Search

Small molecular G-protein plays a key role in several diseases. This study was designed to reveal the role of RhoA signaling in the pathophysiology of neuropathic pain in mice. Partial sciatic nerve injury caused thermal hyperalgesia, mechanical allodynia, and increased plasma membrane translocation of RhoA in the lumber spinal cord. GFAP-immunoreactivity (ir), Iba-1-ir, and Rho kinase 2 (ROCK2-ir) was also increased in the ipsilateral spinal dorsal horn of nerve-ligated mice. Moreover, partial nerve ligation increased the expression of phosphorylated myristoylated alanine-rich protein kinase C substrate (MARCKS)-ir in the ipsilateral spinal dorsal horn. Daily intrathecal administration of simvastatin, beginning 3 days before nerve injury, completely blocked all these changes in nerve-ligated mice. Pharmacological inhibition of ROCK also attenuated the increased expression of GFAP-ir and phosphorylated MARCKS-ir. Together, it is suggested that astrogliosis initiated by the activation of RhoA/ROCK signaling results in MARCKS phosphorylation in nerve terminals, which leads to hyperalgesia in neuropathic pain. Furthermore, simvastatin exerts antihyperalgesic and antiallodynic effects through the inhibition of spinal RhoA activation. [ABSTRACT FROM AUTHOR]

Highlights: [•] Partial sciatic nerve injury elicited neuropathic pain. [•] Phosphorylation of spinal MARCKS was increased in nerve ligation. [•] Neuropathic pain was attenuated by geranylgeranyl transferase inhibitor. [•] MARCKS protein phosphoryation was mediated by protein isoprelylation. [•] Inhibition of protein isoprenylation could relive neuropathic pain. [Copyright &y& Elsevier]

Abstract: Renal ischemia produces sympathoexcitation, which is responsible for the development of ischemic acute kidney injury. Stimulation of central opioid receptors activates the renal sympathetic nerve. The present study examined the effect of an opioid receptor antagonist naloxone on the ischemia/reperfusion-induced renal dysfunction in mice. Blood urea nitrogen (BUN) and plasma creatinine increased 24 h after the renal ischemia/reperfusion. Intraperitoneal or intracerebroventricular, but not intrathecal, pretreatment with naloxone suppressed the renal ischemia/reperfusion-induced increases in BUN and plasma creatinine. This effect of naloxone was reversed by subcutaneous pretreatment with morphine. Selective MOP receptor antagonist β-funaltrexamine (FNA) also suppressed the renal ischemia/reperfusion-induced increases in BUN and plasma creatinine. Moreover, tyrosine hydroxylase expression in the renal tissue increased 24 h after renal ischemia/reperfusion, which was abolished by intraperitoneal or intracerebroventricular pretreatment with naloxone and FNA. Immunohistochemical experiments revealed a significant increase in the number of the Fos family proteins (c-Fos, FosB, Fra-1, and Fra-2) positive cells in the paraventricular nucleus of hypothalamus and supraoptic nucleus 24 h after the renal ischemia/reperfusion. Intracerebroventricular pretreatment with naloxone attenuated the renal ischemia/reperfusion-induced increase in the number of the Fos family proteins positive cells in these areas. Finally, we observed that i.c.v. pretreatment with antiserum against β-endorphin also suppressed the increased blood urea and plasma creatinine. These results suggest that the blockade of central opioid receptors can attenuate the ischemic acute kidney injury through the inhibition of renal sympathoexcitation. The central opioid receptors may thus be a new target for the treatment of ischemic organ failures. [Copyright &y& Elsevier]

Abstract: Carnosine is a biologically active dipeptide that is found in fish and chicken muscle. Recent studies have revealed that carnosine has neuroprotective activity in zinc-induced neural cell apoptosis and ischemic stroke. In the present study, we examined the expression of carnosine in the spinal cord, and the antinociceptive potency of carnosine in a mouse model of inflammation-induced nociceptive pain. Immunohistochemical studies with antiserum against carnosine showed an abundance of carnosine-immunoreactivity in the dorsal horn of the mouse spinal cord. Double-immunostaining techniques revealed that carnosine was expressed in the neurons and astrocytes in the spinal cord. Oral administration of carnosine attenuated the number of writhing behaviors induced by the intraperitoneal administration of 0.6% acetic acid. Treatment with carnosine also attenuated the second phase, but not the first phase, of the nociceptive response to formalin. Moreover, intrathecal, but not intraplanter, administration of carnosine attenuated the second phase of the nociceptive response to formalin. Our immunohistochemical and behavioral data suggest that carnosine has antinociceptive effects toward inflammatory pain, which may be mediated by the attenuation of nociceptive sensitization in the spinal cord. [Copyright &y& Elsevier]

Abstract: We previously demonstrated that intrathecal treatment with substance P metabolite substance P1–7 induced anti-hyperalgesia in diabetic mice. In the present study, we have used a synthetic analog of this peptide, the substance P1–7 amide, showing higher binding affinitiy than the native heptapeptide, for studies of the tail-flick response in diabetic and non-diabetic mice. Intrathecal injection of substance P1–7 amide produced prolongation of the tail-flick latency in both diabetic and non-diabetic mice, an effect that was more pronounced in diabetic mice than non-diabetic mice. Moreover, the observed antinociceptive potency of the substance P1–7 amide was higher in both diabetic and non-diabetic mice in comparison with the native substance P1–7. The antinociceptive effect of substance P1–7 amide was reversed by naloxone but not by the selective opioid receptor antagonist β-funaltrexamine, naltrindole or nor-binaltorphimine, selective for the μ-, δ- or κ-opioid receptor, respectively. In addition, the antinociceptive effect induced by substance P1–7 amide was partly reversed by the σ1 receptor agonist (+)-pentazocine, suggesting a possible involvement of the σ1 receptor for the action of this peptide. These results suggest that the actions of substance P1–7 amide mimic the effects of the native substance P fragment but with higher potency and that the mechanisms for its action may involve the σ1 receptor system. [ABSTRACT FROM AUTHOR]

