A Modified Chinese Herbal Decoction (Kai-Xin-San) Promotes NGF-Induced Neuronal Differentiation in PC12 Cells via Up-Regulating Trk A Signaling.

Kai-Xin-San (KXS), a Chinese herbal decoction, has been applied to medical care of depression for thousands of years. It is composed of two functional paired-herbs: Ginseng Radix et Rhizoma (GR)-Polygalae Radix (PR) and Acori Tatarinowii Rhizoma (ATR)-Poria (PO). The compatibility of the paired-herbs has been frequently changed to meet the criteria of syndrome differentiation and treatment variation. Currently, a modified KXS (namely KXS2012) was prepared by optimizing the combinations of GR-PR and ATR-PO: the new herbal formula was shown to be very effective in animal studies. However, the cellular mechanism of KXS2012 against depression has not been fully investigated. Here, the study on KXS2012-induced neuronal differentiation in cultured PC12 cells was analyzed. In PC12 cultures, single application of KXS2012 showed no effect on the neuronal differentiation, but which showed robust effects in potentiating nerve growth factor (NGF)-induced neurite outgrowth and neurofilament expression. The potentiating effect of KXS2012 was mediated through NGF receptor, tropomyosin receptor kinase (Trk) A: because the receptor expression and activity was markedly up-regulated in the presence of KXS2012, and the potentiating effect was blocked by k252a, an inhibitor of Trk A. Our current results in cell cultures fully support the therapeutic efficacy of KXS2012 against depression.

A Chinese herbal decoction, reformulated from Kai-Xin-San, relieves the depression-like symptoms in stressed rats and induces neurogenesis in cultured neurons.

Kai-Xin-San (KXS), a Chinese herbal decoction for anti-depression, is a combination of paired-herbs, i.e. Ginseng Radix et Rhizoma (GR)-Polygalae Radix (PR) and Acori Tatarinowii Rhizoma (ATR)-Poria (PO). The make-up of the paired-herbs has been commonly revised according to syndrome differentiation and treatment variation of individual. Currently, an optimized KXS (KXS2012) was prepared by functional screening different combination of GR-PR and ATR-PO. The aim of this study was to verify the effect and underlying mechanism of KXS2012 against depression in chronic mild stress (CMS)-induced depressive rats and in primary cultures of neurons and astrocytes. In rat model, the CMS-induced depressive symptoms were markedly alleviated by the treatment with KXS2012. The CMS-suppressed neurotransmitter amounts were restored in the presence of KXS2012. And the expressions of neurotropic factors and its corresponding receptors were increased under KXS2012 administration. In cultured neurons, application of KXS2012 could promote neurogenesis by inducing the expression of synaptotagmin and dendritic spine density. Moreover, application of KXS2012 in cultured astrocytes, or in H2O2-stressed astrocytes, induced the expressions of neurotrophic factors: the increase might be associated with the modification of Erk1/2 and CREB phosphorylation. Our current results fully support the therapeutic efficacy of KXS2012 against depression in cell and animal models.

New perspectives for multi-level regulations of neuronal acetylcholinesterase by dioxins.

Acetylcholinesterase (AChE; EC 3.1.1.7) is a vital functional enzyme in cholinergic neurotransmission which can rapidly hydrolyze neurotransmitter, acetylcholine, in the central and peripheral nervous systems. Emerging evidence showed that in addition to classical environmental AChE inhibitors, e.g. organophosphate and carbamate pesticides, dioxins are a new type of xenobiotic causing impairment of AChE. Dioxin can transcriptionally or post-transcriptionally suppress AChE expression in human neuroblastoma cells or mouse immune cells via the aryl hydrocarbon receptor (AhR) pathway, respectively. Dioxins can affect gene expression through other mechanisms, such as cross-talk with other signaling cascades and epigenetic modulations. Therefore, in this review, by summarizing the known mechanisms of AChE regulation and dioxin-induced gene alteration, potential signaling cascades and epigenetic mechanisms are proposed for dioxin-mediated AChE regulation. Mitogen activated protein (MAP) kinase, 3', 5'-cyclic adenosine monophosphate (cAMP) and calcium-related singaling pathways, as well as potential epigenetic mechanisms, such as DNA methylation, and post-transcriptional regulation via microRNAs, including hsa-miR-132, hsa-miR-212 and hsa-miR-25-3p are discussed here. These proposed mechanisms may be invaluable not only to promote comprehensive understanding of the action mechanisms for dioxin, but to illustrate the molecular basis of dioxin-induced health impacts.

