Carboplatin Enhances the Activity of Human Transient Receptor Potential Ankyrin 1 through the Cyclic AMP-Protein Kinase A-A-Kinase Anchoring Protein (AKAP) Pathways.

Carboplatin, an anticancer drug, often causes chemotherapy-induced peripheral neuropathy (PN). Transient receptor potential ankyrin 1 (TRPA1), a non-selective cation channel, is a polymodal nociceptor expressed in sensory neurons. TRPA1 is not only involved in pain transmission, but also in allodynia or hyperalgesia development. However, the effects of TRPA1 on carboplatin-induced PN is unclear. We revealed that carboplatin induced mechanical allodynia and cold hyperalgesia, and the pains observed in carboplatin-induced PN models were significantly suppressed by the TRPA1 antagonist HC-030031 without a change in the level of TRPA1 protein. In cells expressing human TRPA, carboplatin had no effects on changes in intracellular Ca2+ concentration ([Ca2+]i); however, carboplatin pretreatment enhanced the increase in [Ca2+]i induced by the TRPA1 agonist, allyl isothiocyanate (AITC). These effects were suppressed by an inhibitor of protein kinase A (PKA). The PKA activator forskolin enhanced AITC-induced increase in [Ca2+]i and carboplatin itself increased intracellular cyclic adenosine monophosphate (cAMP) levels. Moreover, inhibition of A-kinase anchoring protein (AKAP) significantly decreased the carboplatin-induced enhancement of [Ca2+]i induced by AITC and improved carboplatin-induced mechanical allodynia and cold hyperalgesia. These results suggested that carboplatin induced mechanical allodynia and cold hyperalgesia by increasing sensitivity to TRPA1 via the cAMP-PKA-AKAP pathway.

Differential Metabolic Responses to Adipose Atrophy Associated with Cancer Cachexia and Caloric Restriction in Rats and the Effect of Rikkunshito in Cancer Cachexia.

Despite the similar phenotypes, including weight loss, reduction of food intake, and lower adiposity, associated with caloric restriction (CR) and cancer cachexia (CC), CC is a progressive wasting syndrome, while mild CR improves whole body metabolism. In the present study, we compared adipose metabolic changes in a novel rat model of CC, mild CR (70% of the food intake of control rats, which is similar to the food consumption of CC rats), and severe CR (30% of the food intake of controls). We show that CC and severe CR are associated with much smaller adipocytes with significantly lower mitochondrial DNA content; but, that mild CR is not. CC and both mild and severe CR similarly upregulated proteins involved in lipolysis. CC also downregulated proteins involved in fatty acid biosynthesis, but mild CR upregulated these. These findings suggest that CC might impair de novo fatty acid biosynthesis and reduce mitochondrial biogenesis, similar to severe CR. We also found that rikkunshito, a traditional Japanese herbal medicine, does not ameliorate the enhanced lipolysis and mitochondrial impairment, but rather, rescues de novo fatty acid biosynthesis, suggesting that rikkunshito administration might have partially similar effects to mild CR.

[6]-gingerol and [6]-shogaol, active ingredients of the traditional Japanese medicine hangeshashinto, relief oral ulcerative mucositis-induced pain via action on Na+ channels.

The traditional Japanese herbal medicine hangeshashinto (HST) has beneficial effects for the treatment of oral ulcerative mucositis (OUM) in cancer patients. However, the ingredient-based mechanism that underlies its pain-relieving activity remains unknown. In the present study, to clarify the analgesic mechanism of HST on OUM-induced pain, we investigated putative HST ingredients showing antagonistic effects on Na+ channels in vitro and in vivo. A screen of 21 major ingredients using automated patch-clamp recordings in channel-expressing cells showed that [6]-gingerol and [6]-shogaol, two components of a Processed Ginger extract, considerably inhibited voltage-activated Na+ currents. These two ingredients inhibited the stimulant-induced release of substance P and action potential generation in cultured rat sensory neurons. A submucosal injection of a mixture of [6]-gingerol and [6]-shogaol increased the mechanical withdrawal threshold in healthy rats. In a rat OUM model, OUM-induced mechanical pain was alleviated 30min after the swab application of HST despite the absence of anti-bacterial and anti-inflammatory actions in the OUM area. A swab application of a mixture of [6]-gingerol and [6]-shogaol induced sufficient analgesia of OUM-induced mechanical or spontaneous pain when co-applied with a Ginseng extract containing abundant saponin. The Ginseng extract demonstrated an acceleration of substance permeability into the oral ulcer tissue without an analgesic effect. These findings suggest that Na+ channel blockage by gingerol/shogaol plays an essential role in HST-associated analgesia of OUM-induced pain. This pharmacological mechanism provides scientific evidence supporting the use of this herbal medicine in patients suffering from OUM-induced pain.