Abstract: Diabetic neuropathy is one of the most common complications of diabetes and causes various problems in daily life. Several investigations have noted that many factors in the spinal cord are involved in the symptoms of painful diabetic neuropathy, and there are very few effective therapeutic regimens. In the present study, we sought to elucidate the role of the RhoA/Rho kinase (ROCK) pathway in thermal hyperalgesia in diabetic mice. The intracellular localization of RhoA and the expression of eNOS were measured by western blotting. Thermal hyperalgesia was assessed by the tail-flick test and mechanical allodynia was assessed by automated von Frey filament test in streptozotocin(STZ)-induced diabetic mice. The spinal cord of STZ-treated diabetic mice showed increased membrane-bound RhoA compared to non-diabetic control. Treatment with the RhoA inhibitor exoenzyme C3, Clostridium botulinum, and the ROCK inhibitor Y27632 attenuated thermal hyperalgesia and mechanical allodynia in diabetic mice. Moreover, daily treatment with simvastatin attenuated all of those changes in diabetic mice. The expression of eNOS and NO metabolite contents in the spinal cord was decreased in diabetic mice, and these changes were normalized by treatment with simvastatin. The present results show that HMG-CoA reductase inhibitors have an inhibitory effect on thermal hyperalgesia in diabetic mice, which is mediated by an increase in NO production through the inhibition of RhoA/ROCK pathways. These results suggest that ROCK inhibitors and HMG-CoA inhibitors may be attractive compounds to relieve the symptoms of painful diabetic neuropathies. [Copyright &y& Elsevier]

Abstract: Diabetic neuropathy is one of the most common complications in diabetes, and hyperalgesia and allodynia are serious symptoms of diabetic neuropathy. There are few therapeutic options available for the treatment of such diabetic painful neuropathy. While several reports have indicated that an abnormality of intracellular signaling molecules is involved in the pathogenesis of diabetic painful neuropathy, agents that affect these intracellular signaling molecules have failed to deliver convincing results in clinical trials. Recently, the small molecular G-protein RhoA has been shown to be involved in the pathogenesis of diabetic nephropathy. RhoA and its downstream kinase Rho kinase (ROCK) have been shown to modulate nociceptive transmission in the spinal cord. In this report, we provide a brief overview of the role of the RhoA/ROCK pathway in diabetic complications. We especially focus on the role of the spinal RhoA/ROCK pathway in the pathogenesis of diabetic painful neuropathy. Findings on the association between the spinal RhoA/ROCK pathway and diabetic painful neuropathy may lead to new strategies for its treatment. [ABSTRACT FROM AUTHOR]

Abstract: Mechanical allodynia is a major complication in diabetic mellitus. Peripheral σ1 receptors were shown to be involved in nociceptive perception. We therefore investigated the effect of σ1 receptor ligand (+)-pentazocine injected into the dorsal surface of the hindpaw on mechanical allodynia in streptozotocin-induced diabetic mice. Injection of (+)-pentazocine (30μg) into the dorsal surface of the hindpaw did not affect the mechanical threshold and hindpaw NO contents in non-diabetic mice, whereas the mechanical allodynia and hindpaw contents of NO metabolites in diabetic mice were normalized by (+)-pentazocine. These effects of (+)-pentazocine in diabetic mice were inhibited by pretreatment with an σ receptor antagonist BD1047 into the same area, but not by systemic pretreatment with a κ-opioid receptor antagonist nor-binaltorphimine. These results suggest that (+)-pentazocine injected into the dorsal surface of the hindpaw increases the lowered mechanical threshold in diabetic mice through the activation of peripheral σ1 receptors. This attenuation may be, in part, due to the normalization of increased peripheral NO contents in the hindpaw of diabetic mice. [Copyright &y& Elsevier]

Abstract: We have recently explored the role of the tachykinin substance P neuroactive fragment substance P1–7 in the mediation of anti-inflammatory effects using a blister model in the rat paw (Wiktelius et al., 2006). We observed that this heptapeptide induced a dose-dependent inhibitory effect on the substance P-induced response, which was reversible by the non-selective opioid receptor antagonist naloxone. In the present study, we examined the ability of substance P1–7 to induce antihyperalgesic effects in streptozotocin-induced diabetic mice. We found that the substance P fragment strongly and dose-dependently produced antihyperalgesia in diabetic mice. This effect was reversed by naloxone but not by the selective opioid receptor antagonist β-funaltrexamine, naltrindole or nor-binaltorphimine, selective for the µ-, δ- or κ-opioid receptor, respectively. In addition, the antihyperalgesic effect induced by substance P1–7 was partly reversed by a σ1 receptor agonist (+)-pentazocine, but not a σ1 receptor antagonist BD1047 ([2-(3,4-dichlorophenyl)ethyl]-N-methyl-2-(diamino)ethylamine), suggesting that involvement of the naloxone-sensitive σ-receptor for the action of the SP related heptapeptides. These results suggest that hyperalgesia in diabetic mice may be, in part, due to the enhanced endogenous σ1 receptor systems in the spinal cord. [Copyright &y& Elsevier]

Abstract: Sensory abnormality is one of the serious complications in diabetes. Since the effective therapeutic regimen to ameliorate the diabetic sensory abnormality is very few, the present study was then designed to investigate the effect of zinc l-carnosine on the changes of nociceptive threshold in diabetic mice. Zinc l-carnosine (75–300 mg/kg, p.o.) was administered once daily from 1 day after streptozotocin treatment. Diabetic mice showed shorter tail-flick latency at 1–4 weeks after streptozotocin treatment and longer tail-flick latency at 6–9 weeks after its treatment. The shortened tail-flick latency in early stage of diabetic mice was ameliorated by treatment with zinc l-carnosine. Moreover, zinc l-carnosine also slowed the onset of hypoalgesia in diabetic mice. Tail-flick latency in non-diabetic mice was not affected by the zinc l-carnosine treatment, indicating that zinc l-carnosine did not affect normal nociceptive transmission. Moreover, l-carnosine, but not zinc sulfate, ameliorated the abnormal sensory perception in diabetic mice. Interestingly, the ameliorative effect of zinc l-carnosine on the abnormal sensory perception in diabetic mice is much stronger than that of l-carnosine. These results provide the evidence of the ameliorative potential of zinc l-carnosine on the progressive diabetic neuropathy. Moreover, l-carnosine combined with zinc shows more potent amelioration of abnormal sensory perception in diabetic mice than by itself. [Copyright &y& Elsevier]