Optimizing the compatibility of paired-herb in an ancient Chinese herbal decoction Kai-Xin-San in activating neurofilament expression in cultured PC12 cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Kai-Xin-San (KXS), a well-known traditional Chinese herbal decoction, has been widely used to treat mental depression and memory loss in China. It has a combination of four herbs: Ginseng Radix et Rhizoma (GR; root and rhizome of Panax ginseng C. A. Mey.), Polygalae Radix (PR; root of Polygala tenuifolia Wild.), Acori Tatarinowii Rhizoma (ATR; rhizome of Acorus tatarinowii Schott), and Poria (PO; sclerotium of Poriacocos (Schw.) Wolf), from which a pairing of two herbs was considered as paired-herb, such as the pairing of GR-PR and ATR-PO. The depression-induced neural cell loss is one of the major pathogenesis in depression. Here, an optimized KXS by changing the ratio of paired-herbs in KXS was demonstrated aiming at promoting neural cell differentiation. MATERIALS AND METHODS: Quantitative assessment of chemical markers in each herbal extract was determined by LC-MS. Promoters of neurofilaments, NF68 and NF200, linked with luciferase reporter gene (pNF68-Luc and pNF200-Luc) were applied in cultured pheochromocytoma (PC12) cells to study the transcriptional activation of each herbal extract. The effect of GR-PR and ATR-PO in improving NF promoter activity was analyzed by Compusyn software. The activation of PKA was indicated. RESULTS: In PC12 cells, an optimized KXS named KXS1:5 having 1:5 of GR-PR:ATR-PO had greater capability in promoting the expression of neurofilament. The synergistic effect of GR-PR and ATR-PO on the improved efficiency was further determined. Moreover, the treatment of H89, a PKA inhibitor, significantly inhibited the induced NF promoter activity. CONCLUSION: These results indicated an optimized KXS by optimizing the compatibility of paired-herb and this compatibility was proven to exert synergistic effect. Moreover, the underlying mechanism was mediated by a PKA signaling pathway.

A standardized extract of the fruit of Ziziphus jujuba (Jujube) induces neuronal differentiation of cultured PC12 cells: a signaling mediated by protein kinase A.

The fruit of Ziziphus jujuba Mill., known as Chinese date or jujube, is consumed as a health supplement worldwide. To study the role of jujube in brain benefits, its effects on neuronal differentiation of PC12 cells were studied. Application of jujube water extract induced neurite outgrowth of PC12 cells, >25% of which were differentiated; this effect was similar to that of nerve growth factor. In parallel, the expressions of neurofilaments (NFs) in jujube-treated cultures showed a dose-dependent increase, with the highest inductions by ∼150% for NF68 and NF160 and by ∼100% for NF200. Application of H89, a protein kinase A inhibitor, attenuated jujube-induced neurite outgrowth of the cultures. Besides, using jujube extract induced the phosphorylation of cAMP responsive element binding protein on PC12 cells, which was blocked by H89. These results support the use of jujube as a food supplement for the prevention of neurodegenerative diseases in which neurotrophin deficiency is involved.

Flavonoids, derived from traditional Chinese medicines, show roles in the differentiation of neurons: possible targets in developing health food products.

Flavonoids, a family of phenolic compounds, are distributed in a variety of fruits, vegetables, tea, and wine. More importantly, many flavonoids are served as the active ingredients in traditional Chinese herbal medicines, which in general do not have side effects. Several lines of evidence support that flavonoids have impacts on many aspects of human health, including anti-tumor, anti-oxidation, and anti-inflammation. Recently, there is significant attention focused on the neuronal beneficial effects of flavonoids, including the promotion of nervous system development, neuroprotection against neurotoxin stress, as well as the promotion of memory, learning, and cognitive functions. Here, the activities of flavonoids on the development of nervous system are being summarized and discussed. The flavonoids from diverse herbal medicines have significant effects in different developmental stages of nervous systems, including neuronal stem cell differentiation, neurite outgrowth, and neuronal plasticity. These findings imply that flavonoids are potential candidates for the development of health supplements in preventing birth defects and neuronal diseases.

Song bu li decoction, a traditional uyghur medicine, protects cell death by regulation of oxidative stress and differentiation in cultured PC12 cells.