Therapeutic potential of ghrelin and des-acyl ghrelin against chemotherapy-induced cardiotoxicity.

Cancer was considered an incurable disease for many years; however, with the development of anticancer drugs and state-of-the art technologies, it has become curable. Cardiovascular diseases in patients with cancer or induced by cancer chemotherapy have recently become a great concern. Certain anticancer drugs and molecular targeted therapies cause cardiotoxicity, which limit the widespread implementation of cancer treatment and decrease the quality of life in cancer patients significantly. The anthracycline doxorubicin (DOX) causes cardiotoxicity. The cellular mechanism underlying DOX-induced cardiotoxicity include free-radical damage to cardiac myocytes, leading to mitochondrial injury and subsequent death of myocytes. Recently, circulating orexigenic hormones, ghrelin and des-acyl ghrelin, have been reported to inhibit DOX-induced cardiotoxicity. However, little is known about the molecular mechanisms underlying their preventive effects. In the present study, we show the possible mechanisms underlying the effects of ghrelin and des-acyl ghrelin against DOX-induced cardiotoxicity through in vitro and in vivo researches.

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.

Enhancement of catecholamine release from PC12 cells by the traditional Japanese medicine, rikkunshito.

BACKGROUND: Rikkunshito is a traditional Japanese herbal medicine that is used to treat appetite loss associated with cancer and other disorders. The formulation contains various constituents that influence cell signaling, and rikkunshito may accordingly affect human homeostasis through multiple regulatory pathways, including those governed by the endocrine system. We investigated the actions of rikkunshito on catecholamine release from PC12 cells, an adrenal chromaffin cell line. METHODS: The actions of rikkunshito on PC12 cells were evaluated by measuring intracellular cAMP levels, tyrosine hydroxylase (TH) and vasoactive intestinal peptide (VIP) mRNA expression levels, and catecholamine levels in the culture medium. The transcriptional activation of VIP gene by rikkunshito was assessed by using a VIP promoter-driven reporter gene assay. RESULTS: Rikkunshito dose-dependently enhanced forskolin-induced elevations in cAMP in PC12 cells, and also increased the gene expression of TH and VIP. The transcriptional activation of VIP gene by rikkunshito was confirmed. Norepinephrine and dopamine secretion into the culture medium of PC12 cells were also dose-dependently augmented by rikkunshito and/or forskolin, but experiments with a protein kinase C (PKC) activator and a phosphodiesterase inhibitor revealed that the effects of rikkunshito were not simply due to the modulation of PKC or phosphodiesterase activity. CONCLUSIONS: These findings suggest that rikkunshito enhances the release of catecholamines by a novel mechanism involving cAMP.

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 patient's 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.

Hepcidin expression in the trigeminal ganglion and the oral mucosa in an oral ulcerative mucositis rat model.

Severe intraoral pain induces difficulty in eating and speaking, leading to a decline in the quality of life. However, the molecular mechanisms underlying intraoral pain remain unclear. Here, we investigated gene modulation in the trigeminal ganglion and intraoral pain-related behavior in a rat model of acetic acid-induced oral ulcerative mucositis. Oral ulceration was observed on day 2 after acetic acid treatment to the oral mucosa of male Wistar rats, causing spontaneous pain and mechanical allodynia. Deoxyribonucleic acid microarray analysis of trigeminal ganglion tissue indicated that Hamp (a hepcidin gene that regulates cellular iron transport) was the most upregulated gene. In the oral ulcerative mucositis model, the upregulation of Hamp was also induced in the ulcer region but not in the liver, with no increase in hepcidin levels in the plasma and saliva, indicating that hepcidin was produced locally in the ulcer region in the model. Systemic antibiotic pretreatment did not increase the mRNA levels of Hamp in the trigeminal ganglion and ulcer regions. Hepcidin injection into the oral mucosa enhanced neuronal excitability in response to noxious mechanical stimulation of the oral mucosa in trigeminal spinal subnucleus interpolaris/caudalis neurons. These results imply that oral ulcerative mucositis induces oral mucosal pain because of infectious inflammation of the ulcerative area and potentiates Hamp, which represents anti-bacterial and anti-peptidase gene expression in the ulcer region and trigeminal ganglion. The regulation of cellular iron transport by hepcidin is likely involved in oral ulcerative mucositis-induced pain.