Abstract: Neuropathy accompanied by abnormal sensory perception is the most common complication in insulin-dependent and -independent diabetes mellitus. Since there are very few effective therapeutic regimens for sensory abnormalities in diabetes, we examined the effect of cytidine 5′-diphosphocholine (CDP)-choline on the thermal nociceptive threshold in streptozotocin-induced diabetic mice using the tail-flick test. Diabetic mice showed a shorter tail-flick latency at 1–4 weeks after streptozotocin treatment and a longer tail-flick latency after 8–12 weeks. This hyper- and hypoalgesia in diabetic mice was almost completely inhibited by daily treatment with CDP-choline (100mg/kg/day, p.o.) beginning on the day of streptozotocin treatment. Daily treatment with CDP-choline beginning 5 weeks after streptozotocin treatment attenuated the development of hypoalgesia. Diabetic mice showed a significant increase in Na+-K+-ATPase activity at 3 weeks after streptozotocin treatment, whereas Na+-K+-ATPase activity was decreased at 12 weeks after treatment. These alterations were normalized by daily treatment with CDP-choline (100mg/kg/day, p.o.) beginning the day of streptozotocin treatment. These results provide evidence to support the therapeutic potency of CDP-choline on the development of thermal hyper- and hypoalgesia and the progression of thermal hypoalgesia in diabetic mice. Moreover, these effects of CDP-choline may result from the normalization of Na+-K+-ATPase activity. [Copyright &y& Elsevier]

Abstract: Hypoalgesia is one of the serious complications in diabetes. Since there are few therapeutic treatments for this diabetic hypoalgesia, the present study was designed to examine the effect of acetyl-L-carnitine (ALC) on the changes of nociceptive threshold in diabetic mice. For prophylactic study, ALC was administered once daily from 1 day after the streptozotocin treatment. Diabetic mice showed shorter tail-flick latency at 1–4 weeks after the streptozotocin treatment and longer tail-flick latency at 6–9 weeks after the streptozotocin treatment. The shortened tail-flick latency in early stage of diabetic mice was not affected by prophylactic treatment with ALC. On the other hand, ALC dose-dependently improved the hypoalgesia in diabetic mice. For therapeutic study, ALC was administered once daily from 7 weeks after the streptozotocin treatment, when tail-flick latency was already prolonged. The therapeutic treatment with ALC also ameliorated the prolonged tail-flick latency in diabetic mice. Both prophylactic and therapeutic treatment with ALC did not affect the tail-flick latency in non-diabetic mice, indicating ALC did not affect the general nociceptive transmission. These results provide evidence of the prophylactic and therapeutic potential of ALC on the progressive diabetic neuropathy. [Copyright &y& Elsevier]

Isoprenylation is crucial for the biological activation of small molecular G proteins. Activation of Rho/Rho kinase (ROCK) signaling has been reported to be involved in the initiation and maintenance of hyperalgesia caused by nerve injury and inflammation. The present study was then undertaken to examine whether the protein isoprenylation could affect thermal nociceptive threshold in the mouse spinal cord. Intrathecal administration of mevalonate (0.05-5.0 micromol) dose-dependently decreased the paw-withdrawal latencies for the thermal stimulation, indicating that mevalonate induces thermal hyperalgesia. Intrathecal pretreatment with a geranylgeranyl transferase I inhibitor GGTI-2133 (0.001-1.0 nmol) or a ROCK inhibitor Y27632 (0.001-1.0 nmol) completely blocked the mevalonate-induced thermal hyperalgesia. On the other hand, mevalonate-induced thermal hyperalgesia was only slightly attenuated by a farnesyl transferase inhibitor FTI-277 (0.01-1.0 nmol). Intrathecal injection of mevalonate increased the amount of geranylgeranylated RhoA in the spinal cord, which was completely blocked by intrathecal pretreatment with GGTI-2133. Intrathecal injection of mevalonate also produced RhoA translocation from cytosol to plasma membrane. This mevalonate-induced RhoA translocation was also blocked by intrathecal pretreatment with GGTI-2133, indicating that the RhoA translocation is triggered by RhoA geranylgeranylation. Moreover, inhibition of mevalonate synthesis by HMG-CoA reductase inhibition with simvastatin attenuated the second phase, but not the first phase, of nociceptive response to formalin. Our present results suggest that mevalonate sensitizes the spinal nociceptive transmission, which is mediated by the activation of ROCK following the RhoA geranylgeranylation. [ABSTRACT FROM AUTHOR]

Abstract: Isoprenylation is crucial for the biological activation of small molecular G proteins. Activation of Rho/Rho kinase (ROCK) signaling has been reported to be involved in the initiation and maintenance of hyperalgesia caused by nerve injury and inflammation. The present study was then undertaken to examine whether the protein isoprenylation could affect thermal nociceptive threshold in the mouse spinal cord. Intrathecal administration of mevalonate (0.05–5.0μmol) dose-dependently decreased the paw-withdrawal latencies for the thermal stimulation, indicating that mevalonate induces thermal hyperalgesia. Intrathecal pretreatment with a geranylgeranyl transferase I inhibitor GGTI-2133 (0.001–1.0nmol) or a ROCK inhibitor Y27632 (0.001–1.0nmol) completely blocked the mevalonate-induced thermal hyperalgesia. On the other hand, mevalonate-induced thermal hyperalgesia was only slightly attenuated by a farnesyl transferase inhibitor FTI-277 (0.01–1.0nmol). Intrathecal injection of mevalonate increased the amount of geranylgeranylated RhoA in the spinal cord, which was completely blocked by intrathecal pretreatment with GGTI-2133. Intrathecal injection of mevalonate also produced RhoA translocation from cytosol to plasma membrane. This mevalonate-induced RhoA translocation was also blocked by intrathecal pretreatment with GGTI-2133, indicating that the RhoA translocation is triggered by RhoA geranylgeranylation. Moreover, inhibition of mevalonate synthesis by HMG-CoA reductase inhibition with simvastatin attenuated the second phase, but not the first phase, of nociceptive response to formalin. Our present results suggest that mevalonate sensitizes the spinal nociceptive transmission, which is mediated by the activation of ROCK following the RhoA geranylgeranylation. [Copyright &y& Elsevier]

