• Natural Product Sciences
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• v.17 no.4
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• pp.303-308
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• 2011

Spirodela polyrrhiza L. Schleid. (Lemnaceae), also known as 'duckweed', is a traditional medicine in Korea. The whole plant is used to treat many diseases, including the common cold, edema, acute nephritis, and urticaria. The present study investigated antinociceptive properties of the EtOAc soluble fraction of S. polyrrhiza (ESP). The antinociceptive activities of ESP were studied using experimental models of pain, including thermal nociception methods, such as the tail immersion test and the hotplate test. Moreover, we studied chemical nociception induced by intraperitoneal acetic acid and subplantar formalin in mice. ESP exhibited dose-dependent antinociceptive activity in both thermal and chemical pain models. In a drug combination test using the opioid receptor antagonist naloxone, diminished analgesic activities of ESP were observed, indicating that the antinociceptive activity of ESP is mediated by opioid receptors.

• The Korean Journal of Pain
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• v.37 no.1
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• pp.26-33
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• 2024

Background: Sitagliptin is an antidiabetic drug that inhibits dipeptidyl peptidase-4 enzyme. This study aimed to investigate the antinociceptive and anti-inflammatory effects of sitagliptin in formalin and carrageenan tests and determine the possible mechanism(s) of its antinociceptive activity. Methods: Male Swiss mice (25-30 g) and male Wistar rats (180-220 g) were used for formalin and carrageenan tests, respectively. In the formalin test, paw licking time and in the carrageenan test, paw thickness were considered as indexes of pain behavior and inflammation respectively. Three doses of sitagliptin (2.5, 5, and 10 mg/kg) were used in these tests. Also, several antagonists and enzyme inhibitors were used to evaluate the role of adrenergic, serotonergic, dopaminergic, and opioid receptors as well as the NO/cGMP/K_ATP pathway in the antinociceptive effect of sitagliptin (5 mg/kg). Results: Sitagliptin showed significant antinociceptive and anti-inflammatory effects in the formalin and carrageenan tests respectively. In the carrageenan test, all three doses of sitagliptin significantly (P < 0.001) reduced paw thickness. Pretreatment with yohimbine, prazosin, propranolol, naloxone, and cyproheptadine could not reverse the antinociceptive effect of sitagliptin (5 mg/Kg), which indicates that adrenergic, opioid, and serotonin receptors (5HT₂) are not involved in the antinociceptive effects. L-NAME, methylene blue, glibenclamide, ondansetron, and sulpiride were able to reverse this effect. Conclusions: NO/cGMP/K_ATP, 5HT₃ and D₂ pathways play an important role in the antinociceptive effect of sitagliptin. Additionally significant anti-inflammatory effects observed in the carrageenan test might contribute in reduction of pain response in the second phase of the formalin test.

• Advances in Traditional Medicine
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• v.7 no.1
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• pp.100-102
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• 2007

The crude ethanol extract of leaves of Avicennia officinalis Linn. (Family: Avicenniaceae) was screened for its antinociceptive activity. The extract produced significant writhing inhibition in acetic acid-induced writhing in mice at the oral dose of 250 and 500 mg/kg body weight (P < 0.001) comparable to the standard drug diclofenac sodium at the dose of 25 mg/kg of body weight. The result tends to suggest the antinociceptive activity of the extract.

• The Korean Journal of Pain
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• v.14 no.2
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• pp.150-155
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• 2001

Background: Tramadol is known to be a weak opioid. However, it has also been shown that tramadol is an effective norepinephrine and serotonin uptake blocker, which may be effective in the treatment of neuropathic pain. The present study was undertaken in order to assess the antinociceptive action of tramadol and to investigate possible antinociceptive mechanisms by using antagonists in an animal neuropathic pain models in rats. Methods: Rats were prepared with tight ligation at the left 5 and 6th lumbar spinal nerves (Kim and Chung's neuropathic pain model). The antinociceptive effects of tramadol (10, 20, and 50 mg/kg i.p.) in rats with neuropathic pain were assessed. Additionally, following coadministration of antagonists such as naloxone (1 mg/kg i.p.), yohimbine (1 mg/kg i.p.) and ritanserin (1 mg/kg i.p.) with 50 mg/kg of tramadol, the responses to mechanical and thermal stimuli were measured over a two-hour period. Results: Tramadol displayed potent antinociceptive effects in a dose-dependent manner on rats with neuropathic pain (P < 0.05). The effects of tramadol were inhibited by coadministered naloxone and yohimbine in rats with mechanical and thermal allodynia, respectively (P < 0.05). However, there were no significant changes in the pain behaviors in the case of ritanserin. Conclusions: Tramadol showed significant antinociceptive effects in rats with regards to neuropathic pain against both mechanical and thermal allodynia. The antinociceptive effect on the mechanical stimuli is medicated via an opioid receptor. However, it appears that the antinociceptive effects on thermal allodynia are mediated via a noradrenalin receptor vice a serotonergic receptor.

• Biomolecules & Therapeutics
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• v.3 no.1
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• pp.54-57
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• 1995

The effect of Ruthenium Red on the antinociceptive action of capsaicinoids was investigated using tail-flick test in mice. Capsaicin and KR-25018, when administered subcutaneously, had a potent antinociceptive effect against noxious heat stimulus. Ruthenium Red which is known to block the calcium channel coupled to the capsaicin receptor, when injected intraperitoneally more than 5 mg/kg, showed severe sedation and apparent antinociceptive effect against noxious heat stimulus. The 2.5 mg/kg Ruthenium Red, at which dose any significant sedative effect was not shown, had no effect on the antinociceptive effects of capsaicin and KR-25018. Considering this result, the antinociceptive effect of capsaicinoid may not be related to the Ruthenium Red sensitive calcium channel which is activated by capsaicin.

