Mitsutoshi Yuzurihara

EFFECTS OF CYCLOHEXIMIDE ON DELAYED NEURONAL DEATH IN RAT HIPPOCAMPUS

The effect of cycloheximide, a protein synthesis inhibitor, on hippocampal selective neuronal death was morphologically studied in rats subjected to 10 min forebrain ischemia using a 4-vessel occlusion model. Neuronal damage in the hippocampal CA1 subfield 72 h after ischemic insult was dramatically decreased by the lasting inhibition of protein synthesis through consecutive administration of cycloheximide. Cycloheximide, which was administered once within the first 24 h of recirculation, showed protective action on ischemic cell necrosis and its most potent effect was observed when injected at 12 h of post-ischemia. After 36 h of recirculation, however, treatment with cycloheximide could no longer prevent cell death. The possibility is considered that hippocampal delayed neuronal death following transient ischemia is caused by abnormal protein(s).

Suppressive effect of Yokukansan on excessive release of glutamate and aspartate in the hippocampus of zinc-deficient rats

Abstract Yokukansan (TJ-54), a herbal medicine, has been used as a cure for insomnia and irritability in children. Yokukansan also improves behavioral and psychological symptoms such as agitation, aggression and irritability in patients with dementia including Alzheimers disease, in which the glutamatergic neurotransmitter system is perturbed. However, the action of Yokukansan in synaptic neurotransmission is unknown. In the present study, the action of Yokukansan in the glutamatergic neurotransmitter system was examined in zinc-deficient rats, a neurological disease model, in which the glutamatergic neurotransmitter system is perturbed. Administration of Yokukansan significantly suppressed the increase in extracellular concentrations of glutamate and aspartate in the hippocampus after stimulation with 100 mM KCl, but not the increase in extracellular concentrations of glycine and taurine, suggesting that Yokukansan is involved in modulation of excitatory neurotransmitter systems. The present study demonstrates that Yokukansan is a possible medicine for prevention or cure of neurological diseases associated with excitotoxicity.

Antispasmodic effect of shakuyakukanzoto extract on experimental muscle cramps in vivo: Role of the active constituents of Glycyrrhizae radix

ETHNOPHARMACOLOGICAL RELEVANCEnShakuyakukanzoto (SKT) composed of Glycyrrhizae radix (G. radix) and Paeoniae radix (P. radix) has been traditionally used in Japan, Korea and China as an antispasmodic drug for the treatment of skeletal muscle cramps and intestinal cramps.nnnAIM OF THIS STUDYnTo evaluate the antispasmodic activity of SKT and its two components, as well as to identify the key constituents of the components which mediate this effect in skeletal muscles in vivo.nnnMATERIALS AND METHODSnAn experimental cramp model was constructed to evaluate the effects of peripherally-acting muscle relaxants on electrically-induced cramps under physiological conditions. This was accomplished by surgically isolating the motor supply to the gastrocnemius muscle in an anesthetized rat and delivering electrical stimuli to an isolated tibial nerve to induce tetanic contractions. We first tested dantrolene, a well-known peripherally-acting relaxant, to determine the sensitivity and reliability of our experimental model. We then evaluated the effects of SKT, P. radix, G. radix, and the eight active constituents of G. radix against tetanic contractions.nnnRESULTSnWe found that dantrolene (10 and 30 mg/kg, i.d.) rapidly and significantly inhibited tetanic contractions (P<0.01) irrespective of dose. SKT (0.5, 1.0, and 2.0 g/kg, i.d.) and G. radix (0.5 and 1.0 g/kg, i.d.) also significantly inhibited tetanic contractions (P<0.01) but in a dose-dependent manner owing to the actions of six of the eight active constituents in G. radix (liquiritin apioside, liquiritigenin, isoliquiritin apioside, isoliquiritigenin, glycycoumarin, and glycyrrhetinic acid, 20 μmol/kg, i.v.). These constituents, which include flavonoids, a triterpenoid, and a courmarin derivative, demonstrated temporal variations in their inhibitory activity. In contrast, P. radix (0.5 and 1.0 g/kg, i.d.) did not show a statistically significant antispasmodic effect in our study; however, we previously found that it had a significant antinociceptive effect.nnnCONCLUSIONSnOur findings show that SKT inhibits tetanic contractions in vivo and that G. radix is the main antispasmodic component due to the actions of its active constituents, thus supporting the traditional use of SKT. We further propose that SKT containing the antispasmodic G. radix and antinociceptive P. radix is a pharmaceutically elegant option for muscle cramps as treatment requires a two-pronged approach, i.e., inhibition of hyperexcitable skeletal tissues and modulation of the pain accompanying cramps.