Beta-arrestins have been suggested to regulate μ-, δ-, and κ-opioid receptor-mediated responses. In the present study, we examined the effects of pretreatment with β-arrestin-2 antibody on tail-flick inhibition induced by opioid receptor agonists in the mouse spinal cord. Intrathecal (i.t.) pretreatment with β-arrestin-2 antibody potentiated the antinociception induced by i.t.-administered μ-opioid receptor agonists [d-Ala2,NMePhe4,Gly-ol5]enkephalin (DAMGO) and endomorphin-1, but not endomorphin-2, the δ-opioid receptor agonist [d-Ala2]deltorphin II or the κ-opioid receptor agonist U50,488H. The present result suggests that β-arrestin-2 may tonically down-regulate a selected population of μ-opioid receptors activated by endomorphin-1 or DAMGO in the mouse spinal cord. [Copyright &y& Elsevier]

Superficial layers of the dorsal horn receive a dense plexus of nerve fibers immunoreactive to pituitary adenylate cyclase activating polypeptide (PACAP). In vivo experiments were conducted in the mice to evaluate the effects of PACAP-38, herein referred to as PACAP, PACAP receptor antagonist PACAP(6–38) and PACAP-antiserum on nociceptive behaviors induced by radiant heat, intrathecally administered N-methyl-d-aspartate (NMDA) or intraplantarly administered formalin. PACAP (0.05–0.5 μg) dose-dependently decreased the paw-withdrawal latencies induced by thermal stimulation and enhanced the aversive licking and biting behaviors induced by intrathecally injected NMDA. Pretreatment with the PACAP receptor antagonist PACAP(6–38) (0.5–2 μg) or PACAP-antiserum (1:500–2000 dilution) dose-dependently attenuated the second phase, but not the first phase, of nociceptive responses to formalin. Next, the effects of PACAP on NMDA- and kainate-induced currents evoked in single dorsal horn neurons were studied. Whole-cell patch recordings were made from superficial dorsal horn neurons of spinal cord slices from 14- to 20-day-old mice. PACAP at the concentrations of 100 and 200 nM, which caused no significant change of holding currents, increased NMDA-but not kainate-induced currents in superficial dorsal horn neurons. Our results suggest that exogenously applied PACAP sensitizes the dorsal horn neurons to formalin stimulation, and facilitates NMDA receptor-mediated nociceptive response. As a corollary, PACAP, which may be released from primary afferent fibers potentiates nociceptive transmission to the dorsal horn by interacting primarily with NMDA receptors. [Copyright &y& Elsevier]

The present study has shown that there is no correlation between the free curing contraction of three selected addition-type silicone impression materials and the effective contraction determined as the accuracy of stone dies produced in dental impressions of these materials. Depending on specific rheologic properties, the free curing contraction of an impression material can be partly compensated for by flow. [ABSTRACT FROM AUTHOR]

The curing contraction of addition-type silicone impression materials was measured by the mercury bath method. The results point to a classification of this group of materials into the following two types: 1: materials with maximum 0.08% polymerization contraction at 22°C 15 min after mixing and maximum 0.03% contraction at 22°C during storage from 15 min to 24 h (Permagum®, President®, Reflect® and Reprosil®). 2: materials with more than 0.08% polymerization contraction at 22°C 15 min after mixing and significantly more than 0.03% contraction during storage at 22°C from 15 min to 24 h (Exaflex®, Xantogum®). [ABSTRACT FROM AUTHOR]

Simple Summary: In recent years, much research has focused on how exercise improves cancer prognosis and how the protein myokine, which is associated with exercise, inhibits cancer progression. However, there have been few detailed studies on oral cancer. This study is the first to show that exercise inhibits the progression of oral cancer. While other studies have shown that exercise suppresses growth, decreases the tumor formation rate, or improves survival in patients with other organ cancers, this study showed that exercise inhibits tumor formation and growth in oral cancer and prolongs survival. Furthermore, while many studies have demonstrated an indirect immune-mediated mechanism by which exercise suppresses cancer, this study suggests the additional possibility that myokines released by exercise directly affect oral cancer cells. This study has the above novelties. Major advances have been made in cancer treatment, but the prognosis for elderly cancer patients with sarcopenia and frailty remains poor. Myokines, which are thought to exert preventive effects against sarcopenia, have been reported to be associated with the prognosis of various cancers, but their effect on head and neck squamous cell carcinoma (HNSCC) is unknown. The aim of this study was to clarify the influence of exercise on the control of HNSCC and to examine the underlying mechanism involved. Mice were injected with HSC-3-M3 cells, a human cell line of highly metastatic and poorly differentiated tongue cancer, at the beginning of the study. Just prior to transplantation, blood was collected from the mice, and the levels of myokines were measured by ELISA. Oncostatin M (OSM), a selected myokine, was added to HSC-3-M3 cells, after which the cell proliferation ability, cell cycle, and protein expression were analyzed in vitro. Tumor cell viability was lower (control: 100%, exercise: 75%), tumors were smaller (control: 26.2 mm3, exercise: 6.4 mm3), and survival was longer in the exercise group than in the control group in vivo. OSM inhibited HSC-3-M3 cell proliferation in a concentration-dependent manner in vitro. The addition of OSM increased the proportion of cells in the G0/G1 phase, decreased the proportion of cells in the G2/M phase, and increased the expression of the CDK inhibitors p21 and p27. These results indicate that exercise may directly inhibit the proliferation of HNSCC cell lines via OSM. [ABSTRACT FROM AUTHOR]

Background: The changes in body image caused by breast deformities and postoperative pain have a detrimental influence on the physical and mental health of patients with breast cancer. The postoperative quality of life (QOL) of these patients reduces significantly owing to the changes in the breast, an organ unique to women, that occur following breast cancer surgery. Case presentation: This case report presents the case of a Asian woman in her early 40 s with postoperative hypertrophic scarring and contraction of the scar following mastectomy; the patient presented with decreased range of motion of the upper arm, hyperpigmentation from radiation burns, changes in breast shape, and chronic pain. The patient received a combination therapy comprising Basalt Stone Treatment and the application of horse placenta extract. As a result of a total of eight sessions conducted once every two weeks, the patient's pain and scar improved. No adverse events were observed after the therapy. Conclusion: Combination therapy with Basalt Stone Treatment and horse placenta extract improved the chronic pain and scar after breast cancer surgery. [ABSTRACT FROM AUTHOR]