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

BACKGROUND: Kampo 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. METHODS: A 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). RESULTS: Valid 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. CONCLUSIONS: To 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.

Tokishakuyakusan ameliorates lowered body temperature after immersion in cold water through the early recovery of blood flow in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: 'Cold feeling' is a subjective feeling of unusual coldness that aggravates fatigue, stiffness, and other symptoms, thereby reducing quality of life. Tokishakuyakusan (TSS) is a Kampo medicine reported to improve cold feeling and is used to treat symptoms aggravated by cold feeling. However, the mechanism of action of TSS is unclear. Cold feeling may involve reduced blood flow and subsequent inhibition of heat transport. Therefore, elucidating the effects of TSS on blood flow is one of the most important research topics for clarifying the mechanism of action of TSS. AIM OF THE STUDY: We aimed to evaluate the effect of TSS on recovery from lowered body temperature by the immersion of rats in cold water and to clarify the involvement of blood flow in the action of TSS. MATERIALS AND METHODS: After female Wistar rats underwent 9 days of low room temperature stress loading (i.e. room temperature of 18 °C), they were subjected to immersion in cold water (15 °C) for 15 min. Body surface temperature, rectal temperature, and plantar temperature were measured before and after immersion in cold water. Blood flow was measured before and after immersion in cold water without low room temperature stress loading. TSS (0.5 g/kg or 1 g/kg) or the vehicle (i.e. distilled water) was orally administered once daily for 10 days for the measurement of body temperature or once 30 min before immersion in cold water for the measurement of blood flow. In addition, we examined the effect of TSS on calcitonin gene-related peptide (CGRP) release from dorsal root ganglion (DRG) cells, the effect of TSS ingredients on transient receptor potential (TRP) channels, and the effect of TSS ingredients on the membrane potential of vascular smooth muscle cells and evaluated the mechanism of the effects of TSS on blood flow. RESULTS: Body temperature and blood flow decreased after immersion in cold water and then recovered over time. A comparison of body temperature at each timepoint or area under the curve showed that TSS (1 g/kg) accelerated the recovery of body surface temperature, rectal temperature, and blood flow. TSS significantly increased CGRP release from DRG cells, which disappeared after pretreatment with HC-030031 (a transient receptor potential ankyrin 1 [TRPA1] antagonist). The effects of seven TSS ingredients on TRP channels were examined. The agonistic effect on TRPA1 was observed for atractylodin, atractylodin carboxylic acid and levistolide A. Among the TSS ingredients, atractylodin carboxylic acid had significant hyperpolarising effects. CONCLUSIONS: The mechanism by which TSS accelerates the recovery of lowered body temperature in rats after immersion in cold water may involve the acceleration of the recovery of lowered blood flow. Increased CGRP release from DRG cells by TSS, TRPA1 activation by TSS ingredients, and membrane potential changes in vascular smooth muscle cells caused by TSS ingredients are part of the mechanism of action of TSS. These findings may partly contribute to the interpretation of the beneficial effects of TSS on cold feeling.

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

The effects of yokukansan and donepezil on learning disturbance and aggressiveness were examined in amyloid ß protein (Aß)-injected mice. Intellicage tests showed that both yokukansan and donepezil ameliorated Aß-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 Aß-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.

The ameliorating effects of tokishakuyakusan in a rat model of implantation failure involves endometrial gland leukemia inhibitory factor and decidualization.

