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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Avalia??o farmacol?gica das atividades antinociceptiva e anti-inflamat?ria do composto (?)-4-cloro-6-(naftaleno-1-il)-tetrahidro-2h-pirano-2-il-metanol / Antinociceptive and anti-inflammatory profile of (?)-4-chloro-6-(naphthalen-1-yl)-tetrahydro-2H-pyran-2-yl-methanol

Gon?alves, Gabriela Mastrangelo 23 February 2016 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-02-14T12:00:15Z No. of bitstreams: 1 2016 - Gabriela Mastrangelo Gon?alves.pdf: 1218648 bytes, checksum: d31754b24278f68ec75382b5ff3932c0 (MD5) / Made available in DSpace on 2017-02-14T12:00:15Z (GMT). No. of bitstreams: 1 2016 - Gabriela Mastrangelo Gon?alves.pdf: 1218648 bytes, checksum: d31754b24278f68ec75382b5ff3932c0 (MD5) Previous issue date: 2016-02-23 / Funda??o Carlos Chagas Filho de Amparo ? Pesquisa do Estado do RJ - FAPERJ / Several drugs in current use were discovered during experimental tests and by observing animals. When a new compound looks promising, it usually undergoes changes in its chemical structure in order to perfect its selectivity, potency and therapeutic efficacy. The aim of this study was to evaluate the antinociceptive and anti-inflammatory activities of a new synthetic hybrid compound (?)-4-chloro-6-(naphthalen-1-yl)-tetrahydro-2H-pyran-2-yl-methanol (CTHP) prepared from a previous prototype acid, (?) - cis- (6-ethyl-tetrahydropyran-2-yl) Formic. The compound CTHP was evaluated in acute pain induction assays. Oral administration of the compound was able to induce antinociceptive activity in models of writhing induced by acetic acid, formalin (both stages) and tail flick. To elucidate the mechanism of action of the compound, the tail flick model was used. This model was perform by prior administration of naloxone (opioid antagonist non-selective), where we observed the inhibition of the effect produced by the compound. The selective involvement of opioid receptors (?, ? and ?) was then evaluated by prior administration of methylnaltrexone, naltrindol, and nor-binaltorphimine, respectively, where only nor-binaltorphimine was able to reduce the analgesic effect of the compound. To evaluate the possible role of the NO/cGMP/KATP, animals were pretreated with N-nitro-L-arginine methyl ester (L-NAME), 1H- [1,2,4 ] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ) (inhibitor of guanylate cyclase sensitive to nitric oxide), and glibenclamide (blocker of the ATP-regulated potassium channels), where reduction was observed with the administration of analgesic effect prior to all of these. In the tolerance induction test, both morphine and compound developed tolerance, however the compound perform at a slower rate and developed cross-tolerance with morphine. To assess the involvement of serotonin pathway in the activity of the compound, daily administration for 3 days of 4-chloro-DL-phenylalanine (inhibitor of the enzyme tryptophan hydroxylase) was performed. No changes in the analgesic effect of the compound was noted, with regard to the involvement of serotonin pathway. The open field model was used to assess the possibility of interference from motor performance on the analgesic effect, which demonstrated absence of this interference. As for anti-inflammatory activity results in paw edema test indicate anti-oedematogenic effect of compound. There was a decrease in the number of total leukocytes, indicating that the compound was able to reduce existing inflammation in leukocyte migration in the air pouch model. The compound also demonstrated an inhibitory activity on TNF-? production and selective inhibition of COX-2 enzyme. These results indicate significant antinociceptive activity of the compound without evidence of motor impairment. The compound CTHP showed central analgesic effect, which has contribution of opioid systems (selective for the ?-like receptors) and nitrergic in its mechanism of action. It has also showed an anti-inflammatory activity, with inhibition of leukocyte migration, TNF-? production and selective inhibitory activity on COX-2. / Diversos f?rmacos de uso corrente foram descobertos durante ensaios experimentais e mediante a observa??o em animais. Quando um novo composto parece promissor, geralmente este sofre altera??es em sua estrutura qu?mica a fim de aperfei?oar a sua seletividade, pot?ncia e efic?cia terap?utica. O objetivo deste estudo foi avaliar as atividades antinociceptiva e anti-inflamat?ria de um novo composto sint?tico (?)-4-cloro-6-(naftaleno-1-il)-tetrahidro-2h-pirano-2-il-metanol (CTHP) preparado a partir de um prot?tipo anterior, ?cido (?)-cis-(6-etil-tetrahidropirano-2-il) f?rmico. O composto CTHP foi avaliado em ensaios de indu??o de dor aguda. A administra??o oral do composto foi capaz de induzir atividade antinociceptiva nos modelos de contor??es abdominais induzidas por ?cido ac?tico, formalina (em ambas as fases) e retirada da cauda. Para elucida??o do mecanismo de a??o do composto, o modelo de retirada de cauda foi utilizado. Neste modelo foi realizada a administra??o pr?via de naloxona (antagonista opioide n?o-seletivo), em que foi observada a inibi??o do efeito produzido pelo composto. Assim, foi ent?o avaliada a participa??o seletiva de receptores opioides (?, ? e ?), atrav?s de administra??o pr?via de metilnaltrexona, naltrindol e nor-binaltorfimina, respectivamente, onde somente a nor-binaltorfimina foi capaz de reduzir o efeito antinociceptivo do composto. Para avaliar a poss?vel participa??o da via NO/GMPc/KATP, os animais foram pr?-tratados com N-nitro-arginina-L-metil ?ster (L-NAME), 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalina-1-ona (ODQ) (inibidor da guanilato ciclase sens?vel ao ?xido n?trico) e glibenclamida (bloqueador de canais de pot?ssio regulados por ATP), foi observado redu??o do efeito antinociceptivo com a administra??o pr?via de todos estes. No teste de indu??o de toler?ncia, tanto a morfina quanto o composto desenvolveram toler?ncia, por?m o composto de forma mais lenta e houve desenvolvimento de toler?ncia cruzada com a morfina. Para avaliar o envolvimento da via serotonin?rgica na atividade do composto, foi realizada a administra??o di?ria por 3 dias de 4-cloro-DL-fenilalanina (inibidor da enzima triptofano hidroxilase). Nenhuma altera??o no efeito antinociceptivo do composto foi observado, no que diz respeito ao envolvimento da via serotonin?rgica. J? o modelo de campo aberto foi utilizado para avaliar a possibilidade de interfer?ncia da performance motora sobre o efeito antinociceptivo, foi demonstrada aus?ncia desta interfer?ncia. Quanto ? atividade anti-inflamat?ria, o resultado no teste de edema de pata indica efeito antiedematog?nico do composto. Houve uma diminui??o na quantidade de leuc?citos totais, indicando que o composto foi capaz de reduzir a migra??o leucocit?ria na inflama??o existente na bolsa de ar subcut?neo. O composto tamb?m demonstrou atividade inibit?ria sobre a produ??o de TNF-? e inibi??o seletiva da enzima COX-2. Esses resultados indicam atividade antinociceptiva significativa do composto, sem evid?ncias de comprometimento motor. O composto CTHP demonstrou efeito antinociceptivo central, tendo este ?ltimo contribui??o dos sistemas opioide (seletivo para receptores do tipo ?) e nitr?rgico em seu mecanismo de a??o. E ainda, atividade anti-inflamat?ria, com inibi??o da migra??o leucocit?ria, de TNF-? e atividade inibit?ria seletiva sobre COX-2.