Dopamine (DA)'s relationship with addiction is complex, and the related pathways in the mesocorticolimbic system are used to deliver DA, regulating both behavioral and perceptual actions. Specifically, the mesolimbic pathway connecting the ventral tegmental area (VTA) and the nucleus accumbens (NAc) is crucial in regulating memory, emotion, motivation, and behavior due to its responsibility to modulate dopamine. To better investigate the relationship between DA and addiction, more advanced mapping methods are necessary to monitor its production and propagation accurately and efficiently. In this study, we incorporate dLight1.2 adeno-associated virus (AAV) into our latest CMOS (complementary metal-oxide semiconductor) imaging platform to investigate the effects of two pharmacological substances, morphine and cocaine, in the NAc using adult mice. By implanting our self-fabricated CMOS imaging device into the deep brain, fluorescence imaging of the NAc using the dLight1.2 AAV allows for the visualization of DA molecules delivered from the VTA in real time. Our results suggest that changes in extracellular DA can be observed with this adapted system, showing potential for new applications and methods for approaching addiction studies. Additionally, we can identify the unique characteristic trend of DA release for both morphine and cocaine, further validating the underlying biochemical mechanisms used to modulate dopaminergic activation. [ABSTRACT FROM AUTHOR]

In this research, we combined our ultralight micro-imaging device for calcium imaging with microdialysis to simultaneously visualize neural activity in the dorsal raphe nucleus (DRN) and measure serotonin release in the central nucleus of the amygdala (CeA) and the anterior cingulate cortex (ACC). Using this platform, we observed brain activity following nociception induced by formalin injection in the mouse's hind paw. Our device showed that DRN fluorescence intensity increased after formalin injection, and the increase was highly correlated with the elevation in serotonin release in both the CeA and ACC. The increase in calcium fluorescence intensity occurred during the acute and inflammatory phases, which suggests the biphasic response of nociceptive pain. Furthermore, we found that the increase in fluorescence intensity was positively correlated with mouse licking behavior. Lastly, we compared the laterality of pain stimulation and found that DRN fluorescence activity was higher for contralateral stimulation. Microdialysis showed that CeA serotonin concentration increased only after contralateral stimulation, while ACC serotonin release responded bilaterally. In conclusion, our study not only revealed the inter-regional serotonergic connection among the DRN, the CeA, and the ACC, but also demonstrated that our device is feasible for multi-site implantation in conjunction with a microdialysis system, allowing the simultaneous multi-modal observation of different regions in the brain. [ABSTRACT FROM AUTHOR]

Previous human and rodent studies indicated that nociceptive stimuli activate many brain regions that is involved in the somatosensory and emotional sensation. Although these studies have identified several important brain regions involved in pain perception, it has been a challenge to observe neural activity directly and simultaneously in these multiple brain regions during pain perception. Using a transgenic mouse expressing G-CaMP7 in majority of astrocytes and a subpopulation of excitatory neurons, we recorded the brain activity in the mouse cerebral cortex during acute pain stimulation. Both of hind paw pinch and intraplantar administration of formalin caused strong transient increase of the fluorescence in several cortical regions, including primary somatosensory, motor and retrosplenial cortex. This increase of the fluorescence intensity was attenuated by the pretreatment with morphine. The present study provides important insight into the cortico-cortical network during pain perception. • Neural activity was recorded from multiple brain regions under pain perception. • The primary somatosensory cortex, motor cortex, and retrosplenial cortex were activated. • Bilateral cerebral hemisphere was activated under inflammatory pain. • This provided crucial insights into cortico-cortical networks during pain perception. [ABSTRACT FROM AUTHOR]

Rationale: The traditional antihistamine chlorpheniramine ameliorates panic attacks, phobias, and lowered mood, and this therapeutic effect is independent of the blockade of histamine H receptors. Since chlorpheniramine inhibits the reuptake of serotonin (5-HT), the anxiolytic-like effect of chlorpheniramine may be produced by an increase in serotonergic function. Objective: To elucidate the mechanisms underlying the anxiolytic-like effects of chlorpheniramine in mice, we examined the involvement of 5-HT systems in the prefrontal cortex that is a crucial region in the regulation of emotional function. Results: Chlorpheniramine (0.05-5 mg/kg, i.p.) dose-dependently and significantly decreased the duration of freezing behavior in both the elevated open-platform and conditioned fear tests. The anti-freezing effects of chlorpheniramine (5 mg/kg, i.p.) in these tests were inhibited by pretreatment with the non-selective antagonist at 5-HT receptors, methiothepin (0.01 mg/kg, s.c.). In addition, the local injection of chlorpheniramine (10-100 ng/mouse) and 5-HT (1-10 μg/mouse) into the medial part of the prefrontal cortex (mPFC) dose-dependently and significantly decreased the duration of freezing behavior in the elevated open-platform test. In a microdialysis study, chlorpheniramine (0.5 and 5 mg/kg, i.p.) dose-dependently and significantly increased the extracellular 5-HT level in the mPFC. In addition, the local perfusion of chlorpheniramine (10 and 30 μM), but not of the selective H1 receptor antagonist, cetirizine, into the mPFC markedly increased the extracellular 5-HT level in the mPFC. Conclusion: The anxiolytic-like effect of chlorpheniramine is produced, at least in part, by the facilitation of serotonergic neurotransmission in the PFC. [ABSTRACT FROM AUTHOR]

Abstract: The traditional Japanese Kampo medicine Yokukansan (YKS, Yi-gan san in Chinese) has been demonstrated to improve the behavioral and psychological symptoms of dementia (BPSD), such as anxiety, hallucinations, agitation and irritability. The aim of this study was to elucidate the mechanism of the anxiolytic-like effects of YKS and Chotoko, which is an active component of YKS. Oral treatment with YKS (300 and 1000mg/kg) significantly increased the number of head-dipping behaviors in mice in the hole-board test. Head-dipping behavior in mice was also significantly increased by treatment with Chotoko (50 and 100mg/kg, p.o.). In addition, oral treatment with the water-extracted fractions from YKS (YKS-W; 250 and 500mg/kg, p.o.) and Chotoko (Chotoko-W; 10 and 30mg/kg) significantly increased the number of head-dipping behaviors in mice. On the other hand, treatment with the methanol-extracted fraction of YKS (YKS-Met; 15 and 30mg/kg, p.o.) did not affect head-dipping behavior. The total distance and number of rearing behaviors were not affected by treatment with any of these drugs. The increase in the number of head-dipping behaviors by treatment with YKS-W (500mg/kg, p.o.) and Chotoko-W (30mg/kg, p.o.) was inhibited by pretreatment with the benzodiazepine receptor antagonist flumazenil (1mg/kg, i.v.). In the elevated plus-maze test, the percentage of time spent in open arms was increased in YKS (1000mg, p.o.) treatment. Based on these results, we suggest that YKS produces an anxiolytic-like effect mediated by the benzodiazepine system. Chotoko is an effective component of YKS for producing an anxiolytic-like effect. The effective compound(s) should be contained, at least in part, in the water-soluble fraction of YKS. [Copyright &y& Elsevier]

