• The Journal of Korean Physical Therapy
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• v.18 no.2
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• pp.25-34
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• 2006

Purpose: This study conducted quantitative sensory test and nociceptive flexion reflex(NFR) measurement to examine degree of pain depending on polarity of high voltage pulsed current(HVPC) of hyperalgesia site in hyperalgesia rat by local thermal injury. mechanical pain threshold, thermal pain threshold and root mean square of NFR were measured. Methods: This study was conducted with control group I of hyperalgesia rat at hind paw by thermal injury and experimental groups divided into cathodal HVPC group II, anodal HVPC group III and alternate HVPC group IV. It measured pain threshold and root mean square(RMS) of NFR and obtained the following results. Results: Mechanical pain threshold of hyperalgeisa site was significantly increased at groups II, III and IV applying HVPC group compared to control group, but there was no difference among HVPC groups. Thermal pain threshold of hyperalgesia site showed a significant increase in group II. Group III showed significant difference after 4 days of hyperalgesia. RMS of NFR at hyperalgeisa site was significantly reduced in group II after 2 days of hyperalgesia. Group III showed significant decrease after 5 and 6 days of hyperalgesia. Conclusion: Consequently it was found that application of HVPC of hyperalgesia site increased pain threshold at hyperalgesia site by mechanical stimuli and thermal stimuli. NFR by electrical stimuli was similar to pain threshold by mechanical stimuli. Effects by polarity of HVPC showed the greatest reduction of hyperalgesia when cathodal electrode was used.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.2
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• pp.83-90
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• 2017

PURPOSE: Central post-stroke pain (CPSP), a chronic pain condition of stroke patients, can impair activities of daily living and worsen the quality of life (QOL), thereby negatively influencing the rehabilitation process. However, CPSP remains an underestimated complication of stroke. This study aimed to describe the prevalence and types of new-onset chronic pain and to identify the relation between pain and QOL in stroke patients. METHODS: All patients hospitalized because of a diagnosis of stroke were included. Questionnaire was used. Pain intensity was measured using Numerical rating scale (NRS), and pain characteristics were assessed using DN4. QOL was measured using SF-36. Descriptive statistics were used to analyze the characteristics and pain data, and chi-square test was used to compare QOL categorical data between the nociceptive and neurological pain groups. RESULTS: CPSP development was reported by 34% of the post-stroke pain patients. Perceived QOL was low in both groups, especially with respect to the physical functioning, bodily pain, physical-role functioning, emotional-role functioning, and mental health domains. However, no significant difference was observed in QOL between the nociceptive and neurological pain groups (p<.05). CONCLUSION: Our results indicated that CPSP is a common and disabling complication that is difficult to treat, often decreases QOL, and may negatively affect rehabilitation treatment.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.5
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• pp.281-288
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• 2004

The present study was undertaken to confirm whether melittin, a major constituent of whole bee venom (WBV), had the ability to produce the same nociceptive responses as those induced by WBV. In the behavioral experiment, changes in mechanical threshold, flinching behaviors and paw thickness (edema) were measured after intraplantar (i.pl.) injection of WBV (0.1 mg & 0.3 mg/paw) and melittin (0.05 mg & 0.15 mg/paw), and intrathecal (i.t.) injection of melittin $(6{\mu}g)$. Also studied were the effects of i.p. (2 mg & 4 mg/kg), i.t. $(0.2{\mu}g\;&\;0.4{\mu}g)$ or i.pl. (0.3 mg) administration of morphine on melittin-induced pain responses. I.pl. injection of melittin at half the dosage of WBV strongly reduced mechanical threshold, and increased flinchings and paw thickness to a similar extent as those induced by WBV. Melittin- and WBV-induced flinchings and changes in mechanical threshold were dose- dependent and had a rapid onset. Paw thickness increased maximally about 1 hr after melittin and WBV treatment. Time-courses of nociceptive responses induced by melittin and WBV were very similar. Melittin-induced decreases in mechanical threshold and flinchings were suppressed by i.p., i.t. or i.pl. injection of morphine. I.t. administration of melittin $(6{\mu}g)$ reduced mechanical threshold of peripheral receptive field and induced flinching behaviors, but did not cause any increase in paw thickness. In the electrophysiological study, i.pl. injection of melittin increased discharge rates of dorsal horn neurons only with C fiber inputs from the peripheral receptive field, which were almost completely blocked by topical application of lidocaine to the sciatic nerve. These findings suggest that pain behaviors induced by WBV are mediated by melittin-induced activation of C afferent fiber, that the melittin-induced pain model is a very useful model for the study of pain, and that melittin-induced nociceptive responses are sensitive to the widely used analgesics, morphine.

