Antinociceptive effect of Gosha-jinki-gan, a Kampo medicine, in streptozotocin-induced diabetic mice

Effectiveness of the Traditional Japanese Medicine Goshajinkigan in Preventing Paclitaxel-Induced Peripheral Neuropathy: A Multicenter Randomized Comparative Trial

Objective: Development of chemotherapy-induced peripheral neuropathy (CIPN) poses significant challenges in cancer treatment, often leading to dose reductions or treatment discontinuation. Goshajinkigan (GJG), a traditional Japanese medicine, has shown promise for alleviating CIPN symptoms. This multicenter, randomized controlled trial aimed to prospectively examine the efficacy of GJG in preventing paclitaxel-induced peripheral neuropathy. Methods: This study enrolled 55 patients with ovarian cancer undergoing first-line chemotherapy using paclitaxel and carboplatin. The participants were randomized into Groups A (GJG initiation after onset of grade 2 neuropathy) and B (prophylactic administration of GJG from 1 week before chemotherapy). The primary endpoints were the proportion with a maximum sensory neuropathy grade and visual analog scale (VAS) scores. The secondary endpoints were the rate of chemotherapy completion and paclitaxel dose reduction due to neurotoxicity. Results: Prophylactic GJG administration (Group B) resulted in significant benefits. While both groups had a similar incidence of grade 2 sensory neuropathy, all patients in Group B with grade 2 neuropathy completed treatment without requiring additional analgesics. Group B exhibited lower VAS scores by the end of the study, reduced reliance on adjuvant analgesics (27.3% vs 66.7% in Group A), and significantly less frequent persistent CIPN 6 months post-chemotherapy (18.2% vs 55.6% in Group A). No differences were observed in the chemotherapy completion rates or CIPN-related changes between the groups. Conclusion: GJG, when administered prophylactically, showed potential for mitigating CIPN symptoms during paclitaxel chemotherapy. While promising, further research with placebo controls and objective measures is essential to comprehensively validate these findings.

Behavioral and Immunohistochemical Evidence for Suppressive Effects of Goshajinkigan on Salicylate-Induced Tinnitus in Rats

Many people are affected by tinnitus, a sensation of ringing in the ear despite the absence of external sound. Goshajinkigan (GJG) is one of the formulations of Japanese traditional herbal medicine and is prescribed for the palliative treatment of patients with tinnitus. Although GJG is clinically effective in these patients, its behavioral effects and the underlying neuroanatomical substrate have not been modeled in animals. We modeled tinnitus using salicylate-treated rats, demonstrated the effectiveness of GJG on tinnitus, and examined the underlying neuronal substrate with c-Fos expression. Intraperitoneal injection of sodium salicylate (400 mg/kg) into rats for three consecutive days significantly increased false positive scores, which were used to assess tinnitus behavior. When GJG was orally administered one hour after each salicylate injection, the increase in tinnitus behavior was suppressed. The analysis of c-Fos expression in auditory-related brain areas revealed that GJG significantly reduced the salicylate-induced increase in the number of c-Fos-expressing cells in the auditory cortices, inferior colliculus, and dorsal cochlear nucleus. These results suggest a suppressive effect of GJG on salicylate-induced tinnitus in animal models.

Risk factors for interstitial lung disease induced by gemcitabine plus albumin-bound paclitaxel therapy in pancreatic ductal adenocarcinoma patients

Background

Gemcitabine plus nab-paclitaxel (GnP) therapy is used for unresectable pancreatic ductal adenocarcinoma, but may cause interstitial lung disease (ILD) as a serious side effect. However, the risk factors for ILD in patients receiving GnP therapy are not well established. Here, we retrospectively investigated the incidence of GnP-induced ILD in pancreatic ductal adenocarcinoma patients, and the risk factors.

Methods

We investigated the patients’ background, laboratory data, previous treatment history, concomitant medications, number of doses of GnP, cumulative dosage and administration period, and occurrence of side effects.

Results

Of the 105 patients included in this study, ILD occurred in 10 (9.5%). Patients with ILD had a significantly higher frequency of concomitant treatment with Kampo medicines, especially goshajinkigan, which is considered to help prevent chemotherapy-induced peripheral neuropathy (CIPN) (odds ratio: 11.5, 95% confidence interval: 2.67–49.38). No significant differences were observed in other clinical characteristics. Notably, the severity of CIPN in patients who used goshajinkigan for prevention was not significantly different from that in patients who did not use goshajinkigan in this study.

Conclusions

These results suggest that administration of goshajinkigan to patients receiving GnP therapy for prevention of CIPN may need to be reconsidered.

Mechanical allodynia triggered by cold exposure in mice with the Scn11a p.R222S mutation: a novel model of drug therapy for neuropathic pain related to NaV1.9

Mutations within the SCN11A gene which encodes the voltage-gated sodium channel NaV1.9 mainly expressed in small fiber sensory neurons have been associated with neuropathic disorders; however, suitable medications have not been fully investigated. To develop drug therapies against NaV1.9-related neuropathic pain, we aimed to establish a novel model using mice carrying the Scn11a p.R222S mutation initially identified in patients with familial episodic limb pain that is characterized by paroxysmal pain induced by fatigue or bad weather conditions. We investigated the influence of cold exposure (4 °C, overnight) on the behavioral and biochemical phenotypes of Scn11a p.R222S mutant (R222S) and wild type C57BL/6N (WT) mice. We also tested the effects of acetaminophen (125, 250 mg/kg, perorally, p.o.) and traditional Japanese medicine, goshajinkigan (0.5 or 1.0 g/kg, p.o.), which are analgesic drugs prescribed to patients with neuropathic pain, in this model of cold-induced mechanical allodynia in R222S mice.Cold-exposed R222S mice exhibited enhanced mechanical allodynia and thermal hypersensitivity compared with WT mice. The decrease of the mechanical withdrawal threshold in R222S mice was reversible 24 h after housing at room temperature. There was no significant change in the levels of interleukin-1β, interleukin-6, tumor necrosis factor-α, or interferon-γ in the plasma or spinal cords of WT and R222S mice after cold exposure. Both acetaminophen (250 mg/kg) and goshajinkigan (1.0 g/kg) significantly attenuated mechanical allodynia in R222S mice. The model of cold-induced mechanical allodynia in mice with the Scn11a p.R222S mutation is novel and useful for evaluating analgesic drugs for intractable neuropathies related to NaV1.9.

Effects of alkaloids on peripheral neuropathic pain: a review

Neuropathic pain is a debilitating pathological pain condition with a great therapeutic challenge in clinical practice. Currently used analgesics produce deleterious side effects. Therefore, it is necessary to investigate alternative medicines for neuropathic pain. Chinese herbal medicines have been widely used in treating intractable pain. Compelling evidence revealed that the bioactive alkaloids of Chinese herbal medicines stand out in developing novel drugs for neuropathic pain due to multiple targets and satisfactory efficacy. In this review, we summarize the recent progress in the research of analgesic effects of 20 alkaloids components for peripheral neuropathic pain and highlight the potential underlying molecular mechanisms. We also point out the opportunities and challenges of the current studies and shed light on further in-depth pharmacological and toxicological studies of these bioactive alkaloids. In conclusion, the alkaloids hold broad prospects and have the potentials to be novel drugs for treating neuropathic pain. This review provides a theoretical basis for further applying some alkaloids in clinical trials and developing new drugs of neuropathic pain.

Neoline, an active ingredient of the processed aconite root in Goshajinkigan formulation, targets Nav1.7 to ameliorate mechanical hyperalgesia in diabetic mice

ETHNOPHARMACOLOGICAL RELEVANCE

Goshajinkigan (GJG), a traditional Japanese Kampo formula, has been shown to exhibit several pharmacological actions, including antinociceptive effects. Processed aconite root (PA), which is considered to be an active ingredient of GJG, has also been demonstrated to have an ameliorative effect on pain, such as diabetic peripheral neuropathic pain. We recently identified neoline as the active ingredient of both GJG and PA that is responsible for its effects against oxaliplatin-induced neuropathic pain in mice.

