Herbal formula SYJN increases neurotrophin-3 and nerve growth factor expression in brain regions of rats exposed to chronic unpredictable stress

Kamikihito reduces β-amyloid25-35-induced axon damage via neurotrophic factors

The Japanese herbal medicine kamikihito (KKT) is widely used for insomnia, anorexia, anemia, and depression. Recently, the efficacy of KKT against Alzheimer's disease (AD) has been demonstrated in clinical and non-clinical studies. To address the mechanism underlying the effect of KKT on AD, we examined the effects of KKT in β-amyloid (Aβ)25-35-exposed primary cultured neurons. The effects of KKT on Aβ25-35-induced neurotoxicity were assessed by immunocytochemical assays and Sholl analysis of neurites, and the influence of KKT on neurotrophic factor (NF) gene expression was examined using RT-PCR analysis. As a result, Aβ25-35 exposure attenuated the arborization of neurites of single cultured hippocampal neurons, and KKT treatment for 3 days ameliorated the Aβ25-35-induced impairment of tau-positive axon outgrowth. This ameliorative effect of KKT was largely abolished by the Trk inhibitor K252a, and expression of NFs, nerve growth factor (Ngf), brain-derived neurotrophic factor (Bdnf), neurotrophin-3 (NT-3) was significantly increased by KKT. These results indicate that KKT ameliorates axonal atrophy via NFs signaling, providing a mechanistic basis for treatment of AD with KKT.

Is neurotrophin-3 (NT-3): a potential therapeutic target for depression and anxiety?

Introduction: Neurotrophin-3 (NT-3) is thought to play a role in the neurobiological processes implicated in mood and anxiety disorders. NT-3 is a potential pharmacological target for mood disorders because of its effects on monoamine neurotransmitters, regulation of synaptic plasticity and neurogenesis, brain-derived neurotrophic factor (BDNF) signaling boosting, and modulation of the hypothalamic-pituitary-adrenal (HPA) axis. The mechanisms underlying NT-3 anxiolytic properties are less clear and require further exploration and definition. Areas covered: The evidence that supports NT-3 as a pharmacological target for anxiety and mood disorders is presented and this is followed by a reflection on the quandaries, stumbling blocks, and future perspectives for this novel target. Expert opinion: There is evidence for miRNAs being key post-transcriptional regulators of neurotrophin-3 receptor gene (NTRK3) in anxiety disorders; however, the anxiolytic properties of NT-3 need further examination and delineation. Moreover, NT-3 expression by non-neuronal cells and its role in brain circuits that participate in anxiety and mood disorders require further scrutiny. Further work is vital before progression into clinical trials can be realized.

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.

GC-MS analysis of volatile compounds of Perilla frutescens Britton var. Japonica accessions: Morphological and seasonal variability

OBJECTIVE

To investigate the composition of volatile compounds in the different accessions of Perilla frutescens (P. frutescens) collected from various habitats of China and Japan.

METHODS

In the present study, the essential oil from the leaves of P. frutescens cultivars from China and Japan was extracted by hydro-distillation and the chemical composition and concentration of the volatile components present in the oils were determined by gas chromatography-mass spectrometry (GC-MS) analysis.

RESULTS

Among the volatile components, the major proportion was of perilla ketone, which was followed by elemicin and beta-caryophyllene in the Chinese Perilla cultivars. The main component in the oil extracted from the Japanese accessions was myristicin, which was followed by perilla ketone and beta-caryophyllene. We could distinguish seven chemotypes, namely the perilla ketone (PK) type, perilla ketone, myristicin (PM) type, perilla ketone, unknown (PU) type, perilla ketone, beta-caryophyllene, myristicine (PB) type, perilla ketone, myristicin, unknown (PMU) type, perilla ketone, elemicine, myristicin, beta-caryophyllene (PEMB) type, and the perilla ketone, limonene, beta-cryophyllene, myristicin (L) type. Most of the accessions possessed higher essential oil content before the flowering time than at the flowering stage. The average plant height, leaf length, leaf width of the Chinese accessions was higher than those of the Japanese accessions.

CONCLUSION

The results revealed that the harvest time and geographical origin caused polymorphisms in the essential oil composition and morphological traits in the Perilla accessions originating from China and Japan. Therefore, these chemotypes with desirable characters might be useful for industrial exploitation and for determining the harvest time.

