RESUMEN
BACKGROUND: Sleep disorders induce anxiety and forgetfulness and change habits. The chemical hypnotic drugs currently used have serious side effects and, therefore, people are drawn towards using natural compounds such as plant-based healing agents. Abscisic acid (ABA) is produced in a variety of mammalian tissues and it is involved in many neurophysiological functions. OBJECTIVE: To investigate the possible effect of ABA on pentobarbital-induced sleep and its possible signaling through GABA-A and PPAR (γ and ß) receptors, in male Wistar rats. METHODS: The possible effect of ABA (5 and 10 µg/rat, intracerebroventricularly) on sleep onset latency time and duration was evaluated in a V-maze model of sleep. Pentobarbital sodium (40 mg/kg, intraperitoneally) was injected to induce sleep 30 min after administration of ABA. PPARß (GSK0660, 80 nM/rat), PPARγ (GW9662, 3 nM/rat) or GABA-A receptor (bicuculline, 6 µg/rat) antagonists were given 15 min before ABA injection. Diazepam (2 mg/kg, intraperitoneally) was used as a positive control group. RESULTS: ABA at 5 µg significantly boosted the pentobarbital-induced subhypnotic effects and promoted induction of sleep onset in a manner comparable to diazepam treatment. Furthermore, pretreatment with bicuculline significantly abolished the ABA effects on sleep parameters, while the amplifying effects of ABA on the induction of sleep onset was not significantly affected by PPARß or PPARγ antagonists. The sleep prolonging effect of ABA was significantly prevented by both PPAR antagonists. CONCLUSIONS: The data showed that ABA boosts pentobarbital-induced sleep and that GABA-A, PPARß and PPARγ receptors are, at least in part, involved in ABA signaling.
Asunto(s)
Ácido Abscísico/farmacología , PPAR gamma/metabolismo , PPAR-beta/metabolismo , Receptores de GABA-A/metabolismo , Sueño , Animales , Masculino , Pentobarbital/farmacología , Reguladores del Crecimiento de las Plantas/farmacología , Ratas , Ratas Wistar , Transducción de SeñalRESUMEN
ABSTRACT Background: Sleep disorders induce anxiety and forgetfulness and change habits. The chemical hypnotic drugs currently used have serious side effects and, therefore, people are drawn towards using natural compounds such as plant-based healing agents. Abscisic acid (ABA) is produced in a variety of mammalian tissues and it is involved in many neurophysiological functions. Objective: To investigate the possible effect of ABA on pentobarbital-induced sleep and its possible signaling through GABA-A and PPAR (γ and β) receptors, in male Wistar rats. Methods: The possible effect of ABA (5 and 10 µg/rat, intracerebroventricularly) on sleep onset latency time and duration was evaluated in a V-maze model of sleep. Pentobarbital sodium (40 mg/kg, intraperitoneally) was injected to induce sleep 30 min after administration of ABA. PPARβ (GSK0660, 80 nM/rat), PPARγ (GW9662, 3 nM/rat) or GABA-A receptor (bicuculline, 6 µg/rat) antagonists were given 15 min before ABA injection. Diazepam (2 mg/kg, intraperitoneally) was used as a positive control group. Results: ABA at 5 µg significantly boosted the pentobarbital-induced subhypnotic effects and promoted induction of sleep onset in a manner comparable to diazepam treatment. Furthermore, pretreatment with bicuculline significantly abolished the ABA effects on sleep parameters, while the amplifying effects of ABA on the induction of sleep onset was not significantly affected by PPARβ or PPARγ antagonists. The sleep prolonging effect of ABA was significantly prevented by both PPAR antagonists. Conclusions: The data showed that ABA boosts pentobarbital-induced sleep and that GABA-A, PPARβ and PPARγ receptors are, at least in part, involved in ABA signaling.