AIM OF THE STUDY

In the present study, we investigated whether GJG, PA, and neoline could inhibit Nav1.7 voltage-gated sodium channel (VGSC) current and whether neoline could ameliorate mechanical hyperalgesia in diabetic mice.

MATERIALS AND METHODS

To assess the electrophysiological properties of GJG extract formulation, powdered PA, and neoline on Nav1.7 VGSCs, whole-cell patch clamp recording was performed using human HEK293 cells expressing Nav1.7 VGSCs. In addition, the ameliorative effects of neoline on diabetic peripheral neuropathic pain were evaluated using the von Frey test in streptozotocin (STZ)-induced diabetic model mice.

RESULTS

GJG extract formulation significantly inhibited Nav1.7 VGSC peak current. Powdered PA also inhibited Nav1.7 VGSC peak current. Like GJG and PA, neoline could inhibit Nav1.7 VGSC current. When diabetic mice were treated with neoline by intraperitoneal acute administration, the mechanical threshold was increased in diabetic mice, but not in non-diabetic mice, in a behavioral study.

CONCLUSION

These results suggest that neoline might be a novel active ingredient of GJG and PA that is one of responsible ingredients for ameliorating mechanical hyperalgesia in diabetes via the inhibition of Nav1.7 VGSC current at least.

Goshajinkigan, a Traditional Japanese Medicine, Suppresses Voltage-Gated Sodium Channel Nav1.4 Currents in C2C12 Cells

Goshajinkigan (GJG) is a traditional Japanese Kampo medicine used clinically to treat muscle pain in Japan. However, its underlying mechanism remains unclear. Since voltage-gated sodium channel (Nav) 1.4 is involved in skeletal muscle contraction, we investigated the possibility that GJG may affect Nav1.4 currents. By using an electrophysiological technique on skeletal muscle cell line C2C12, we found that GJG suppresses Nav1.4 currents in C2C12 cells. It is suggested that GJG may improve skeletal muscle stiffness or cramps by inhibiting abnormal Nav1.4 excitation. GJG may act as a Nav1.4 blocker and may be useful to treat muscle stiffness and clamps as well as easing the pain.

Kampo for the Treatment of Pain in Japan: A Review

Kampo, a branch of traditional Japanese herbal medicine, has been the backbone of Japanese medicine for more than 1500 years. The health insurance system in Japan allows patients to access both Western and Kampo medical care at the same time in the same medical institution. Kampo has been used for the treatment of not only acute but also chronic pain in Japan. In this review, we will elaborate on the short history of Kampo, its basic concepts, and use for the treatment of pain.

Clinical research on the efficacy and safety of Bosinji for low back pain with radiculopathy caused by herniated intervertebral disc of the lumbar spine: A protocol for a multicenter, randomized, controlled equivalence trial

BACKGROUND

A lumbar herniated intervertebral disc (LHIVD) is a common problem that usually causes low back pain and radiating pain. The effectiveness of Bosinji, one of the herbal medicines used for low back pain and radiating pain in patient with LHIVD, has been reported in several studies; however, little clinical evidence is available owing to the methodological limitations in previous studies. Hence, the present study aims to establish the clinical evidence regarding the efficacy and safety of Bosinji in improving pain, function, and quality of life in LHIVD patients.

METHOD/DESIGN

This is a multicenter, open-label, randomized, controlled, and equivalence trial with 2 parallel arms. A total of 74 patients who have low back pain and radiating pain due to LHIVD will be recruited and randomly allocated to the experimental group and control group. The patients in the experimental group and control group will take 2.5 g of Bosinji granule (1.523 g of Bosinji extract) or Loxonin tablet (60 mg of loxoprofen) 3 times a day for 6 weeks. Additionally, both groups will receive the same acupuncture treatment once a week for 6 weeks as a concurrent treatment. Changes in the 100-mm visual analogue scale (VAS) for low back pain after 6 weeks from baseline will be assessed as the primary outcome. Furthermore, the 100-mm VAS for radiating pain, Oswestry disability index (ODI), Roland-Morris disability questionnaire (RMDQ), EuroQol 5 Dimensions 5 Levels (EQ-5D-5L), global perceived effect (GPE), and deficiency syndrome of kidney index (DSKI) will be used to evaluate secondary outcomes. Outcomes will be assessed at baseline and at 3, 6, and 10 weeks after screening. For the safety evaluation, laboratory examinations including complete blood count, liver function test, renal function test, blood coagulation test, inflammation test, and urine analysis will be conducted before and after taking the medications.

DISCUSSION

The results of this trial will be used to establish clinical evidence regarding the use of Bosinji with acupuncture treatment in the treatment of patients with LHIVD.

TRIAL REGISTRATION NUMBER

NCT03386149 (clinicaltrials.gov) and KCT0002848 (Clinical Research Information Service of the Republic of Korea).

Kampo Medicines for Frailty in Locomotor Disease

Frailty is a syndrome that includes broad problems of senility and consists of three domains: physical, psychological, and social. Kampo medicine is used for intervention in cases of hypofunction in a mental or physical state. Kampo treatment, using Hojin formulations such as Hachimijiogan and Gosyajinkigan, is useful in patients with “jinkyo,” or kidney hypofunction. Ketsu includes both blood and its metabolic products that circulate throughout the body. Oketsu is a disturbance of ketsu and is considered to be a microcirculation disorder. Anti-oketsu formulations, such as Keishibukuryogan and Jidabokuippo, are useful in the treatment of trauma patients who are experiencing swelling and pain. “Ki” is the universal energy that exists in the world. Hoki formulations, such as Rikkunshito and Hochuekkito, are useful in patients with poor appetites for reinforcing vital energy. Juzentaihoto and Ninjinyoeito are useful in patients with hypofunction of ki and ketsu, which are accompanying symptoms of coldness or cutaneous dryness. Thus, Kampo medicines can be used as a superior approach for the management of frailty.

De Novo RNA Sequencing and Expression Analysis of Aconitum carmichaelii to Analyze Key Genes Involved in the Biosynthesis of Diterpene Alkaloids

Aconitum carmichaelii is an important medicinal herb used widely in China, Japan, India, Korea, and other Asian countries. While extensive research on the characterization of metabolic extracts of A. carmichaelii has shown accumulation of numerous bioactive metabolites including aconitine and aconitine-type diterpene alkaloids, its biosynthetic pathway remains largely unknown. Biosynthesis of these secondary metabolites is tightly controlled and mostly occurs in a tissue-specific manner; therefore, transcriptome analysis across multiple tissues is an attractive method to identify the molecular components involved for further functional characterization. In order to understand the biosynthesis of secondary metabolites, Illumina-based deep transcriptome profiling and analysis was performed for four tissues (flower, bud, leaf, and root) of A. carmichaelii, resulting in 5.5 Gbps clean RNA-seq reads assembled into 128,183 unigenes. Unigenes annotated as possible rate-determining steps of an aconitine-type biosynthetic pathway were highly expressed in the root, in accordance with previous reports describing the root as the accumulation site for these metabolites. We also identified 21 unigenes annotated as cytochrome P450s and highly expressed in roots, which represent candidate unigenes involved in the diversification of secondary metabolites. Comparative transcriptome analysis of A. carmichaelii with A. heterophyllum identified 20,232 orthogroups, representing 30,633 unigenes of A. carmichaelii, gene ontology enrichment analysis of which revealed essential biological process together with a secondary metabolic process to be highly enriched. Unigenes identified in this study are strong candidates for aconitine-type diterpene alkaloid biosynthesis, and will serve as useful resources for further validation studies.