Neuroprotective mechanism of BNG-1 against focal cerebral ischemia: a neuroimaging and neurotrophin study

BNG-1 is a herb complex used in traditional Chinese medicine to treat stroke. In this study, we attempted to identify the neuroprotective mechanism of BNG-1 by using neuroimaging and neurotrophin analyses of a stroke animal model. Rats were treated with either saline or BNG-1 for 7 d after 60-min middle cerebral artery occlusion by filament model. The temporal change of magnetic resonance (MR) imaging of brain was studied using a 7 Tesla MR imaging (MRI) system and the temporal expressions of neurotrophin-3 (NT-3), brain-derived neurotrophic factor (BDNF), and nerve growth factor (NGF) in brain were analyzed before operation and at 4 h, 2 d, and 7 d after operation. Compared with the saline group, the BNG-1 group exhibited a smaller infarction volume in the cerebral cortex in T2 image from as early as 4 h to 7 d, less edema in the cortex in diffusion weighted image from 2 to 7 d, earlier reduction of postischemic hyperperfusion in both the cortex and striatum in perfusion image at 4 h, and earlier normalization of the ischemic pattern in the striatum in susceptibility weighted image at 2 d. NT-3 and BDNF levels were higher in the BNG-1 group than the saline group at 7 d. We concluded that the protective effect of BNG-1 against cerebral ischemic injury might act through improving cerebral hemodynamics and recovering neurotrophin generation.

The Effect of Perilla frutescens Extract on the Oxidative Stability of Model Food Emulsions

The polyphenolic profile of leaves and stalks of Perilla frutescens, was assessed as a source of natural antioxidants. The amount of caffeic and rosmarinic acids, determined by high-performance liquid chromatography (HPLC), were 0.51 mg/g dry weight (DW) and 2.29 mg/g DW, respectively. The measurement of scavenging capacity against the 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical cation, the oxygen radical absorbance capacity (ORAC), and the ferric reducing antioxidant power (FRAP) were 65.03 mg Trolox equivalents (TE)/g DW, 179.60 mg TE/g DW and 44.46 mg TE/g DW, respectively. P. frutescens extracts also showed good antioxidant properties in 10% sunflower oil-in-water emulsions during storage at 32 °C. Perilla extract at 320 ppm was as effective as butylated hydroxyanisole (BHA) at 20 ppm in slowing down the formation of hydroperoxides as measured by peroxide value, thiobarbituric acid reactive substances and hexanal content. The results of this study indicate that extract of P. frutescens may be suitable for use in the food matrix to help achieve potential health benefits.

Traditional Chinese medicine and Western psychopharmacology: building bridges

This paper demonstrates that in the treatment of psychiatric disorders, there are striking similarities between the mechanisms of psychoactive agents used in Traditional Chinese Medicine (TCM) and those of western psychopharmacology. While western researchers search for new treatments and novel mechanisms of action, investigators in Asia are analyzing traditional remedies in order to understand the mechanisms responsible for their effectiveness. A review of contemporary pharmacologic studies of agents used in TCM for psychiatric indications reveals that virtually all of the active principles of drug action established in 20th century psychopharmacology were encountered empirically in Chinese herbal medicine over the past 2000 years. Building bridges between these two traditions may thus be of benefit to both cultures. In addition to providing western patients with a wider selection of treatment options, the effort may help Asian clinicians and researchers avoid some of the errors that have troubled their western counterparts.

A review on bioactivities of perilla: progress in research on the functions of perilla as medicine and food

Perilla is a useful pharmaceutical and food product and is empirically consumed by humans. However, its properties have not been evaluated extensively. In this review, we summarize the progress made in research, focusing on the bioactivities of perilla. There are many in vitro and animal studies on the cytostatic activity and antiallergic effects, respectively, of perilla and its constituents. However, its influence on humans remains unclear. Hence, investigating and clarifying the physiological effects of perilla and its constituents on humans are imperative in the future to adhere to the ideals of evidence-based medicine.

Chronic stress induces neurotrophin-3 in rat submandibular gland

PURPOSE

Plasma neurotrophin-3 (NT-3) levels are associated with several neural disorders. We previously reported that neurotrophins were released from salivary glands following acute immobilization stress. While the salivary glands were the source of plasma neurotrophins in that situation, the association between the expression of neurotrophins and the salivary gland under chronic stress conditions is not well understood. In the present study, we investigated whether NT-3 levels in the salivary gland and plasma were influenced by chronic stress.

MATERIALS AND METHODS

Expressions of NT-3 mRNA and protein were characterized, using real-time polymerase chain reactions, enzyme-linked immunosorbent assay, and immunohistochemistry, in the submandibular glands of male rats exposed to chronic stress (12 h daily for 22 days).

RESULTS

Plasma NT-3 levels were significantly increased by chronic stress (p<0.05), and remained elevated in bilaterally sialoadenectomized rats under the same condition. Since chronic stress increases plasma NT-3 levels in the sialoadenectomized rat model, plasma NT-3 levels were not exclusively dependent on salivary glands.

CONCLUSION

While the salivary gland was identified in our previous study as the source of plasma neurotrophins during acute stress, the exposure to long-term stress likely affects a variety of organs capable of releasing NT-3 into the bloodstream. In addition, the elevation of plasma NT-3 levels may play important roles in homeostasis under stress conditions.