52

Comparação dos efeitos farmacológicos do canabidiol e seu análogo sintético HU-474 / Comparative study of pharmacological effects of cannabidiol and its synthetic analog HU-474

Nicole Rodrigues da Silva 27 January 2016 (has links)
Vários estudos indicam que o canabidiol (CBD) apresenta grande potencial terapêutico por possuir propriedades anti-inflamatória, analgésica, anticonvulsivante, anticompulsiva, entre outras. No entanto, o CBD apresenta baixa biodisponibilidade, o que pode comprometer seu uso clínico. Além disso, os múltiplos efeitos farmacológicos do CBD ocorrem por diferentes mecanismos. Nesse sentido, o desenvolvimento de compostos com efeitos semelhantes ao CBD, porém mais potentes e/ou com melhor perfil farmacocinético, seria importante. Assim, no presente estudo, nós avaliamos os efeitos induzidos por um derivado fluorado do CBD, o HU-474, comparando-os com aqueles induzidos pelo CBD. Para isso, camundongos suíços machos foram submetidos a modelos animais sensíveis a drogas anticompulsivas (teste de enterrar esferas) e antinociceptivas (teste da placa quente, contorção abdominal e hiperalgesia inflamatória). Para o estudo dos mecanismos envolvidos nos efeitos destes compostos, foram utilizados os antagonistas dos receptores canabinóides CB1, AM251, e CB2, AM630. Adicionalmente, nós avaliamos se o HU-474 induziria os efeitos clássicos (tétrade canabinóide) observados após a administração de agonistas dos receptores CB1 como hipolocomoção, hipotermia, catalepsia e antinocicepção. Os possíveis efeitos antinociceptivos e da tétrade canabinóide induzidos pelo CBD e HU-474 foram comparados com os efeitos induzidos pelo WIN55,212-2, uma agonista dos receptores CB1/2. Foi observado que o CBD (30 e 60mg/kg) e o HU-474 (10mg/kg) induziram uma diminuição no número de esferas enterradas, efeito comparado ao da fluoxetina e atenuado pelos antagonistas AM251 e AM630. Como esperado, o WIN55,212-2 induziu a tétrade canabinóide, um efeito não observado com o CBD e HU-474. No teste da placa quente o HU-474 (30 mg/kg) e WIN55,212-2 (5mg/kg) induziram efeito antinociceptivo. O pré- tratamento com AM251 e AM630 atenuaram os efeitos do HU-474 e WIN55,212-2. No teste de contorção abdominal induzida pelo ácido acético, o CBD (30 e 90 mg/kg), HU-474 (30mg/kg) e WIN55,212-2 (3 e 5mg/kg) induziram efeito antinociceptivo caracterizado pela redução no número de contorções abdominais. O pré-tratamento com AM251 atenuou o efeito apenas do WIN55,212-2, mas não dos outros compostos. Já o antagonista AM630 não foi capaz de atenuar o efeito de nenhum dos compostos testados. No modelo de hiperalgesia inflamatória induzida por carragenina, o CBD (30 e 90mg/kg), HU-474 (3, 10 e 30mg/kg) e WIN55,212-2 (1mg/kg) foram capazes de diminuir a intensidade de hiperalgesia mecânica, avaliada pelo método de von Frey. Sendo que os efeitos do WIN55,212-2, CBD e HU-474 foram atenuados pelo pré-tratamento com AM251 e AM630. Estes resultados indicam que o HU-474 induz efeitos anticompulsivos semelhantes ao CBD, mas em doses mais baixas, através de mecanismo dependente da ativação dos receptores CB1 e CB2. Além disso, o HU-474 apresentou propriedades antinociceptivas em todos os testes utilizados, em doses semelhantes ou menores que o CBD. Os efeitos antinociceptivos dos três compostos testados foram dependentes da ativação de receptores CB1 e CB2, com exceção do teste de contorção abdominal, onde os efeitos do CBD e HU-474 não foram bloqueados por nenhum dos dois antagonistas testados. Diferente do WIN55,212-2, o CBD e HU-474 não induziram tétrade canabinóide. Esses resultados evidenciaram efeitos mais significativos do HU-474, indicando que a adição de um átomo de flúor a molécula de CBD foi capaz de melhorar o seu perfil farmacológico. Além disso, os resultados com o pré-tratamento com os antagonistas AM251 e AM630 nos permitem sugerir um mecanismo misto, visto que há o envolvimento dos receptores CB1 e CB2. Desse modo, esse novo composto poderia ser uma alternativa terapêutica para o tratamento do transtorno obsessivo-compulsivo, bem como dores agudas em doses menores que o CBD / Cannabidiol (CBD) has several therapeutic properties such as antiinflammatory, analgesic, anticonvulsivant and anticompulsive. These multiple pharmacological effects occur by different mechanisms. However, CBD exhibits low bioavailability, which may compromise its clinical use. Thus, the development of CBD analogues, more powerful and/or better pharmacokinetic profile would be interest. Here, we evaluated the effects of a fluorinated derivative of CBD, HU-474, comparing its effects with those induced by CBD. Male Swiss mice were submitted to animal models predictive to anti-compulsive (marble burying test) and antinociceptive drugs (hot plate, abdominal writhing and inflammatory hyperalgesia test). To study the mechanisms involved in their effects were used antagonist of the cannabinoid receptor CB1(AM251) and CB2 (AM630). We also evaluated whether HU-474 would induce the classic effects (cannabinoid tetrad) observed after the administration of CB1 receptors agonists. The cannabinoid tetrad is characterized by hypolocomotion, hypothermia, catalepsy, and antinociception. The possible antinociceptive effects and cannabinoid tetrad induced by CBD and HU-474 were compared with those induced by WIN55,212-2, a CB1/2 receptor agonist. CBD (30 and 60mg/kg), and HU-474 (10mg/kg) decreased the number of buried marble, an effect compared with fluoxetine an attenuated by AM251 and AM630. As expected, WIN55,212-2 induced the cannabinoid tetrad, an effect that was not observed after CBD or HU-474 administration. In the hot plate test, HU-474 (30mg/kg) and WIN55,212-2 (5mg/kg) induced antinociceptive effect. Pretreatment with AM251 and AM640 attenuated the effects induced