Molecular signaling underlying bulleyaconitine A (BAA)-induced microglial expression of prodynorphin

Bulleyaconitine (BAA) has been shown to possess antinociceptive activities by stimulation of dynorphin A release from spinal microglia. This study investigated its underlying signal transduction mechanisms. The data showed that (1) BAA treatment induced phosphorylation of CREB (rather than NF-κB) and prodynorphin expression in cultured primary microglia, and antiallodynia in neuropathy, which were totally inhibited by the CREB inhibitor KG-501; (2) BAA upregulated phosphorylation of p38 (but not ERK or JNK), and the p38 inhibitor SB203580 (but not ERK or JNK inhibitor) and p38β gene silencer siRNA/p38β (but not siRNA/p38α) completely blocked BAA-induced p38 phosphorylation and/or prodynorphin expression, and antiallodynia; (3) BAA stimulated cAMP production and PKA phosphorylation, and the adenylate cyclase inhibitor DDA and PKA inhibitor H-89 entirely antagonized BAA-induced prodynorphin expression and antiallodynia; (4) The Gs-protein inhibitor NF449 completely inhibited BAA-increased cAMP level, prodynorphin expression and antiallodynia, whereas the antagonists of noradrenergic, corticotrophin-releasing factor, A1 adenosine, formyl peptide, D1/D2 dopamine, and glucagon like-peptide-1 receptors failed to block BAA-induced antiallodynia. The data indicate that BAA-induced microglial expression of prodynorphin is mediated by activation of the cAMP-PKA-p38β-CREB signaling pathway, suggesting that its possible target is a Gs-protein-coupled receptor - "aconitine receptor", although the chemical identity is not illustrated.

Potential application of the Kampo medicine goshajinkigan for prevention of chemotherapy-induced peripheral neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is one of the most common and severe adverse effects related to cancer treatment. Unfortunately, although several agents and protocols have been proposed, no prophylactic strategies have yet to be proven useful. Therefore, new alternative therapies have been considered for CIPN prevention. Herbal medicine in Japan, called Kampo medicine, is derived from traditional Chinese medicine. Goshajinkigan (GJG) is a Kampo medicine, that is comprised of ten herbs. The aim of this work is to analyse the results of pre-clinical and clinical studies on the potential applications of GJG in CIPN prevention.

Anti-allodynic effect of Buja in a rat model of oxaliplatin-induced peripheral neuropathy via spinal astrocytes and pro-inflammatory cytokines suppression

BACKGROUND

Oxaliplatin, a widely used anticancer drug against metastatic colorectal cancer, can induce acute peripheral neuropathy, which is characterized by cold and mechanical allodynia. Activation of glial cells (e.g. astrocytes and microglia) and increase of pro-inflammatory cytokines (e.g. IL-1β and TNF-α) in the spinal cord play a crucial role in the pathogenesis of neuropathic pain. Our previous study demonstrated that Gyejigachulbu-Tang (GBT), a herbal complex formula, alleviates oxaliplatin-induced neuropathic pain in rats by suppressing spinal glial activation. However, it remains to be elucidated whether and how Buja (Aconiti Tuber), a major ingredient of GBT, is involved in the efficacy of GBT.

METHODS

Cold and mechanical allodynia induced by an oxaliplatin injection (6 mg/kg, i.p.) in Sprauge-Dawley rats were evaluated by a tail immersion test in cold water (4 °C) and a von Frey hair test, respectively. Buja (300 mg/kg) was orally administrated for five consecutive days after the oxaliplatin injection. Glial activation in the spinal cord was quantified by immunohistochemical staining using GFAP (for astrocytes) and Iba-1 (for microglia) antibodies. The amount of spinal pro-inflammatory cytokines, IL-1β and TNF-α, were measured by ELISA.

RESULTS

Significant behavioral signs of cold and mechanical allodynia were observed 3 days after an oxaliplatin injection. Oral administration of Buja significantly alleviated oxaliplatin-induced cold and mechanical allodynia by increasing the tail withdrawal latency to cold stimuli and mechanical threshold. Immunohistochemical analysis showed the activation of astrocytes and microglia and the increase of the IL-1β and TNF-α levels in the spinal cord after an oxaliplatin injection. Administration of Buja suppressed the activation of spinal astrocytes without affecting microglial activation and down-regulated both IL-1β and TNF-α levels in the spinal cord.

CONCLUSIONS

Our results indicate that Buja has a potent anti-allodynic effect in a rat model of oxaliplatin-induced neuropathic pain, which is associated with the inhibition of activation of astrocytes and release of pro-inflammatory cytokines in the spinal cord. Thus, our findings suggest that administration of Buja could be an alternative therapeutic option for the management of peripheral neuropathy, a common side-effect of oxaliplatin.

Ester Hydrolysis Differentially Reduces Aconitine-Induced Anti-hypersensitivity and Acute Neurotoxicity: Involvement of Spinal Microglial Dynorphin Expression and Implications for Aconitum Processing

Aconitines, including bulleyaconitine A, probably the most bioactive and abundant alkaloids in Aconitum plant, are a group of diester C19-diterpenoid alkaloids with one acetylester group attached to C8 of the diterpenoid skeleton and one benzoylester group to C14. Hydrolysis of both groups is involved in the processing of Aconitum, a traditional Chinese medicinal approach. We recently demonstrated that bulleyaconitine A produced anti-hypersensitivity, which was mediated by stimulation of spinal microglial dynorphin A expression. This study aimed to elucidate whether the acetylester and benzoylester groups are involved in aconitine-induced dynorphin A expression, anti-hypersensitivity, neurotoxicity in neuropathic rats. Intrathecal administration of aconitine and benzoylaconine (but not aconine) attenuated mechanical allodynia and heat hyperalgesia, with normalized ED₅₀ values of 35 pmol and 3.6 nmol, respectively. Aconitine and benzoylaconine anti-allodynia was completely blocked by the microglial inhibitor, dynorphin A antiserum, and κ-opioid receptor antagonist. Aconitine and benzoylaconine, but not aconine, stimulated dynorphin A expression in cultured primary spinal microglia, with EC₅₀ values of 32 nM and 3 μM, respectively. Intrathecal aconitine, benzoylaconine and aconine induced flaccid paralysis and death, with normalized TD₅₀ values of 0.5 nmol, 0.2 μmol, and 1.6 μmol, respectively. The TD₅₀/ED₅₀ ratios of aconitine and benzolyaconine were 14:1 and 56:1. Our results suggest that both the C8-acetyl and C14-benzoyl groups are essential for aconitine to stimulate spinal microglial dynorphin A expression and subsequent anti-hypersensitivity, which can be separated from neurotoxicity, because both benzoylaconine and aconine differentially produced anti-hypersensitivity and neurotoxicity due to their different stimulatory ability on dynorphin A expression. Our results support the scientific rationale for Aconitum processing, but caution should be taken to avoid overprocessing and excess hydrolysis of benzolyaconine to aconine.

Ignavine: a novel allosteric modulator of the μ opioid receptor

Processed Aconiti tuber (PAT) is used to treat pain associated with various disorders. Although it has been demonstrated that the κ opioid receptor (KOR) signaling pathway is a mediator of the analgesic effect of PAT, active components affecting opioid signaling have not yet been identified. In this study, we explored candidate components of PAT by pharmacokinetic analysis and identified ignavine, which is a different structure from aconitine alkaloids. A receptor binding assay of opioid receptors showed that ignavine specifically binds the μ opioid receptor (MOR), not the KOR. Receptor internalization assay in MOR-expressing cell lines revealed that ignavine augmented the responses produced by D-Ala(2)-N-Me-Phe(4)-Gly-ol(5)-enkephalin (DAMGO), a representative MOR agonist, at a low concentration and inhibited it at a higher concentration. Ignavine also exerted positive modulatory activity for DAMGO, endomorphin-1 and morphine in cAMP assay. Additionally, ignavine alone showed an analgesic effect in vivo. In silico simulation analysis suggested that ignavine would induce a unique structural change distinguished from those induced by a representative MOR agonist and antagonist. These data collectively suggest the possibility that ignavine could be a novel allosteric modulator of the MOR. The present results may open the way for the development of a novel pain management strategy.

The prophylactic effects of a traditional Japanese medicine, goshajinkigan, on paclitaxel-induced peripheral neuropathy and its mechanism of action

Background

This study aimed to evaluate the prophylactic effect of goshajinkigan (GJG) on paclitaxel (PTX)-induced neuropathy and to elucidate the mechanism of action.