ETHNOPHARMACOLOGICAL RELEVANCE: Tokishakuyakusan (TSS) is a Kampo medicine that is prescribed for the treatment of infertility in Japan. However, its precise mechanism of action remains unclear. AIM OF THE STUDY: Leukemia inhibitory factor (LIF) in the endometrium plays an indispensable role in embryo implantation and is linked to infertility or implantation failure. Previously, we demonstrated that TSS ameliorated implantation failure induced by mifepristone (RU-486), an antagonist of progesterone, in rats. Herein, we aimed to clarify whether the ameliorating effect of TSS on implantation failure in the rat model involves endometrial LIF. Additionally, we determined whether decidualization, the dysfunction of which is linked to infertility or implantation failure similar to LIF, progesterone, and other implantation-related factors, are involved in the effect of TSS. MATERIALS AND METHODS: The implantation failure rat model was developed via the subcutaneous administration of RU-486 (7 mg/kg) on day 3 post-coitus. Sesame oil was administered as the vehicle control. Rats were fed a diet containing 1% or 3% TSS or a control diet from day 13 pre-coitus. Subsequently, the implantation sites were assessed, and plasma progesterone levels were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) on day 8 post-coitus. The LIF mRNA of the endometrial gland, which was segmented via laser-microdissection from the endometrial tissue, was measured, and endometrial LIF immunostaining was carried out on day 5. The gene expression of different factors related to implantation, including decidualization and progesterone-responsiveness on days 5 and 6, were measured. The human endometrial Ishikawa cell line derived from human adenocarcinoma was treated with TSS (30-300 µg/mL) for 24 h, and the LIF concentrations in the cell culture supernatants were measured. RESULTS: RU-486 decreased the number of implantation sites in the uterus of rats; however, the decrease was significantly alleviated by TSS (3%-diet), which tended to increase plasma progesterone. In rats with RU-486-induced implantation failure, endometrial gland LIF mRNA and endometrial LIF protein were markedly decreased while the gene expression of both decidualization-related factors such as interleukin-11, insulin-like growth factor binding protein-1, and cyclooxygenase-2, and progesterone responsive-related factors such as FK506 binding protein 5, were significantly decreased. These changes in the uterus of rats with implantation failure were significantly alleviated by TSS (3%-diet). Additionally, TSS significantly enhanced LIF protein production and LIF mRNA in Ishikawa cells. CONCLUSIONS: The mechanism whereby TSS ameliorates RU-486-induced implantation failure in rats may involve the alleviation of decreased LIF production derived from the endometrial gland, and a dysfunction of decidualization, including lower progesterone responsiveness in the model. These findings may partly contribute to the interpretation of the beneficial effects of TSS on infertility.

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. METHODS: The effect of yokukansan on social interactions, including social and aggressive behaviour, was examined in PCA-injected rats. Concentration and release level of serotonin (5-HT) in the hypothalamus were measured. KEY FINDINGS: PCA reduced not only the 5-HT concentration but also the high K(+)-induced 5-HT release in the rat hypothalamus. Social interaction tests showed a significant decrease in social behaviour and a significant increase in aggressive behaviour in the PCA-treated rats. The decrease in social behaviour was ameliorated by the 5-HT1A agonist buspirone and further decreased by a 5-HT1A antagonist, N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl)cyclo-hexanecarboxamide trihydrochloride (WAY-100635), whereas it was further decreased by the 5-HT2A agonist, 2,5-dimethoxy-4-iodoamphetamine (DOI), and ameliorated by the 5-HT2A antagonist ketanserin. On the other hand, the increase in aggressive behaviour was ameliorated by buspirone but not affected by WAY-100635, whereas it was enhanced by DOI and ameliorated by ketanserin. A single injection of yokukansan ameliorated the PCA-induced decrease in social behaviour but not aggressive behaviour. Chronic treatment for 14 days with yokukansan ameliorated PCA-induced abnormal behaviour, decreased social behaviour and increased aggressive behaviour, but it did not ameliorate PCA-induced decreases in the cerebral 5-HT concentration and 5-HT release. The ameliorative effects of chronic yokukansan on behaviour were counteracted by co-administration of WAY-100635. CONCLUSIONS: These results suggest that yokukansan might have two different effects: an acute effect on social behaviour and a chronic effect on aggressive behaviour. One of the mechanisms of these effects of yokukansan may be related to the agonistic effect on 5-HT1A receptors.

Leukemia inhibitory factor via the Toll-like receptor 5 signaling pathway involves aggravation of cachexia induced by human gastric cancer-derived 85As2 cells in rats.