Although the etiology of major depressive disorder remains poorly understood, reduced gamma oscillations is an emerging biomarker. Olfactory bulbectomy, an established model of depression that reduces limbic gamma oscillations, suffers from non-specific effects of structural damage. Here, we show that transient functional suppression of olfactory bulb neurons or their piriform cortex efferents decreased gamma oscillation power in limbic areas and induced depression-like behaviors in rodents. Enhancing transmission of gamma oscillations from olfactory bulb to limbic structures by closed-loop electrical neuromodulation alleviated these behaviors. By contrast, silencing gamma transmission by anti-phase closed-loop stimulation strengthened depression-like behaviors in naive animals. These induced behaviors were neutralized by ketamine treatment that restored limbic gamma power. Taken together, our results reveal a causal link between limbic gamma oscillations and depression-like behaviors in rodents. Interfering with these endogenous rhythms can affect behaviors in rodent models of depression, suggesting that restoring gamma oscillations may alleviate depressive symptoms. • Suppression of OB or OB-PirC pathway decreases gamma and induces depressive symptoms • Anti-phase closed-loop stimulation of PirC gamma resembles depressive symptoms • Ketamine improves depressive symptoms induced by anti-phase gamma stimulation • In-phase gamma stimulation alleviated symptoms induced by LPS Li et al. report a causal link between limbic gamma oscillations and depression-like behaviors in rats. Interfering with the endogenous rhythms can affect mood-related behaviors in rat models of depression, suggesting that restoring gamma oscillations may improve depressive symptoms. [ABSTRACT FROM AUTHOR]

Objective: The capitulum of Chrysanthemum indicum (Compositae) is the source of a crude drug used in Japanese traditional Kampo and traditional Chinese medicine. Previous research showed that C. indicum flowers promote adipocyte differentiation through the activation of peroxisome proliferator-activated receptor (PPAR)-γ that may be an important mechanism for controlling systemic insulin resistance or other biological functions. Materials and Methods: The capitulum of C. indicum was extracted with methanol, and its PPAR-γ agonistic activity was measured using luciferase assay. The active ingredients were isolated by the activity-guided fractionations. Results: We isolated (Z)-tonghaosu and (E)-tonghaosu, and (E)-tonghaosu had PPAR-γ agonistic constituents by the activity-guided fractionation from the capitulum of C. indicum. The isomer (Z)-tonghaosu did not show PPAR-γ-agonistic activity. Conclusion: (E)-tonghaosu is one of the active ingredients as PPAR-γ agonist in the capitulum of C. indicum. Abbreviations used: ANOVA: One-way analysis of variance; DMEM: Dulbecco's modified minimum essential medium; FBS: Fetal bovine serum; HPLC: High-performance liquid chromatography; MCI: Methanol extract of the capitulum of Chrysanthemum indicum; NMR: Nuclear magnetic resonance; PPAR: Peroxisome proliferator-activated receptor. [ABSTRACT FROM AUTHOR]

Cilnidipine is a dihydropyridine derivative that inhibits N-type and L-type voltage-gated Ca 2+ channels (VDCCs). We recently reported that a selective N-type VDCC blocker attenuated the spinal long-term potentiation (LTP) of C-fiber-evoked field potentials recorded in the spinal dorsal horn of rats, which served as a model for examining synaptic function during central pain sensitization. In this study, we investigated the effects of cilnidipine on the changes related to neuropathic pain induced by nerve injury. Mechanical allodynia and hyperalgesia were evaluated by von Frey test and pin prick test, respectively. Spinal LTP of C-fiber-evoked field potentials were evaluated by in vivo electrophysiology. Intrathecally administrated cilnidipine attenuated mechanical allodynia and hyperalgesia in the spared nerve injury mouse model. Using in vivo electrophysiology in rats, cilnidipine (10 µm) administered spinally inhibited the induction and maintenance of high-frequency stimulation-induced LTP of C-fiber-evoked field potentials, while basal C-fiber-evoked field potentials in naïve rats were unaffected. The basal C-fiber-evoked field potentials in nerve-injured rats were strongly inhibited by cilnidipine. Treatment with a specific N-type VDCC blocker, ω-conotoxin GVIA, which reportedly attenuates C-fiber-evoked field potentials both before and after the induction of LTP, attenuated mechanical allodynia and hyperalgesia in nerve-injured mice. By contrast, an L-type VDCC blocker, nicardipine attenuated only mechanical hyperalgesia, but not mechanical allodynia in nerve-injured mice, and also attenuated the established LTP of C-fiber-evoked field potentials in rats. These results suggested that N-type and L-type VDCC blockers may effectively alleviate the hyperalgesia and allodynia associated with neuropathic pain without affecting normal pain perception. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Processed aconite root (PA, the root of Aconitum carmichaeli , Ranunculaceae) is a crude drug used in traditional Chinese or Japanese kampo medicine to generate heat in the body and to treat pain associated with coldness. Oxaliplatin (L-OHP) is a platinum-based anticancer drug that frequently causes acute and chronic peripheral neuropathies, including cold and mechanical hyperalgesia. Aim of the study We investigated the effects of PA on L-OHP-induced peripheral neuropathies and identified the active ingredient within PA extract. Materials and methods L-OHP was intraperitoneally injected into mice, and PA boiled water extract was orally administered. Cold and mechanical hyperalgesia were evaluated using the acetone test and the von Frey filament method, respectively. Dorsal root ganglion (DRG) neurons were isolated from normal mice and cultured with L-OHP with or without PA extract. Cell viability and neurite elongation were evaluated. Results PA extract significantly attenuated cold and mechanical hyperalgesia induced by L-OHP in mice. In cultured DRG neurons, L-OHP reduced cell viability and neurite elongation in a dose-dependent manner. Treatment with PA extract significantly alleviated the L-OHP-induced reduction of neurite elongation, while the cytotoxicity of L-OHP was not affected. Using activity-guided fractionation, we isolated neoline from PA extract as the active ingredient. Neoline significantly alleviated L-OHP-induced reduction of neurite elongation in cultured DRG neurons in a concentration-dependent manner. Moreover, subcutaneous injection of neoline attenuated cold and mechanical hyperalgesia in L-OHP-treated mice. PA extract and neoline did not show sedation and motor impairment. Conclusions The present study indicates that PA and its active ingredient neoline are promising agents to alleviate L-OHP-induced neuropathic pain. [ABSTRACT FROM AUTHOR]

