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Investigation of the effects of chlorogenic acid, ferulic acid, gallic acid and quercetin on pain sensitivity threshold in rats
S222
P.1.g. Basic and clinical neuroscience − Neuropharmacology
published that Ctr9 is a new direct partner and regulator of DAT [1]. Methods: First, we used yeast-2-hybrid screening to identify a new partner of DAT. Next, different molecular, cellular, biochemical, neuronatomical and in vivo approaches (including virusmediated modulation of gene expression) were used to characterize the interaction of DAT with its new partner. Results: We have identified snapin, a SNARE-associated protein implicated in synaptic transmission, as a new binding partner of the carboxylic terminal of DAT, and determined the domains required for this interaction in both proteins. We also characterized the DAT-snapin interface by the generation of a 3D modelleing. In situ hybridization assays showed that snapin is expressed in vivo in dopaminergic neurons along with DAT. By different approaches we demonstrated that both proteins colocalise in cultured cells and brain, and are present in the same protein complex. With functional studies we have shown that snapin produces an important decrease in DAT activity. Finally, using a shRNA lentivirus directed against snapin, we have demonstrated that the downregulation of snapin produces an increase in DAT levels and activity in vivo, which is accompanied by a higher locomotor behavioural response to amphetamine and higher DA levels. Conclusions: Our data show that snapin is a new direct partner and regulator of DAT, and we provide evidence for the relevance of this regulation in vivo. Thus, snapin represents a direct link between exocytotic and reuptake mechanisms, and can be considered a new potential target for the modulation of DA transmission. References [1] De Gois, S., Slama, P., Pietrancosta, N., Erdozain, A.M., Louis, F., Bouvrais-Veret, C., Daviet, L., and Giros, B. 2015. Ctr9, a Protein in the Transcription Complex Paf1, Regulates Dopamine Transporter Activity at the Plasma Membrane. J. Biol. Chem. 290:17848−62. Disclosure statement: This work was funded by Canadian Institutes of Health Research (to BG), Schizo Oui Association (to AME), and the Basque Government (IT616−13 to JJMM).
P.1.g.013 Investigation of the effects of chlorogenic acid, ferulic acid, gallic acid and quercetin on pain sensitivity threshold in rats S. Valcheva-Kuzmanova1 ° , A. Georgieva1 , I. Belcheva2 , S. Belcheva2 , R. Tashev2 1 Medical University, Preclinical and Clinical Pharmacology, Varna, Bulgaria; 2 Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria Introduction: Chlorogenic acid (CGA), ferulic acid (FA) and gallic acid (GA) are abundant polyphenols in human diet. Quercetin (Q), one of the most widely distributed flavonoids in nature, has been studied for a wide range of activities. There are some data on the effects of CGA, FA and Q in painful conditions. CGA showed an analgesic effect in a model of carrageenin-induced rat paw inflammation [1]. CGA decreased the excitability of neurons in trigeminal hyperalgesic conditions in neuropathic and inflammatory pain [2]. Sodium ferulate reduced the thermal and mechanical hyperalgesia in chronic neuropathic pain injury [3]. Chronic administration of Q could increase the threshold of thermal nociception in diabetic rats [4]. There are no data on the effects of the three phenolic acids and Q on nociception in the absence of tissue injury. Aim: The aim of this study was to investigate and compare the effects of CGA, FA, GA and Q on pain sensitivity threshold to mechanical pressure on uninflamed rat hind paw.
