopaminergic transporter (DAT), as well as increasing α-synuclein protein levels with transformed dopamine catabolism as well as inhibited dopamine turnover. Besides, TGP treatment helped reversed apoptosis signaling molecules Bcl-2/Bax' reduction; meanwhile improving p-CREBS¹³³ the factor of growth signaling in the substantia nigra' decrease.

CONCLUSION

These results suggested that TGP can enhance dopaminergic neuron's cell survival in the SNpc in virtue of the activated cAMP/PKA/CREB factor of growth on inhibiting the pathway of second messenger apoptosis as well. In conclusion, the current findings indicate TGP is expected to be a new cure for PD.

L-theanine ameliorate depressive-like behavior in a chronic unpredictable mild stress rat model via modulating the monoamine levels in limbic-cortical-striatal-pallidal-thalamic-circuit related brain regions

L-theanine, originally found in green tea, elicits various physiological effects, such as promoting relaxation, improving concentration and learning ability, and providing antianxiety-like and antidepressant-like properties. This study aims to investigate the effects of L-theanine (2 mg/kg) on monoamine levels in an animal model of depression. The effect of l-theanine on the symptoms of depression was examined through the open-field test, sucrose preference test, and forced swim test. The monoamine neurotransmitters that involve serotonin (5-HT), norepinephrine (NE), and dopamine (DA) were measured in the limbic-cortical-striatal-pallidal-thalamic (LCSPT)-circuit related brain regions, including the prefrontal cortex (PFC), nucleus accumbens (NAC), striatum (ST), amygdala, and hippocampus (HIP). L-theanine ameliorated the depressive-like behaviors in the chronic unpredictable mild stress (CUMS) rat model. In the PFC, NAC, and HIP, L-theanine administration significantly increased the levels of 5-HT, NE, and DA. In the ST, the levels of 5-HT and DA were increased after the administration of L-theanine. However, in the HIP, only the level of DA significantly changed after the treatment of L-theanine. Taken together, these results indicated that L-theanine has possibly antidepressant-like effects in the CUMS rat model, which could be mediated by the monoamine neurotransmitters in the LCSPT-circuit related brain regions.

Phytochemistry and pharmacology of anti-depressant medicinal plants: A review

Stress renders an individual to experience mental pressure and exhaustion which brings about feelings of anxiety, depression, anger and/or other negative emotions. Depression affects a person's state of mind, behaviour, health and is often associated with suicide. The use of anti-depressant drugs as therapeutic agents is associated with symptoms such as, delayed onset of action, side-effects, drug-drug and dietary interactions, sexual dysfunction, cardiac toxicity, etc. Thus, there is need to target these issues and improve current treatment options. Medicinal plants have long been used in discovering novel treatment strategies and compounds with promising roles in treating various disease conditions. There has been an increase, worldwide, in the use of medicinal plants and herbs for developing nutraceuticals for treatment of depression and other psychiatric disorders. Medicinal plants in their natural forms are valuable as they are rich in various phytochemical compounds. These phytochemical compounds have pharmacological roles in treating various diseases conditions; apart from being widely available in nature and commercially beneficial. The phytochemical compounds in plants are constantly being explored through various experimental studies to determine the molecular basis of how medicinal plants work in relation to drugs and diseases and to develop neutraceuticals for improving conditions. This review summarizes 110 medicinal plants and their phytochemical constituents that have been shown to possess anti-depressant activity. This review also highlights the various mechanisms of anti-depressant action of some of these plants and their plant parts like roots, stem, leaves, flowers, fruit or whole plant; phytochemical compounds showing anti-depressant activity such flavanoids, steroids, saponins, sugars, lectins, alkaloids, etc.; and various anti-depressant screening models used such as tail suspension test, forced swim test, chronic unpredictable stress test, sucrose preference test, monoamine oxidase inhibition assay, learned helplessness test, open field test, hole board test, etc. However, mechanistic evaluation of many of these plants still needs to be investigated and explored.

Research Progress in the Effect of Traditional Chinese Medicine for Invigoration on Neurotransmitter Related Diseases

Tonic traditional Chinese medicine is widely used in clinical practice and is categorized into four main drugs, namely, Qi-supplementing, Blood-enriching, Yin-nourishing, and Yang-tonifying. Neurotransmitters play a coordinating role in the nervous system, visceral function, and stress response. The excitation or suppression of the central nervous system is closely related to various diseases, such as insomnia, depression, Alzheimer's disease, Parkinson's disease, and perimenopausal syndrome. An increasing amount of evidence shows that Chinese tonic herb and its active ingredients can delay the occurrence and development of these diseases by modulating related neurotransmitters and their receptors, including norepinephrine (NE), serotonin (5-HT), dopamine (DA), acetylcholine (ACh), and γ-aminobutyric acid (GABA). In the present report, studies on the treatment of these neurotransmitter related diseases in relation to the application of tonic Chinese medicine are reviewed.