by HU-474 and WIN55,212-2. In the abdominal writhing test induced by acetic acid, CBD (30 and 90mg/kg), HU-474 (30mg/kg) and WIN55,212-2 (3 and 5mg/kg) induced antinociceptive effects characterized by a reduction in the number of writhing. Pretreatment with AM251 only attenuated the effect of WIN55,212-2, but not of the other compounds, while AM630 didn\"t attenuated the effect of any of the tested compounds. In an inflammatory hyperalgesia model induced by carrageenan, CBD (30 and 90mg/kg), HU-474 (3, 10 and 30mg/kg) and WIN55,212-2 (1mg/kg) decreased the intensity of mechanical hyperalgesia measured by electronic von Frey method. The effects of all compounds were attenuated by the pretreatment with AM251 and AM630. These results indicate that HU-474 exhibits anti-compulsive effects similar to CBD, but at lower doses, through a mechanism dependent of the activation of CB1 and CB2 receptors. Furthermore, HU-474 showed antinociceptive properties in all tests at similar or lower doses than CBD. The antinociceptive effects of the three compounds tested were dependent on the activation of CB1 and CB2 receptors, excepted to the writhing test, where the effects of CBD and HU-474 were not attenuated by any of the two antagonists tested. Moreover, unlike WIN55,212-2, CBD and HU- 474 didn\'t induce cannabinoid tetrad. These results showed more significant effects of HU-474, indicating that the addition of fluoride improved the pharmacological profile of CBD. Furthermore, the results with pretreatment with the antagonist AM251 and AM630 allow us to suggest that these effects involve the activation of CB1 and CB2 receptors. Thus, this new compound could be a therapeutical alternative for the treatment of obsessive-compulsive disorder and acute pain in lower doses than CBD
53

Avalia??o do potencial anti-nociceptivo e antiinflamat?rio do ?cido pip?rico / Drugs currently used in pain and inflammation are responsible for a large number of adverse effects, due to chronic use, producing in the patients a decrease of symptoms, but not an overall improvement in quality of life, therefore it is of extreme importance to search for new drugs. Piperine is the main active compound of black pepper (Piper nigrum), known in Brazil as black pepper, popularly used by several beneficial effects. Studies in vitro and in vivo show that piperine has functional involvement in antidepressant, hepatoprotective, anti-metastatic antiparasitic, antithyroid, immunomodulatory, anti-inflammatory and analgesic effects. To improve the selectivity and potency, molecular changes were made in the piperine, obtaining the piperic acid. The objective of this study was to evaluate, through of models of acute and chronic pain, and inflammation; a potential nociceptive and anti-inflammatory compound. In the model of writhing induced by acetic acid was observed a percentage inhibition of writhes of 77,9% compared to the control, in the highest dose tested (10mg / kg). In the formalin test, the compound inhibited both phases of the test, wich the dose of 10mg/kg The inhibitory effect was 30% in stage 1 and stage 2 at 67%. The increase in the latency time in tail flick test had an earlier action compared to morphine and the piperic acid increased the latency time in 58% in 80min time in relation to baseline. We investigated the possible pathways involved in the mechanism of action of the compound by prior administration of antagonists in the tail flick test. We found that the muscarinic antagonist, atropine, was able to completely inhibit the effect of the compound, demonstrating the involvement of the cholinergic pathway in the mechanism of action. The opioid and nitrergic pathways and the potassium channel ATPdependent are not involved in the mechanism of action, since these antagonists do not inhibit the effect of the compound. The compound was able to inhibit capsaicin-induced nociception, capsaicina is agonist TRPV1, in 45,34% demonstrating the involvement of TRPV1. The von Frey test evaluate allodynia after chronic constriction of the sciatic nerve. In this test, the compound did not show antinociceptive activity with the doses tested. The open field test was used to determine the influence of the compound on the animal's mobility, and we observe that the action of the compound did not interfere on animal's motor performance. The antiinflammatory activity was evaluated in models of inflammation induced by carrageenan. In the paw oedema test, the compound significantly reduced the oedema at doses of 5 and 10 mg/kg. In the air pouch test, we found that the leukocyte migration was reduced, as well as the production of TNF-? and IL-1?. The piperic acid was shown to be selective for COX-1 in the assessment of enzymatic activity of COX-1 and COX-2. We suggest that the effects of piperine can be mediated primarily through the portion of the molecule related to piperic acid

Oliveira, Poliana de Araujo 25 July 2016 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-11-08T15:16:23Z No. of bitstreams: 1 2016 - Poliana de Araujo Oliveira.pdf: 1134800 bytes, checksum: 79b02bbcfb332c5fbb799d7840ccc773 (MD5) / Made available in DSpace on 2017-11-08T15:16:23Z (GMT). No. of bitstreams: 1 2016 - Poliana de Araujo Oliveira.pdf: 1134800 bytes, checksum: 79b02bbcfb332c5fbb799d7840ccc773 (MD5) Previous issue date: 2016-07-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Drugs currently used in pain and inflammation are responsible for a large number of adverse effects, due to chronic use, producing in the patients a decrease of symptoms, but not an overall improvement in quality of life, therefore it is of extreme importance to search for new drugs. Piperine is the main active compound of black pepper (Piper nigrum), known in Brazil as black pepper, popularly used