Cancer cachexia is highly prevalent in gastric cancer patients and characterized by decreased food consumption and body weight. We previously created a rat model of cancer cachexia using MKN45cl85 and 85As2 cells derived from human gastric cancer. The 85As2 cells induced cachexia more potently compared to MKN45cl85 cells. To clarify the mechanism underlying the difference in the cachexia-inducing ability of these cells, we conducted DNA microarray analysis, focusing on cell proliferation and the production of leukemia inhibitory factor (LIF), a cachexia-inducing factor. The plasma human LIF levels of 85As2-induced cachexic rats increased as symptoms worsened, whereas the plasma levels of MKNcl85 were low. 85As2 cells displayed more genetic changes compared to MKN45cl85 cells, which were related to Toll-like receptor (TLR) 4/5 signaling. Stimulation of both cells with TLR4 (lipopolysaccharide) or TLR5 (flagellin) agonists did not affect proliferation. However, in 82As2 cells, LIF production was significantly increased by stimulation with TLR5, which was suppressed by an inhibitor of interleukin-1 receptor-associated kinase-1/4, which are important factors in the TLR5 signaling pathway. The increase in LIF production resulting from activation of the TLR5 signaling pathway may contribute to the cachexia-inducing ability of 85As2 cells.

Modulation of synaptic inputs in magnocellular neurones in a rat model of cancer cachexia.

In cancer cachexia, abnormal metabolism and neuroendocrine dysfunction cause anorexia, tissue damage and atrophy, which can in turn alter body fluid balance. Arginine vasopressin, which regulates fluid homeostasis, is secreted by magnocellular neurosecretory cells (MNCs) of the hypothalamic supraoptic nucleus. Arginine vasopressin secretion by MNCs is regulated by both excitatory and inhibitory synaptic activity, alterations in plasma osmolarity and various peptides, including angiotensin II. In the present study, we used whole-cell patch-clamp recordings of brain slices to determine whether hyperosmotic stimulation and/or angiotensin II potentiate excitatory synaptic input in a rat model of cancer cachexia, similar to their effects in normal (control) rats. Hyperosmotic (15 and 60 mmol L-1   mannitol) stimulation and angiotensin II (0.1 µmol L-1 ) increased the frequency, but not the amplitude, of miniature excitatory postsynaptic currents in normal rats; in model rats, both effects were significantly attenuated. These results suggest that cancer cachexia alters supraoptic MNC sensitivity to osmotic and angiotensin II stimulation.

Development of ghrelin resistance in a cancer cachexia rat model using human gastric cancer-derived 85As2 cells and the palliative effects of the Kampo medicine rikkunshito on the model.

Cancer cachexia (CC) is a multifactorial disease characterized by decreased food intake and loss of body weight due to reduced musculature with or without loss of fat mass. Patients with gastric cancer have a high incidence of cachexia. We previously established a novel CC rat model induced by human gastric cancer-derived 85As2 cells in order to examine the pathophysiology of CC and identify potential therapeutics. In patients with CC, anorexia is often observed, despite elevation of ghrelin, suggesting that ghrelin resistance may develop in these patients. In this study, we aimed to clarify the occurrence of ghrelin resistance in CC rats accompanied by anorexia and we investigated whether rikkunshito (RKT), a traditional Japanese Kampo medicine that potentiates ghrelin signaling, ameliorated CC-related anorexia through alleviation of ghrelin resistance. 85As2-tumor-bearing rats developed severe CC symptoms, including anorexia and loss of body weight/musculature, with the latter symptoms being greater in cachectic rats than in non-tumor-bearing or pair-fed rats. CC rats showed poor responses to intraperitoneal injection of ghrelin. In CC rats, plasma ghrelin levels were elevated and hypothalamic anorexigenic peptide mRNA levels were decreased, whereas hypothalamic growth hormone secretagogue receptor (GHS-R) mRNA was not affected. In vitro, RKT directly enhanced ghrelin-induced GHS-R activation. RKT administrated orally for 7 days partly alleviated the poor response to ghrelin and ameliorated anorexia without affecting the elevation of plasma ghrelin levels in CC rats. The expression of hypothalamic orexigenic neuropeptide Y mRNA but not hypothalamic GHS-R mRNA was increased by RKT. Thus, the 85As2 cell-induced CC rat model developed ghrelin resistance, possibly contributing to anorexia and body weight loss. The mechanism through which RKT ameliorated anorexia in the CC rat model may involve alleviation of ghrelin resistance by enhancement of ghrelin signaling. These findings suggest that RKT may be a promising agent for the treatment of CC.

