Nobiletin-rich kososan, a Kampo formula, prevents the onset of apathy-like behavior and neuroinflammation in sickness behavior mouse model induced by increasing doses of lipopolysaccharide

Infectious diseases are often concomitant with symptoms of lassitude and emotional disturbances, including depression, the so-called sickness behavior. Kososan, a Kampo (traditional Japanese herbal) formula, has been clinically used for depressive mood, with demonstrated efficacy in stress-induced depressive-like behavior mouse models. Additionally, our previous study has shown that nobiletin-rich kososan (NKS) prevents aging-related depressive-like behaviors and neuroinflammation in mice. Here, we examined whether NKS alleviates depressive-like behavior and neuroinflammation in a mouse model of sickness behavior induced by lipopolysaccharide (LPS). Repeated oral administration of NKS and the positive control antidepressant paroxetine (Paro) significantly prevented this behavior. NKS and Paro significantly increased the anti-inflammatory milieu in the hippocampus and prefrontal cortex (PFC), as well as brain microglia, of LPS-injected mice. The expression of the vascular tight junction protein claudin-5 was also significantly increased by the treatment with NKS, but not with Paro, in the hippocampus and PFC of LPS-injected mice. In vitro analysis using brain microvascular endothelial cells (BMVECs) showed that incubation with 5% serum derived from mice orally administered NKS resulted in a significant increase in the expression of anti-inflammatory heme oxygenase 1 as well as autophagic flux markers. Moreover, the claudin-5 levels in BMVECs were also increased under LPS-stimulated conditions. These results suggest that NKS exerts prophylactic effects against the LPS-induced apathy-like behavior, partly mediated by the increase in the anti-inflammatory milieu and in the levels of tight junction proteins in the brain. This study provides scientific evidence supporting the potential efficacy of NKS in preventing post-infection depression.

Possible role of exercise therapy on depression: Effector neurotransmitters as key players

About 280 million people suffer from depression as the most common neurological disorder and the most common cause of death worldwide. Exercise with serotonin released in the brain by the 5-HT3-IGF-1 mechanism can lead to antidepressant effects. Swimming exercise has antidepressant effects by increasing the sensitivity of serotonin 5-HT2 receptors and postsynaptic 5-HT1A receptors, increasing 5-HT and 5HIAA levels, increasing TPH and serotonin, and decreasing inflammatory levels of IFN-γ and TNF-α. Anaerobic and aerobic exercises increase beta-endorphin, enkephalin, and dynorphin and have antidepressant effects. Exercise by increasing dopamine, D1R, and D2R leads to the expression of BDNF and activation of TrkB and has antidepressant behavior. Exercise leads to a significant increase in GABAAR (γ2 and α2 subunits) and reduces neurodegenerative disorders caused by GABA imbalance through anti-inflammatory pathways. By increasing glutamate and PGC1α and reducing glutamatergic neurotoxicity, exercise enhances neurogenesis and synaptogenesis and prevents neurodegeneration and the onset of depression. Irisin release during exercise shows an important role in depression by increasing dopamine, BDNF, NGF, and IGF-1 and decreasing inflammatory mediators such as IL-6 and IL-1β. In addition, exercise-induced orexin and NPY can increase hippocampal neurogenesis and relieve depression. After exercise, the tryptophan to large neutral amino acids (TRP/LNAA) ratio and the tryptophan to branched-chain amino acids (BCAA) ratio increase, which may have antidepressant effects. The expression of M5 receptor and nAChR α7 increases after exercise and significantly increases dopamine and acetylcholine and ameliorates depression. It appears that during exercise, muscarinic receptors can reduce depression through dopamine in the absence of acetylcholine. Therefore, exercise can be used to reduce depression by affecting neurotransmitters, neuromodulators, cytokines, and/or neurotrophins.

Protective Role and Functional Engineering of Neuropeptides in Depression and Anxiety: An Overview

Behavioral disorders, such as anxiety and depression, are prevalent globally and touch children and adults on a regular basis. Therefore, it is critical to comprehend how these disorders are affected. It has been demonstrated that neuropeptides can influence behavior, emotional reactions, and behavioral disorders. This review highlights the majority of the findings demonstrating neuropeptides' behavioral role and functional engineering in depression and anxiety. Gut-brain peptides, hypothalamic releasing hormone peptides, opioid peptides, and pituitary hormone peptides are the four major groups of neuropeptides discussed. Some neuropeptides appear to promote depression and anxiety-like symptoms, whereas others seem to reduce it, all depending on the receptors they are acting on and on the brain region they are localized in. The data supplied here are an excellent starting point for future therapy interventions aimed at treating anxiety and depression.