by several beneficial effects. Studies in vitro and in vivo show that piperine has functional involvement in antidepressant, hepatoprotective, anti-metastatic antiparasitic, antithyroid, immunomodulatory, anti-inflammatory and analgesic effects. To improve the selectivity and potency, molecular changes were made in the piperine, obtaining the piperic acid. The objective of this study was to evaluate, through of models of acute and chronic pain, and inflammation; a potential nociceptive and anti-inflammatory compound. In the model of writhing induced by acetic acid was observed a percentage inhibition of writhes of 77,9% compared to the control, in the highest dose tested (10mg / kg). In the formalin test, the compound inhibited both phases of the test, wich the dose of 10mg/kg The inhibitory effect was 30% in stage 1 and stage 2 at 67%. The increase in the latency time in tail flick test had an earlier action compared to morphine and the piperic acid increased the latency time in 58% in 80min time in relation to baseline. We investigated the possible pathways involved in the mechanism of action of the compound by prior administration of antagonists in the tail flick test. We found that the muscarinic antagonist, atropine, was able to completely inhibit the effect of the compound, demonstrating the involvement of the cholinergic pathway in the mechanism of action. The opioid and nitrergic pathways and the potassium channel ATPdependent are not involved in the mechanism of action, since these antagonists do not inhibit the effect of the compound. The compound was able to inhibit capsaicin-induced nociception, capsaicina is agonist TRPV1, in 45,34% demonstrating the involvement of TRPV1. The von Frey test evaluate allodynia after chronic constriction of the sciatic nerve. In this test, the compound did not show antinociceptive activity with the doses tested. The open field test was used to determine the influence of the compound on the animal's mobility, and we observe that the action of the compound did not interfere on animal's motor performance. The antiinflammatory activity was evaluated in models of inflammation induced by carrageenan. In the paw oedema test, the compound significantly reduced the oedema at doses of 5 and 10 mg/kg. In the air pouch test, we found that the leukocyte migration was reduced, as well as the production of TNF-? and IL-1?. The piperic acid was shown to be selective for COX-1 in the assessment of enzymatic activity of COX-1 and COX-2. We suggest that the effects of piperine can be mediated primarily through the portion of the molecule related to piperic acid / Os f?rmacos atualmente utilizados em dor e inflama??o s?o respons?veis por um grande n?mero de efeitos adversos, e devido ao uso cr?nico, fazem com que o paciente tenha uma diminui??o dos sintomas, mas n?o uma total melhoria da qualidade de vida, sendo assim ? de extrema import?ncia a busca por novos f?rmacos. A piperina ? o principal composto ativo da pimenta preta (Piper nigrum), mais conhecida no Brasil como pimenta do reino, popularmente utilizada por diversos efeitos ben?ficos. Estudos in vitro e in vivo demonstram que a piperina tem envolvimento funcional como antidepressivo, hepatoprotetor, antiparasit?rio antimetast?tico, antitiroidiano, imunomodulador, anti-inflamat?rio e analg?sico. A fim de produzir melhora em sua seletividade e pot?ncia, altera??es moleculares foram realizadas na piperina, obtendo-se ent?o o ?cido pip?rico. O objetivo deste trabalho foi avaliar, atrav?s da execu??o de modelos experimentais de dor aguda, cr?nica e inflama??o, o potencial farmacol?gico antinociceptivo e anti-inflamat?rio do composto. No modelo de contor??es abdominais induzidas por ?cido ac?tico foi verificada um percentual de inibi??o das contor??es de 77,9% comparado ao controle, na maior dose testada (10mg/kg). No modelo da formalina o composto inibiu ambas as fases do modelo, com a dose de 10mg/kg o efeito inibit?rio chegou a 30% na 1? fase e 67% na 2? fase. O aumento do tempo de lat?ncia no modelo de retirada de cauda com o composto foi alcan?ado mais precocemente do que a morfina, o ACP aumentou o tempo de lat?ncia em 58% no tempo de 80 min comparado a linha de base na maior dose testada. Investigamos as poss?veis vias envolvidas no mecanismo de a??o do composto atrav?s da administra??o pr?via de antagonistas, no modelo de retirada de cauda. Verificamos que o antagonista de receptores muscar?nicos, atropina, foi capaz de inibir completamente o efeito do composto, demonstrando a participa??o da via colin?rgica no mecanismo de a??o. As vias opioide, nitr?rgica e o canal de pot?ssio dependente de ATP parecem n?o estar envolvidas no mecanismo de a??o, visto que os antagonistas destas vias n?o inibiram o efeito do composto. O composto inibiu a nocicep??o induzida pela capsaicina, que ? agonista de receptores TRPV1 em 45,34%, demonstrando envolvimento de TRPV1. No modelo de Von Frey avaliamos a alodinia ap?s a constri??o cr?nica do nervo ci?tico. Neste modelo, o composto n?o demonstrou atividade antinociceptiva nas doses testadas. O modelo de campo aberto foi usado para verificar a influ?ncia do composto sobre a mobilidade do animal, e observamos que o mesmo n?o interfere no desempenho motor do animal. A atividade anti-inflamat?ria foi avaliada em modelos de inflama??o induzido por carragenina. No modelo de edema de pata, o composto reduziu o edema em 75% na dose de 10mg/kg. No modelo da bolsa de ar subcut?nea verificamos que a migra??o leucocit?ria foi reduzida assim como a produ??o de TNF-? e IL-1?. O ?cido pip?rico demonstrou ser seletivo para COX-1, na avalia??o da atividade enzim?tica de COX-1 e COX-2. Podemos sugerir que os efeitos da piperina podem ser mediados atrav?s da por??o da mol?cula referente ao ?cido pip?rico.