Results

There was a time-dependent irreversible decrease in pain threshold in PTX group. In PTX/GJG group, pain threshold showed changes in the same level as control. Electron microscope showed that although the ganglion cells of control and PTX/GJG groups were normal, degeneration of the nucleus and swelling of the mitochondria were observed in PTX group. Expression of transient receptor potential vanilloid 4 (TRPV4) gene in PTX group significantly increased compared with that in control and PTX/GJG groups. In TRPV4 knock-out mice, no PTX-induced hyperalgesia was observed, and there was no significant difference in pain threshold between the 3 groups.

Conclusions

These results showed that PTX induced hyperalgesia by enhancing TRPV4 expression, and suggested that GJG might alleviate hyperalgesia by preventing degeneration of the ganglion cells and suppressing TRPV4 expression.

Gosha-jinki-gan reduced oxaliplatin-induced hypersensitivity to cold sensation and its effect would be related to suppression of the expression of TRPM8 and TRPA1 in rats

Peripheral neuropathy is a common side effect of the chemotherapeutic agent oxaliplatin (Oxp), and is associated with hypersensitivity to cold sensation in the acute stage. Recently, gosha-jinki-gan (GJG), a Japanese herbal medicine, was reported to improve Oxp-induced cold hypersensitivity. However, the mechanism for this effect was not elucidated. We hypothesized that the effect of GJG on Oxp-induced cold hypersensitivity may be associated with the expression of the transient receptor potential melastatin 8 (TRPM8) and transient receptor potential ankyrin 1 (TRPA1) channels, which are cold-gated ion channels. To assess this hypothesis, we examined alteration of the withdrawal response to cold stimulation following coadministration of GJG and Oxp in rats, and the relationship between this altered withdrawal response and the expression of TRPM8 and TRPA1 mRNA in the dorsal root ganglia (DRG). Assessment of cold hypersensitivity was performed at 4 and 10°C using a cold plate. Compared with Oxp administration alone, coadministration of GJG (oral dose: 1 g/kg/day for 12 days) and Oxp (intraperitoneal dose: 4 mg/kg twice a week) significantly reduced the withdrawal response to cold stimulation. On the 12th day of drug administration, the L4-L6 DRG were removed and the expression of TRPM8 and TRPA1 mRNA was determined using RT-PCR. The expression of TRPM8 and TRPA1 in the DRG of rats that were coadministered GJG and Oxp decreased significantly compared with that in the rats administered Oxp alone. These results suggest that coadministration of GJG may improve Oxp-induced cold hypersensitivity by suppressing the overexpression of TRPM8 and TRPA1 mRNA.

The review of innovative integration of Kampo medicine and Western medicine as personalized medicine at the first multidisciplinary pain center in Japan

Background

The Japanese medical system is unique because it is the only country in the world where Western medicine and traditional Japanese medicine including Kampo medicine, traditional Japanese herbal medicine, are used in our daily clinical practice. Pain is essentially an interactive psychophysiological behavior pattern. Thus, an interdisciplinary approach is often recommended in providing appropriate therapeutic care for the patients suffering from chronic and intractable pain. In addition, we have been prescribing Kampo medicines in combination with Western medicines as personalized medicine in order to treat patients with chronic pain at our pain center. The aim of our study was to conduct a survey on the current use and the effect of Kampo medicines in our multidisciplinary pain center.

Methods

Retrospective analysis was performed on 221 out of 487 patients suffering from chronic pain.

Results

The most frequent medical complaints for which Kampo medicines were prescribed were lower back/lower limb pain, neck/upper limb pain, various facial pains, headache/migraine, whiplash-associated disorder, and frozen shoulder. Kampo medicines were prescribed based on patient-centered Kampo diagnosis. Moreover, several Kampo medicines generally for the management of psychological symptoms were prescribed for about 70% of the patients. Pain improvement in the patients was categorized as follows: 26.3% with marked improvement, 12.7% with moderate improvement, 38.9% with some improvement, and 19.9% with no improvement.

Conclusions

Two thirds of the chronic pain patients with the use of Kampo medicines combined with Western medicine experienced further pain improvements.

Long-term effects of goshajinkigan in prevention of diabetic complications: a randomized open-labeled clinical trial

Objective. This clinical trial was designed to investigate whether goshajinkigan reduces the onset of diabetic complications or not. Materials and Methods. A total of 332 type 2 diabetic mellitus patients were registered from 9 clinical centers from March 2000 to August 2007. Patients were randomly assigned to take goshajinkigan extract powder, 2.5 grams for 3 times a day or no kampo therapy, additionally to the regular treatment. The primary endpoints were the onset of macrovascular diseases or progression of nephropathy or retinopathy. Statistical analysis was performed by the intention-to-treat method. Results. After 5 years of observation, 116 patients were submitted to analysis. Among them, no macrovascular events were observed in both groups. Although 43 participants had upstaging of retinopathy or nephropathy in total, there was no significant difference between goshajinkigan group and control group. Deterioration of ankle reflex was suppressed in goshajinkigan group. Also glycated hemoglobin, and fasting plasma glucose were decreased in the goshajinkigan group. Conclusion. Although the power of analysis was too low to demonstrate any effects of goshajinkigan on the progression of macrovascular diseases, retinopathy or nephropathy, goshajinkigan may be beneficial for diabetic neuropathy and glycemic control.

Efficacy of goshajinkigan for oxaliplatin-induced peripheral neuropathy in colorectal cancer patients

Objective. To evaluate the efficacy of Goshajinkigan for oxaliplatin-induced peripheral neuropathy in colorectal cancer patients. Patients. Colorectal cancer patients (N = 29) who received ≥4 weeks of Goshajinkigan for oxaliplatin-induced peripheral neuropathy during chemotherapy at Kyoto Prefectural University of Medicine were (Goshajinkigan group) compared to 44 patients who had not received Goshajinkigan during the same period (non-Goshajinkigan group). Main Outcome Measures. The effect of Goshajinkigan was graded as curative, effective, stabilizing, or deleterious. The relationships between the grade of peripheral neuropathy and the dose of oxaliplatin in the Goshajinkigan and non-Goshajinkigan groups were evaluated. Results. The effect of Goshajinkigan on peripheral neuropathy in the Goshajinkigan group was curative, effective, stabilizing, and deleterious in 3.4, 20.7, 69.0, and 6.9% of patients, compared to the effect in the non-Goshajinkigan group (4.5, 15.9, 45.5, and 34.1%). The ratio of deleterious effects was significantly different between these two groups (P = 0.04). A Kaplan-Meier analysis in relation to the cumulative dose of oxaliplatin showed that the incidence of grade 3 peripheral neuropathy tended to be less in the Goshajinkigan group (P = 0.05). There were no significant differences in time to treatment failure and severe adverse events between these two groups. Conclusions. Goshajinkigan prevented exacerbation of oxaliplatin-induced peripheral neuropathy. This trial is registered with UMIN000009956

A survey of chinese medicinal herbal treatment for chemotherapy-induced oral mucositis

Oral mucositis is one of the common side effects of chemotherapy treatment with potentially severe implications. Despite several treatment approaches by conventional and complementary western medicine, the therapeutic outcome is often not satisfactory. Traditional Chinese Medicine (TCM) offers empirical herbal formulas for the treatment of oral ulceration which are used in adaptation to chemotherapy-induced mucositis. While standard concepts for TCM treatment do not exist and acceptance by conventional oncologists is still low, we conducted a review to examine the evidence of Chinese herbal treatment in oral mucositis. Eighteen relevant studies on 4 single herbs, 2 combinations of 2 herbs, and 11 multiherbal prescriptions involving 3 or more compounds were included. Corresponding molecular mechanisms were investigated. The knowledge about detailed herbal mechanisms, especially in multi-herbal prescriptions is still limited. The quality of clinical trials needs further improvement. Meta-analysis on the existent database is not possible but molecular findings on Chinese medicinal herbs indicate that further research is still promising for the treatment of chemotherapy-induced oral mucositis.

Can medical herbs stimulate regeneration or neuroprotection and treat neuropathic pain in chemotherapy-induced peripheral neuropathy?