Preventive effect of a Kampo medicine, kososan, on recurrent depression in a mouse model of repeated social defeat stress

Depression is deemed a mood disorder characterized by a high rate of relapse. Therefore, overcoming of the recurrent depression is globally expecting. Kososan, a traditional Japanese herbal medicine, has been clinically used for mild depressive mood, and our previous studies have shown some evidence for its antidepressive-like efficacy in experimental animal models of depression. However, it remains unclear whether kososan has beneficial effects on recurrent depression. Here, we examined its effect using a mouse model of modified repeated social defeat stress (SDS) paradigm. Male BALB/c mice were exposed to a 5-min SDS from unfamiliar aggressive CD-1 mice for 5 days. Kososan extract (1.0 kg/kg/day) or an antidepressant milnacipran (60 mg/kg/day) was administered orally for 26 days (days 7-32) to depression-like mice with social avoidant behaviors on day 6. Single 5 min of SDS was subjected to mice recovered from the social avoidance on day 31, and then the recurrence of depression-like behaviors was evaluated on day 32. Hippocampal gene expression patterns were also assayed by DNA microarray analysis. Water- or milnacipran-administered mice resulted in a recurrence of depression-like behaviors by re-exposure of single SDS, whereas kososan-administered mice did not recur depression-like behaviors. Distinct gene expression patterns were also found for treating kososan and milnacipran. Collectively, this finding suggests that kososan exerts a preventive effect on recurrent depression-like behaviors in mice. Pretreatment of kososan is more useful for recurrent depression than that of milnacipran.

Kampo formulas alleviate aging-related emotional disturbances and neuroinflammation in male senescence-accelerated mouse prone 8 mice

Aging-induced neuroinflammation, also known as neuroinflammaging, plays a pivotal role in emotional disturbances, including depression and anxiety, in older individuals, thereby leading to cognitive dysfunction. Although numerous studies have focused on therapeutic strategies for cognitive impairment in older individuals, little research has been performed on treating its preceding emotional disturbances. Here, we examined whether Kampo formulas (kososan [KS], nobiletin-rich kososan [NKS], and hachimijiogan [HJG]) can ameliorate aging-induced emotional disturbances and neuroinflammation in mice. The depression-like behaviors observed in SAMP8 mice, relative to normally aging SAMR1 mice, were significantly prevented by treatment with Kampo formulas for 13 weeks. Western blot analysis revealed that hippocampal neuroinflammation was significantly abrogated by Kampo formulas. KS and NKS also significantly attenuated the hippocampal neuroinflammatory priming induced by lipopolysaccharide (LPS, 0.33 mg/kg, i.p.) challenge in SAMP8 mice. Hippocampal IL-1β, IL-6, and MCP-1 levels were significantly decreased in NKS-treated SAMP8 mice. KS and NKS showed significantly reduced tau accumulation in the brains of SAMP8 mice. RNA-sequencing revealed that each Kampo formula led to unique dynamics of hippocampal gene expression and appeared to abrogate hippocampal inflammatory responses. HJG significantly blocked the LPS-induced increase in serum IL-6 and MCP-1. These results suggest that Kampo formulas would be useful for treating aging-induced depression, in part by regulating neuroinflammatory pathways. This finding may pave the way for the development of therapeutic strategies for aging-related emotional disturbances, which may contribute to the prevention of cognitive dysfunction in older individuals.

Kososan, a Kampo medicine, prevents a social avoidance behavior and attenuates neuroinflammation in socially defeated mice

Background

Kososan, a Kampo (traditional Japanese herbal) medicine, has been used for the therapy of depressive mood in humans. However, evidence for the antidepressant efficacy of kososan and potential mechanisms are lacking. Recently, it has been recognized that stress triggers neuroinflammation and suppresses adult neurogenesis, leading to depression and anxiety. Here, we examined whether kososan extract affected social behavior in mice exposed to chronic social defeat stress (CSDS), an animal model of prolonged psychosocial stress, and neuroinflammation induced by CSDS.