54

Comparação dos efeitos farmacológicos do canabidiol e seu análogo sintético HU-474 / Comparative study of pharmacological effects of cannabidiol and its synthetic analog HU-474

Silva, Nicole Rodrigues da 27 January 2016 (has links)
Vários estudos indicam que o canabidiol (CBD) apresenta grande potencial terapêutico por possuir propriedades anti-inflamatória, analgésica, anticonvulsivante, anticompulsiva, entre outras. No entanto, o CBD apresenta baixa biodisponibilidade, o que pode comprometer seu uso clínico. Além disso, os múltiplos efeitos farmacológicos do CBD ocorrem por diferentes mecanismos. Nesse sentido, o desenvolvimento de compostos com efeitos semelhantes ao CBD, porém mais potentes e/ou com melhor perfil farmacocinético, seria importante. Assim, no presente estudo, nós avaliamos os efeitos induzidos por um derivado fluorado do CBD, o HU-474, comparando-os com aqueles induzidos pelo CBD. Para isso, camundongos suíços machos foram submetidos a modelos animais sensíveis a drogas anticompulsivas (teste de enterrar esferas) e antinociceptivas (teste da placa quente, contorção abdominal e hiperalgesia inflamatória). Para o estudo dos mecanismos envolvidos nos efeitos destes compostos, foram utilizados os antagonistas dos receptores canabinóides CB1, AM251, e CB2, AM630. Adicionalmente, nós avaliamos se o HU-474 induziria os efeitos clássicos (tétrade canabinóide) observados após a administração de agonistas dos receptores CB1 como hipolocomoção, hipotermia, catalepsia e antinocicepção. Os possíveis efeitos antinociceptivos e da tétrade canabinóide induzidos pelo CBD e HU-474 foram comparados com os efeitos induzidos pelo WIN55,212-2, uma agonista dos receptores CB1/2. Foi observado que o CBD (30 e 60mg/kg) e o HU-474 (10mg/kg) induziram uma diminuição no número de esferas enterradas, efeito comparado ao da fluoxetina e atenuado pelos antagonistas AM251 e AM630. Como esperado, o WIN55,212-2 induziu a tétrade canabinóide, um efeito não observado com o CBD e HU-474. No teste da placa quente o HU-474 (30 mg/kg) e WIN55,212-2 (5mg/kg) induziram efeito antinociceptivo. O pré- tratamento com AM251 e AM630 atenuaram os efeitos do HU-474 e WIN55,212-2. No teste de contorção abdominal induzida pelo ácido acético, o CBD (30 e 90 mg/kg), HU-474 (30mg/kg) e WIN55,212-2 (3 e 5mg/kg) induziram efeito antinociceptivo caracterizado pela redução no número de contorções abdominais. O pré-tratamento com AM251 atenuou o efeito apenas do WIN55,212-2, mas não dos outros compostos. Já o antagonista AM630 não foi capaz de atenuar o efeito de nenhum dos compostos testados. No modelo de hiperalgesia inflamatória induzida por carragenina, o CBD (30 e 90mg/kg), HU-474 (3, 10 e 30mg/kg) e WIN55,212-2 (1mg/kg) foram capazes de diminuir a intensidade de hiperalgesia mecânica, avaliada pelo método de von Frey. Sendo que os efeitos do WIN55,212-2, CBD e HU-474 foram atenuados pelo pré-tratamento com AM251 e AM630. Estes resultados indicam que o HU-474 induz efeitos anticompulsivos semelhantes ao CBD, mas em doses mais baixas, através de mecanismo dependente da ativação dos receptores CB1 e CB2. Além disso, o HU-474 apresentou propriedades antinociceptivas em todos os testes utilizados, em doses semelhantes ou menores que o CBD. Os efeitos antinociceptivos dos três compostos testados foram dependentes da ativação de receptores CB1 e CB2, com exceção do teste de contorção abdominal, onde os efeitos do CBD e HU-474 não foram bloqueados por nenhum dos dois antagonistas testados. Diferente do WIN55,212-2, o CBD e HU-474 não induziram tétrade canabinóide. Esses resultados evidenciaram efeitos mais significativos do HU-474, indicando que a adição de um átomo de flúor a molécula de CBD foi capaz de melhorar o seu perfil farmacológico. Além disso, os resultados com o pré-tratamento com os antagonistas AM251 e AM630 nos permitem sugerir um mecanismo misto, visto que há o envolvimento dos receptores CB1 e CB2. Desse modo, esse novo composto poderia ser uma alternativa terapêutica para o tratamento do transtorno obsessivo-compulsivo, bem como dores agudas em doses menores que o CBD / Cannabidiol (CBD) has several therapeutic properties such as antiinflammatory, analgesic, anticonvulsivant and anticompulsive. These multiple pharmacological effects occur by different mechanisms. However, CBD exhibits low bioavailability, which may compromise its clinical use. Thus, the development of CBD analogues, more powerful and/or better pharmacokinetic profile would be interest. Here, we evaluated the effects of a fluorinated derivative of CBD, HU-474, comparing its effects with those induced by CBD. Male Swiss mice were submitted to animal models predictive to anti-compulsive (marble burying test) and antinociceptive drugs (hot plate, abdominal writhing and inflammatory hyperalgesia test). To study the mechanisms involved in their effects were used antagonist of the cannabinoid receptor CB1(AM251) and CB2 (AM630). We also evaluated whether HU-474 would induce the classic effects (cannabinoid tetrad) observed after the administration of CB1 receptors agonists. The cannabinoid tetrad is characterized by hypolocomotion, hypothermia, catalepsy, and antinociception. The possible antinociceptive effects and cannabinoid tetrad induced by CBD and HU-474 were compared with those induced by WIN55,212-2, a CB1/2 receptor agonist. CBD (30 and 60mg/kg), and HU-474 (10mg/kg) decreased the number of buried marble, an effect compared with fluoxetine an attenuated by AM251 and AM630. As expected, WIN55,212-2 induced the cannabinoid tetrad, an effect that was not observed after CBD or HU-474 administration. In the hot plate test, HU-474 (30mg/kg) and WIN55,212-2 (5mg/kg) induced antinociceptive effect. Pretreatment with AM251 and AM640 attenuated the effects induced by HU-474 and WIN55,212-2. In the abdominal writhing test induced by acetic acid, CBD (30 and 90mg/kg), HU-474 (30mg/kg) and WIN55,212-2 (3 and 5mg/kg) induced antinociceptive effects characterized by a reduction in the number of writhing. Pretreatment with AM251 only attenuated the effect of WIN55,212-2, but not of the other compounds, while AM630 didn\"t attenuated the effect of any of the tested compounds. In an inflammatory hyperalgesia model induced by carrageenan, CBD (30 and 90mg/kg), HU-474 (3, 10 and 30mg/kg) and WIN55,212-2 (1mg/kg) decreased the intensity of mechanical hyperalgesia measured by electronic von Frey method. The effects of all compounds were attenuated by the pretreatment with AM251 and AM630. These results indicate that HU-474 exhibits anti-compulsive effects similar to CBD, but at lower doses, through a mechanism dependent of the activation of CB1 and CB2 receptors. Furthermore, HU-474 showed antinociceptive properties in all tests at similar or lower doses than CBD. The antinociceptive effects of the three compounds tested were dependent on the activation of CB1 and CB2 receptors, excepted to the writhing test, where the effects of CBD and HU-474 were not attenuated by any of the two antagonists tested. Moreover, unlike WIN55,212-2, CBD and HU- 474 didn\'t induce cannabinoid tetrad. These results showed more significant effects of HU-474, indicating that the addition of fluoride improved the pharmacological profile of CBD. Furthermore, the results with pretreatment with the antagonist AM251 and AM630 allow us to suggest that these effects involve the activation of CB1 and CB2 receptors. Thus, this new compound could be a therapeutical alternative for the treatment of obsessive-compulsive disorder and acute pain in lower doses than CBD