Oseltamivir, an anti-influenza virus drug, induces marked hypothermia in normal mice. We have proposed that the hypothermic effect arises from inhibition of the nicotinic acetylcholine receptor function of sympathetic ganglion neurons which innervate the brown adipose tissue (a heat generator). It has been reported that local anesthetics inhibit nicotinic acetylcholine receptor function by acting on its ionic channels, and that bupropion, a nicotinic antagonist, induces hypothermia. In this study, we compared the effects of oseltamivir, procaine and bupropion on body temperature, cardiovascular function and neuromuscular transmission. Intraperitoneal administration of oseltamivir (100 mg/kg), procaine (86.6 mg/kg) and bupropion (86.7 mg/kg) lowered the core body temperature of normal mice. At lower doses (10–30 mg/kg oseltamivir, 8.7–26 mg/kg procaine and bupropion), when administered subcutaneously, the three drugs antagonized the hypothermia induced by intraperitoneal injection of nicotine (1 mg/kg). In anesthetized rats, intravenous oseltamivir (30–100 mg/kg), procaine (10 mg/kg) and bupropion (10 mg/kg) induced hypotension and bradycardia. Oseltamivir alone (100 mg/kg) did not inhibit neuromuscular twitch contraction of rats, but at 3–30 mg/kg it augmented the muscle-relaxing effect of d-tubocurarine. Similar effects were observed when lower doses of procaine (10–30 mg/kg) and bupropion (3–10 mg/kg) were administered, suggesting that systemic administration of oseltamivir inhibits muscular nicotinic acetylcholine receptors. These results support the idea that the hypothermic effect of oseltamivir is due to its effects on sympathetic ganglia which innervate the brown adipose tissue, and suggest that oseltamivir may exert non-selective ion channel blocking effects like those of ester-type local anesthetics. [ABSTRACT FROM AUTHOR]

Abstract: Treatment with atypical antipsychotic drugs is known to increase the risk of glucose intolerance and diabetes. However, the mechanism of this effect is unclear. Since central adenosine 5?-monophosphate-activated protein kinase (AMPK) plays an important role in regulating nutrient homeostasis, the present study was performed to examine the involvement of central AMPK in the glucose intolerance induced by olanzapine, an atypical antipsychotic drug, in mice. Acute intraperitoneal treatment with olanzapine dose-dependently increased blood glucose levels in the glucose tolerance test. Intracerebroventricular administration of olanzapine also increased blood glucose levels in the glucose tolerance test. The glucose intolerance induced by both intraperitoneal and intracerebroventricular treatment with olanzapine was significantly attenuated by intracerebroventricular pretreatment with the AMPK inhibitor compound C. Intracerebroventricular treatment with the AMPK activator AICAR increased blood glucose levels in the glucose tolerance test, and this increase was inhibited by compound C. Moreover, the hypothalamic level of phosphorylated AMPK after glucose injection was significantly increased by intracerebroventricular pretreatment with olanzapine. Olanzapine did not affect plasma glucagon and insulin levels. Our results indicate that acute treatment with olanzapine causes glucose intolerance through the activation of hypothalamic AMPK. The present study suggests that the inhibition of central AMPK activity may have a therapeutic effect on the metabolic disturbance induced by atypical antipsychotic drugs. [Copyright &y& Elsevier]

Oseltamivir, an anti-influenza virus drug, has strong antipyretic effects in mice ( Biological and Pharmaceutical Bulletin, 31, 2008, 638) and patients with influenza. In addition, hypothermia has been reported as an adverse event. The prodrug oseltamivir is converted to oseltamivir carboxylate ( OC), an active metabolite of influenza virus neuraminidase. In this study, core body temperature was measured in mice, and oseltamivir and OC were administered intracerebroventricularly (i.c.v.) or intraperitoneally (i.p). Low i.c.v. doses of oseltamivir and OC dose-dependently produced hypothermia. Zanamivir (i.c.v.), another neuraminidase inhibitor, did not produce hypothermia. These results suggested that the hypothermic effects of oseltamivir (i.p. and i.c.v.) and OC (i.c.v.) are not due to neuraminidase inhibition. OC (i.p.) did not lower body temperature. Although mecamylamine (i.c.v.) blocked the hypothermic effect of nicotine-administered i.c.v., the hypothermic effects of oseltamivir and OC (i.c.v.) were not blocked by mecamylamine (i.c.v.). The effect of oseltamivir (i.p.) was markedly increased by s.c.-pre-administered mecamylamine and also hexamethonium, a peripherally acting ganglionic blocker, suggesting their potentiating interaction at peripheral sites. The hypothermic effect of nicotine (i.c.v.) was decreased by lower doses of oseltamivir (i.c.v.), suggesting the anti-nicotinic action of oseltamivir. These results suggest that oseltamivir (i.p.) causes hypothermia through depression of sympathetic temperature regulatory mechanisms via inhibition of nicotinic receptor function and through unknown central mechanisms. [ABSTRACT FROM AUTHOR]