The antidepressant-like effect of trans-astaxanthin involves the serotonergic system

The antidepressant-like effect of trans-astaxanthin, a compound present rich in algae, was evaluated through behavioral and neurochemical methods. Results showed that trans-astaxanthin treatment significantly decreased the immobility time in force swim test and tail suspension test, but did not influence locomotor activity. Trans-astaxanthin treatment did not effectively antagonize hypothermia and ptosis induced by reserpine. However, pre-treatment with para-chlorophenylalanine abolished the anti-immobility effect of trans-astaxanthin in force swim and tail suspension test. These results suggested that the mechanism of antidepressant-like effect of trans-astaxanthin may involve the serotonergic system, but not noradrenaline system. This hypothesis was confirmed by neurochemical assays which showed that trans-astaxanthin increased serotonin levels in the hippocampus, frontal cortex, striatum and hypothalamus. Furthermore, our data suggested that trans-astaxanthin decreased indoleamine 2, 3-dioxygenase activity in the hippocampus, frontal cortex and hypothalamus. Inhibition of indoleamine 2,3-dioxygenase activity subsequently decreased the kynurenine/tryptophan ratio and increased the serotonin/tryptophan ratio in these brain regions. Taken together, these findings indicate that the antidepressant-like effect of trans-astaxanthin involves the serotonergic system.

Paeoniflorin Ameliorates Chronic Stress-Induced Depression-Like Behaviors and Neuronal Damages in Rats via Activation of the ERK-CREB Pathway

Neuronal damage is related to the onset and treatment of depressive disorders. Antidepressant-like effects have been elicited by paeoniflorin on animal models. The aim of this study is to demonstrate whether the neuroprotective effect of paeoniflorin on rats suffered from chronic unpredictable mild stress (CUMS) was regulated by the ERK-CREB signaling pathway. Results showed that paeoniflorin not only ameliorated depressive-like behavior with low locomotor activity and prolonged immobility duration in our forced swimming test but also reduced sucrose consumption. Paeoniflorin treatment decreased the degree of neuronal damage in the hippocampus of the model rats. Conversely, it markedly increased the mRNA levels of ERK1, ERK2, and CREB and the levels of ERK, p-ERK, CREB, and p-CREB protein expression in the hippocampus. Blockade of the ERK-CREB axis with the ERK-specific inhibitor U0126 repressed the neuroprotective and antidepressant-like effects of paeoniflorin on rats in the setting of chronic-mild-stress and abolished the recoveries of p-ERK mediated by paeoniflorin treatment. Thus, paeoniflorin possibly exerted a neuroprotective effect modulated by the ERK-CREB signaling pathway on CUMS-induced hippocampal damage in rats.

Fisetin provides antidepressant effects by activating the tropomyosin receptor kinase B signal pathway in mice

Depression has been associated with a low-grade chronic inflammatory state, suggesting a potential therapeutic role for anti-inflammatory agents. Fisetin is a naturally occurring flavonoid in strawberries that has anti-inflammatory activities, but whether fisetin has antidepressant effects is unknown. In this study, we exposed mice to spatial restraint for 2 weeks with or without treatment with fisetin. Immobility time in the forced swimming and tail suspension test after this restraint increased in the untreated group, but this increase did not occur in the fisetin group. We administered fisetin to Abelson helper integration site-1 (Ahi1) knockout mice, which have depressive phenotypes. We found that fisetin attenuated the depressive phenotype of these Ahi1 knockout mice. We further investigated the potential mechanism of fisetin's antidepressant effects. Because TrkB is a critical signaling pathway in the mechanisms of depression, we examined whether phosphorylated TrkB was involved in the antidepressant effects of fisetin. We found that fisetin increased phosphorylated TrkB level without altering total TrkB; this increase was attenuated by K252a, a specific TrkB inhibitor. Taken together, our results demonstrated that fisetin may have therapeutic potential for treating depression and that this antidepressant effect may be mediated by the activation of the TrkB signaling pathway.

Neuroplasticity-related mechanisms underlying the antidepressant-like effects of traditional herbal medicines

Traditional herbal medicine can offer efficacious and safe alternative pharmacotherapies for depression. The ability of an herbal medicine to produce neuroadaptive processes, that enhance neuroplasticity and cellular resilience in response to chronic stress, may point to its antidepressant potential. We suggest that among many investigated herbal medicines, those that can enhance neuroplasticity may have stronger therapeutic potential. The current article presents a summary of traditional herbal medicines, which are thought to exert antidepressant-like effects in chronic stress models via neuroplasticity enhancement. Brain-derived neurotrophic factor (BDNF) is a biomarker for neuroplasticity-related mechanisms compromised in depression and recovered by conventional antidepressants, including synaptic plasticity, cell survival, neurogenesis and spine formation. We therefore presumed that if an herbal medicine up-regulates BDNF in the hippocampus and/or prefrontal cortex (PFC), its antidepressant-like effect is mediated, at least partially, via neuroplasticity-related mechanisms. Literature search was performed using the general terms depression, stress, neuroplasticity and herbal medicines. Screening of retrieved preclinical studies revealed 30 traditional herbal medicines: 8 single herbs, 15 bioactive constituents, and 7 herbal formulas. The antidepressant-like effects of these medicines were associated with reversal of chronic stress-induced impairment in neuroplasticity, most notably by BDNF up-regulation, activation of BDNF downstream signaling pathways and increase in neurogenesis in the hippocampus and/or PFC/frontal cortex. In light of the ability of these medicines to enhance neuroplasticity, we suggest that they may be suitable candidates for clinical investigation in depressed individuals. Once their efficacy, tolerability and safety will be substantiated, they may serve as natural alternatives to conventional antidepressants.