• Korean Journal of Pharmacognosy
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• v.50 no.4
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• pp.272-276
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• 2019

Corylopsis gotoana has been widely used as a traditional medicine for the treatment of lots of disease including cold, edema and vomiting. However pharmacological and phytochemical studies on the C. gotoana are extremely limited. Here in this study, the author investigated the anti-nociceptive effects of the methanolic extract of Corylopsis gotoana (MCG) using various pain models. In the present study, MCG exhibited strong and dose-dependent anti-nociceptive activities on various experimental pain models including thermal nociception and chemical nociception, compared to positive control such as tramadol and indomethacin. In addition, the result from combination test using naloxone, analgesic activity of MCG was slightly reduced, indicating that MCG acts as a partial opioid receptor agonist. These results demonstrated that MCG has potent analgesic potential and thus it may be possibly used as a valuable anti-nociceptive agent.

• Biomolecules & Therapeutics
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• v.24 no.4
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• pp.418-425
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• 2016

We measured anti-nociceptive activity of prim-o-glucosylcimifugin (POG), a molecule from Saposhnikovia divaricate (Turcz) Schischk. Anti-nociceptive or anti-inflammatory effects of POG on a formalin-induced tonic nociceptive response and a complete Freund's adjuvant (CFA) inoculation-induced rat arthritis pain model were studied. Single subcutaneous injections of POG produced potent anti-nociception in both models that was comparable to indomethacin analgesia. Anti-nociceptive activity of POG was dose-dependent, maximally reducing pain 56.6% with an $ED_{50}$ of 1.6 mg. Rats given POG over time did not develop tolerance. POG also time-dependently reduced serum TNF${\alpha}$, IL-$1{\beta}$ and IL-6 in arthritic rats and both POG and indomethacin reduced spinal prostaglandin E2 ($PGE_2$). Like indomethacin which inhibits cyclooxygenase-2 (COX-2) activity, POG dose-dependently decreased spinal COX-2 content in arthritic rats. Additionally, POG, and its metabolite cimifugin, downregulated COX-2 expression in vitro. Thus, POG produced potent anti-nociception by downregulating spinal COX-2 expression.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.2
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• pp.77-86
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• 2005

In this study, we examined the morphine-induced modulation of the nociceptive spinal dorsal horn neuronal activities before and after formalin-induced inflammatory pain. Intradermal injection of formalin induced time-dependent changes in the spontaneous activity of nociceptive dorsal horn neurons. In naive cats before the injection of formalin, iontophoretically applied morphine attenuated the naturally and electrically evoked neuronal responses of dorsal horn neurons. However, neuronal responses after the formalin-induced inflammation were significantly increased by morphine. Bicuculline, $GABA_A$ antagonist, increased the naturally and electrically evoked neuronal responses of dorsal horn neurons. This increase in neuronal responses due to bicuculline after the formalin-induced inflammation was larger than that in the naive state, suggesting that basal $GABA_A$ tone increased after the formalin injection. Muscimol, $GABA_A$ agonist, reduced the neuronal responses before the treatment with formalin, but not after formalin treatment, again indicating an increase in the GABAergic basal tone after the formalin injection which saturated the neuronal responses to GABA agonist. Morphine-induced increase in the spinal nociceptive responses after formalin treatment was inhibited by co-application of muscimol. These data suggest that formalin-induced inflammation increases $GABA_A$ basal tone and the inhibition of this augmented $GABA_A$ basal tone by morphine results in a paradoxical morphineinduced increase in the spinal nociceptive neuronal responses after the formalin-induced inflammation.