Chemotherapy-induced neuropathy (CIPN) has a relevant impact on the quality of life of cancer patients. There are no curative conventional treatments, so further options have to be investigated. We conducted a systematic review in English and Chinese language databases to illuminate the role of medical herbs. 26 relevant studies on 5 single herbs, one extract, one receptor-agonist, and 8 combinations of herbs were identified focusing on the single herbs Acorus calamus rhizoma, Cannabis sativa fructus, Chamomilla matricaria, Ginkgo biloba, Salvia officinalis, Sweet bee venom, Fritillaria cirrhosae bulbus, and the herbal combinations Bu Yang Huan Wu, modified Bu Yang Huan Wu plus Liuwei Di Huang, modified Chai Hu Long Gu Mu Li Wan, Geranii herba plus Aconiti lateralis praeparata radix , Niu Che Sen Qi Wan (Goshajinkigan), Gui Zhi Jia Shu Fu Tang (Keishikajutsubuto), Huang Qi Wu Wu Tang (Ogikeishigomotsuto), and Shao Yao Gan Cao Tang (Shakuyakukanzoto). The knowledge of mechanism of action is still limited, the quality of clinical trials needs further improvement, and studies have not yielded enough evidence to establish a standard practice, but a lot of promising substances have been identified. While CIPN has multiple mechanisms of neuronal degeneration, a combination of herbs or substances might deal with multiple targets for the aim of neuroprotection or neuroregeneration in CIPN.

Significance of Kampo, traditional Japanese medicine, in supportive care of cancer patients

The current standard treatment for cancer is a multidisciplinary therapy whereby various types of treatment are properly combined. Chemotherapy with multiple anticancer drugs is now common, and traditional, complementary, and alternative therapies are adopted as supportive measures. Medical care in Japan is distinguished by the ability for patients to access both Western and Kampo medical cares at the same time. There is a high degree of trust in the safety of Kampo therapies because they are practiced by medical doctors who are educated with fundamental diagnosis of Western medicine. Highly reliable clinical studies are being published, demonstrating that palliative or supportive care for cancer patients using Kampo preparations alleviates adverse effects of chemotherapy or radiotherapy. This paper reports the circumstances around cancer care in Japan where traditional therapeutic Kampo formulas are used for patients undergoing cancer treatment with cutting-edge chemotherapy, specifically to alleviate adverse effects of anticancer drugs.

Protective effects of the herbal medicine goshajinkigan in a rat model of non-alcoholic fatty liver disease

This study was designed to investigate the effect of an herbal medicine-goshajinkigan (GJ)-on the regulation of total body weight, as well as liver and adipose tissue weights in rats fed a highfat diet (HFD) and drinking of 30% sucrose (HFDS) (HFD; the rats received 19.6% energy from carbohydrates, 18.2% from proteins, and 62.2% from lipids; total energy, 506 kcal/100 g). Control rats were fed a standard diet (the rats received 60.5% energy from carbohydrates, 26.2% from proteins, and 13.3% from lipids; total energy, 360 kcal/100 g). Over a period of 12 weeks, rats were allowed free access to either the standard diet or HFDS containing 0, 1, or 3% GJ. In comparison with the control group, the HFDS rats showed a significant decrease in overall body weight and adipose tissue weight, and an increase in liver weight at 12 weeks. GJ treatment significantly reversed the HFDS-induced decrease in body and adipose tissue weight and reduced the elevated liver weight dose-dependently. Similarly, GJ reduced the elevated serum aspartate aminotransferase levels observed in HFDS rats. These results suggest that GJ may have the potential to alleviate damage to the liver in subjects with long-term consumption of HFDS.

[Kampo medicines as useful therapeutic agents in clinical practice of neurology: case reports & representative medicines]

Doctors in any department should have at least minimum knowledge of Kampo medicines. However, doctors who specialize in neurology often have inadequate knowledge of Kampo medicines. The efficacy of Kampo medicines in treating intractable diseases such as neurodegenerative diseases is not adequately understood and needs to be investigated in the future. On the other hand, Kampo medicines are often effective for treating common symptoms such as headache, dysesthesia, pain, and vertigo, encountered in daily medical practice. Because many patients suffer from these symptoms, the impact of these symptoms on our society is not small, even though the causes of these symptoms are not crucial. Having the skill to prescribe even a dozen or so Kampo medicines (for example, goshuyuto, goreisan, goshajinkigan, sokeikakketsuto) increases the treatment options and may be very beneficial in daily medical practice. In this article, I provide instructions on the use of representative Kampo medicines and present some case reports to elucidate their use. Amassing and sharing clinical experiences regarding the use of Kampo medicines would strengthen the medical evidences of Kampo medicines.

Effects of Gosha-jinki-gan (Chinese herbal medicine: Niu-Che-Sen-Qi-Wan) on hyperinsulinemia induced in rats fed a sucrose-rich diet

We investigated the effects of a Chinese herbal medicine, Gosha-jinki-gan (GJG), on the regulation of insulin levels in rats fed a sucrose-rich diet (SRD). Normal Wistar rats in the SRD group were fed an SRD for 4 weeks. Increased dietary sucrose did not alter plasma glucose levels but it increased plasma insulin levels at 2 and 4 weeks in the SRD-fed rats relative to control rats that were fed standard chow. GJG treatment significantly suppressed the SRD-induced elevation in plasma insulin levels. These results suggest that GJG improves hyperinsulinemia caused by an SRD.

Objective evaluation of the alleviating effects of Goshajinkigan on peripheral neuropathy induced by paclitaxel/carboplatin therapy: A multicenter collaborative study

Paclitaxel/carboplatin chemotherapy for cancer (TC therapy) exhibits neurotoxicity and causes peripheral neuropathy at a high frequency, which is difficult to cope with. In this study, we investigated the efficacy of Goshajinkigan, a traditional Japanese herbal medicine, for TC therapy-induced peripheral neuropathy. The subjects included in our study were patients with ovarian or endometrial cancer who underwent TC therapy and developed peripheral neuropathy. The patients were randomly divided into Group A, comprising of 14 patients (vitamin B12 treatment), and Group B, comprising of 15 patients (vitamin B12 + Goshajinkigan treatment). The observation period was 6 weeks following treatment initiation, and the evaluation items were as follows: i) the current perception threshold (CPT value) of the peripheral nerve, ii) visual analogue scale for numbness, iii) National Cancer Institute Common Terminology Criteria for Adverse Events v3.0 grade of neurotoxicity, and iv) a questionnaire on the subjective symptoms of peripheral neuropathy (functional assessment of cancer therapy-taxane). These were compared between the groups and no significant differences were noted in any item. However, CTCAE grade 3 neurotoxicity developed in 2 patients (14.3%) after 6 weeks of administration in Group A, whereas no neurotoxicity was observed in Group B. When the change in the frequency of abnormal CPT ratio at 6 weeks of administration from that before treatment was compared between the groups, the frequency of abnormal value was significantly lower in Group B than in Group A (p<0.05). This suggests that Goshajinkigan inhibits the progression of peripheral neuropathy.

Goshajinkigan reduces oxaliplatin-induced peripheral neuropathy without affecting anti-tumour efficacy in rodents

Oxaliplatin is a key drug in the treatment of colorectal cancer, but it causes acute and chronic neuropathies in patients. Goshajinkigan (GJG) is a Kampo medicine that is used for the treatments of several neurological symptoms including pain and numbness. More recently, GJG has been reported to prevent the oxaliplatin-induced peripheral neuropathy in clinical studies. No experimental study, however, has been conducted to date to determine the effect of GJG on pain behaviour in a rat model of oxaliplatin-induced neuropathy. Moreover, the impact on the anti-tumour effect of oxaliplatin remains unknown. In the present study, we examined the effects of GJG on the peripheral neuropathy and anti-tumour activity of oxaliplatin in rodents. Repeated administration of oxaliplatin caused cold hyperalgesia from days 3 to 37 and mechanical allodynia from days 21 to 28. Repeated administration of GJG prevented the oxaliplatin-induced cold hyperalgesia but not mechanical allodynia and axonal degeneration in rat sciatic nerve. Single administration of GJG reduced both cold hyperalgesia and mechanical allodynia after the development of neuropathy. In addition, GJG did not affect the anti-tumour effect of oxaliplatin in the tumour cells or tumour cells-implanted mice. These results suggest that GJG relieves the oxaliplatin-induced cold hyperalgesia and mechanical allodynia without affecting anti-tumour activity of oxaliplatin, and, therefore, may be useful for the oxaliplatin-induced neuropathy in clinical practice.