Albiflorin ameliorates obesity by inducing thermogenic genes via AMPK and PI3K/AKT in vivo and in vitro

OBJECTIVE

Brown adipose tissue (BAT) activation has been identified as a possible target to treat obesity and to protect against metabolic diseases by increasing energy consumption. We explored whether albiflorin (AF), a natural compound, could contribute to lowering the high risk of obesity with BAT and primary brown preadipocytes in vivo and in vitro.

MATERIALS/METHODS

Human adipose tissue-derived mesenchymal stem cells (hAMSCs) were cultured with adipogenic differentiation media with or without AF. Male C57BL/6J mice (n=5 per group) were fed a high-fat diet (HFD) for six weeks with or without AF. Brown preadipocytes from the interscapular BAT of mice were cultured with or without AF.

RESULTS

In white adipogenic differentiation of hAMSCs, AF treatment significantly reduced the formation of lipid droplets and the expression of adipogenesis-related genes. In HFD-induced obese C57BL/6J mice, AF treatment significantly reduced body weight gain as well as the weights of the white adipose tissue, liver and spleen. Furthermore, AF induced the expression of genes involved in thermogenic function in BAT. In primary brown adipocytes, AF effectively stimulated the expressions of thermogenic genes and markedly up-regulated the AMP-activated protein kinase (AMPK) signaling pathway. Pretreatment with phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 nullified the induction of the thermogenic genes by AF in primary brown adipocytes. Moreover, AF activated beige cell marker genes induced by the pharmacological activation of peroxisome proliferator-activated receptor γ in hAMSCs.

CONCLUSION

This study shows that AF prevents the development of obesity in hAMSCs and mice fed an HFD and that it is also capable of stimulating the differentiation of brown adipocytes through the modulation of thermogenic genes by AMPK and PI3K/AKT.

Anti-PTSD-like effects of albiflorin extracted from Radix paeoniae Alba

ETHNOPHARMACOLOGY RELEVANCE

Post-traumatic stress disorder (PTSD) is a severe psychiatric disorder that is characterized by symptoms of re-experiencing, avoidance and hyperarousal, as well as social and professional dysfunction at least one month after the exposure to a traumatic event. Biosynthesis of allopregnanolone has been suggested as one of the important contributors to PTSD. Albiflorin (AF) extracted from Radix paeoniae Alba had been shown to be effective in the therapy of depression. However, few studies were concerned about the anti-PTSD-like effects of AF.

AIM OF THE STUDY

The current study aimed to evaluate the anti-PTSD-like effects of AF in an animal model and its possible mechanism.

MATERIALS AND METHODS

To evaluate this, the single prolonged stress (SPS) model was used in the present study. The SPS rats were administered by AF (at doses of 3.5, 7 and 14.0mg/kg, i.g.) after induction of SPS from days 2-13. After the exposure to SPS, behavioral assessments were conducted, including contextual fear paradigm (CFP), elevated plus-maze test (EPMT), open-field test (OFT). The rats were decapitated at the end of the behavioral tests and levels of allopregnanolone in prefrontal cortex, hippocampus and amygdala were measured by enzyme linked immunosorbent assay (ELISA).

RESULTS

It had been shown that behavioral deficits of SPS rats were reversed by AF (7.0 and 14.0mg/kg, i.g.), which attenuated the PTSD-like associated contextual freezing behavior in CFP and improved PTSD-like associated anxiogenic behavior in EPMT without affecting locomotor activity in OFT. Moreover, decreased levels of allopregnanolone in prefrontal cortex, hippocampus, and amygdala were reversed by AF (7.0 and 14.0mg/kg, i.g.), respectively.

CONCLUSION

In summary, the present study indicated that AF exerted the anti-PTSD-like effects, which maybe associated with allopregnanolone biosynthesis in the brain.

Antidepressant-like effects of albiflorin extracted from Radix paeoniae Alba

ETHNOPHARMACOLOGY RELEVANCE

Albiflorin, a monoterpene glycoside, is a main component of Radix paeoniae Alba, which could be a Chinese herbal medicine used in the treatment of psychiatric disorders. However, the exact role of albiflorin in depression is poorly understood.