Song Bu Li decoction (SBL) is a traditional Uyghur medicinal herbal preparation, containing Nardostachyos Radix et Rhizoma. Recently, SBL is being used to treat neurological disorders (insomnia and neurasthenia) and heart disorders (arrhythmia and palpitation). Although this herbal extract has been used for many years, there is no scientific basis about its effectiveness. Here, we aimed to evaluate the protective and differentiating activities of SBL in cultured PC12 cells. The pretreatment of SBL protected the cell against tBHP-induced cell death in a dose-dependent manner. In parallel, SBL suppressed intracellular reactive oxygen species (ROS) formation. The transcriptional activity of antioxidant response element (ARE), as well as the key antioxidative stress proteins, was induced in dose-dependent manner by SBL in the cultures. In cultured PC12 cells, the expression of neurofilament, a protein marker for neuronal differentiation, was markedly induced by applied herbal extract. Moreover, the nerve growth factor- (NGF-) induced neurite outgrowth in cultured PC12 cells was significantly potentiated by the cotreatment of SBL. In accord, the expression of neurofilament was increased in the treatment of SBL. These results therefore suggested a possible role of SBL by its effect on neuron differentiation and protection against oxidative stress.

Flavonoids induce the expression of synaptic proteins, synaptotagmin, and postsynaptic density protein-95 in cultured rat cortical neuron.

Flavonoids, a family of phenolic compounds, are widely present in our daily diet and exist in traditional Chinese medicines, in which they act as the major active functional ingredients. Different lines of evidence indicate that flavonoids have positive impacts on human health. Here, different subclasses of flavonoids were analyzed for their inductive roles in promoting the expression of synaptic proteins, synaptotagmin, and post-synaptic density protein-95 in cultured rat cortical neurons. Among the screened 65 flavonoids, (-)-catechin, luteolin, and isorhamnetin, in micromolar concentration, were found to induce the expression of synaptic proteins in a dose-dependent manner: the induction values were from 2- to 8-fold that of the control. Similar results were revealed in the flavonoid-treated hippocampal neurons. The identification of these synapse-promoting flavonoids could be very useful in finding potential drugs, or food supplements, for treating various neurodegenerative diseases, including Alzheimer's disease and depression.

Synergistic Action of Flavonoids, Baicalein, and Daidzein in Estrogenic and Neuroprotective Effects: A Development of Potential Health Products and Therapeutic Drugs against Alzheimer's Disease.

Despite the classical hormonal effect, estrogen has been reported to mediate neuroprotection in the brain, which leads to the searching of estrogen-like substances for treating neurodegenerative diseases. Flavonoids, a group of natural compounds, are well known to possess estrogenic effects and used to substitute estrogen, that is, phytoestrogen. Flavonoid serves as one of the potential targets for the development of natural supplements and therapeutic drugs against different diseases. The neuroprotection activity of flavonoids was chosen for a possible development of anti-Alzheimer's drugs or food supplements. The estrogenic activity of two flavonoids, baicalein and daidzein, were demonstrated by their strong abilities in stimulating estrogen receptor phosphorylation and transcriptional activation of estrogen responsive element in MCF-7 breast cells. The neuroprotection effects of flavonoids against ß -amyloid (A ß ) were revealed by their inhibition effects on in vitro A ß aggregation and A ß -induced cytotoxicity in PC12 neuronal cells. More importantly, the estrogenic and neuroprotective activities of individual flavonoid could be further enhanced by the cotreatment in the cultures. Taken together, this synergistic effect of baicalein and daidzein might serve as a method to improve the therapeutic efficacy of different flavonoids against A ß , which might be crucial in developing those flavonoidsin treating Alzheimer's disease in the future.

Flavonoids induce the synthesis and secretion of neurotrophic factors in cultured rat astrocytes: a signaling response mediated by estrogen receptor.

Neurotrophic factors are playing vital roles in survival, growth, and function of neurons. Regulation of neurotrophic factors in the brain has been considered as one of the targets in developing drug or therapy against neuronal disorders. Flavonoids, a family of multifunctional natural compounds, are well known for their neuronal beneficial effects. Here, the effects of flavonoids on regulating neurotrophic factors were analyzed in cultured rat astrocytes. Astrocyte is a major secreting source of neurotrophic factors in the brain. Thirty-three flavonoids were screened in the cultures, and calycosin, isorhamnetin, luteolin, and genistein were identified to be highly active in inducing the synthesis and secretion of neurotrophic factors, including nerve growth factor (NGF), glial-derived neurotrophic factor (GDNF), and brain-derived neurotrophic factor (BDNF). The inductions were in time- and dose-dependent manners. In cultured astrocytes, the phosphorylation of estrogen receptor was triggered by application of flavonoids. The phosphorylation was blocked by an inhibitor of estrogen receptor, which in parallel reduced the flavonoid-induced expression of neurotrophic factors. The results proposed the role of flavonoids in protecting brain diseases, and therefore these flavonoids could be developed for health food supplement for patients suffering from neurodegenerative diseases.