• Advances in Traditional Medicine
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• v.6 no.4
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• pp.344-348
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• 2006

The crude methanolic extract of the bark of Cerbera odollam Gaertn. was evaluated for its possible antinociceptive and neuropharmacological activities in animal models. At the dose of 250 and 500 mg/kg body weight, the extract showed a significant antinociceptive effect in acetic acid induced writhing in mice comparable to that produced by aspirin, used as standard drug (P<0.001). The extract significantly reduced the time of onset of sleep (P<0.01) and potentiated the pentobarbital induced sleeping time in mice at the dose of 400 mg/kg of body weight significantly (P<0.001). It also decreased the open field score in open field test significantly at the dose of 400 mg/kg of body weight (P < 0.05). The obtained results tend to suggest the probable antinociceptive and neuropharmacological activities of the crude extract.

• Natural Product Sciences
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• v.17 no.3
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• pp.256-260
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• 2011

Polygoni multiflori Ramulus, the stem of Polygonum multiflorum Thunb., has been widely used as a traditional medicine for the treatment of many diseases. Presently, antinociceptive tests of the butanolic fraction of P. multiflorum (SPB) were performed using several thermal and chemical pain models. SPB had strong and dosedependent antinociceptive activities, both thermal and chemical, compared to the reference drugs Tramadol and Indomethacin. In combination with naloxone, the analgesic activity of SPB was unchanged indicating that the antinociceptive activity of SPB was not due to action as an opioid receptor agonist. The present results indicate the potential of SPB as an analgesic agent for pain control.

• Journal of Veterinary Clinics
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• v.24 no.4
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• pp.499-502
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• 2007

The study was performed to assess the antinociceptive efficacy of Korean bee venom(BV) in the rat formalin test. Korean BV was collected using BV collector devices in which an electrical impulse is used to stimulate the worker bee(Apis mellifera L.) to sting and release venom. After collection, whole Korean BV was evaporated until dry using BV collector. Experiments were performed on male Sprague-Dawley rats(weighing 260-270, 6 weeks old). Rats divided into 4 groups, each comprising 8 rats. BV was diluted and amounts of 6 mg/kg body weight(BW), 0.6 mg/kg BW and 0.06 mg/kg BW were tested. BV was subcutaneously injected to produce an antinociceptive effect and the antinociceptive efficacy was evaluated using a rat formalin test. BV was subcutaneously injected into an acupoint(Zusanli, ST36) at 15 min prior to 1% formalin($50{\mu}l$) injection. The antinociceptive effect observed during 60 min following formalin administration. BV produced antinociceptive efficacy from 10 to 60 min after formalin injection. The antinociceptive efficacy of Korean BV showed a dose-dependent response. These results suggest that Korean BV may be a suitable and preferred choice for antinociceptive efficacy in pain management.

• Biomolecules & Therapeutics
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• v.21 no.5
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• pp.391-397
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• 2013

In the present study, we aimed to analyze the antinociceptive, immunomodulatory and antipyretic activities of nymphayol were investigated in wistar rats and mice. Antinociceptive effect was evaluated by acetic acid induced writhing, formalin induced paw licking and hot-plate tests. Immunomodulatory activity was assessed by neutrophil adhesion test, humoral response to sheep red blood cells, delayed-type hypersensitivity, phagocytic activity and cyclophosphamide induced myelosuppression. Antipyretic activity was evaluated by yeast induced hyperthermia in rats. Nymphayol produced significant (p<0.05) antinociceptive activity in acetic acid induced writhing response and late phase of the formalin induced paw licking response. Pre-treatment with nymphayol (50 mg/kg, oral) evoked a significant increase in neutrophil adhesion to nylon fibres. The augmentation of humoral immune response to sheep red blood cells by nymphayol (50 mg/kg) was evidenced by increase in antibody titres in rats. Oral administration of nymphayol (50 mg/kg) to rats potentiated the delayed-type hypersensitivity reaction induced by sheep red blood cells. Treatment with nymphayol showed a significant (p<0.05) reduction in pyrexia in rats. The results suggest that nymphayol possesses potent anti-nociceptive, immunomodulatory and antipyretic activities.

• Korean Journal of Plant Resources
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• v.23 no.6
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• pp.513-518
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• 2010

In the present study, the antinociceptive profiles of Dianthus chinensis L extract were examined in ICR mice. Dianthus chinensis L extract administered orally (200 mg/kg) showed an antinociceptive effect as measured by the tail-flick and hot-plate tests. In addition, Dianthus chinensis L extract attenuated the writhing numbers in the acetic acid-induced writhing test. Furthermore, the cumulative nociceptive response time for intrathecal (i.t.) injection of substance P ($0.7\;{\mu}g$) was diminished by Dianthus chinensis L extract. Intraperitoneal (i.p.) pretreatment with yohimbine ($\alpha_2$-adrenergic receptor antagonist) attenuated antinociceptive effect induced by Dianthus chinensis L extract in the writhing test. However, naloxone (opioid receptor antagonist) or methysergide (5-HT serotonergic receptor antagonist) did not affect antinociception induced by Dianthus chinensis L extract in the writhing test. Our results suggest that Dianthus chinensis L extract shows an antinociceptive property in various pain models. Furthermore, this antinociceptive effect of Dianthus chinensis L extract may be mediated by $\alpha_2$-adrenergic receptor, but not opioidergic and serotonergic receptors.