Changes in circulating cytokine levels in midlife women with psychological symptoms with selective serotonin reuptake inhibitor and Japanese traditional medicine

OBJECTIVEnThe aim of the present study was to compare the effects on serum cytokine concentrations of paroxetine, a selective serotonin re-uptake inhibitor, and kamishoyosan, a Japanese traditional medicine, in midlife women with psychological symptoms.nnnMETHODSnSeventy-six women with psychological symptoms such as anxiety and mild depression as menopausal symptoms were enrolled in this study. Thirty-eight women received oral administration of 10mg paroxetine every day, and 38 women received oral administration of kamshoyosan every day for 6 months. Overall climacteric symptoms were assessed using Greenes climacteric scale. Serum levels of cytokines were measured using a multiplexed human cytokine assay.nnnRESULTSnGreenes total scores in both women treated with paroxetine and in women treated with kamishoyosan decreased significantly. Percentage decreases in Greenes total, psychological and vasomotor scores during the 6-month period in the paroxetine group were significantly greater than those in the kamishoyosan group. Serum IL-6 concentration in women treated with paroxetine decreased significantly. Serum concentrations of IL-8, IL-10, macrophage inflammatory protein (MIP)-1beta and monocyte chemoattractant protein-1 in women treated with paroxetine decreased significantly. On the other hand, serum IL-6 concentration in women treated with kamishoyosan decreased significantly, but other serum concentrations did not change significantly.nnnCONCLUSIONnDecrease in IL-6 concentration may be involved in the mechanism of the actions of both paroxetine and kamishoyosan in women with psychological symptoms, and IL-6 may therefore be useful as a marker of treatment. The action of paroxetine may also be associated with decreases in IL-8, IL-10, MIP-1beta.

Effects of Japanese traditional medicines on circulating cytokine levels in women with hot flashes.

Objective:The effects of the Japanese traditional medicines keishibukuryogan and kamishoyosan on circulating cytokines were examined to clarify the difference in the actions of Japanese traditional medicines in women with hot flashes. Methods:Seven premenopausal, 51 perimenopausal, 45 spontaneously postmenopausal and 17 surgically postmenopausal women who had complained of hot flashes were enrolled in this study. Eighty women who hoped to receive Japanese traditional medicines were randomly assigned in open, parallel-group fashion to a keishibukuryogan group or kamishoyosan group. Forty women who did not want any treatment for hot flashes were followed up for 6 months as a control group. Serum levels of cytokines were measured using a multiplexed human cytokine assay. Results:The proportions of responders in women treated with keishibukuryogan and kamishoyosan were 73.7% and 69.2%, respectively. Serum monocyte chemotactic protein-1 level in women treated with keishibukuryogan decreased significantly (P = 0.0037). On the other hand, concentrations of interleukin (IL)-6 and macrophage inflammatory protein-1&bgr; in women treated with kamishoyosan decreased significantly (P = 0.019 and P = 0.039, respectively). In both keishibukuryogan and kamishoyosan responder groups, serum IL-8 concentrations were reduced significantly (P = 0.021 and P = 0.014, respectively). Conclusions:Both treatments with keishibukuryogan and kamishoyosan reduce the circulating IL-8 level, which is involved in thermoregulation in perimenopausal women with hot flashes. In addition, keishibukuryogan decreases circulating monocyte chemotactic protein-1 level in postmenopausal women.

Associations of circulating adiponectin with estradiol and monocyte chemotactic protein-1 in postmenopausal women.

Objective: The aim of the present study was to clarify the association of serum adiponectin concentrations with serum 17&bgr;-estradiol concentrations in pre-, peri-, and postmenopausal women. In addition, the associations of serum adiponectin with serum concentrations of proinflammatory and anti-inflammatory cytokines were examined in women during the menopausal transition. Design: A total of 197 women were enrolled in this study: 33 premenopausal women, 80 perimenopausal women, and 84 postmenopausal women. Serum adiponectin concentration was measured by an enzyme-linked immunosorbent assay. Serum concentrations of the proinflammatory cytokines interleukin (IL)-1&bgr;, IL-6, and tumor necrosis factor &agr;, anti-inflammatory cytokine IL-10, and the chemokines IL-8, macrophage inflammatory protein-1&bgr; and monocyte chemotactic protein-1 were measured by using a multiplexed human cytokine assay. Results: Serum adiponectin concentration showed a significant negative correlation with serum estradiol concentration (r = −0.400, P = 0.001) in postmenopausal women but not in pre- and perimenopausal women, and this correlation was significant after adjustment for age and body mass index. Serum adiponectin concentration also showed a significant negative correlation with serum monocyte chemotactic protein-1 concentration (r = −0.244, P = 0.05) in postmenopausal women. Conclusion: An increase in adiponectin level due to a decrease in estradiol results in a reduction in monocyte chemotactic protein-1 level in postmenopausal women, suggesting that adiponectin may be associated with a protective role against insulin resistance and atherosclerosis, which occur in the postmenopausal stage.