AIM OF THE STUDY

The current study aimed to evaluate the antidepressant effect of albiflorin in mice and rats, and the possible mechanism was also determined.

MATERIALS AND METHODS

The antidepressant-like effects of albiflorin was determined by using animal models of depression including forced swim and tail suspension tests in mice and chronic unpredictable stress (CUS) in rats. The acting mechanism was explored by determining the effect of albiflorin on the expression of brain-derived neurotrophic factor (BDNF) in the hippocampus by western blot and the levels of monoamine in the hippocampus by HPLC.

RESULTS

Our results showed that 7 days treatment with albiflorin significantly decreased immobility time in the forced swimming test (FST) and the tail suspension test (TST) at doses of 3.5, 7.0 and 14.0mg/kg without alter the locomotor activity in mice. Moreover, western blot analysis showed that albiflorin could increase the expression of BDNF in the hippocampus. We further exposed rats to a chronic unpredictable stress (CUS) protocol for a period of 35d to induce depressive-like behaviors. We found that chronic treatment with albiflorin, at doses of 7.0 and 14.0mg (i.g., once daily for 35d), restored the sucrose preference in CUS rats. In the open-field test, albiflorin significantly increased the number of crossings and rearings in the CUS rats at three doses. Moreover, chronic treatment with albiflorin up-regulated the hippocampal BDNF expression levels and the hippocampal 5-HT, 5-HIAA, and NA levels.

CONCLUSION

Albiflorin produced significant antidepressant-like effects, which were closely related to the hippocampal 5-HT/NE increase and BDNF expression. Our data indicated that albiflorin could be a potential anti-depressant drug.

Evaluation of the Anxiolytic and Antidepressant Activities of the Aqueous Extract from Camellia euphlebia Merr. ex Sealy in Mice

Camellia euphlebia Merr. ex Sealy is a traditional Chinese medicine that has been widely used for improvement of human emotions in the Guangxi Province of southern China. However, there are no studies about the anxiolytic and antidepressant activities of Camellia euphlebia. This study evaluated the anxiolytic and antidepressant activities of the aqueous extract from Camellia euphlebia (CEE) in mice. We found that administration of 400 mg/kg CEE or 20 mg/kg fluoxetine for 7 days significantly reduced the immobility time in both TST and FST. Oral administration of 100 mg/kg extract or 4 mg/kg diazepam for 7 days significantly increased the percentage of time spent and the number of entries into the open arms of the EPMT. In addition, the time spent by mice in the illuminated side of the LDBT was increased. Furthermore, pretreatment with 400 mg/kg CEE for 7 days significantly elevated the level of 5-HT and DA in the whole brain of mice. These results provide support for the potential anxiolytic and antidepressant activity of Camellia euphlebia and contribute towards validation of the traditional use of Camellia euphlebia in the treatment of emotional disorders.

Antidepressant-Like Effect of the Leaves of Pseudospondias microcarpa in Mice: Evidence for the Involvement of the Serotoninergic System, NMDA Receptor Complex, and Nitric Oxide Pathway

Depression continues to be a major global health problem. Although antidepressants are used for its treatment, efficacy is often inconsistent. Thus, the search for alternative therapeutic medicines for its treatment is still important. In this study, the antidepressant-like effect of Pseudospondias microcarpa extract (30-300 mg kg(-1), p.o.) was investigated in two predictive models of depression--forced swimming test and tail suspension test in mice. Additionally, the mechanism(s) of action involved were assessed. Acute treatment with the extract dose dependently reduced immobility of mice in both models. The antidepressant-like effect of the extract (100 mg kg(-1), p.o.) was blocked by p-chlorophenylalanine and cyproheptadine but not prazosin, propranolol, or yohimbine. Concomitant administration of D-cycloserine and the extract potentiated the anti-immobility effect. In contrast, D-serine, a full agonist of glycine/NMDA receptors, abolished the effects. Anti-immobility effects of PME were prevented by pretreatment of mice with L-arginine (750 mg kg(-1), i.p.) and sildenafil (5 mg kg(-1), i.p.). On the contrary, pretreatment of mice with L-NAME (30 mg kg(-1), i.p.) or methylene blue (10 mg kg(-1), i.p.) potentiated its effects. The extract produces an antidepressant-like effect in the FST and TST that is dependent on the serotoninergic system, NMDA receptor complex, and the nitric oxide pathway.

Orientin improves depression-like behavior and BDNF in chronic stressed mice

SCOPE

Oxidative stress is involved in chronic stress-induced depression and the disruption of neurotransmission and neuroplasticity. Recently, orientin, a phenolic compound abundant in some fruits, millet, and herbs, has been shown to have antioxidant properties. This study investigated the potential antidepressant effects of orientin against chronic stress and its underlying mechanisms.