Methods: Male Wistar rats (200–250 g) were divided into 20 groups of 10 animals. Rats were treated orally in the course of 7, 14, 21 and 30 days. For each experimental period, there were 5 groups of animals: Control, CGA, FA, GA and Q. Control groups received saline (10 ml/kg) while the other groups were treated respectively with CGA, FA, GA and Q given at an equal dose of 20 mg/kg as a 10 ml/kg solution. After each treatment period, the paw pressure Randall-Selitto test was carried out using an analgesimeter (Ugo Basile). The analgesimeter applied increasing pressure to the rat paw. The pressure at which the rat pulled back its paw as a result of pain sensation was measured in arbitrary units. Results were analyzed by Student’s t-test. GraphPad Prism statistical software was used. Summary of results: For each treatment period, the pain threshold of the animals belonging to CGA, FA, GA and Q groups was compared to that of the respective control group. The tested substances for all treatment periods showed a tendency to elevate the pain threshold but the increase was not statistically significant. The effects of the four treatments did not significantly differ from one another. The highest pain threshold elevation was induced after 7 days by GA and Q (7% vs. Control), after 14 days − by Q (3% vs. Control), after 21 days − by FA and GA (8% vs. Control), and after 30 days − by CGA and FA (7% vs. Control). As is obvious from these results, the prolongation of treatment from 7 to 30 days did not significantly affect the pain threshold elevation. Conclusion: CGA, FA, GA and Q had no significant effects on pain sensitivity of the uninflamed rat paw. As the elevation in the reaction threshold to pressure of an uninflamed paw can be produced only by centrally acting drugs such as the opioid analgesics [5], the results from the experiment suggested that the investigated phenolic acids and Q showed no central opioid-like analgesic activity. References [1] dos Santos, M.D., Almeida, M.C., Lopes, N.P., de Souza, G.E., 2006. Evaluation of the anti-inflammatory, analgesic and antipyretic activities of the natural polyphenol chlorogenic acid. Biol Pharm Bull 29(11), 2236–2240. [2] Zhang, Y.-J., Lu, X.-W., Song, N., Kou, L., Wu, M.-K., Liu, F., Wang, H., Shen, J.-F., 2014. Chlorogenic acid alters the voltage-gated potassium channel currents of trigeminal ganglion neurons. Int J Oral Sci 6, 233–240. [3] Zhang, A., Gao, Y., Zhong, X., Xu, C., Li, G., Liu, S., Lin, J., Li, X., Zhang, Y., Liu, H., Linag, S., 2010. Effect of sodium ferulate on the hyperalgesia mediated by P2X3 receptor in the neuropathic pain rats. Brain Res 1313, 215–221. [4] Narenjkar, J., Roghani, M., Alambeygi, H., Sedaghati, F., 2011. The effect of the flavonoid quercetin on pain sensation in diabetic rats. Basic Clin Neurosci 2(3), 51−57. [5] Swingle, K.F., 1974. Evaluation of antiinflammatory activity, in: Scherrer R.A., Whitehouse, M.W., Anti-inflammatory Agents Part II: Chemistry and Pharmacology, Academic Press, New York, pp. 34–123.
P.1.g.014 The effects of electroconvulsive seizure on the transcription of PAR family of bZIP genes via changes in Egr1 expression in the rat frontal cortex Y.S. Kim1 ° , T. Youn1 , S.H. Kim1 , H.G. Park2 , I.W. Chung1 1 Dongguk University Ilsan Hospital, Psychiatry, Goyang-Si, South-Korea; 2 Seoul National University Hospital, Biomedical Institute, Seoul, South-Korea Electroconvulsive therapy (ECT) has been used to treat psychiatric disorders such as depression, mania, and schizophrenia.
P.1.g. Basic and clinical neuroscience − Neuropharmacology
published that Ctr9 is a new direct partner and regulator of DAT [1]. Methods: First, we used yeast-2-hybrid screening to identify a new partner of DAT. Next, different molecular, cellular, biochemical, neuronatomical and in vivo approaches (including virusmediated modulation of gene expression) were used to characterize the interaction of DAT with its new partner. Results: We have identified snapin, a SNARE-associated protein implicated in synaptic transmission, as a new binding partner of the carboxylic terminal of DAT, and determined the domains required for this interaction in both proteins. We also characterized the DAT-snapin interface by the generation of a 3D modelleing. In situ hybridization assays showed that snapin is expressed in vivo in dopaminergic neurons along with DAT. By different approaches we demonstrated that both proteins colocalise in cultured cells and brain, and are present in the same protein complex. With functional studies we have shown that snapin produces an important decrease in DAT activity. Finally, using a shRNA lentivirus directed against snapin, we have demonstrated that the downregulation of snapin produces an increase in DAT levels and activity in vivo, which is accompanied by a higher locomotor behavioural response to amphetamine and higher DA levels. Conclusions: Our data show that snapin is a new direct partner and regulator of DAT, and we provide evidence for the relevance of this regulation in vivo. Thus, snapin represents a direct link between exocytotic and reuptake mechanisms, and can be considered a new potential target for the modulation of DA transmission. References [1] De Gois, S., Slama, P., Pietrancosta, N., Erdozain, A.M., Louis, F., Bouvrais-Veret, C., Daviet, L., and Giros, B. 2015. Ctr9, a Protein in the Transcription Complex Paf1, Regulates Dopamine Transporter Activity at the Plasma Membrane. J. Biol. Chem. 290:17848−62. Disclosure statement: This work was funded by Canadian Institutes of Health Research (to BG), Schizo Oui Association (to AME), and the Basque Government (IT616−13 to JJMM).