Isorhamnetin, A Flavonol Aglycone from Ginkgo biloba L., Induces Neuronal Differentiation of Cultured PC12 Cells: Potentiating the Effect of Nerve Growth Factor.

Flavonoids, a group of compounds mainly derived from vegetables and herbal medicines, share a chemical resemblance to estrogen, and indeed some of which have been used as estrogen substitutes. In searching for possible functions of flavonoids, the neuroprotective effect in brain could lead to novel treatment, or prevention, for neurodegenerative diseases. Here, different subclasses of flavonoids were analyzed for its inductive role in neurite outgrowth of cultured PC12 cells. Amongst the tested flavonoids, a flavonol aglycone, isorhamnetin that was isolated mainly from the leaves of Ginkgo biloba L. showed robust induction in the expression of neurofilament, a protein marker for neurite outgrowth, of cultured PC12 cells. Although isorhamnetin by itself did not show significant inductive effect on neurite outgrowth of cultured PC12 cells, the application of isorhamnetin potentiated the nerve growth factor- (NGF-)induced neurite outgrowth. In parallel, the expression of neurofilaments was markedly increased in the cotreatment of NGF and isorhamnetin in the cultures. The identification of these neurite-promoting flavonoids could be very useful in finding potential drugs, or food supplements, for treating various neurodegenerative diseases, including Alzheimer's disease and depression.

Molecular Assembly and Biosynthesis of Acetylcholinesterase in Brain and Muscle: the Roles of t-peptide, FHB Domain, and N-linked Glycosylation.

Acetylcholinesterase (AChE) is responsible for the hydrolysis of the neurotransmitter, acetylcholine, in the nervous system. The functional localization and oligomerization of AChE T variant are depending primarily on the association of their anchoring partners, either collagen tail (ColQ) or proline-rich membrane anchor (PRiMA). Complexes with ColQ represent the asymmetric forms (A(12)) in muscle, while complexes with PRiMA represent tetrameric globular forms (G(4)) mainly found in brain and muscle. Apart from these traditional molecular forms, a ColQ-linked asymmetric form and a PRiMA-linked globular form of hybrid cholinesterases (ChEs), having both AChE and BChE catalytic subunits, were revealed in chicken brain and muscle. The similarity of various molecular forms of AChE and BChE raises interesting question regarding to their possible relationship in enzyme assembly and localization. The focus of this review is to provide current findings about the biosynthesis of different forms of ChEs together with their anchoring proteins.

Baicalin, a flavone, induces the differentiation of cultured osteoblasts: an action via the Wnt/beta-catenin signaling pathway.

Flavonoids, a group of natural compounds found in a variety of vegetables and herbal medicines, have been intensively reported on regarding their estrogen-like activities and particularly their ability to affect bone metabolism. Here, different subclasses of flavonoids were screened for their osteogenic properties by measuring alkaline phosphatase activity in cultured rat osteoblasts. The flavone baicalin derived mainly from the roots of Scutellaria baicalensis showed the strongest induction of alkaline phosphatase activity. In cultured osteoblasts, application of baicalin increased significantly the osteoblastic mineralization and the levels of mRNAs encoding the bone differentiation markers, including osteonectin, osteocalcin, and collagen type 1α1. Interestingly, the osteogenic effect of baicalin was not mediated by its estrogenic activity. In contrast, baicalin promoted osteoblastic differentiation via the activation of the Wnt/ß-catenin signaling pathway; the activation resulted in the phosphorylation of glycogen synthase kinase 3ß and, subsequently, induced the nuclear accumulation of the ß-catenin, leading to the transcription activation of Wnt-targeted genes for osteogenesis. The baicalin-induced osteogenic effects were fully abolished by DKK-1, a blocker of Wnt/ß-catenin receptor. Moreover, baicalin also enhanced the mRNA expression of osteoprotegerin, which could regulate indirectly the activation of osteoclasts. Taken together, our results suggested that baicalin could act via Wnt/ß-catenin signaling to promote osteoblastic differentiation. The osteogenic flavonoids could be very useful in finding potential drugs, or food supplements, for treating post-menopausal osteoporosis.

The extract of Rhodiolae Crenulatae Radix et Rhizoma induces the accumulation of HIF-1α via blocking the degradation pathway in cultured kidney fibroblasts.