METHODS AND RESULTS

The chronic unpredictable mild stress (CUMS) model was used to investigate the effects of orientin on behavior and biochemical alterations in mice. After 2 weeks of the CUMS protocol, the mice were treated with orientin (20 mg/kg and 40 mg/kg, oral gavage) for 3 weeks. Administration of orientin significantly alleviated the CUMS-induced depression-like behavior, including sucrose preference reduction, locomotor activity decline, and hypomotility. Orientin treatment attenuated the oxidative stress markers and increased the concentrations of serotonin and norepinephrine in the hippocampus and prefrontal cortex of CUMS mice. Orientin treatment also increased the brain-derived neurotrophic factor and synapse-associated proteins (synaptophysin and postsynaptic density protein 95) of CUMS mice.

CONCLUSION

Orientin exerts antidepressant-like effects on CUMS mice, specifically by improving central oxidative stress, neurotransmission, and neuroplasticity. Therefore, supplementation with orientin-enriched food or fruit could be beneficial as a preventive strategy for chronic stress-induced depression.

Herbal Medicine for Anxiety, Depression and Insomnia

The prevalence and comorbidity of psychiatric disorders such as depression, anxiety and insomnia are very common. These well-known forms of psychiatric disorders have been affecting many people from all around the world. Herb alone, as well as herbal formula, is commonly prescribed for the therapies of mental illnesses. Since various adverse events of western medication exist, the number of people who use herbs to benefit their health is increasing. Over the past decades, the exploration in the area of herbal psychopharmacology has received much attention. Literatures showed a variety of herbal mechanisms of action used for the therapy of depression, anxiety and insomnia, involving reuptake of monoamines, affecting neuroreceptor binding and channel transporter activity, modulating neuronal communication or hypothalamic-pituitary adrenal axis (HPA) etc. Nonetheless, a systematic review on herbal pharmacology in depression, anxiety and insomnia is still lacking. This review has been performed to further identify modes of action of different herbal medicine, and thus provides useful information for the application of herbal medicine.

Antidepressant effects of the water extract from Taraxacum officinale leaves and roots in mice

CONTEXT

The leaves and roots of the Taraxacum officinale F. (Asteraceae) is widely used as traditional medicinal herb in Eastern Asian countries.

OBJECTIVE

In the present study, the antidepressant-like effects of the water extract of T. officinale (WETO) leaves and roots were investigated in mice using forced swimming test (FST), tail suspension test (TST) and open field test (OFT).

MATERIALS AND METHODS

Effects of acute (1-day) and chronic treatments (14-days) with WETO (50, 100 and 200 mg/kg) on the behavioral changes in FST, TST and OFT, and the serum corticotrophin releasing factor (CRF), adrenocorticotropic hormone (ACTH) and corticosterone concentration were assessed in mice.

RESULTS

Chronic treatment (14-days) with WETO at the doses of 50, 100 and 200 mg/kg significantly decreased the immobility time in both FST (92.6, 85.1 and 77.4 s) and TST (84.8, 72.1 and 56.9 s). Acute treatment (1-day) with WETO at a dose of 200 mg/kg also markedly decreased the immobility time in both FST (81.7 s) and TST (73.2 s). However, all treatments did not affect the locomotor activity in the OFT. Moreover, FST induced a significant increase in serum CRF (5.8 ng/ml), ACTH (104.7 pg/ml) and corticosterone levels (37.3 ng/ml). Chronic treatment (14-days) with WETO decreased the serum CRF (200 mg/kg: 3.9 ng/ml) and corticosterone (50 mg/kg: 29.9 ng/ml; 100 mg/kg: 22.5 ng/ml; 200 mg/kg: 19.8 ng/ml) levels.

DISCUSSION AND CONCLUSION

These results clearly demonstrated the antidepressant effects of WETO in animal models of behavioral despair and suggested the mechanism involved in the neuroendocrine system.

Screening of the antidepressant-like effect of the traditional Chinese medicinal formula Si-Ni-San and their possible mechanism of action in mice

BACKGROUND

The traditional Chinese medicine formula Si-Ni-San has well therapeutic applications in improvement of mental diseases including depression. However, the neuropharmacological and neuroendocrine mechanisms of the formula on antidepressant-like action have not been reported.

OBJECTIVE

Herein, we explored the antidepressant-like effect and its mechanism of Si-Ni-San.

MATERIALS AND METHODS

Acute effect of Si-Ni-San on the immobility time was assessed in the mouse forced swim test (FST) and tail suspension test (TST). Moreover, we investigated the neurochemical, neuroendocrine, and neurotrophin systems involved in the antidepressant-like effect of this formula.

RESULTS

Si-Ni-San significantly decreased the immobility time after acute treatment in the mouse TST (1300 mg/kg) but not in the FST compared with the control group. In addition, pretreatment of mice with PCPA or AMPT prevented the anti-immobility effect of Si-Ni-San (1300 mg/kg) in the TST. Moreover, acute Si-Ni-San (1300 mg/kg) decreased serum corticosterone levels, elevated serotonin (5-HT), norepinephrine (NE), and dopamine (DA) levels without affecting brain-derived neurotrophic factor (BDNF) levels in the whole brain exposed to TST.