The astrocyte-targeted therapy by Bushi for the neuropathic pain in mice

Background

There is accumulating evidence that the activation of spinal glial cells, especially microglia, is a key event in the pathogenesis of neuropathic pain. However, the inhibition of microglial activation is often ineffective, especially for long-lasting persistent neuropathic pain. So far, neuropathic pain remains largely intractable and a new therapeutic strategy for the pain is still required.

Methods/Principal Findings

Using Seltzer model mice, we investigated the temporal aspect of two types of neuropathic pain behaviors, i.e., thermal hyperalgesia and mechanical allodynia, as well as that of morphological changes in spinal microglia and astrocytes by immunohistochemical studies. Firstly, we analyzed the pattern of progression in the pain behaviors, and found that the pain consisted of an “early induction phase” and subsequent “late maintenance phase”. We next analyzed the temporal changes in spinal glial cells, and found that the induction and the maintenance phase of pain were associated with the activation of microglia and astrocytes, respectively. When Bushi, a Japanese herbal medicine often used for several types of persistent pain, was administered chronically, it inhibited the maintenance phase of pain without affecting the induction phase, which was in accordance with the inhibition of astrocytic activation in the spinal cord. These analgesic effects and the inhibition of astrocytic activation by Bushi were mimicked by the intrathecal injection of fluorocitrate, an inhibitor of astrocytic activation. Finally, we tested the direct effect of Bushi on astrocytic activation, and found that Bushi suppressed the IL-1β- or IL-18-evoked ERK1/2-phosphorylation in cultured astrocytes but not the ATP-evoked p38- and ERK1/2-phosphorylation in microglia in vitro.

Conclusions

Our results indicated that the activation of spinal astrocytes was responsible for the late maintenance phase of neuropathic pain in the Seltzer model mice and, therefore, the inhibition of astrocytic activation by Bushi could be a useful therapeutic strategy for treating neuropathic pain.

Inhibitory effects of processed Aconiti tuber on morphine-induced conditioned place preference in rats

AIM OF THE STUDY

Our previous studies indicated that processed Aconiti tuber (PAT), a traditional Chinese herbal medicine, had antinociceptive effects and inhibitory effects on morphine tolerance by activation of kappa-opioid receptor (KOR). Preclinical studies also demonstrated that KOR agonists functionally attenuate addictive behaviors of morphine, such as conditioned place preference (CPP). Therefore, we hypothesize that PAT may inhibit morphine-induced CPP in rats.

MATERIALS AND METHODS

(1) Five groups of rats (n=8 for each group) were alternately subcutaneous (s.c.) injected with morphine 10mg/kg (one group receive normal saline as a control) and normal saline for 8 days and oral co-administrated with distilled water or PAT 0.3, 1.0, or 3.0 g/kg daily on days 2-9 during CPP training, respectively. (2) Other four groups of rats were randomly s.c. injected with nor-binaltorphimine (nor-BNI; 5mg/kg) or normal saline (as a control) 120 min before alternately s.c. with morphine and normal saline and oral co-administrated with distilled water or PAT 3.0 g/kg daily. Each rat was acquired pre-conditioning and post-conditioning CPP data and assayed dynorphin concentrations by radioimmunoassay in rat's nucleus accumbens (NAc) after CPP training.

RESULTS

(1) PAT 1.0 or 3.0 g/kg dose-dependently decreased the morphine-induced increase of CPP scores. (2) Nor-BNI completely antagonized the inhibition of PAT on morphine-induced CPP. (3) PAT dose-dependently increased dynorphin content in rats' NAc after CPP training.

CONCLUSIONS

(1) PAT dose-dependently inhibited morphine-induced CPP. (2) The inhibition of PAT on morphine-induced CPP was probably due to activation of KOR by increasing dynorphin release in rats' NAc.

Anti-hypersensitivity effects of Shu-jing-huo-xue-tang, a Chinese herbal medicine, in CCI-neuropathic rats

AIM OF THE STUDY

Shu-jing-huo-xue-tang (SJHXT) (Japanese name: Sokei-kakketu-to), a traditional Chinese herbal medicine composed of 17 crude drugs, has been prescribed over hundreds of years for treatment of chronic pain syndromes. We evaluated if oral SJHXT could suppress neuropathic pain behaviors in rats with chronic constriction injury (CCI) of the sciatic nerve.

MATERIALS AND METHODS

(1) Rats received repeated oral SJHXT 0.5 or 1.0 g/kg once daily for 14 days starting 24 h after CCI surgery, while neuropathic manifestations were evaluated until day 20 post-CCI. (2) Other groups of rats received single oral SJHXT 1.0 g/kg on day 14 post-CCI. (3) Additional groups of rats received oral SJHXT 1.0 g/kg on day 14 post-CCI, concomitantly with intraperitoneal yohimbine 1 mg/kg or methysergide 5 mg/kg. Neuropathic manifestations, including mechanical allodynia and thermal hyperalgesia, were evaluated with paw withdrawal responses to increasing mechanical pressure and radiant heat, respectively.

RESULTS

Mechanical allodynia and thermal hyperalgesia developed by day 14 post-CCI. Repeated oral SJHXT for 14 days produced anti-allodynic and anti-hyperalgesic effects that outlasted the period of drug administration. Single oral SJHXT on day 14 also produced significant anti-allodynic and anti-hyperalgesic effects, which were inhibited by yohimbine, an alpha-2 adrenoceptor antagonist, but not by methysergide, a serotonin receptor antagonist.

CONCLUSIONS

Oral SJHXT produced anti-hypersensitivity effects by actions on alpha-2 adrenoreceptors in CCI-neuropathic rats, and chronic oral administration of SJHXT could produce the long-lasting anti-hypersensitivity effects.

Gosha-jinki-gan reduces transmitter proteins and sensory receptors associated with C fiber activation induced by acetic acid in rat urinary bladder

AIM

We determined if Gosha-jinki-gan, a traditional Chinese herbal mixture, reduced the presence of the tachykinins neurokinin A, neurokinin B, and substance P, as well as the transient receptor potential vanilloid 1 (TRPV1) and P2X3 purine receptors that are functionally associated with C fibers in the urinary bladder.

METHODS

Thirty-six female rats were fed with either a standard diet or one supplemented with 1.08% Gosha-jinki-gan. After 4 weeks, the urinary bladders were instilled with either saline or 0.1% acetic acid. After 30 min, the bladders were removed and expression of the tachykinins and the TRPV1 and P2X3 receptors was determined by immunohistochemistry and mRNA expression.

RESULTS

In rats fed with the standard diet, the tachykinins and the TRPV1 and P2X3 receptors expressed nearby or within urothelium of the acetic acid-treated rats increased compared with the saline-instilled rats. In rats pretreated with Gosha-jinki-gan, the tachykinins and the TRPV1 and P2X3 receptors in the acetic acid-treated rats also increased compared with the saline-instilled rats. However, with the instillation of acetic acid, the tachykinins and the TRPV1 and P2X3 receptors of Gosha-jinki-gan pretreated rats decreased compared with standard diet fed rats. The mRNA expression levels of neurokinin A, substance P, and the TRPV1 receptor in acetic acid-treated Gosha-jinki-gan pretreated rats were lower than that in acetic acid-treated standard diet fed rats. Gosha-jinki-gan did not destroy nerve fibers within the bladders.

CONCLUSIONS

Gosha-jinki-gan partially reduced the tachykinins and TRPV1 and P2X3 purine receptors without destroying the nerve fibers.

High doses of processed Aconiti tuber inhibit the acute but potentiate the chronic antinociception of morphine

AIM OF THE STUDY

In this study, we investigated the effects of processed Aconiti tuber (PAT), an oriental herbal medicine, at analgesic doses on acute morphine antinociception in morphine-naïve mice and morphine tolerance in morphine-tolerant mice.