Abstract: We examined the involvement of tetrodotoxin (TTX)-resistant sodium channels in the peripheral mechanisms of the cough reflex in mice. We also examined the possibility of using ambroxol as an effective antitussive agent, and found that it produced antitussive effects through the inhibition of TTX-resistant sodium channels. The inhalation of fenvalerate, at concentrations of 0.3, 1 and 3μg/ml, for 5min produced coughs in a concentration-dependent manner. Pretreatment with tetrodotoxin, at a dose of 1μg/kg, s.c., slightly but significantly reduced the number of fenvalerate (3μg/ml)-induced coughs. However, the number of fenvalerate-induced coughs in tetorodotoxin-treated mice was still significantly greater than those in vehicle (0.4% DMSO) alone inhaled mice. On the other hand, pretreatment with tetrodotoxin, at a dose of 1μg/kg, s.c., almost completely reduced the number of citric acid (0.25M)-induced coughs to the level in vehicle (saline) alone inhaled mice. Pretreatment with ambroxol, at doses of 10, 30, 100 and 300mg/kg, p.o., dose-dependently and significantly reduced the number of fenvalerate (3μg/ml)-induced coughs. The present findings indicate that TTX-resistant sodium channels may play an important role in the enhancement of C-fiber-mediated cough pathways. Furthermore, ambroxol may prove to be a useful cough suppressant. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the relation between bronchoconstriction and cough induced by methacholine (Mch) inhalation and to elucidate the role of C-fibers and rapidly adapting irritant receptors (RARs) in these reactions in conscious guinea pigs. The authors measured enhanced pause (Penh) as an index of bronchoconstriction and also measured the number of coughs induced by Mch inhalation in conscious guinea pigs. The authors also examined the effects of pretreatment with procaterol, capsaicin desensitization and moguisteine on these responses. There was a significant positive correlation between the increase in Penh and the number of coughs induced by Mch inhalation. Procaterol (0.1 mg/kg, intraperitoneal [i.p.]) completely abolished both the Mch-induced increase in Penh and cough. Capsaicin desensitization had no effect on Penh or the number of coughs. Moguisteine (0.02, 0.2, or 2 mg/kg, i.p.) dose-dependently inhibited the number of coughs but not the increase in Penh induced by Mch inhalation. Bronchoconstriction causes cough via RARs, but not C-fibers. Neither RARs nor C-fibers are involved in Mch-induced bronchoconstriction itself. [ABSTRACT FROM AUTHOR]

Beacon is a 73-amino acid peptide encoded by a novel gene in the hypothalamus of Israeli sand rat Psammomys obesus. Reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemical techniques were used to investigate the presence of beacon mRNA and the distribution of beacon-immunoreactivity (irBC) in the hypothalamus of ICR mice. RT-PCR experiments revealed beacon mRNA in the mouse hypothalamus. Using a rabbit polyclonal antiserum directed against the synthetic C-terminal peptide fragment (47–73), irBC was detected in the mouse hypothalamus and pituitary. In the hypothalamus, irBC was concentrated in perikarya of the supraoptic (SO), paraventricular (PVH) and accessory neurosecretory nuclei and in cell processes of the median eminence and pituitary stalk. In the pituitary, irBC was noted mainly in the posterior lobe. Double-labeling the hypothalamic sections with guinea-pig vasopressin-antiserum or mouse monoclonal oxytocin-antibody and beacon-antiserum revealed that <30% of vasopressin-immunoreactive neurons and nearly all oxytocin-immunoreactive neurons in the PVH and SO were irBC. The result shows the presence of beacon mRNA in the mouse hypothalamus, and the distribution of irBC is distinctively different from that reported in the hypothalamus of Psammomys obesus, but similar to that of the Sprague–Dawley rats described in our earlier study. More interestingly, Blast search uncovered a 73-amino acid peptide, human ubiquitin-like 5, which has the same exact sequence as beacon. Thus, irBC observed in the mouse brain could be that of ubiquitin-like 5. [Copyright &y& Elsevier]

With the use of an antiserum against human apelin-36, apelin-immunoreactivity (irAP) was detected in neurons and cell processes of the supraoptic nucleus (SO), paraventricular nucleus (PVH), accessory neurosecretory nuclei (Acc) and suprachiasmatic nucleus. Strongly labeled cells/processes were noted in the internal layer of the median eminence, infundibular stem, anterior and posterior pituitary. Double-labeling the sections with goat polyclonal neurophysin I-antiserum and rabbit polyclonal apelin-antiserum revealed a population of magnocellular neurons in the PVH, SO and Acc expressing both irAP and neurophysin I-immunoreactivity (irNP), the latter being a marker of oxytocin-containing neurons. By inference, the AP-positive but irNP-negative magnocellular neurons could be vasopressin-containing. The presence of irAP in certain hypothalamic nuclei and pituitary suggests that the peptide may be a signaling molecule released from the hypothalamic-hypophysial axis. [Copyright &y& Elsevier]

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. 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. 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. 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. 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. Image 1 [ABSTRACT FROM AUTHOR]

Processed aconite root (PA), the root of Aconitum carmichaeli (Ranunculaceae), is a crude drug used in traditional Chinese or Japanese kampo medicine to treat pain associated with coldness. In our previous study, PA and its active ingredient, neoline, alleviated oxaliplatin-induced peripheral neuropathy in mice. The present study investigated the effects of PA on a murine peripheral neuropathy model induced by intraperitoneal injection of paclitaxel and partial ligation of the sciatic nerve (Seltzer model), and identified its active ingredients. PA powder (1 g/kg/day) was orally administered, and either neoline or benzoylmesaconine (10 mg/kg/day) was subcutaneously injected into the murine model. Mechanical hyperalgesia was evaluated via the von Frey filament method. PA extract was orally administered to rats; blood samples were chronologically collected, and the plasma concentrations of Aconitum alkaloids were measured. The contents of Aconitum alkaloids in commercial PA products were also measured. PA extract and neoline significantly attenuated the mechanical hyperalgesia induced by either paclitaxel or partial ligation of the sciatic nerve in mice. In the plasma samples of rats treated with PA extract, higher concentrations of benzoylmesaconine and neoline were apparent among Aconitum alkaloids. The contents of benzoylmesaconine and neoline varied among PA products with different processing procedures. Subcutaneous injection of benzoylmesaconine did not attenuate the hyperalgesia induced by each paclitaxel, partial ligation of the sciatic nerve, or oxaliplatin in mice. The present results indicate that PA and its active ingredient, neoline, are promising agents for the alleviation of neuropathic pain. Neoline can be used as a marker compound to determine the quality of the PA products for the treatment of neuropathic pain. Image 1 [ABSTRACT FROM AUTHOR]