Kiyoshi Terawaki

Partial agonistic effect of yokukansan on human recombinant serotonin 1A receptors expressed in the membranes of Chinese hamster ovary cells

ETHNOPHARMACOLOGICAL RELEVANCE Yokukansan (YKS) is a traditional Japanese medicine consisted of seven medicinal herbs and has been used for treatment of neurosis, insomnia, and behavioral and psychological symptoms of dementia (BPSD) in Japan. AIM OF THE STUDY The aim of the present study is to clarify the intrinsic activity of YKS on serotonin (5-HT)1A and 5-HT2A receptors and also to determine the constituent herbs which are responsible for the effect of YKS. MATERIALS AND METHODS The dry powdered extracts of YKS, seven constituent herbs, and YKS-analogues which were produced by eliminating one of the constituent herbs from YKS in the manufacturing process, were used for the evaluation. Competitive binding assays for 5-HT receptors and [(35)S]GTPgammaS binding assays for the evaluation of agonistic/antagonistic activity were performed using Chinese hamster ovary cell membranes stably expressing human recombinant 5-HT1A or 5-HT2A receptors. RESULTS YKS (6.25-400 microg/ml) concentration-dependently inhibited the binding of [(3)H]8-OH-DPAT to 5-HT1A receptors. The IC(50) value was estimated to be 61.2 microg/ml. In contrast, YKS failed to inhibit the binding of [(3)H]ketanserin to 5-HT2A receptors. Only Uncaria hook (3.13-50 microg/ml), of the seven constituent herbal extracts, inhibited the [(3)H]8-OH-DPAT binding to 5-HT1A receptors in a concentration-dependent manner, and the IC(50) value was estimated to be 7.42 microg/ml. The extracts of YKS or Uncaria hook increased [(35)S]GTPgammaS binding to 5-HT1A receptors to approximately 50% of that of a full agonist, 5-HT. Both the competitive binding and [(35)S]GTPgammaS binding of YKS to 5-HT1A receptors were remarkably attenuated by eliminating Uncaria hook from YKS, but it was almost unchanged when one of the other constituent herbs was eliminated from YKS. CONCLUSION These results suggest that YKS has a partial agonistic effect on 5-HT1A receptors, which is mainly attributed to Uncaria hook.

Effect of yokukansan, a traditional Japanese medicine, on social and aggressive behaviour of para-chloroamphetamine-injected rats

Objectives Yokukansan, a traditional Japanese medicine, has been approved by the Ministry of Health, Labour, and Welfare of Japan as a remedy for neurosis, insomnia or night crying and irritability in children. It has recently been reported to improve behavioural and psychological symptoms of dementia, such as hallucinations, agitation, and aggressiveness in patients with some forms of senile dementia. Little is known about the mechanism underlying the effectiveness of yokukansan. Our aim was to clarify the involvement of yokukansan in serotonergic function in para‐chloroamphetamine (PCA)‐induced aggressive behaviour in rats.

A Review of Traditional Japanese Medicines and their Potential Mechanism of Action

Traditional Japanese herbal, or Kampo medicine was developed and modified from Chinese herbal medicine. After the Japanese government approved Kampo for clinical use, much attention has been paid to establishing scientific evidence for the effectiveness of these medicines. Recent progress has been made in elucidating the mechanisms of action of some types of Kampo medicine, including rikkunshito (RKT), daikenchuto, and yokukansan. In this review, we focused on identifying the target molecules and the active ingredients of RKT. Thus far, many target molecules have been implicated in the mechanism of action of Kampo medicines, such as ion channels, enzymes, and receptors. In particular, G protein-coupled receptors are attractive candidates for explaining herbal medicine activity. This is particularly true of RKT, which is composed of 8 independent, crude drug extracts. Recent reports have shown that RKT elicits its effects through dual action to the G protein-coupled receptors: inhibition of serotonergic 5-HT2C and 5-HT2B receptors and activation of ghrelin receptors via specific ingredients of RKT. In addition, we suggest that the identification of the effective ingredients from Kampo medicines could contribute to the discovery and development of new drugs by means of modern high-throughput drug screening technology.