RESUMO Introdução: Os distúrbios do sono induzem a ansiedade e esquecimento e mudam hábitos. Os medicamentos hipnóticos químicos utilizados atualmente têm efeitos colaterais graves e, portanto, as pessoas são atraídas para o uso de compostos naturais, como agentes de cura à base de plantas. O ácido abscísico (ABA) é produzido em uma variedade de tecidos de mamíferos e está envolvido em muitas funções neurofisiológicas. Objetivo: Investigar o possível efeito do ABA no sono induzido por pentobarbital e sua possível sinalização por meio dos receptores GABA-A e PPAR (γ e β), em ratos Wistar machos. Métodos: O possível efeito do ABA (5 e 10 µg/rato, intracerebroventricularmente) no tempo de latência e duração do início do sono foi avaliado em um modelo de labirinto em V de sono. Pentobarbital sódico (40 mg/kg, intraperitonealmente) foi injetado para induzir o sono 30 minutos após a administração de ABA. PPARβ (GSK0660, 80 nM/rato), PPARγ (GW9662, 3 nM/rato) ou antagonistas do receptor GABA-A (bicuculina, 6 µg/rato) foram administrados 15 minutos antes da injeção de ABA. Diazepam (2 mg/kg, intraperitonealmente) foi utilizado como grupo de controle positivo. Resultados: ABA a 5 µg aumentou significativamente os efeitos sub-hipnóticos induzidos por pentobarbital e promoveu a indução do início do sono de forma comparável ao tratamento com diazepam. Além disso, o pré-tratamento com bicuculina aboliu significativamente os efeitos do ABA nos parâmetros do sono, ao passo que os efeitos amplificadores do ABA na indução do início do sono não foram significativamente afetados pelos antagonistas do PPARβ ou PPARγ. O efeito de prolongamento do sono do ABA foi significativamente prevenido por ambos os antagonistas do PPAR. Conclusões: Os dados mostraram que o ABA estimula o sono induzido por pentobarbital e que os receptores GABA-A, PPARβ e PPARγ estão, pelo menos em parte, envolvidos na sinalização ABA.
Asunto(s)
Animales , Masculino , Ratas , Sueño , Ácido Abscísico/farmacología , Receptores de GABA-A/metabolismo , PPAR-beta/metabolismo , PPAR gamma/metabolismo , Pentobarbital/farmacología , Reguladores del Crecimiento de las Plantas/farmacología , Transducción de Señal , Ratas WistarRESUMEN
OBJECTIVE: The phytohormone abscisic acid (ABA) as a signaling molecule exists in various types of organisms from early multicellular to animal cells and tissues. It has been demonstrated that ABA has an antinociceptive effect in rodents. The present study was designed to assess the possible role of PKA and phosphorylated ERK (p-ERK) on the antinociceptive effects of intrathecal (i.t.) ABA in male Wistar rats. METHODS: The animals were cannulated intrathecally and divided into different experimental groups (n=6â7): Control (no surgery), vehicle (received ABA vehicle), ABA-treated groups (received ABA in doses of 10 or 20 µg/rat), ABA plus H.89 (PKA inhibitor)-treated group which received the inhibitor 15 min prior to the ABA injection. Tail-flick and hot-plate tests were used as acute nociceptive stimulators to assess ABA analgesic effects. p-ERK was evaluated in the dorsal portion of the spinal cord using immunoblotting. RESULTS: Data showed that a microinjection of ABA (10 and 20 µg/rat, i.t.) significantly increased the nociceptive threshold in tail flick and hot plate tests. The application of PKA inhibitor (H.89, 100 nM/rat) significantly inhibited ABA-induced analgesic effects. Expression of p-ERK was significantly decreased in ABA-injected animals, which were not observed in the ABA+H.89-treated group. CONCLUSIONS: Overall, i.t. administration of ABA (10 µg/rat) induced analgesia and p-ERK down-expression likely by involving the PKA-dependent mechanism.