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Efeito da fotobioestimulação na neuropatia periférica de ratos com diabetes mellitus tipo 1 induzido por estreptozotocina. / Effect of photobiostimulation on peripheral neuropathy of rats with type 1 diabetes mellitus induced by streptozotocin.

Rocha, Igor Rafael Correia 11 December 2017 (has links)
O diabetes mellitus é uma doença crônica com mais de 3500 anos de história na qual sua primeira descrição é encontrada no mais antigo tratado médico escrito pela civilização egípcia, o papiro de Ebers. O diabetes mellitus é uma síndrome metabólica caracterizada por aumento significativo nos níveis de glicose na circulação sanguínea, condição conhecida por hiperglicemia. O estado hiperglicêmico danifica estrutural e fisiologicamente as fibras nervosas periféricas ocasionando a neuropatia diabética periférica (processo degenerativo). Esta neuropatia leva o paciente, a uma vida cheia de limitações e incapacidades. As principais queixas apresentadas quanto à neuropatia diabética periférica é a dor crônica, alteração motora e significativa falta de sensibilidade nos membros periféricos, podendo resultar em algumas situações com a amputação do membro inferior. Cabe mencionar que não há na clínica tratamento com foco na degeneração periférica ocasionada pelo diabetes mellitus tipo 1, assim como não há tratamento eficaz para a melhora do quadro nociceptivo (dor), daí a necessidade da pesquisa sobre outras modalidades terapêuticas que devolvam e restaurem a qualidade de vida daqueles acometidos por tal doença. Neste projeto foi utilizado o modelo de neuropatia diabética periférica por diabetes mellitus tipo 1 induzida pela administração de estreptozotocina e sugerido como proposta de tratamento a técnica de laserterapia para interferir no processo de degeneração das fibras nervosas periféricas assim como, na melhora do quadro nociceptivo (dor) analisado pelos modelos de alodinia tátil, hiperalgesia mecânica e hiperalgesia térmica antes, durante e depois do tratamento proposto. O presente estudo demonstrou que a técnica de laserterapia como proposta de tratamento além de melhorar o quadro nociceptivo foi capaz de modular algumas citocinas (interleucinas) pró e antiinflamatórias (TNFα, IL-6, IL-10) no nervo isquiático de ratos diabéticos tratados com a referida técnica. Ainda, em relação às fibras nervosas periféricas, a técnica de laserterapia reverteu o processo degenerativo de tais fibras, representado pela modulação das proteínas estruturais como a laminina e a proteína zero. A técnica de laserterapia também foi capaz de modular os receptores dos produtos finais da glicação avançada (RAGE), um importante componente ativador do fator de transcrição nuclear NF-κB responsável por induzir a liberação de citocinas (interleucinas) pró-inflamatória no nervo isquiático de ratos diabéticos. Os resultados observados demonstraram significativamente a eficácia da técnica de laserterapia como proposta útil para o tratamento da neuropatia diabética periférica. Porém, é necessário que mais estudos sejam realizados a fim de melhor elucidar os mecanismos moleculares que medeiam o efeito terapêutico da técnica de laserterapia. / Diabetes mellitus is a chronic disease with more than 3,500 years of history in which its first description is found in the oldest medical treatise written by the Egyptian civilization, the Ebers papyrus. Diabetes mellitus is a metabolic syndrome characterized by a significant increase in glucose levels in the bloodstream, a condition known as hyperglycemia. The hyperglycemic state damages the peripheral nerve fibers structurally and physiologically, causing peripheral diabetic neuropathy (degenerative process). This neuropathy leads to the patient, a life full of limitations and incapacities. The main complaints regarding peripheral diabetic neuropathy are chronic pain, motor impairment and significant lack of sensation in the peripheral limbs, resulting fatally in some situations with lower limb amputation. It should be mentioned that there is no treatment in the clinic with a focus on the peripheral degeneration caused by type 1 diabetes mellitus, as there is no effective treatment for the improvement of the nociceptive (pain) situation, hence the need for research on other therapeutic modalities that return and restore quality of life of those affected by this disease. In this project, the model of diabetic peripheral neuropathy due to type 1 diabetes mellitus induced by the administration of streptozotocin was used and the proposed technique of laser therapy to interfere in the process of degeneration of the peripheral nerve fibers as well as in the improvement of the nociceptive ) analyzed by the models of tactile allodynia, mechanical hyperalgesia and thermal hyperalgesia before, during and after the proposed treatment. The present study demonstrated that the laser therapy technique as a treatment proposal for peripheral diabetic neuropathy in an animal model of type 1 diabetes mellitus induced by streptozotocin in addition to improving the nociceptive condition (pain) was able to modulate some pro-and anti-inflammatory cytokines (interleukins) (TNFα, IL-6, IL-10) on the sciatic nerve of diabetic rats treated with said technique. Still, in relation to peripheral nerve fibers, the laser therapy technique reversed the degenerative process of these fibers, represented by the modulation of the laminin and zero protein structural proteins. The laser therapy technique was also capable of modulating advanced glycation end-receptor (RAGE) receptors, an important activating component of the NF-κB nuclear transcription factor responsible for inducing the release of proinflammatory cytokines (interleukins) in rats\' sciatic nerve diabetics. The results showed a significant efficacy of the laser therapy technique as a useful proposal for the treatment of peripheral diabetic neuropathy. However, further studies are needed to better elucidate the molecular mechanisms that measure the therapeutic effect of the laser therapy technique.