CONCLUSION

The acute antidepressant-like action of Si-Ni-San is mediated by the monoaminergic and neuroendocrine systems although underlying mechanism still remains to be further elucidated, and this formula should be further investigated as an alternative therapeutic approach for the treatment of depression.

Anti-Viral Activity of Water Extract of Paeonia lactiflora Pallas Against Human Respiratory Syncytial Virus in Human Respiratory Tract Cell Lines

Paeonia lactiflora Pallas (P. lactiflora, Ranunculaceae) is a common ingredient of Sheng-Ma-Ge-Gen-Tang (SMGGT; Shoma-kakkon-to) and Ge-Gen-Tang (GGT; kakkon-to). SMGGT and GGT are different prescriptions of traditional Chinese medicine with different ingredients designed for airway symptoms. Both SMGGT and GGT have anti-viral activity against human respiratory syncytial virus (HRSV). Therefore, P. lactiflora was hypothesized to be the effective ingredient of both SMGGT and GGT against HRSV. However, P. lactiflora does not have any proven antiviral activity. This study used both human upper (Human larynx epidermoid carcinoma cell line, HEp-2) and lower (human lung carcinoma cell line, A549) respiratory tract cells to test the hypothesis that a hot water extract of P. lactiflora could effectively inhibit plaque formation induced by HRSV infection. The ability of P. lactiflora to stimulate anti-viral cytokines was evaluated by enzyme-linked immunosorbent assay (ELISA). The results showed that P. lactiflora was time-dependently and dose-dependently effective against HRSV in HEp-2 and A549 cells, particularly supplemented before viral inoculation (p < 0.0001). 10 μg/ml P. lactiflora had a comparable anti-HRSV activity with 10 μg/ml ribavirin, a broad-spectrum antiviral agent. P. lactiflora was dose-dependently effective against viral attachment (p < 0.0001), with a better effect on A549 cells (p < 0.0001). P. lactiflora was time-dependently (p < 0.0001) and dose-dependently (p < 0.0001) effective against viral penetration. Moreover, P. lactiflora stimulated IFN-β secretion without any effect on TNF-α secretion. Therefore, P. lactiflora could be beneficial at preventing HRSV infection by inhibiting viral attachment, internalization, and stimulating IFN secretion.

Essential oil of Perilla frutescens-induced change in hippocampal expression of brain-derived neurotrophic factor in chronic unpredictable mild stress in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Perilla frutescens (Perilla leaf), a traditional Chinese medicinal herb, has been used for centuries to treat various conditions including depression. A previous study of the authors demonstrated that essential oil of Perilla frutescens (EOPF) attenuated the depressive-like behavior in mice.

AIM OF THE STUDY

This study was undertaken to explore the dynamic change of behaviors and brain-derived neurotrophic factor (BDNF) expression induced by chronic unpredictable mild stress (CUMS), and improved by EOPF.

MATERIALS AND METHODS

Four separate CUMS experimental groups (1-week, 2-week, 3-week and 4-week treatment) were treated with EOPF (3 mg/kg and 6 mg/kg, p.o.) or fluoxetine (20 mg/kg, p.o.), followed by sucrose preference, locomotor activity, immobility and hippocampal BDNF measurement.

RESULTS

EOPF, as well as fluoxetine, restored the CUMS-induced decreased sucrose preference and increased immobility time, without affecting body weight gain and locomotor activity. Furthermore, CUMS (3 or 4-week) produced a reduction in both BDNF mRNA and protein expression in the hippocampus, which were ameliorated by EOPF (4-week) and fluoxetine (3 or 4-week) treatment.

CONCLUSION

These results presented here show that BDNF is expressed depending on length of CUMS procedure and EOPF administration. And this study might contribute to the underlying reason for the slow onset of antidepressant activity in clinic.

Antidepressant-like effect of oleanolic acid in mice exposed to the repeated forced swimming test

