scholarly journals Novel 1,3,4-Oxadiazole Derivatives of Pyrrolo[3,4-d]pyridazinone Exert Antinociceptive Activity in the Tail-Flick and Formalin Test in Rodents and Reveal Reduced Gastrotoxicity

2020 ◽  
Vol 21 (24) ◽  
pp. 9685
Author(s):  
Marta Szandruk-Bender ◽  
Benita Wiatrak ◽  
Łukasz Szczukowski ◽  
Piotr Świątek ◽  
Maria Rutkowska ◽  
...  

Despite the availability of the current drug arsenal for pain management, there is still a clinical need to identify new, more effective, and safer analgesics. Based on our earlier study, newly synthesized 1,3,4-oxadiazole derivatives of pyrrolo[3,4-d]pyridazinone, especially 10b and 13b, seem to be promising as potential analgesics. The current study was designed to investigate whether novel derivatives attenuate nociceptive response in animals subjected to thermal or chemical noxious stimulus, and to compare this effect to reference drugs. The antinociceptive effect of novel compounds was studied using the tail-flick and formalin test. Pretreatment with novel compounds at all studied doses increased the latency time in the tail-flick test and decreased the licking time during the early phase of the formalin test. New derivatives given at the medium and high doses also reduced the late phase of the formalin test. The achieved results indicate that new derivatives dose-dependently attenuate nociceptive response in both models of pain and exert a lack of gastrotoxicity. Both studied compounds act more efficiently than indomethacin, but not morphine. Compound 13b at the high dose exerts the greatest antinociceptive effect. It may be due to the reduction of nociceptor sensitization via prostaglandin E2 and myeloperoxidase levels decrease.

Author(s):  
Saurabh Kansal ◽  
Rohan Sirohi ◽  
Ruchika Agarwal

Background: Some antiepileptic drugs have been shown to be clinically efficacious in treatment of neuropathic pain and are being used by clinician.Methods: This study determined the analgesic effect of gabapentin (a conventional anticonvulsant) and levitiracetam (a novel anticonvulsant) in rats in different types of acute and chronic nociceptive test like tail flick and formalin test and compared its potency with a conventional non opioid analgesic diclofenac.Results: Per oral administration of gabapentin produced no any marked effect on early phase response of formalin test but significantly suppressed the late phase response while levitiracetam produced no any type of significant effect in both phases. In tail flick test gabapentin as well as levitiracetam produced no any significant analgesic effect while diclofenac produced significant reduction of pain in tail flick test as well as in both phases of formalin test.Conclusions: Thus, we have observed that gabapentin produced antinociception in chronic pain as second phase of formalin test reflects chronic inflammatory pain while levitiracetam did not produce any type of antinociceptive effect as it could not suppress the pain significantly in both tail flick and formalin test. 


2000 ◽  
Vol 28 (02) ◽  
pp. 291-299 ◽  
Author(s):  
Ching-Liang Hsieh ◽  
Chi-Chung Kuo ◽  
Yueh-Sheng Chen ◽  
Tsai-Chung Li ◽  
Ching-Tou Hsieh ◽  
...  

Although electroacupuncture (EA) has been widely used to treat pain, the optimal frequency of EA therapy remains unclear. The study sought to determine the effect of different EA frequencies in a Sprague-Dawley (SD) rat model of pain. Electric stimulation (ES) at frequencies of 2 Hz, 15 Hz or 100 Hz was applied to the ipsilateral or contralateral sciatic nerve of the injected hindpaw of SD rats. Formalin (50 μl, 5%) was subcutaneously injected into the plantar surface of the left hindpaw to induce a nociceptive response. Behavior, including licking and biting, was observed to have two distinct periods, an early phase during the first 5 mins and a late phase from 21-35 mins after injection. The total biting or licking count served as an Indicator of nociceptive response. Our results indicate that ES of the ipsilateral sciatic nerve at a frequency of 2 Hz or 15 Hz reduced the nociceptive responses in both the early and the late phases of the formalin test, whereas ES at 2 Hz had greater antinociceptive effect than ES at 15 Hz in the early phase. No similar analgesic effect in the early phase was observed for ES at 100 Hz. Both pretreatment with ES at 2 Hz and naloxone (3 mg/kg, s.c.) produced a greater antinociceptive response in the late phase than when ES at 2 Hz was delivered immediately after formalin administration. In addition, ES of the neck muscle or contralateral sciatic nerve at a frequency of 2 Hz also decreased licking and biting activity in both phases. The results of this study indicate that different analgesic mechanisms are involved in the response to ES at frequencies of 2 Hz, 15 Hz and 100 Hz, and that ES at 2 Hz has a greater analgesic effect on formalin-induced nociceptive response, especially when it is delivered prior to the onset of pain. The analgesic effect of ES may be mediated via a central origin in the supraspinal level. These findings suggest that 2 Hz may be a good frequency selection for clinical EA applications in analgesia, and that pretreatment with EA at 2 Hz may be an effective method to treat post-operative pain.