Methods

In the CSDS paradigm, C57BL/6J mice were exposed to 10 min of social defeat stress from an aggressive CD-1 mouse for 10 consecutive days (days 1–10). Kososan extract (1.0 g/kg) was administered orally once daily for 12 days (days 1–12). On day 11, the social avoidance test was performed to examine depressive- and anxious-like behaviors. To characterize the impacts of kososan on neuroinflammation and adult neurogenesis, immunochemical analyses and ex vivo microglial stimulation assay with lipopolysaccharide (LPS) were performed on days 13–15.

Results

Oral administration of kososan extract alleviated social avoidance, depression- and anxiety-like behaviors, caused by CSDS exposure. CSDS exposure resulted in neuroinflammation, as indicated by the increased accumulation of microglia, the resident immune cells of the brain, and their activation in the hippocampus, which was reversed to normal levels by treatment with kososan extract. Additionally, in ex vivo studies, CSDS exposure potentiated the microglial pro-inflammatory response to a subsequent LPS challenge, an effect that was also blunted by kososan extract treatment. Indeed, the modulatory effect of kososan extract on neuroinflammation appears to be due to a hippocampal increase in an anti-inflammatory phenotype of microglia while sparing an increased pro-inflammatory phenotype of microglia caused by CSDS. Moreover, reduced adult hippocampal neurogenesis in defeated mice was recovered by kososan extract treatment.

Conclusions

Our findings suggest that kososan extract prevents a social avoidant behavior in socially defeated mice that is partially mediated by the downregulation of hippocampal neuroinflammation, presumably by the relative increased anti-inflammatory microglia and regulation of adult hippocampal neurogenesis. Our present study also provides novel evidence for the beneficial effects of kososan on depression/anxiety and the possible underlying mechanisms.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-017-0876-8) contains supplementary material, which is available to authorized users.

Murine Depression Model and its Potential Applications for Discovering Foods and Farm Products with Antidepressant-Like Effects

Advanced societies face increased health problems related to various stresses. Chronic psychological stress is a major risk factor for psychiatric disorders such as depression. Although therapeutic agents reduce several symptoms of depression, most have side effects in a broad range of the population. Furthermore, some victims of depression do not show significant improvement with any drugs, so alternative approaches are needed. Good dietary habits may potentially reduce depressive symptoms, but there is little scientific evidence thus far. Murine depression models are useful to test nutritional approaches in vivo. Our model mice subjected to a subchronic mild social defeat stress (sCSDS) paradigm show several alterations in physiological parameters and social behavior. These stress-induced symptoms in sCSDS mice can be used as cues to identify antidepressant-like natural resources including foods and farm products. We previously discovered that sCSDS mice show more vulnerability to social stress by changing dietary condition. In addition, we developed a more objective system for analyzing mouse behavior using a 3D depth-sensing camera to understand relationships between diet and behavior. The combination of sCSDS mice with 3D behavioral analysis is a powerful method for screening ingredients in foods and farm products for antidepressant-like effects.

Traditional Japanese medicines inhibit compound action potentials in the frog sciatic nerve

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Japanese (Kampo) medicines have a variety of clinical effects including pain alleviation, but evidence for a mechanism for their pain relief has not yet been elucidated fully. Considering that Kampo medicine contains many plant-derived chemicals having an ability to inhibit nerve action potential conduction, it is possible that this medicine inhibits nerve conduction. The purpose of the present study was to know how various Kampo medicines affect nerve conduction.

MATERIALS AND METHODS

We examined the effects of Kampo and crude medicines on compound action potentials (CAPs) recorded from the frog sciatic nerve by using the air-gap method.

RESULTS

Daikenchuto, rikkosan, kikyoto, rikkunshito, shakuyakukanzoto and kakkonto concentration-dependently reduced the peak amplitude of the CAP. Among the Kampo medicines, daikenchuto was the most effective in inhibiting CAPs. Daikenchuto is composed of three kinds of crude medicine, Japanese pepper, processed ginger and ginseng radix. When the crude medicines were tested, Japanese pepper and processed ginger reduced CAP peak amplitudes, while ginseng radix hardly affected CAPs. Moreover, there was an interaction between the Japanese pepper and processed ginger activities in such that one medicine at low but not high concentrations increased the extent of the inhibition by the other one that was co-applied.