MATERIALS AND METHODS

In acute experiments, mice received subcutaneous (s.c.) morphine (2, 5, or 10 mg/kg) and oral distilled water or PAT (0.3, 1.0, or 3.0 g/kg). The mechanical nociceptive threshold (MNT) and thermal nociceptive latency (TNL) were measured with the tail pressure test and tail flick test, respectively, before, and at 30, 60, 90, and 120 min after s.c. morphine injection. In chronic experiments, mice received s.c. morphine (10 mg/kg) and oral distilled water or PAT (0.3, 1.0, or 3.0 g/kg) once daily for 11 days. MNT was measured before, and at 60 min after, and TNL was measured before, and at 30 min after, daily morphine injections on days 1-11.

RESULTS

PAT at analgesic doses inhibited the acute antinociceptive effect of morphine dose-dependently in morphine-naïve mice. In contrast, PAT at analgesic doses potentiated the chronic antinociceptive effect of morphine dose-dependently by inhibiting the development of morphine tolerance dose-dependently. These effects of PAT on acute and chronic morphine antinociception were mediated through activation of kappa-opioid receptors.

CONCLUSIONS

These results indicated that chronic co-administration of PAT at analgesic doses with morphine could provide better-maintained morphine analgesia in a long-term morphine treatment after initial inhibition of acute morphine antinociception for a brief period of time.

The comparison of effects of processed Aconiti tuber, U50488H and MK-801 on the antinociceptive tolerance to morphine

In the previous studies, we demonstrated that an oriental herbal medicine, processed Aconiti tuber (PAT), at subanalgesic doses could inhibit or reverse the antinociceptive tolerance to morphine. In the present study, we compared the effect of PAT, trans-(+/-)-3,4-dichloro-N-methyl-N-(2-(1-pyrrolidin)cyclohexyl)-benzeneacetamide methane sulfonate hydrate (U50488H), a selective kappa opioid receptor (KOR) agonist, and (-)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine-maleate (MK-801), a N-methyl-D-aspartate (NMDA) receptor antagonist, on the antinociceptive tolerance to morphine in the same experimental condition. Mice received subcutaneous morphine (10 mg/kg), and oral PAT at a subanalgesic dose (0.3 g/kg for mechanical or 1.0 g/kg for thermal test), or intraperitoneal U50488H at a subanalgesic dose (3 mg/kg), or MK-801 at a subanalgesic dose (0.1 mg/kg) once daily for 14 days. The mechanical nociceptive threshold was measured before, and at 60 min by tail pressure testing, and thermal nociceptive latency was measured before, and at 30 min by hot plate testing, after daily morphine injections. PAT and U50488H could not only inhibit the development of morphine tolerance but also reverse the already-developed morphine tolerance, while MK-801 could only inhibit the development of morphine tolerance but not reverse the already-developed morphine tolerance, in both mechanical and thermal nociceptive tests. These data suggested that PAT, an indirect-acting KOR agonist, share the common pharmacological property of KOR agonists on morphine tolerance, and that PAT may be superior to some NMDA receptor antagonists which do not reverse already-developed morphine tolerance.

Criteria for creating and assessing mouse models of diabetic neuropathy

Diabetic neuropathy (DN) is a serious and debilitating complication of both type 1 and type 2 diabetes. Despite intense research efforts into multiple aspects of this complication, including both vascular and neuronal metabolic derangements, the only treatment remains maintenance of euglycemia. Basic research into the mechanisms responsible for DN relies on using the most appropriate animal model. The advent of genetic manipulation has moved mouse models of human disease to the forefront. The ability to insert or delete genes affected in human patients offers unique insight into disease processes; however, mice are still not humans and difficulties remain in interpreting data derived from these animals. A number of studies have investigated and described DN in mice but it is difficult to compare these studies with each other or with human DN due to experimental differences including background strain, type of diabetes, method of induction and duration of diabetes, animal age and gender. This review describes currently used DN animal models. We followed a standardized diabetes induction protocol and designed and implemented a set of phenotyping parameters to classify the development and severity of DN. By applying standard protocols, we hope to facilitate the comparison and characterization of DN across different background strains in the hope of discovering the most human like model in which to test potential therapies.

Effects of hPTH (1-34) and Gosha-jinki-gan on the trabecular bone microarchitecture in ovariectomized rat tibia

Although human parathyroid hormone (1-34) [hPTH (1-34)] was reported to improve osteoporotic bone loss, little is known about the anti-osteoporotic effect of the traditional Chinese medicine, Gosha-jinki-gan (GJG). The purpose of this present study was to clarify and compare the effects of hPTH (1-34) and GJG on trabecular bone microarchitecture in ovariectomized (OVX) rat tibia by using microcomputed tomography (micro-CT). Thirty 12-week-old Sprague-Dawley female rats were underwent ovariectomy (OVX) or sham operation. Four weeks later, the ovariectomized rats were further divided into OVX, OVX + PTH, and OVX + GJG groups. hPTH (1-34) was administered subcutaneously at a dose of 20 microg/kg, 3 times/week, and OVX + GJG group received 0.05% aqueous solution of GJG as the only drinking fluid for 8 weeks respectively. The three-dimensional (3D) trabecular microarchitecture of the bone in the proximal tibial metaphysis was evaluated by micro-CT. In the OVX + PTH group, trabecular bone volume (BV/ TV), number (Tb.N) and thickness (Tb.Th) were significantly increased, structure model index (SMI) and trabecular bone pattern factor (TBPf) decreased when compared with the OVX group. In comparison to the OVX group, BV/TV and Tb.N were significantly greater, while SMI and TBPf had no marked changes in the OVX + GJG group. These results suggest that the administration of hPTH (1-34) restore the trabecular bone volume and improve the microstuctural property as well, while GJG reduce the bone loss without affecting its microstructural property in ovariectomized rats.

Inhibition of morphine tolerance by processed Aconiti tuber is mediated by kappa-opioid receptors

Previously, we found that processed Aconiti tuber (PAT) could inhibit morphine tolerance in mice. In the present study, we investigated mechanisms underlying this effect. Mice received subcutaneous (s.c.) morphine (10 mg/kg) and oral PAT at a subanalgesic dose (0.3 g/kg), once a day for 12 days. Additional PAT-treated groups received morphine and PAT, at 120 min after pretreatment with s.c. clocinnamox mesylate (C-CAM) (0.5 mg/kg), or nor-binaltorphimine (nor-BNI) (5 mg/kg). The antinociceptive effect was assessed with the tail pressure test, at 60 min after the daily s.c. morphine injections were given. In the placebo-treated group, repeated morphine injections caused morphine tolerance, and morphine antinociception was abolished by day 6, whereas in PAT-treated groups, significant antinociception was maintained until day 12, suggesting that PAT inhibited morphine tolerance, thereby sustaining morphine antinociception. C-CAM, a selective mu-opioid receptor (MOR) antagonist, blocked morphine antinociception whereas nor-BNI, a selective kappa-opioid receptor (KOR) antagonist, did not. However, both C-CAM and nor-BNI could block the antinociception maintained by the morphine-PAT combination. Results of the study suggested that chronic treatment with PAT at a subanalgesic dose maintained MOR-mediated morphine antinociception by attenuating development of morphine tolerance, and that this tolerance-attenuating effect of PAT was mediated by KOR.

Effects of processed Aconiti tuber and its ingredient alkaloids on the development of antinociceptive tolerance to morphine

Processed Aconiti tuber (PAT) is a herbal medicine that has been widely used as an analgesic since ancient times. We investigated effects of subanalgesic doses of PAT on morphine tolerance in mice. Mice received subcutaneous morphine (10 mg/kg) and oral PAT at subanalgesic doses (0.1 or 0.3 g/kg), once a day for 7 days. Mechanical nociceptive thresholds were measured using the tail pressure test, at 60 min after the daily s.c. morphine injections. In the placebo-treated group, repeated administration of s.c. morphine resulted in development of analgesic tolerance. In the PAT-treated groups, oral PAT attenuated morphine tolerance, dose-dependently. The main ingredient alkaloid of PAT causing its tolerance-attenuating activity was mesaconitine, but other ingredient alkaloids, such as aconitine and hypaconitine, also contributed to this activity. In addition, repeated treatment with PAT could reverse already-developed morphine tolerance. Subanalgesic doses of oral PAT thus can attenuate and reverse morphine tolerance in mice.