Asunto(s)
Ácido Abscísico/farmacología , Analgésicos/farmacología , Proteínas Quinasas Dependientes de AMP Cíclico/efectos de los fármacos , Quinasas MAP Reguladas por Señal Extracelular/efectos de los fármacos , Reguladores del Crecimiento de las Plantas/farmacología , Médula Espinal/metabolismo , Animales , Western Blotting , Proteínas Quinasas Dependientes de AMP Cíclico/análisis , Quinasas MAP Reguladas por Señal Extracelular/análisis , Péptidos y Proteínas de Señalización Intracelular/farmacología , Masculino , Ratas Wistar , Valores de Referencia , Reproducibilidad de los Resultados , Médula Espinal/efectos de los fármacos , Factores de TiempoRESUMEN
Abstract Objective: The phytohormone abscisic acid (ABA) as a signaling molecule exists in various types of organisms from early multicellular to animal cells and tissues. It has been demonstrated that ABA has an antinociceptive effect in rodents. The present study was designed to assess the possible role of PKA and phosphorylated ERK (p-ERK) on the antinociceptive effects of intrathecal (i.t.) ABA in male Wistar rats. Methods: The animals were cannulated intrathecally and divided into different experimental groups (n=6‒7): Control (no surgery), vehicle (received ABA vehicle), ABA-treated groups (received ABA in doses of 10 or 20 µg/rat), ABA plus H.89 (PKA inhibitor)-treated group which received the inhibitor 15 min prior to the ABA injection. Tail-flick and hot-plate tests were used as acute nociceptive stimulators to assess ABA analgesic effects. p-ERK was evaluated in the dorsal portion of the spinal cord using immunoblotting. Results: Data showed that a microinjection of ABA (10 and 20 µg/rat, i.t.) significantly increased the nociceptive threshold in tail flick and hot plate tests. The application of PKA inhibitor (H.89, 100 nM/rat) significantly inhibited ABA-induced analgesic effects. Expression of p-ERK was significantly decreased in ABA-injected animals, which were not observed in the ABA+H.89-treated group. Conclusions: Overall, i.t. administration of ABA (10 µg/rat) induced analgesia and p-ERK down-expression likely by involving the PKA-dependent mechanism.
Resumo Objetivo: O ácido fito-hormônio abscísico (ABA) existe como molécula sinalizadora em vários tipos de organismos, de multicelulares a células e tecidos animais. Foi demonstrado que o ABA tem efeito antinociceptivo em roedores. O presente estudo foi desenhado para avaliar o possível papel da PKA e da ERK fosforilada (p-ERK) nos efeitos antinociceptivos do ABA intratecal (i.t.) em ratos Wistar machos. Métodos: Os animais foram canulados por via i.t. e divididos em diferentes grupos experimentais (n=6‒7): controle (sem cirurgia), veículo (veículo ABA recebido), grupos tratados com ABA (recebeu ABA em doses de 10 ou 20 µg/rato), grupo tratado com ABA mais H.89 (inibidor de PKA) que recebeu o inibidor 15 minutos antes da injeção de ABA. Os testes de movimento da cauda e placa quente foram utilizados como estimuladores nociceptivos agudos para avaliar os efeitos analgésicos da ABA. A p-ERK foi avaliada na porção dorsal da medula espinhal por imunotransferência. Resultados: A microinjeção de ABA (10 e 20 µg/rato, i.t.) aumentou significativamente o limiar nociceptivo nos testes de movimento da cauda e placa quente. A aplicação de inibidor de PKA (H.89, 100 nM/rato) inibiu significativamente os efeitos analgésicos induzidos por ABA. A expressão de p-ERK diminuiu significativamente em animais injetados com ABA que não foram observados no grupo tratado com ABA+H.89. Conclusões: No geral, a administração i.t. de ABA (10 µg/rato) induziu a analgesia e expressão negativa de p-ERK provavelmente envolvendo mecanismo dependente de PKA.
Asunto(s)
Animales , Masculino , Reguladores del Crecimiento de las Plantas/farmacología , Médula Espinal/metabolismo , Ácido Abscísico/farmacología , Proteínas Quinasas Dependientes de AMP Cíclico/efectos de los fármacos , Quinasas MAP Reguladas por Señal Extracelular/efectos de los fármacos , Analgésicos/farmacología , Valores de Referencia , Médula Espinal/efectos de los fármacos , Factores de Tiempo , Western Blotting , Reproducibilidad de los Resultados , Ratas Wistar , Proteínas Quinasas Dependientes de AMP Cíclico/análisis , Quinasas MAP Reguladas por Señal Extracelular/análisis , Péptidos y Proteínas de Señalización Intracelular/farmacologíaRESUMEN
BACKGROUND: Ducrosia anethifolia has been recommended as a remedy for neurological disorders. However, the anticonvulsant effects of D. anethifolia essential oil (DAEO) and its major constituent α-pinene have not yet been clarified. METHODS: A rat model of pentylenetetrazole (PTZ)-induced convulsions was used. Oxidant and antioxidant parameters were assayed in the temporal lobe. RESULTS: The data showed that DAEO (50, 100 and 200 mg/kg, i.p.) and α-pinene (0.2 and 0.4 mg/kg i.p.) delayed the initiation time, and reduced the duration of myoclonic and tonic-clonic seizures following PTZ injection. The PTZ produced oxidative stress so that malondialdehyde and hydrogen peroxide levels were increased and catalase and peroxidase activity decreased. Pretreatment with DAEO and α-pinene significantly inhibited the above-mentioned enzymatic changes in PTZ-treated animals. CONCLUSION: The results suggest that α-pinene, at teast in part, was responsible for the induction of the anticonvulsant and antioxidant effects of DAEO in rats.