Effects of yokukansan and donepezil on learning disturbance and aggressiveness induced by intracerebroventricular injection of amyloid β protein in mice

The effects of yokukansan and donepezil on learning disturbance and aggressiveness were examined in amyloid β protein (Aβ)‐injected mice. Intellicage tests showed that both yokukansan and donepezil ameliorated Aβ‐induced learning disturbance, but the ameliorating effect of donepezil was not enhanced by concomitant administration of yokukansan. On the other hand, a social interaction test showed that Aβ‐induced aggressiveness was ameliorated by yokukansan, but not by donepezil. Co‐administration of both drugs also ameliorated aggressiveness, as did yokukansan alone. In vitro binding assays revealed that yokukansan did not bind to choline receptors or transporters. In vitro enzyme assays revealed that yokukansan did not affect choline acetyltransferase activity or inhibit acetylcholinesterase activity, as did donepezil. These results suggest that yokukansan might ameliorate aggressiveness without interfering with the pharmacological efficacy (antidementia effect) of donepezil and also that concomitant administration of yokukansan might be useful for amelioration of aggressiveness, which was not lessened by donepezil. The difference in the efficacies of both drugs may be due to a difference in their pharmacological mechanisms. Copyright

New cancer cachexia rat model generated by implantation of a peritoneal dissemination-derived human stomach cancer cell line

Cancer cachexia (CC), a syndrome characterized by anorexia and body weight loss due to low fat-free mass levels, including reduced musculature, markedly worsens patient quality of life. Although stomach cancer patients have the highest incidence of cachexia, few experimental models for the study of stomach CC have been established. Herein, we developed stomach CC animal models using nude rats subcutaneously implanted with two novel cell lines, i.e., MKN45c185, established from the human stomach cancer cell line MKN-45, and 85As2, derived from peritoneal dissemination of orthotopically implanted MKN45c185 cells in mice. Both CC models showed marked weight loss, anorexia, reduced musculature and muscle strength, increased inflammatory markers, and low plasma albumin levels; however, CC developed earlier and was more severe in rats implanted with 85As2 than in those implanted with MKN45cl85. Moreover, human leukemia inhibitory factor (LIF), a known cachectic factor, and hypothalamic orexigenic peptide mRNA levels increased in the models, whereas hypothalamic anorexigenic peptide mRNA levels decreased. Surgical removal of the tumor not only abolished cachexia symptoms but also reduced plasma LIF levels to below detectable limits. Importantly, oral administration of rikkunshito, a traditional Japanese medicine, substantially ameliorated CC-related anorexia and body composition changes. In summary, our novel peritoneal dissemination-derived 85As2 rat model developed severe cachexia, possibly caused by LIF from cancer cells, that was ameliorated by rikkunshito. This model should provide a useful tool for further study into the mechanisms and treatment of stomach CC.

The gene expression of the hypothalamic feeding-regulating peptides in cisplatin-induced anorexic rats.

Cisplatin has been widely used; however, various disadvantageous side effects afflict patients. Rikkunshito (RKT), a traditional Japanese herbal medicine, has been widely prescribed in Japan to improve anorexia; but the mechanisms are unknown. Here we studied whether RKT could improve anorexia induced by cisplatin and changes in feeding-regulating peptides in the hypothalamus in rats. Adult male rats were divided into 4 groups: water+saline (WS), water+cisplatin (WC), RKT+saline (RS), and RKT+cisplatin (RC) groups. Water or RKT (1g/kg) was intragastrically administered for 4 days, from day -1 to day 2, and saline or cisplatin (6mg/kg) was intraperitoneally (i.p.) administered at day 0. After i.p. administration, cumulative food intake, water intake, urine volume and body weight were measured. The rats were then decapitated, followed by removal of the brain, and feeding-regulating peptides in the hypothalamus were measured by in situ hybridization histochemistry. In the three-day measurements, there were no significant changes in cumulative water intake and urine volume. The body weight and cumulative food intake in WC significantly decreased compared to WS, whereas these were not observed in RC. Pro-opiomelanocortin (POMC) and cocaine and amphetamine-regulated transcript (CART) in the arcuate nucleus (ARC) in WC significantly increased, and neuropeptide Y (NPY) in the ARC decreased compared to WS, whereas those in RS and RC were comparable to WS. These results suggest that RKT may have therapeutic potential for anorexia induced by cisplatin.