Pain-relieving effects of processed Aconiti tuber in CCI-neuropathic rats

Neuropathic pain is often refractory to conventional pain therapies and thus requires exploration of effective drugs. We evaluated if processed Aconiti tuber (PAT), a traditional oriental herbal medicine that has been used as an analgesic, relieves neuropathic pain in the rat chronic constriction injury (CCI) model. Ten to 14 days after CCI in the right hind paw, six groups of rats received oral placebo, or PAT at 0.5, 1, 2, 3, or 5 g/kg. Additional groups received oral PAT, 2 g/kg, after pretreatment with intraperitoneal naloxone; intraperitoneal nor-binaltorphimine (norBNI); or intrathecal norBNI. As indicators of mechanical allodynia and thermal hyperalgesia, the pressure threshold of paw withdrawal (PWT) in response to linearly increasing pressure, and latency to paw withdrawal (PWL) in response to radiant heat, were measured before and after drug administration. Oral PAT dose-dependently increased PWT and PWL, which had been decreased due to CCI. The increases in PWT and PWL by oral PAT were inhibited by intraperitoneal and intrathecal norBNI: a selective kappa-opioid receptor antagonist, but not by intraperitoneal naloxone. These results indicate that oral PAT can alleviate mechanical allodynia and thermal hyperalgesia, dose-dependently, via spinal kappa-opioid receptor mechanisms in a rat CCI neuropathic pain model.

Antinociceptive Effect of Shakuyakukanzoto, a Kampo Medicine, in Diabetic Mice

In this study, the antinociceptive effect of shakuyakukanzoto was investigated using streptozotocin-induced diabetic mice to certify its analgesic effect on diabetic patients. Shakuyakukanzoto (0.5 and 1.0 g/kg, p.o.) significantly increased the nociceptive threshold in diabetic mice. The antinociceptive activity of shakuyakukanzoto in diabetic mice was not antagonized by beta-funaltrexamine, naltrindole, or nor-binaltorphimine. The increased antinociceptive activity of (1.0 g/kg, p.o.) in diabetic mice was abolished by yohimbine (15 microg, i.t.), but not by NAN-190 (1 microg, i.t.), methysergide (15 microg, i.t.), or MDL-72222 (15 microg, i.t.). In shakuyakukanzoto diabetic mice treated with 6-hydroxydopamine (20 microg, i.t.) chemically lesioned noradrenergic pathways, shakuyakukanzoto (1.0 g/kg, p.o.) failed to exhibit an antinociceptive effect. Furthermore, the antinociceptive activity induced by norepinephrine (0.06 - 2 microg, i.t.) was markedly more potent in diabetic mice than in non-diabetic mice at the same dose. These results suggest that the antinociceptive effect of shakuyakukanzoto in diabetic mice is not mediated by the opioid systems and that this effect appears via selective activation of the spinal descending inhibitory alpha2-adrenergic systems without activating the serotonergic systems. The spinal alpha2-adrenoceptor-mediated analgesic mechanism was enhanced in diabetic mice, suggesting that shakuyakukanzoto exhibits its effect by activating the descending noradrenergic neurons.

Inhibition Mechanism of Gosha-jinki-gan on the Micturition Reflex in Rats

We investigated the actions of Gosha-jinki-gan, a traditional Japanese medicine containing processed Aconiti tubers, on urinary bladder function in anesthetized rats. In cystometrical investigations, Gosha-jinki-gan (1.0 g/kg, i.d.) increased bladder capacity as well as micturition threshold pressure. In addition, it decreased the frequency of distension-induced rhythmic bladder contractions. However, it did not influence the amplitude of bladder contractions induced by electrical stimulation of the pontine micturition center. The inhibitory effect of Gosha-jinki-gan on bladder motility was abolished by pretreatment with nor-binaltorphimine (10 mg/kg, s.c.), and was diminished by the concomitant use of anti-dynorphin A antiserum (10 microg, i.t.), yohimbine (10 microg, i.t.), or methysergide (20 microg, i.t.). Processed Aconiti tuber extract (27 mg/kg, i.d.) also suppressed bladder motility, and the effect was abolished by nor-binaltorphimine. These results suggest that Gosha-jinki-gan attenuates bladder sensation via the kappa-opioid receptor-stimulating action of processed Aconiti tuber. Gosha-jinki-gan may be a useful anti-pollakiuria agent that does not influence bladder contractility at micturition.

Effect of diabetes on pinacidil-induced antinociception in mice

The antinociceptive effects of pinacidil, an adenosine triphosphate (ATP)-sensitive K(+)i (K(ATP)) channel opener, were examined using the tail-flick test in non-diabetic and diabetic mice. Pinacidil i.c.v. produced dose-dependent antinociception in both non-diabetic and diabetic mice. There was no significant difference between the antinociceptive effect of i.c.v. pinacidil in non-diabetic mice and diabetic mice. The i.t. administration of pinacidil also produced dose-dependent antinociception in both non-diabetic and diabetic mice, however, the antinociceptive effect of i.t. pinacidil in diabetic mice was significantly greater than that in non-diabetic mice. The antinociceptive effect of i.c.v. or i.t. pinacidil was significantly antagonized by i.c.v. or i.t. glibenclamide, a K(ATP) channel blocker in both non-diabetic and diabetic mice. In non-diabetic mice, the antinociceptive effect of i.c.v. or i.t. administration of pinacidil was significantly antagonized by beta-funaltrexamine, a mu-opioid receptor antagonist, 7-benzylidenenaltrexone, a delta1-opioid receptor antagonist, naltriben, a delta2-opioid receptor antagonist, and nor-binaltorphimine, a kappa-opioid receptor antagonist. In diabetic mice, the antinociceptive effect of i.c.v. pinacidil was significantly reduced by 7-benzylidenenaltrexone, naltriben, and nor-binaltorphimine. However, beta-funaltrexamine had no effect on antinociception induced by i.c.v. pinacidil in diabetic mice. On the other hand, the antinociceptive effect of i.t. pinacidil was significantly antagonized by beta-funaltrexamine, 7-benzylidenenaltrexone, naltriben, and nor-binaltorphimine in diabetic mice. These results indicated that pinacidil produced antinociception through the release of opioid peptides acting at mu-, delta- and kappa-opioid receptors in surpraspinal and spinal cord of non-diabetic mice. On the other hand, in diabetic mice, the antinociception-induced by pinacidil was mediated through the release of opioid peptides acting at delta- and kappa-opioid receptors supraspinally, whereas pinacidil produced antinociception through the release of opioid peptides acting at mu-, delta-, and kappa-opioid receptors spinally.

Antinociceptive effect of U-50488H, a kappa-opioid agonist, in streptozotocin-induced diabetic mice

We compared the antinociceptive activity of a kappa-opioid agonist, U-50488H, in streptozotocin-induced diabetic mice with that in non-diabetic mice. Subcutaneously administered U-50488H (3 and 10 mg kg(-1)) showed a more potent antinociceptive effect, as evaluated by the tail-pressure method, in diabetic mice than in non-diabetic mice. Increased antinociceptive activity of U-50488H observed in diabetic mice was also observed in mice given U-50488H intrathecally (3 and 10 microg). However, there were no differences observed between diabetic and non-diabetic mice given U-50488H intracerebroventricularly (3 and 10 microg). Although the antinociceptive effect of U-50488H (3 mg kg(-1), s.c.) in non-diabetic mice was increased by treatment with PD135158 (100 ng, i.c.v.), a cholecystokininB (CCKB) antagonist, the antinociceptive activity of U-50488H which was enhanced in diabetic mice was not influenced by PD135158. Moreover, the increased antinociceptive activity of U-50488H (3 mg kg(-1), s.c.) in diabetic mice diminished when desulfated octapeptide of cholecystokinin (3-100 ng, i.c.v.), a CCKB agonist, was administered. These results suggested that diabetic mice were selectively hyper-responsive to spinal kappa-opioid receptor-mediated antinociception. The function of the analgesia inhibitory system in which cholecystokinin is used as a transmitter might be diminished in diabetic mice.