Asunto(s)
Anticonvulsivantes/farmacología , Apiaceae/química , Monoterpenos Bicíclicos/farmacología , Aceites Volátiles/farmacología , Convulsiones/tratamiento farmacológico , Animales , Anticonvulsivantes/química , Antioxidantes/análisis , Antioxidantes/metabolismo , Monoterpenos Bicíclicos/química , Catalasa/análisis , Cromatografía Líquida de Alta Presión , Peróxido de Hidrógeno/análisis , Peroxidación de Lípido/efectos de los fármacos , Masculino , Malondialdehído/análisis , Aceites Volátiles/química , Estrés Oxidativo/efectos de los fármacos , Pentilenotetrazol , Peroxidasa/análisis , Ratas Wistar , Reproducibilidad de los Resultados , Convulsiones/metabolismo , Lóbulo Temporal/efectos de los fármacos , Lóbulo Temporal/metabolismo , Factores de Tiempo , Resultado del TratamientoRESUMEN
ABSTRACT Ducrosia anethifolia has been recommended as a remedy for neurological disorders. However, the anticonvulsant effects of D. anethifolia essential oil (DAEO) and its major constituent α-pinene have not yet been clarified. Methods: A rat model of pentylenetetrazole (PTZ)-induced convulsions was used. Oxidant and antioxidant parameters were assayed in the temporal lobe. Results: The data showed that DAEO (50, 100 and 200 mg/kg, i.p.) and α-pinene (0.2 and 0.4 mg/kg i.p.) delayed the initiation time, and reduced the duration of myoclonic and tonic-clonic seizures following PTZ injection. The PTZ produced oxidative stress so that malondialdehyde and hydrogen peroxide levels were increased and catalase and peroxidase activity decreased. Pretreatment with DAEO and α-pinene significantly inhibited the above-mentioned enzymatic changes in PTZ-treated animals. Conclusion: The results suggest that α-pinene, at teast in part, was responsible for the induction of the anticonvulsant and antioxidant effects of DAEO in rats.
RESUMO A Ducrosia anethifolia tem sido recomendada como remédio para os distúrbios neurológicos. No entanto, os efeitos anticonvulsivantes do óleo essencial de Ducrosia anethifolia (DAEO) e do seu principal constituinte atfa-pineno (α-pineno) ainda não foram clarificados. Métodos: Foi utilizado um modelo de rato de convulsões induzidas por pentilenotetrazol (PTZ). Os parâmetros oxidante e antioxidante foram ensaiados no lobo temporal do cérebro. Resultados: Os dados mostraram que DAEO (50, 100 e 200 mg / kg, i.p.) e α-pineno (0,2 e 0,4 mg / kg i.p.) retardaram o tempo de iniciação e reduziram a duração das crises mioclônicas e tônico-clônicas após a injeção de PTZ. O PTZ produziu estresse oxidativo, de modo que os níveis de malondialdeído (MDA) e de peróxido de hidrogênio aumentaram e a atividade da catalase e da peroxidase diminuiu. O pré-tratamento com DAEO e α-pineno inibiu significativamente as alterações enzimáticas mencionadas em animais tratados com PTZ. Conclusão: O resultado sugere que α-pineno, peto menos em parte, é responsável peta indução dos efeitos anticonvulsivantes e antioxidantes da DAEO em ratos.