The study aimed to explore the antidepressant-like effect of oleanolic acid and its possible mechanism related to the monoaminergic system and neurotrophin in mice exposed to the repeated forced swimming test (FST). Both the duration and the latency of immobility affected by oleanolic acid (10, 20 and 40 mg/kg) were evaluated in the FST repeated at intervals on days 1, 7 and 14, followed by neurochemical and brain-derived neurotrophic factor (BDNF) analyses in the mouse brain regions of frontal cortex and whole hippocampus. A repeated analysis of variance (ANOVA) indicated that over retesting the immobility time increased, whereas latency to immobility tended to decrease. Minute-by-minute analysis showed that immobility time also increased during the 4-min course of the test. In addition, post-hoc Dunnett's test demonstrated that sub-chronic and chronic, but not acute, oleanolic acid treatment reduced the immobility time (sub-chronic: 20 mg/kg, 43.5%; chronic: 10 mg/kg, 19.3%; 20 mg/kg, 31.8%) and increased the latency to immobility (sub-chronic: 10 mg/kg, 60.6%; 20 mg/kg, 80.1%; chronic: 10 mg/kg, 121.8%; 20 mg/kg, 140.8%; 40 mg/kg, 80.0%). Furthermore, chronic administration of oleanolic acid significantly increased serotonin (5-HT) levels (frontal cortex: 44.5%, 41.9%, 27.5% for 10, 20, 40 mg/kg; hippocampus: 57.2%, 80.9% for 10, 20 mg/kg), decreased 5-hydroxyindoleacetic acid (5-HIAA)/5-HT ratio (frontal cortex: 31.6%, 30.1%, 23.5%; hippocampus: 40.6%, 47.7%, 29.2% for 10, 20, 40 mg/kg) and elevated norepinephrine (NE) levels (hippocampus: 20 mg/kg, 45.4%) but did not alter dopamine (DA) levels. Moreover, BDNF levels in the two brain regions were also elevated by chronic oleanolic acid treatment (frontal cortex: 20 mg/kg, 67.2%; hippocampus: 10 mg/kg, 36.4%; 20 mg/kg, 55.1%). Taken together, these findings imply that functions of 5-HT, NE and BDNF may be involved in the antidepressant-like effect of oleanolic acid.

Rosmarinus officinalis polyphenols produce anti-depressant like effect through monoaminergic and cholinergic functions modulation

Rosmarinus officinalis (R. officinalis), a culinary aromatic and medicinal plant, is very rich in polyphenols and flavonoids with high antioxidant properties. This plant was reported to exert multiple benefits for neuronal system and alleviate mood disorder. In our previous study, we demonstrated that R. officinalis and its active compounds, luteolin (Lut), carnosic acid (CA), and rosmarinic acid (RA), exhibited neurotrophic effects and improved cholinergic functions in PC12 cells in correlation with mitogen-activated protein kinase (MAPK), ERK1/2 signaling pathway. The current study was conducted to evaluate and understand the anti-depressant effect of R. officinalis using tail suspension test (TST) in ICR mice and PC12 cells as in vitro neuronal model. Proteomics analysis of PC12 cells treated with R. officinalis polyphenols (ROP) Lut, CA, and RA revealed a significant upregulation of tyrosine hydroxylase (TH) and pyruvate carboxylase (PC) two major genes involved in dopaminergic, serotonergic and GABAergic pathway regulations. Moreover, ROP were demonstrated to protect neuronal cells against corticosterone-induced toxicity. These results were concordant with decreasing immobility time in TST and regulation of several neurotransmitters (dopamine, norepinephrine, serotonin and acetylcholine) and gene expression in mice brain like TH, PC and MAPK phosphatase (MKP-1). To the best of our knowledge this is the first evidence to contribute to the understanding of molecular mechanism behind the anti-depressant effect of R. officinalis and its major active compounds.

The antidepressant-like effects of paeoniflorin in mouse models

Peony is often used in Chinese herbal medicine for the treatment of depression-like disorders. Our previous studies have demonstrated that the total glycosides of peony exert antidepressant-like effects in animal models. Paeoniflorin is the main active glycoside of peony. The aim of this study was to evaluate the antidepressant-like effects of paeoniflorin in mice, as well as its active mechanisms. The results revealed that intraperitoneally injected paeoniflorin significantly reduced the duration of immobility in forced swimming and tail suspension tests. The doses that affected the immobility response did not affect locomotor activity. Furthermore, paeoniflorin antagonized reserpine-induced ptosis, akinesia and hypothermia. Paeoniflorin also significantly increased the levels of serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the hippocampus. These results suggest that the upregulation of serotonergic systems may be an important mechanism for the antidepressant-like effects of paeoniflorin in mice.

Antidepressant-like behavioral, neurochemical and neuroendocrine effects of naringenin in the mouse repeated tail suspension test

Our previous study demonstrated that the citrus bioflavonoid naringenin ameliorated behavioral alterations via the central serotonergic and noradrenergic systems in the tail suspension test (TST) induced mice. To better understand its pharmacological activity, mice were submitted to three 6min-TSTs one week apart (Day 1: test, Day 7: retest 1, Day 14: retest 2) followed by hippocampal glucocorticoid receptor (GR), monoamine neurotransmitters and serum corticosterone measurement. The results suggested that repeated TST detected the gradual increase in the efficacy of naringenin over time, additionally 1-day (20 mg/kg), 7-day (10, 20 mg/kg) and 14-day (5, 10, 20 mg/kg) naringenin treatment markedly decreased the immobility time. Moreover, administration of naringenin for 14 days (20 mg/kg) increased hippocampal serotonin (5-HT), norepinephrine (NE) and GR levels, and reduced serum corticosterone levels in mice exposed to the repeated TST. Overall, the present study indicated that the re-exposure would facilitate the detection of the anti-immobility effects of antidepressant drugs in the mouse TST, and clearly demonstrated that the antidepressant-like effect of naringenin may be mediated by an interaction with neuroendocrine and neurochemical systems.