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Contrôles descendants de la douleur et symptômes douloureux / Downlink controls of pain and painful symptoms

Chebbi, Raja 22 September 2014 (has links)
Les contrôles inhibiteurs diffus induits par stimulation nociceptive (CIDN) représententun des contrôles endogènes descendants de la douleur, qui modulent l'activité desneurones spinaux et trigéminaux. Ils sont sous-tendus par une boucle faisant intervenirdes structures supraspinales. Les réseaux neuronaux qui y sont impliqués sont peuconnus. Par ailleurs, le noyau raphé magnus (NRM) joue un rôle important dans lamodulation descendante de l'activité nociceptive des neurones spinaux et trigéminaux.Cette modulation est à la fois excitatrice et inhibitrice. En effet, l'activation des cellulesON du NRM facilite la transmission nociceptive, alors que l'activation des cellules OFFdu NRM inhibe cette transmission.Dans ce travail, nous nous sommes proposés d’étudier, par une approche électrophysiologiquein vivo, le rôle du NRM dans les contrôles endogènes de la nociception trigéminale.Nous avons alors évalué les effets du blocage pharmacologique du NRM, par la microinjectionde différentes substances bloquant sélectivement ou totalement les cellules ON et/ou OFF duNRM, sur les réponses des neurones à convergence trigéminaux évoquées par des stimulationsnociceptives et non nociceptives et sur les CIDN. Parallèlement, nous avons évalué l'effet dublocage de ce noyau sur la pression artérielle basale et la variation de la pression artérielleévoquée par des stimulations nociceptives.Nos travaux d’électrophysiologie ont permis de montrer que l'inactivation du NRM est àl'origine de trois effets principaux: la facilitation des réponses des neurones àconvergence trigéminaux dues à la mise en jeu des fibres C, la facilitation des réponsesneuronales évoquées par des stimulations mécaniques nociceptives et non nociceptiveset la réduction des CIDN. Ainsi, le NRM semble être impliqué dans les contrôlestoniques et phasiques de la nociception trigéminale. Ces effets dépendent probablementdes neurones OFF ainsi que des neurones sérotoninergiques du NRM. Nos résultatsindiquent également que le NRM est impliqué dans la modulation de la pressionartérielle, que ce soit basale ou déclenchée par une stimulation nociceptive.De façon intéressante, ce travail a permis d'apporter des données nouvelles concernantle réseau neuronal sous-tendant les CIDN. Il semble que de multiples voies ascendanteset descendantes contribuent à ces contrôles inhibiteurs descendants de la douleur. Lesvoies ascendantes impliquent: une voie partant des couches profondes de la moelle etprojetant sur la partie caudale du tronc cérébral et une autre voie partant des couchessuperficielles de la moelle exprimant les récepteurs NK1 et projetant plus rostralementsur le noyau parabrachial. Les voies descendantes impliquent une voie dopaminergiqueet une voie sérotoninergique prenant respectivement origine dans l'hypothalamus et leNRM.En conclusion, nous suggérons qu'un dysfonctionnement du NRM est à l'origine d'unerupture de l'équilibre entre les contrôles inhibiteurs et facilitateurs de la douleurexercés depuis cette structure, au profit d'une augmentation des effets facilitateurset/ou une réduction des effets inhibiteurs. Ce déséquilibre pourrait être à l'origined'une déficience des CIDN ainsi qu'une accentuation des états d'hyperalgésie etd'allodynie, accompagnant les douleurs chroniques. / Absent
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Acetylcholine in Spinal Pain Modulation : An in vivo Study in the Rat

Abelson, Klas January 2005 (has links)
The spinal cord is an important component in the processing and modulation of painful stimuli. Nerve signals from the periphery are relayed and further conducted to the brain (nociception) in the spinal cord, and the most essential modulation of painful information (antinociception) occurs here. Several neurotransmitters are involved in spinal pain modulation, among them acetylcholine. However, the role of acetylcholine has previously been little investigated. In the present thesis, the acetylcholine release in the spinal cord was studied in vivo. By using spinal microdialysis on anaesthetised rats, the effects on the intraspinal acetylcholine release of various receptor ligands and analgesic agents were examined. This, together with pain behavioural tests and in vitro pharmacological assays, was used to evaluate the role of acetylcholine in spinal pain modulation. The four studies in this thesis resulted in the following conclusions: An increased release of spinal acetylcholine is associated with an elevated pain threshold, while a decreased acetylcholine release is associated with hyperalgesia, as seen after systemic treatment with a muscarinic agonist and an antagonist. Lidocaine is a potent analgesic when given systemically. It was found to produce an increase of intraspinal acetylcholine after intravenous injection of analgesic doses. This effect was attenuated after muscarinic, and abolished after nicotinic, receptor blockade. Various a2-adrenergic ligands, associated with nociceptive or antinociceptive effects, were found to affect intraspinal acetylcholine release via action on nicotinic receptors. Finally, the involvement of spinal acetylcholine in the analgesic effects of aspirin and paracetamol was examined. It was found that spinal acetylcholine could participate in the analgesic effects of aspirin, but not of paracetamol. The present thesis provides data that clearly demonstrate a relationship between intraspinal acetylcholine and antinociception, and elucidate interactions between acetylcholine and other mechanisms that mediate antinociception in the spinal cord.