Asunto(s)
Animales , Masculino , Convulsiones/tratamiento farmacológico , Aceites Volátiles/farmacología , Apiaceae/química , Monoterpenos Bicíclicos/farmacología , Anticonvulsivantes/farmacología , Pentilenotetrazol , Convulsiones/metabolismo , Factores de Tiempo , Aceites Volátiles/química , Peroxidación de Lípido/efectos de los fármacos , Catalasa/análisis , Reproducibilidad de los Resultados , Cromatografía Líquida de Alta Presión , Resultado del Tratamiento , Ratas Wistar , Peroxidasa/análisis , Estrés Oxidativo/efectos de los fármacos , Monoterpenos Bicíclicos/química , Peróxido de Hidrógeno/análisis , Malondialdehído/análisis , Anticonvulsivantes/química , Antioxidantes/análisis , Antioxidantes/metabolismoRESUMEN
OBJECTIVE: The neuropeptide orexin-A and its receptors are widely distributed in both hippocampal circuitry and pain transmission pathways. Involvement of the CA1 orexin 1 receptor (OX1R) on the modulation of orofacial pain and pain-induced changes in hippocampal expression of cyclooxygenase-2 (COX-2) and brain-derived neurotrophic factor (BDNF) was investigated. METHODS: Orofacial pain was induced by an intra-lip injection of capsaicin (100 µg). Reverse transcription polymerase chain reaction and immunoblot analysis were used to indicate changes in hippocampal BDNF and COX-2 expression, respectively. RESULTS: Capsaicin induces a significant pain response, which is not affected by either orexin-A or SB-334867-A, an OX1R antagonist. However, an increased expression of COX-2 and decreased expression of BDNF was observed in the hippocampus of animals that received capsaicin or SB-334867-A (80 nM) plus capsaicin. Meanwhile, orexin-A (40 pM) attenuated the effects of capsaicin on the expression of COX-2 and BDNF. CONCLUSIONS: CA1 OX1R activation moderates capsaicin-induced neuronal inflammation and neurotrophic deficiency.
Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/metabolismo , Ciclooxigenasa 2/metabolismo , Dolor Facial/metabolismo , Hipocampo/metabolismo , Receptores de Orexina/metabolismo , Orexinas/farmacología , Animales , Benzoxazoles/farmacología , Capsaicina , Modelos Animales de Enfermedad , Hipocampo/efectos de los fármacos , Masculino , Naftiridinas , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Ratas , Ratas Wistar , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Urea/análogos & derivados , Urea/farmacologíaRESUMEN
ABSTRACT The neuropeptide orexin-A and its receptors are widely distributed in both hippocampal circuitry and pain transmission pathways. Objective: Involvement of the CA1 orexin 1 receptor (OX1R) on the modulation of orofacial pain and pain-induced changes in hippocampal expression of cyclooxygenase-2 (COX-2) and brain-derived neurotrophic factor (BDNF) was investigated. Methods: Orofacial pain was induced by an intra-lip injection of capsaicin (100 μg). Reverse transcription polymerase chain reaction and immunoblot analysis were used to indicate changes in hippocampal BDNF and COX-2 expression, respectively. Results: Capsaicin induces a significant pain response, which is not affected by either orexin-A or SB-334867-A, an OX1R antagonist. However, an increased expression of COX-2 and decreased expression of BDNF was observed in the hippocampus of animals that received capsaicin or SB-334867-A (80 nM) plus capsaicin. Meanwhile, orexin-A (40 pM) attenuated the effects of capsaicin on the expression of COX-2 and BDNF. Conclusions: CA1 OX1R activation moderates capsaicin-induced neuronal inflammation and neurotrophic deficiency.
RESUMO O neuropeptídeo orexina-A e seus receptores estão amplamente distribuídos nos circuitos do hipocampo e nas vias de transmissão da dor. Objetivo: O envolvimento do receptor de orexina 1 CA1 (OX1R) na modulação da dor orofacial e alterações induzidas pela dor na expressão do hipocampo de ciclooxigenase-2 (COX-2) e fator neurotrófico derivado do cérebro (BDNF) foi investigado. Métodos: A dor orofacial foi induzida por injeção intra-labial de capsaicina (100 μg). A reação em cadeia da polimerase de transcrição reversa e a análise de imunotransferência foram utilizadas para indicar alterações na expressão de BDNF e COX-2 no hipocampo, respectivamente. Resultados: A capsaicina induz uma resposta significativa à dor, que não é afetada pela orexina-A ou pelo SB-334867-A, um antagonista do OX1R. No entanto, uma expressão aumentada de COX-2 e uma expressão diminuída de BDNF foi observada no hipocampo de animais que receberam capsaicina ou SB-334867-A (80 nM) mais capsaicina. Enquanto isso, a orexina A (40 pM) atenuou os efeitos da capsaicina na expressão de COX-2 e BDNF. Conclusões: A ativação de CA1 OX1R modera a inflamação neuronal induzida por capsaicina e a deficiência neurotrófica.