Mechanistic study on the antidepressant-like effect of danggui-shaoyao-san, a chinese herbal formula

Danggui-Shaoyao-San (DSS), a famous Chinese herbal formula, has been widely used in the treatment of various diseases. Previous studies have shown that DSS produces antidepressant-like effect in rodents. This study aims to investigate the mechanism(s) underlying the antidepressant-like action of DDS. The results showed that DSS treatment significantly antagonized reserpine-induced ptosis in mice. In addition, DSS treatment significantly increased sucrose consumption in chronic unpredictable stress- (CUS-) treated mice. DSS treatment also markedly attenuated CUS-induced decreases in noradrenaline and dopamine concentrations in mouse brain. Furthermore, DSS treatment significantly reversed CUS-induced increase in serum malondialdehyde (MDA) content and decrease in serum superoxide dismutase (SOD) activity in mice. The results suggest that the antidepressant-like activity of DSS is probably mediated by the modulation of central monoamine neurotransmitter systems and the reduction of oxidative stress.

Role for monoaminergic systems in the antidepressant-like effect of ethanol extracts from Hemerocallis citrina

ETHNOPHARMACOLOGICAL RELEVANCE

Hemerocallis citrina, a traditional herbal medicine, has been used for the improvement of emotions in Eastern-Asia countries.

AIM OF THE STUDY

Herein, we explored the antidepressant-like effect and its monoaminergic mechanism of the ethanol extracts from Hemerocallis citrina (HCE).

MATERIALS AND METHODS

Effect of HCE (90, 180 and 360 mg/kg, p.o.) on the immobility time was assessed in the mouse forced swim test (FST) and tail suspension test (TST), and locomotor activity was evaluated in the open-field test (OFT). Additionally, the monoamine neurotransmitters serotonin (5-HT), noradrenaline (NA) and dopamine (DA) levels involved in the antidepressant-like effect of HCE were also measured in the mice brain regions of frontal cortex and hippocampus.

RESULTS

HCE (90, 180 and 360 mg/kg, p.o.) administration significantly reduced the immobility time in both the FST and TST without accompanying changes in locomotor activity in the OFT. The pretreatment of mice with WAY 100635 (0.1 mg/kg, s.c., a 5-HT(1A) receptor antagonist), cyproheptadine (3 mg/kg, i.p., a 5-HT(2) receptor antagonist), prazosin (62.5 μg/kg, i.p., an α(1)-adrenoceptor antagonist), yohimbine (1 mg/kg, i.p., an α(2)-adrenoceptor antagonist), propranolol (5 mg/kg, i.p., a β-adrenoceptor antagonist) or sulpiride (50 mg/kg, i.p., a dopamine D(2) receptor antagonist), but not SCH23390 (0.05 mg/kg, s.c., a dopamine D(1) receptor antagonist) prevented the antidepressant-like effect of HCE (360 mg/kg, p.o.) in the TST. In addition, HCE enhanced 5-HT and NA levels in the frontal cortex and hippocampus as well as elevated DA levels in the frontal cortex.

CONCLUSION

The results indicate that the antidepressant-like effect of HCE is dependent on the serotonergic (5-HT(1A) and 5-HT(2) receptors), noradrenergic (α(1)-, α(2)- and β-adrenoceptors) and dopaminergic (D(2) receptor) systems as well as the elevation of 5-HT, NA and DA levels in the mouse brain.

Anti-depressant-like effect of peony: a mini-review

CONTEXT

Depression is a common psychiatric disorder, yet the clinical efficacy of antidepression therapies is unsatisfactory. Thus, the search for new anti-depressants continues, and natural products remain a promising source of new therapeutic agents. The root part of Paeonia lactiflora Pall. (Ranunculaceae), known as peony, is often used in Chinese herbal prescriptions for the treatment of depression-like disorders.

OBJECTIVES

The objective of this review is to provide scientific evidence to support further research on peony as a potential anti-depressant drug.

METHODS

This review summarizes the results obtained in our laboratory, together with other literature data obtained through a comprehensive search in databases including PubMed, ScienceDirect, Scirus, and Web of Science.

RESULTS

The peony extract is active in the mouse forced swim test and tail suspension test, and it produces anti-depressant effects in chronic unpredictable mild stress-induced depression model in mice and rats. The anti-depressant mechanisms of peony are likely mediated by the inhibition of monoamine oxidase activity, neuro-protection, modulation of the function of hypothalamic-pituitary-adrenal axis, inhibition of oxidative stress, and the up-regulation of neurotrophins.

CONCLUSIONS

Peony is used clinically to treat depression-like symptoms in Chinese medicine, and it has been shown to possess anti-depressant property in a battery of test models using laboratory animals. Its effect is likely mediated by multiple targets. Further studies are warranted to delineate the molecular mechanisms of action, determine the pharmacokinetics, establish the toxicological profile, and assess the potentials of peony in clinical applications. Identification of the clinically active ingredient(s) is also warranted.