• The Korean Journal of Pain
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• v.37 no.2
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• pp.141-150
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• 2024

Background: Stingless bee propolis is a popular traditional folk medicine and has been employed since ancient times. This study aimed to evaluate the antinociceptive activities of the chemical constituents of aqueous propolis extract (APE) collected by Trigona thoracica in a nociceptive model in mice. Methods: The identification of chemical constituents of APE was performed using high-performance liquid chromatography (HPLC). Ninety-six male Swiss mice were administered APE (400 mg/kg, 1,000 mg/kg, and 2,000 mg/kg) before developing nociceptive pain models. Then, the antinociceptive properties of each APE dose were evaluated in acetic acid-induced abdominal constriction, hot plate test, and formalin-induced paw licking test. Administration of normal saline, acetylsalicylic acid (ASA, 100 mg/kg, orally), and morphine (5 mg/kg, intraperitoneally) were used for the experiments. Results: HPLC revealed that the APE from Trigona thoracica contained p-coumaric acid (R² = 0.999) and caffeic acid (R² = 0.998). Although all APE dosages showed inhibition of acetic acid-induced abdominal constriction, only 2,000 mg/kg was comparable to the result of ASA (68.7% vs. 73.3%, respectively). In the hot plate test, only 2,000 mg/kg of APE increased the latency time significantly compared to the control. In the formalin test, the durations of paw licking were significantly reduced at early and late phases in all APE groups with a decrease from 45.1% to 53.3%. Conclusions: APE from Trigona thoracica, containing p-coumaric acid and caffeic acid, exhibited antinociceptive effects, which supports its potential use in targeting the prevention or reversal of central and peripheral sensitization that may produce clinical pain conditions.

• Journal of Oral Medicine and Pain
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• v.45 no.2
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• pp.48-48
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• 2020

• Natural Product Sciences
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• v.20 no.4
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• pp.301-305
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• 2014

The aim of our study is to investigate the anti-nociceptive and anti-inflammatory properties of an ethanol extract of the leaf and stem of Aralia cordata. Writhing responses induced by acetic acid, tail immersion test, and formalin-induced paw pain response for nociception and formalin-induced paw edema for inflammation were evaluated in mice. A. cordata (50 - 200 mg/kg, p.o.) and ibuprofen (100 mg/kg, p.o.), a positive non-steroidal anti-inflammatory drugs (NSAIDs), inhibited the acetic acid-induced writhing response, but they did not protect the thermal nociception in tail immersion test. However, morphine (5 mg/kg, s.c.) used as positive opioid control alleviated both the acetic acid-induced writhing response and thermal nociception in tail immersion test. In the formalin test, A. cordata (50 - 200mg/kg) and ibuprofen (200mg/kg) inhibited the second phase response (peripheral inflammatory response), but not the first phase response (central response), whereas morphine inhibited both phase pain responses. Both A. cordata (100 mg/kg) and ibuprofen (200 mg/kg) significantly alleviated the formalin-induced increase of paw thickness, the index of inflammation. These results show for the first time that the leaf and stem of A. cordata has a significant anti-nociceptive effect that seems to be peripheral, but not central. A. cordata also displays an anti-inflammatory activity in an acute inflammation model. The present study supports a possible use of the leaf and stem of A. cordata to treat pain and inflammation.

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.6
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• pp.253-257
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• 2007

Among the arthritis symptoms, chronic pain is the most serious, and it can profoundly affect the quality of human life. Unfortunately, the mechanism of development in arthritis and arthritic pain has not yet been precisely elucidated. Accumulating evidence indicates that nitric oxide (NO) plays a pivotal role in nociceptive processing in the spinal cord. However, the modulation mechanism of NO in the peripheral site of arthritis and arthritic pain has not been clarified. Therefore, I determined in the present study which nitric oxide synthase (NOS) was involved in the induction of arthritis and arthritic pain. Monoarthritis was induced by intra-articular injection of carrageenan (2%, $50{\mu}l$) into rats, and resulted in the reduction of weight load on the injected leg, increase of knee joint diameter and inflammatory response. Pre-treatment of rats with L-N6-(1-iminoethyl)-lysine (L-NIL, $500{\mu}g$, in $50{\mu}l$), an inhibitor of inducible NOS (iNOS), partially prevented the induction of pain-related behavior and partially reduced inflammatory response in the synovial membrane in the knee joint. These results suggest that iNOS in the knee joint may play an important role in the induction of pain-related behavior and inflammation, and that NO produced by iNOS may be associated with nociceptive signaling in the peripheral site.