CONCLUSIONS

Kampo medicines have an ability to inhibit nerve conduction. This action of daikenchuto is due to Japanese pepper and processed ginger but not ginseng radix, probably through an interaction between Japanese pepper and processed ginger in a manner dependent on their concentrations. Nerve conduction inhibition could contribute to at least a part of Kampo medicine's clinical effects such as pain alleviation.

Kososan, a standardized traditional Japanese herbal medicine, reverses sleep disturbance in socially isolated mice via GABAA-benzodiazepine receptor complex activation

PURPOSE

Kososan (KSS), a traditional Japanese medicine with a distinct aroma, is clinically used to treat affective disorders but its antidepressant-like effect has not been thoroughly investigated. In this study, we investigated the effects of inhaled and orally administered KSS on sleep disturbances in socially isolated mice.

METHODS

Four-weeks-old male ddy mice were housed either in social isolation or in groups for 4-6 weeks before the experiment. KSS was orally administered (0.5 or 1.0 g/kg) or inhaled (0.5, 1.0, or 2.5 g/0.125 m(3)) 60 min before pentobarbital administration. Stress levels in mice were evaluated by the duration of pentobarbital-induced sleeping time.

RESULTS

Sleeping time was shorter in socially-isolated mice than in group-housed mice. Oral and inhaled KSS prolonged sleeping time in stressed mice, but had no effect on sleeping time of group-housed mice. Prolonged sleeping time after oral KSS was significantly inhibited (p<0.05) by bicuculline (3 mg/kg, i.p.), a GABAA antagonist, but not by flumazenil (3 mg/kg, i.p.), a selective benzodiazepine antagonist. Prolonged sleeping time after KSS inhalation was significantly inhibited (p<0.05) by flumazenil but not by bicuculline.

CONCLUSIONS

Our findings suggest that KSS activates GABAA-benzodiazepine receptor complex and reverses shortened pentobarbital-induced sleep caused by social isolation.

Mood disorders and complementary and alternative medicine: a literature review

Mood disorders are a major public health problem and are associated with considerable burden of disease, suicides, physical comorbidities, high economic costs, and poor quality of life. Approximately 30%-40% of patients with major depression have only a partial response to available pharmacological and psychotherapeutic interventions. Complementary and alternative medicine (CAM) has been used either alone or in combination with conventional therapies in patients with mood disorders. This review of the literature examines evidence-based data on the use of CAM in mood disorders. A search of the PubMed, Medline, Google Scholar, and Quertile databases using keywords was conducted, and relevant articles published in the English language in the peer-reviewed journals over the past two decades were retrieved. Evidence-based data suggest that light therapy, St John's wort, Rhodiola rosea, omega-3 fatty acids, yoga, acupuncture, mindfulness therapies, exercise, sleep deprivation, and S-adenosylmethionine are effective in the treatment of mood disorders. Clinical trials of vitamin B complex, vitamin D, and methylfolate found that, while these were useful in physical illness, results were equivocal in patients with mood disorders. Studies support the adjunctive role of omega-3 fatty acids, eicosapentaenoic acid, and docosahexaenoic acid in unipolar and bipolar depression, although manic symptoms are not affected and higher doses are required in patients with resistant bipolar depression and rapid cycling. Omega-3 fatty acids are useful in pregnant women with major depression, and have no adverse effects on the fetus. Choline, inositol, 5-hydroxy-L-tryptophan, and N-acetylcysteine are effective adjuncts in bipolar patients. Dehydroepiandrosterone is effective both in bipolar depression and depression in the setting of comorbid physical disease, although doses should be titrated to avoid adverse effects. Ayurvedic and homeopathic therapies have the potential to improve symptoms of depression, although larger controlled trials are needed. Mind-body-spirit and integrative medicine approaches can be used effectively in mild to moderate depression and in treatment-resistant depression. Currently, although CAM therapies are not the primary treatment of mood disorders, level 1 evidence could emerge in the future showing that such treatments are effective.