Cephalalgia ◽  
2017 ◽  
Vol 38 (6) ◽  
pp. 1138-1147 ◽  
Author(s):  
Rosaria Greco ◽  
Chiara Demartini ◽  
Anna Maria Zanaboni ◽  
Laura Berliocchi ◽  
Daniele Piomelli ◽  
...  

Background Drugs that modulate endocannabinoid signalling are effective in reducing nociception in animal models of pain and may be of value in the treatment of migraine. Methods We investigated the anti-nociceptive effects of inhibition of monoacylglycerol lipase (MGL), a key enzyme in the hydrolysis of the 2-arachidonoylglycerol, in a rat model of migraine based on nitroglycerin (NTG) administration. We evaluated c-fos expression in specific brain areas and nociceptive behavior in trigeminal and extra-trigeminal body areas. Results URB602, a reversible MGL inhibitor, did not show any analgesic effect in the tail flick test, but it inhibited NTG-induced hyperalgesia in both the tail flick test and the formalin test applied to the hind paw or to the orofacial area. Quite unexpectedly, URB602 potentiated formalin-induced hyperalgesia in the trigeminal area when used alone. The latter result was also confirmed using a structurally distinct, irreversible MGL inhibitor, JZL184. URB602 did not induce neuronal activation in the area of interest, but significantly reduced the NTG-induced neuronal activation in the ventrolateral column of the periaqueductal grey and the nucleus trigeminalis caudalis. Conclusions These findings support the hypothesis that modulation of the endocannabinoid system may be a valuable approach for the treatment of migraine. The topographically segregated effect of MGL inhibition in trigeminal/extra-trigeminal areas calls for further mechanistic research.


2011 ◽  
Vol 02 (02) ◽  
pp. 130-136 ◽  
Author(s):  
Keshab Raj Paudel ◽  
SK Bhattacharya ◽  
GP Rauniar ◽  
BP Das

ABSTRACT Introduction: Newer anticonvulsants have a neuromodulatory effect on pain perception mechanisms in a hyperexcitable and damaged nervous system. Aim: This study was designed to study the analgesic effects of gabapentin alone and in combination with lamotrigine and topiramate in experimental pain models. Materials and Methods: Adult albino mice (n = 490) weighing 20–30 g and rats (n = 130) weighing 100–200 g were injected intraperitoneally with gabapentin, lamotrigine, and topiramate alone and in different dose combinations. The hot-plate method, tail-flick method, capsaicin-induced mechanical hyperalgesia, and formalin assay were used to assess the antinociceptive effects. Results: Of the three antiepileptic drugs, when given separately, gabapentin was more efficacious than either topiramate or lamotrigine in all the pain models. Combination of 25 mg/kg gabapentin with 25 mg/kg topiramate was more efficacious (P <.05) than 50 mg/kg gabapentin alone in the capsaicin-induced mechanical hyperalgesia test. Similarly, 50 mg/kg gabapentin with 50 mg/kg topiramate or 5 mg/kg lamotrigine was more efficacious (P <.05) than 50 or 100 mg/kg gabapentin alone in late-phase formalin-induced behaviors. Conclusions: Combination of gabapentin with either lamotrigine or topiramate produced better results than gabapentin alone in capsaicin-induced mechanical hyperalgesia test and in late-phase formalin-induced behaviors.


Cephalalgia ◽  
2013 ◽  
Vol 34 (8) ◽  
pp. 594-604 ◽  
Author(s):  
R Greco ◽  
AS Mangione ◽  
F Siani ◽  
F Blandini ◽  
M Vairetti ◽  
...  