P.1.g.013 Investigation of the effects of chlorogenic acid, ferulic acid, gallic acid and quercetin on pain sensitivity threshold in rats S. Valcheva-Kuzmanova1 ° , A. Georgieva1 , I. Belcheva2 , S. Belcheva2 , R. Tashev2 1 Medical University, Preclinical and Clinical Pharmacology, Varna, Bulgaria; 2 Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria Introduction: Chlorogenic acid (CGA), ferulic acid (FA) and gallic acid (GA) are abundant polyphenols in human diet. Quercetin (Q), one of the most widely distributed flavonoids in nature, has been studied for a wide range of activities. There are some data on the effects of CGA, FA and Q in painful conditions. CGA showed an analgesic effect in a model of carrageenin-induced rat paw inflammation [1]. CGA decreased the excitability of neurons in trigeminal hyperalgesic conditions in neuropathic and inflammatory pain [2]. Sodium ferulate reduced the thermal and mechanical hyperalgesia in chronic neuropathic pain injury [3]. Chronic administration of Q could increase the threshold of thermal nociception in diabetic rats [4]. There are no data on the effects of the three phenolic acids and Q on nociception in the absence of tissue injury. Aim: The aim of this study was to investigate and compare the effects of CGA, FA, GA and Q on pain sensitivity threshold to mechanical pressure on uninflamed rat hind paw.
Methods: Male Wistar rats (200–250 g) were divided into 20 groups of 10 animals. Rats were treated orally in the course of 7, 14, 21 and 30 days. For each experimental period, there were 5 groups of animals: Control, CGA, FA, GA and Q. Control groups received saline (10 ml/kg) while the other groups were treated respectively with CGA, FA, GA and Q given at an equal dose of 20 mg/kg as a 10 ml/kg solution. After each treatment period, the paw pressure Randall-Selitto test was carried out using an analgesimeter (Ugo Basile). The analgesimeter applied increasing pressure to the rat paw. The pressure at which the rat pulled back its paw as a result of pain sensation was measured in arbitrary units. Results were analyzed by Student’s t-test. GraphPad Prism statistical software was used. Summary of results: For each treatment period, the pain threshold of the animals belonging to CGA, FA, GA and Q groups was compared to that of the respective control group. The tested substances for all treatment periods showed a tendency to elevate the pain threshold but the increase was not statistically significant. The effects of the four treatments did not significantly differ from one another. The highest pain threshold elevation was induced after 7 days by GA and Q (7% vs. Control), after 14 days − by Q (3% vs. Control), after 21 days − by FA and GA (8% vs. Control), and after 30 days − by CGA and FA (7% vs. Control). As is obvious from these results, the prolongation of treatment from 7 to 30 days did not significantly affect the pain threshold elevation. Conclusion: CGA, FA, GA and Q had no significant effects on pain sensitivity of the uninflamed rat paw. As the elevation in the reaction threshold to pressure of an uninflamed paw can be produced only by centrally acting drugs such as the opioid analgesics [5], the results from the experiment suggested that the investigated phenolic acids and Q showed no central opioid-like analgesic activity. References [1] dos Santos, M.D., Almeida, M.C., Lopes, N.P., de Souza, G.E., 2006. Evaluation of the anti-inflammatory, analgesic and antipyretic activities of the natural polyphenol chlorogenic acid. Biol Pharm Bull 29(11), 2236–2240. [2] Zhang, Y.-J., Lu, X.-W., Song, N., Kou, L., Wu, M.-K., Liu, F., Wang, H., Shen, J.-F., 2014. Chlorogenic acid alters the voltage-gated potassium channel currents of trigeminal ganglion neurons. Int J Oral Sci 6, 233–240. [3] Zhang, A., Gao, Y., Zhong, X., Xu, C., Li, G., Liu, S., Lin, J., Li, X., Zhang, Y., Liu, H., Linag, S., 2010. Effect of sodium ferulate on the hyperalgesia mediated by P2X3 receptor in the neuropathic pain rats. Brain Res 1313, 215–221. [4] Narenjkar, J., Roghani, M., Alambeygi, H., Sedaghati, F., 2011. The effect of the flavonoid quercetin on pain sensation in diabetic rats. Basic Clin Neurosci 2(3), 51−57. [5] Swingle, K.F., 1974. Evaluation of antiinflammatory activity, in: Scherrer R.A., Whitehouse, M.W., Anti-inflammatory Agents Part II: Chemistry and Pharmacology, Academic Press, New York, pp. 34–123.
P.1.g.014 The effects of electroconvulsive seizure on the transcription of PAR family of bZIP genes via changes in Egr1 expression in the rat frontal cortex Y.S. Kim1 ° , T. Youn1 , S.H. Kim1 , H.G. Park2 , I.W. Chung1 1 Dongguk University Ilsan Hospital, Psychiatry, Goyang-Si, South-Korea; 2 Seoul National University Hospital, Biomedical Institute, Seoul, South-Korea Electroconvulsive therapy (ECT) has been used to treat psychiatric disorders such as depression, mania, and schizophrenia.