Effects of oral and transdermal estrogen therapies on circulating cytokines and chemokines in postmenopausal women with hysterectomy

OBJECTIVEnThe aim of the present study was to determine the different effects of oral estrogen therapy (ET) and transdermal ET on changes in circulating levels of cytokines and chemokines in relationship to changes in markers of inflammation in postmenopausal women with hysterectomy.nnnMETHODSnFifty-five postmenopausal women with hysterectomy were randomly assigned in open, parallel-group fashion to an oral ET group and a transdermal ET group. Serum levels of cytokines and chemokines were simultaneously measured using a multiplexed human cytokine assay. Serum concentrations of high-sensitive C-reactive protein, soluble vascular cell adhesion molecule-1, soluble intercellular adhesion molecule-1, and E-selectin were measured as vascular inflammation markers.nnnRESULTSnBoth oral ET and transdermal ET significantly decreased serum interleukin (IL)-7 concentrations at 12 months (P=0.020 and P=0.015 respectively). Transdermal ET decreased serum concentrations of IL-8, monocyte chemoattractant protein (MCP)-1, and macrophage inflammatory protein (MIP)-1beta (P=0.05, P=0.019, and P=0.029), but oral ET increased IL-8 level (P=0.025). There were significant differences in percentage changes in IL-8 and MIP-1beta between the oral and transdermal ET groups. Oral ET significantly decreased E-selectin level after 12 months.nnnCONCLUSIONnTransdermal ET reduces circulating levels of IL-8, MCP-1, and MIP-1beta, while both oral ET and transdermal ET reduce circulating level of IL-7.

Antinociceptive effect of paeoniflorin via spinal α2-adrenoceptor activation in diabetic mice

Background: Shakuyakukanzoto (SKT) has been shown to modulate nociception in streptozotocin‐induced diabetic mice via selective activation of the descending noradrenergic systems. However, the active components of SKT that exert the analgesic effect remain unknown. Here, we administered Glycyrrhizae radix (G. radix), Paeoniae radix (P. radix), and the two active constituents of P. radix, paeoniflorin and albiflorin, to determine the components that stimulate spinal α2‐adrenoceptors by promoting noradrenaline release.

Different circulating levels of monocyte chemoattractant protein-1 and interleukin-8 during the menopausal transition

OBJECTIVEnThe aim of the present study was to clarify the changes in circulating cytokines and chemokines in women during the menopausal transition by using a detailed classification.nnnMATERIALS AND METHODSnA total of 554 women were recruited for this study from the outpatient clinic of the Department of Obstetrics and Gynecology, Tokushima University Hospital. We divided the women into seven stages by menstrual regularity and FSH level: mid-reproductive stage, late reproductive stage, early menopausal transition, late menopausal transition, very early postmenopause, early postmenopause and late postmenopause. We measured serum concentrations of nine cytokines (IL-1β, IL-5, IL-6, IL-7, IL-8, IL-10, TNF-α, MIP-1β and MCP-1).nnnRESULTSnSerum IL-8 concentrations in postmenopausal women were significantly (p = 0.001) higher than those in women in the mid- or late reproductive stage and women in early or late menopausal transition. Serum MCP-1 levels in women in late menopausal transition and postmenopause were significantly (p < 0.001) higher than those in women in the mid- or late reproductive stage and women in early menopausal transition. MCP-1 level showed a significant positive correlation (r = 0.215, p < 0.01) with FSH level in women in menopausal transition.nnnCONCLUSIONnBy using a detailed classification of menopausal transition, patterns of changes in IL-8 and MCP-1 levels during the menopausal transition were found to be different. IL-8 level showed a high level after menopause, while MCP-1 level showed a high level in menopausal transition. MCP-1 may be sensitive to hormonal change and may be involved in the development of estrogen deficiency diseases.

Raloxifene reduces circulating levels of interleukin-7 and monocyte chemoattractant protein-1 in postmenopausal women

OBJECTIVEnThe aim of the present study was to determine the effects of raloxifene on changes in circulating levels of cytokines and chemokines in relation to changes in lipid profiles and markers of inflammation in postmenopausal women.nnnMETHODSnFifty-three postmenopausal women aged 45-65 years old were randomly assigned in open, parallel-group fashion to a control group or raloxifene group. Twenty-six women received oral administration of 60 mg raloxifene every day and 27 women did not receive any drugs for 12 months. Serum cytokines levels were simultaneously measured using a multiplexed human cytokine assay.nnnRESULTSnSerum IL-7 concentrations in women who received raloxifene were decreased significantly (p=0.014), and serum monocyte chemoattractant protein (MCP)-1 concentrations in women who received raloxifene were decreased significantly (p=0.0003) at 12 months. In the control group, serum levels of MCP-1 and IL-7 did not show significant changes. There were significant differences (p=0.032 and p=0.0024, respectively) in percentage changes in IL-7 and MCP-1 in the control group and in the raloxifene group. Levels of low-density lipoprotein cholesterol (LDL-C) and E-selectin were decreased significantly in women who received raloxifene, but the percentage changes in LDL-C and E-selectin over a period of 12 months were not significantly correlated with percentage changes in IL-7 and MCP-1 over the same period.nnnCONCLUSIONnCirculating levels of IL-7 and MCP-1 decrease in postmenopausal women who received raloxifene.