Background The release of calcitonin gene-related peptide (CGRP) from trigeminal nerves plays a central role in the pathophysiology of migraine and clinical evidence shows an antimigraine effect for CGRP receptor antagonists. Systemic administration of nitroglycerin (NTG), a nitrovasodilator, consistently provokes spontaneous-like migraine attacks in migraine sufferers; in the rat, systemic NTG induces a condition of hyperalgesia, probably through the activation of cerebral/spinal structures involved in nociceptive transmission. Aim The aim of this article is to test the analgesic effect of the CGRP receptor antagonist MK-8825 in two animal models of pain that may be relevant for migraine: the tail flick test and the formalin test performed during NTG-induced hyperalgesia. Results MK-8825 showed analgesic activity when administered alone at both the tail flick test and the formalin test. Furthermore, the CGRP antagonist proved effective in counteracting NTG-induced hyperalgesia in both tests. MK-8825 indeed reduced the nociceptive behavior when administered either simultaneously or prior to (30–60 minutes before) NTG. Conclusion These data suggest that MK-8825 may represent a potential therapeutic tool for the treatment of migraine.


Cephalalgia ◽  
2015 ◽  
Vol 35 (12) ◽  
pp. 1065-1076 ◽  
Author(s):  
R Greco ◽  
T Bandiera ◽  
AS Mangione ◽  
C Demartini ◽  
F Siani ◽  
...  

Background Systemic nitroglycerin (NTG) activates brain nuclei involved in nociceptive transmission as well as in neuroendocrine and autonomic functions in rats. These changes are considered relevant for migraine because NTG consistently provokes spontaneous-like migraine attacks in migraineurs. Several studies have suggested a relationship between the endocannabinoid levels and pain mediation in migraine. URB937, a peripheral inhibitor of fatty acid amide hydrolase (FAAH)—the enzyme that degrades anandamide, produces analgesia in animal models of pain, but there is no information on its effects in migraine. Aim We evaluated whether URB937 alters nociceptive responses in the animal model of migraine based on NTG administration in male rats, using the tail flick test and the plantar and orofacial formalin tests, under baseline conditions and after NTG administration. Furthermore, we investigated whether URB937 affects NTG-induced c-Fos expression in the brain. Results During the tail flick test, URB937 showed an antinociceptive effect in baseline conditions and it blocked NTG-induced hyperalgesia. URB937 also proved effective in counteracting NTG-induced hyperalgesia during both the plantar and orofacial formalin tests. Mapping of brain nuclei activated by NTG indicates that URB937 significantly reduces c-Fos expression in the nucleus trigeminalis caudalis and the locus coeruleus. Conclusions The data suggest that URB937 is capable of changing, probably via indirect mechanisms, the functional status of central structures that are important for pain transmission in an animal model of migraine.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Suk-Yun Kang ◽  
Dae-Hyun Roh ◽  
Hyun-Woo Kim ◽  
Ho-Jae Han ◽  
Alvin J. Beitz ◽  
...  

The injection of diluted bee venom (DBV) into an acupoint has been used traditionally in eastern medicine to treat a variety of inflammatory chronic pain conditions. We have previously shown that DBV had a potent antinociceptive efficacy in several rodent pain models. However, the peripheral mechanisms underlying DBV-induced antinociception remain unclear. The present study was designed to investigate the role of peripheral epinephrine on the DBV-induced antinociceptive effect in the mouse formalin assay. Adrenalectomy significantly enhanced the antinociceptive effect of DBV during the late phase of the formalin test, while chemical sympathectomy had no effect. Intraperitoneal injection of epinephrine blocked this adrenalectomy-induced enhancement of the DBV-induced antinociceptive effect. Moreover, injection of a phenylethanolamine N-methyltransferase (PNMT) inhibitor enhanced the DBV-induced antinociceptive effect. Administration of nonselectiveβ-adrenergic antagonists also significantly potentiated this DBV-induced antinociception, in a manner similar to adrenalectomy. These results demonstrate that the antinociceptive effect of DBV treatment can be significantly enhanced by modulation of adrenal medulla-derived epinephrine and this effect is mediated by peripheralβ-adrenoceptors. Thus, DBV acupoint stimulation in combination with inhibition of peripheralβ-adrenoceptors could be a potentially novel strategy for the management of inflammatory pain.


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