Rhodiolae Crenulatae Radix et Rhizoma (Rhodiola), the root and rhizome of Rhodiola crenulata (Hook. f. et Thoms.) H. Ohba, has been used as a traditional Chinese medicine (TCM) to increase the body resistance against hypoxia in mountain sickness. The mechanism of this adaptogenic property deriving from Rhodiola, however, has not been revealed. Erythropoietin (EPO) is an erythrocyte-specific hematopoietic hormone that increases the production of red blood cells: this hormone is a crucial factor in regulating the body balance in responding to hypoxia. In cultured kidney fibroblasts (HEK293T), application of water extract deriving from Rhodiola induced the expression of EPO both in mRNA and protein levels. The activation of the Hypoxia Response Element (HRE) located on the promoter region of the EPO gene is one of the mechanisms accounting for transcriptional activation. In addition, the Rhodiola-induced EPO expression was triggered by an increase of hypoxia-inducible factor-1 α (HIF-1 α) protein, via the reduction of HIF-1 α degradation but not the induction of HIF-1 α mRNA. Moreover, the same EPO induction effect by Rhodiola was also observed in cultured liver cells since liver is another vital organ to provide EPO regulation apart from the kidney. These results therefore elucidate one of the molecular mechanisms of this herb in mediating the anti-hypoxia function.

Quality assessment of a formulated Chinese herbal decoction, Kaixinsan, by using rapid resolution liquid chromatography coupled with mass spectrometry: A chemical evaluation of different historical formulae.

Kaixinsan is an ancient Chinese herbal decoction mainly prescribed for patients suffering from mental depression. This decoction was created by Sun Si-miao of Tang Dynasty (A.D. 600) in ancient China, and was composed of four herbs: Radix and Rhizome Ginseng, Radix Polygalae, Rhizoma Acori Tatarinowii and Poria. Historically, this decoction has three different formulations, each recorded at a different point in time. In this study, the chemical compositions of all three Kaixinsan formulae were analyzed. By using rapid resolution LC coupled with a diode-array detector and an ESI triple quadrupole tandem MS (QQQ-MS/MS), the Radix and Rhizome Ginseng-derived ginsenosides including Rb(1), Rd, Re, Rg(1), the Radix Polygalae-derived 3,6'-disinapoyl sucrose, the Rhizoma Acori Tatarinowii-derived α- and ß-asarone and the Poria-derived pachymic acid were compared among the three different formulations. The results showed variations in the solubility of different chemicals between one formula and the others. This systematic method developed could be used for the quality assessment of this herbal decoction.

Galangin, a flavonol derived from Rhizoma Alpiniae Officinarum, inhibits acetylcholinesterase activity in vitro.

Acetylcholinesterase (AChE) inhibitors are widely used for the treatment of Alzheimer's disease (AD). Several AChE inhibitors, e.g. rivastigmine, galantamine and huperzine are originating from plants, suggesting that herbs could potentially serve as sources for novel AChE inhibitors. Here, we searched potential AChE inhibitors from flavonoids, a group of naturally occurring compounds in plants or traditional Chinese medicines (TCM). Twenty-one flavonoids, covered different subclasses, were tested for their potential function in inhibiting AChE activity from the brain in vitro. Among all the tested flavonoids, galangin, a flavonol isolated from Rhizoma Alpiniae Officinarum, the rhizomes of Alpiniae officinarum (Hance.) showed an inhibitory effect on AChE activity with the highest inhibition by over 55% and an IC(50) of 120 microM and an enzyme-flavonoid inhibition constant (K(i)) of 74 microM. The results suggest that flavonoids could be potential candidates for further development of new drugs against AD.

PRiMA directs a restricted localization of tetrameric AChE at synapses.

Acetylcholinesterase (AChE), a highly polymorphic enzyme with various splicing variants and molecular isoforms, plays an essential role in the cholinergic neurotransmission by hydrolyzing acetylcholine into choline and acetate. The AChE(T) variant is expressed in the brain and muscle: this subunit forms non-amphiphilic tetramers with a collagen tail (ColQ) as asymmetric AChE (A(12) AChE) in muscle, and amphiphilic tetramers with a proline-rich membrane anchor (PRiMA) as globular AChE (G(4) AChE) in the brain and muscle. During the brain development, the expression of amphiphilic G(4) AChE is up regulated and becomes the predominant form of AChE there. This up-regulation of G(4) AChE can be attributed to the increased expressions of both AChE(T) and PRiMA. A significant portion of this membrane-bound G(4) AChE is localized at the membrane rafts of the cell membranes derived from the brain. This raft association could be directed by PRiMA via its CRAC (cholesterol recognition/interaction amino acid consensus) motif and C-terminus. In cultured cortical neurons and muscles, the PRiMA-linked AChE was clustered and partially co-localized with synaptic proteins. The restricted localizations suggest that the raft association of PRiMA-linked AChE could account for its synaptic localization and function.