The traditional Japanese medicine hangeshashinto alleviates oral ulcer-induced pain in a rat model.

OBJECTIVE: Recent studies have demonstrated that mouthwash made with the traditional Japanese medicine hangeshashinto exhibits anti-inflammatory action and alleviates oral mucositis scores, including pain complaints, in patients undergoing chemoradiotherapy. However, no study has demonstrated the mechanism underlying how hangeshashinto provides pain relief in oral ulcers. DESIGN: The analgesic effects on pain-related behaviors following the topical application of hangeshashinto were evaluated in an oral ulcer rat model treated with acetic acid using recently developed methods. Indomethacin, the representative anti-inflammatory agent, was intraperitoneally administered. The tissue permeability of the oral mucosa was histologically evaluated after applying the fluorescent substance FluoroGold. RESULTS: The topical application of hangeshashinto in ulcerative oral mucosa suppressed mechanical pain hypersensitivity over 60 min, without any effects on healthy mucosa. The same drug application also inhibited oral ulcer-induced spontaneous pain. Indomethacin administration failed to block the mechanical pain hypersensitivity, though it did largely block spontaneous pain. Topical anesthesia with lidocaine showed hyposensitivity to mechanical stimulation in healthy mucosa. In the ulcer regions in which the oral epithelial barrier was destroyed, deep parenchyma was stained with FluoroGold, in contrast to healthy oral mucosa, in which staining was limiting to the superficial site. CONCLUSIONS: Hangeshashinto leads to long-lasting analgesic effects, specifically in the ulcer region by destroying the epithelial barrier. Hangeshashinto alleviates oral ulcer-induced pain in inflammation-dependent and/or independent manner.

Keishibukuryogan, a Traditional Japanese Medicine, Inhibits Platelet Aggregation in Guinea Pig Whole Blood.

Effects of keishibukuryogan (KBG) on platelet aggregation were investigated. To ensure the specificity of KBG, tokishakuyakusan (TSS) and kamisyoyosan (KSS), which are known to have platelet aggregation-inhibiting effects, and rikkunshito (RKT) and shakuyakukanzoto (SKT), which are considered to be devoid of such effects, were used for comparison. The platelet aggregation of each test drug was measured by the screen filtration pressure method using whole blood of guinea pigs and expressed as a collagen-induced pressure rate (%) or a collagen concentration required for 50% increase in the pressure rate (PATI value). KBG suppressed the collagen-induced whole blood pressure rate increase and increased the PATI value, like TSS and KSS. Neither RKT nor SKT showed these effects. The Moutan cortex and Cinnamomi cortex, the constituent crude drugs of KBG, showed KBG-like pressure rate suppression and PATI-increasing effects. Furthermore, paeonol, a representative component of Moutan cortex, and aspirin which is known to have platelet aggregation-inhibiting activity (COX-1 inhibitor) also showed similar effects. These results suggest that the platelet aggregation-inhibiting activity of the constituent crude drugs Moutan cortex and Cinnamomi cortex is involved in the improving effects of KBG on impaired microcirculation and that paeonol plays a role in these effects.

Effects of the traditional Japanese medicine Unkei-to on the corticotropin-releasing factor-induced increase in locomotor activity.

The effect of Unkei-to, a traditional Japanese herbal medicine and strong in vitro releaser of cytokine-induced neutrophil chemoattractant (CINC), on the increase in locomotor activity induced by intracerebroventricular (icv) injection of corticotropin-releasing factor (CRF) in male rats in a familiar environment was investigated. Oral administration of Unkei-to (100 mg/kg) for 1 week significantly attenuated the CRF-induced increase in locomotor activity. Unkei-to also reduced the CRF-induced accumulation of hypothalamic CINC, which has a functional antagonistic action on the response to CRF; the reduction may reflect an increased release of CINC. These results suggest that Unkei-to has an alleviative effect on the action induced by brain CRF and the mechanism of this effect may partly involve CINC.