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The Impact of Neonatal Inflammatory Insult on Adult Somatosensory Processing: The Role of the Descending Nociceptive Circuit

LaPrairie, Jamie L 29 October 2008 (has links)
The neonatal period represents a critical window of increased neurodevelopmental plasticity in the immature nervous system. Unlike other sensory modalities, which require appropriate stimulation for proper development, maturation of nociceptive circuitry in neonates typically occurs in the absence of noxious stimulation. Premature infants, however, are routinely exposed to multiple invasive medical procedures during neonatal intensive care treatment, which are largely performed in the absence of anesthetics or analgesics. To date, it is largely unknown how exposure to early noxious insult during this time of increased plasticity alters the development of the CNS and influences future nociceptive responses. As previous studies examining the impact of neonatal inflammatory insult on adult nociceptive responses have been conducted primarily in males, the potential adverse effects in females are unknown. Furthermore, the biological mechanisms underlying neonatal insult-induced deficits in nociceptive processing have yet to be elucidated. Therefore, this dissertation addressed the following questions: (1) Does neonatal inflammatory insult differentially alter male and female baseline somatosensory thresholds and response to re-inflammation in adulthood?; (2) Are neonatal inflammation-induced deficits in nociceptive responsiveness mediated by a potentiation in endogenous opioid tone?; and (3) Does pre-emptive morphine analgesia attenuate the behavioral consequences of neonatal inflammatory insult? Collectively, these studies will provide valuable information about the long-term consequences of neonatal noxious stimulation in males and females, which may lead to improved understanding and prevention of the lasting effects of repeated invasive interventions in premature infants in the NICU.
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Sex Differences in Morphine Analgesia and the Descending Modulation of Pain

Loyd, Dayna Ruth 21 August 2008 (has links)
Morphine is the most widely prescribed opiate for alleviation of persistent pain; however, it is becoming increasingly clear that morphine is less potent in women compared to men. Morphine primarily binds mu opioid receptors, which are densely localized in the midbrain periaqueductal gray (PAG). Anatomical and physiological studies conducted in the 1960s identified the PAG, and its projections to the rostral ventromedial medulla (RVM) and spinal cord dorsal horn, as an essential neural circuit mediating opioid-based analgesia. Remarkably, the majority of studies since then were conducted in males with the implicit assumption that this circuit was the same in females; this is not the case. It is now well established that morphine produces greater analgesia in males compared to females in a wide range of vertebrates, however, the mechanism(s) driving this sex difference is not clear. Our recent studies indicate that two factors appear to be contributing to the sexually dimorphic effects of morphine. First, there are sex differences in the anatomy and physiology of the descending inhibitory pathway on which morphine acts to produce analgesia. Specifically, the projections from the PAG to the RVM are sexually dimorphic and activated to a greater degree by both inflammatory pain and systemic morphine in males. In the absence of pain, the PAG-RVM circuit is activated to a greater degree in males compared to females, while this activation steadily declines during the development of tolerance in males only. We also have evidence of a sexually dimorphic expression of mu opioid receptor within the PAG that appears to contribute to sex differences in morphine potency. Microinjection of morphine directly into the PAG produces significantly greater analgesia in males, indicating that the PAG is sufficient for eliciting this sexually dimorphic behavior. Furthermore, mu opioid receptor-expressing PAG neurons are necessary for eliciting a sexually dimorphic response to morphine as lesioning mu opioid receptor-expressing neurons attenuates analgesia in males only. Together, these data indicate that the PAG-RVM pathway and mu opioid receptor expression in the PAG is sexually dimorphic and provides a primary mechanism for sex differences in morphine potency.
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Sex Differences in Morphine Analgesia and the Descending Modulation of Pain

Loyd, Dayna Ruth 21 August 2008 (has links)
Morphine is the most widely prescribed opiate for alleviation of persistent pain; however, it is becoming increasingly clear that morphine is less potent in women compared to men. Morphine primarily binds mu opioid receptors, which are densely localized in the midbrain periaqueductal gray (PAG). Anatomical and physiological studies conducted in the 1960s identified the PAG, and its projections to the rostral ventromedial medulla (RVM) and spinal cord dorsal horn, as an essential neural circuit mediating opioid-based analgesia. Remarkably, the majority of studies since then were conducted in males with the implicit assumption that this circuit was the same in females; this is not the case. It is now well established that morphine produces greater analgesia in males compared to females in a wide range of vertebrates, however, the mechanism(s) driving this sex difference is not clear. Our recent studies indicate that two factors appear to be contributing to the sexually dimorphic effects of morphine. First, there are sex differences in the anatomy and physiology of the descending inhibitory pathway on which morphine acts to produce analgesia. Specifically, the projections from the PAG to the RVM are sexually dimorphic and activated to a greater degree by both inflammatory pain and systemic morphine in males. In the absence of pain, the PAG-RVM circuit is activated to a greater degree in males compared to females, while this activation steadily declines during the development of tolerance in males only. We also have evidence of a sexually dimorphic expression of mu opioid receptor within the PAG that appears to contribute to sex differences in morphine potency. Microinjection of morphine directly into the PAG produces significantly greater analgesia in males, indicating that the PAG is sufficient for eliciting this sexually dimorphic behavior. Furthermore, mu opioid receptor-expressing PAG neurons are necessary for eliciting a sexually dimorphic response to morphine as lesioning mu opioid receptor-expressing neurons attenuates analgesia in males only. Together, these data indicate that the PAG-RVM pathway and mu opioid receptor expression in the PAG is sexually dimorphic and provides a primary mechanism for sex differences in morphine potency.

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