Inhibitory Effects of Isoflavones on Tumor Growth and Cachexia in Newly Established Cachectic Mouse Models Carrying Human Stomach Cancers

Cachexia, a negative prognostic factor, worsens a patients quality of life. We established 2 novel cachexia models with the human stomach cancer cell line MKN-45, which was subcloned to produce potent cachexia-inducing cells by repeating the xenografts in immune-deficient mice. After subsequent xenografts, we isolated potent cachexia-inducing cells (MKN45cl85 and 85As2mLuc). Xenografts of MKN45cl85 cells in mice led to substantial weight loss and reduced adipose tissue and musculature volumes, whereas xenografts of 85As2mLuc cells resulted in highly metastatic and cachectic mice. Surgical removal of tumor tissues helped the mice regain body-weight in both mouse models. In vitro studies using these cells showed that isoflavones reduced their proliferation, implying that the isoflavones possess antiproliferative effects of these cancer cell lines. Isoflavone treatment on the models induced tumor cytostasis, attenuation of cachexia, and prolonged survival whereas discontinuation of the treatment resulted in progressive tumor growth and weight loss. The inhibitory effects of tumor growth and weight loss by isoflavones were graded as soy isoflavone aglycone AglyMax > daidzein > genistein. These results demonstrated that the 2 novel cachectic mouse models appear useful for analyzing the mechanism of cancer cachexia and monitoring the efficacy of anticachectic agents.

The clinical use of Kampo medicines (traditional Japanese herbal treatments) for controlling cancer patients’ symptoms in Japan: a national cross-sectional survey

BackgroundKampo medicines are traditional Japanese medicines produced from medicinal plants and herbs. Even though the efficacy of Kampo medicines for controlling cancer-related symptoms is being reported, their actual nationwide clinical use has not been comprehensively investigated. We aimed to investigate physicians’ recognition of Kampo medicines and their clinical use for cancer patients in the field of palliative care.MethodsA cross-sectional self-administered anonymous questionnaire was distributed to 549 physicians working in palliative care teams at 388 core cancer treatment hospitals and 161 certified medical institutions that have palliative care units (PCUs).ResultsValid responses were obtained from 311 physicians (response rate, 56.7%) who were evenly distributed throughout the country without significant geographical biases. Kampo medicines were prescribed for controlling cancer-related symptoms by 64.3% of the physicians. The symptoms treated with Kampo medicines were numbness/hypoesthesia (n = 99, 49.5%), constipation (n = 76, 38.0%), anorexia/weight loss (n = 72, 36%), muscle cramps (n = 71, 35.5%) and languor/fatigue (n = 64, 32.0%). Regarding open issues about prescription, 60.7% (n = 173) of the physicians raised the issue that the dosage forms need to be better devised.ConclusionsTo increase the clinical use of Kampo medicines, more evidence from clinical studies is necessary. In addition, their mechanisms of action should be clarified through laboratory studies.

Kisspeptin-10 potentiates miniature excitatory postsynaptic currents in the rat supraoptic nucleus.

Kisspeptin is the natural ligand of the G protein-coupled receptor -54 and plays a major role in gonadotropin-releasing hormone secretion in the hypothalamus. Kisspeptin-10 is an endogenous derivative of kisspeptin and has 10 -amino acids. Previous studies have demonstrated that central administration of kisspeptin-10 stimulates the secretion of arginine vasopressin (AVP) in male rats. We examined the effects of kisspeptin-10 on- excitatory synaptic inputs to magnocellular neurosecretory cells (MNCs) including AVP neurons in the supraoptic nucleus (SON) by obtaining in vitro whole-cell patch-clamp recordings from slice preparations of the rat brain. The application of kisspeptin-10 (100 nM-1 μM) significantly increased the frequency of miniature excitatory postsynaptic currents (mEPSCs) in a dose-related manner without affecting the amplitude. The kisspeptin-10-induced potentiation of the mEPSCs was significantly attenuated by previous exposure to the kisspeptin receptor antagonist kisspeptin-234 (100 nM) and to the protein kinase C inhibitor bisindolylmaleimide I (20 nM). These results suggest that kisspeptin-10 participates in the regulation of synaptic inputs to the MNCs in the SON by interacting with the kisspeptin receptor.

Changes in the melanocortin receptors in the hypothalamus of a rat model of cancer cachexia.

MASAMI SUZUKI, MINORU NARITA, MAHO ASHIKAWA, SADAYOSHI FURUTA, MOTOHIRO MATOBA, HIROKI SASAKI, KAZUYOSHI YANAGIHARA, KIYOSHI TERAWAKI, TSUTOMU SUZUKI, AND YASUHITO UEZONO* Division of Cancer Pathophysiology, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan Department of Pharmacology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan Division of Palliative Medicine and Psycho-Oncology Palliative Care Team, National Cancer Center, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan Division of Genetics, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan Laboratory of Molecular Cell Biology, Department of Life Sciences, Yasuda Woman’s University Faculty of Pharmacy, 13-1 Yasuhigashi 6-chome, Asaminami-ku, Hiroshima 731-0153, Japan