Ty after CFA-induced inflammation [7,18,19]. The actual knowledge about TRPA1 channels points to a potential clinical use of TRPA1 antagonists for the control of pain states, however, the number of known selective TRPA1 inhibitors is surprisingly low [13,17]. S-(+)-Dicentrine is an aporphinic alkaloid found in several plant species, mainly from Lauraceae family. Among its biological properties, it has been reported a vasodilator and antihypertensive action [20,21,22], platelet aggregation inhibition [23,24] and even a cytostatic effect against some tumor cell lines from mice and humans [25,26,27,28]. Recently, our research group reported that S-(+)-dicentrine has an important antinociceptive effect in a model of visceral pain in mice [29], which lead us to further investigate 24195657 its effect on inflammatory models of pain, as well as possible mechanisms of action. In this context, here we investigate the antinociceptive effect of S-(+)-dicentrine in the CFA-induced inflammatory pain and show a possible involvement of TRPA1 in its mechanism of action.paw, and held in this position for 5 s with enough force to cause a slight bend in the filament. Positive responses included an abrupt withdrawal of the hindpaw or flinching behaviour immediately following removal of the stimulus. A median paw withdrawal threshold was determined using an adaptation of the Dixon’s up?down method [33].b) Measurement of thermal (heat/cold) hypersensitivity. Thermal hypersensitivity to heat was evalu-ated as previously described by Eddy and Leimbach [34] and adapted by Luszczki and Czuczwar [35]. Animals were Title Loaded From File placed in a hot plate set at 5061uC (Cold-hot Plate, AVS Projetos, Campinas, SP, Brazil) and the nociception was recorded as the latency time to withdrawal, shaking or Title Loaded From File licking the injected paw. A cut-off time of 20 s was used to avoid tissue damage. Cold hypersensitivity was evaluated as described by Flatters and Bennett [36] with minor modifications. Mice were placed in a wire mesh floor and a drop of acetone (20 mL) was gently sprayed in the ventral surface of the right hindpaw. Behavioral response was analyzed during 30 s and recorded in scores: 0?no response; 1?quick withdrawal, flick or stamp the paw; 2?prolonged withdrawal or repeated paw flicking; 3?repeated paw flicking with licking directed at the ventral side of the paw. Acetone application was repeated three times for each hindpaw, with intervals of five minutes, and the sum of the scores was used for data analysis.Methods AnimalsExperiments were conducted using adult male Swiss mice (25?35 g) obtained from the animal facility of Universidade Federal de Santa Catarina (UFSC, Florianopolis, SC, Brazil) and housed in ?collective cages at 2261uC under a 12-h light/dark cycle (lights on at 06:00 h), with free access to food and water. Animals were habituated to the laboratory conditions for at least 1 h before testing and all experiments were performed during the light phase of the cycle. All animal care and experimental procedures were carried out in accordance with the National Institutes of Health Animal Care Guidelines (NIH publications No. 80-23), and conducted following the protocol approved by the Committee for the Ethical Use of Animals of the Universidade Federal de Santa Catarina (CEUA/UFSC, protocol number PP00462, approved in December 9th, 2010). All efforts were made to demonstrate consistent effects of the drug treatments and minimize the number of animals used and their suffering [30].Capsa.Ty after CFA-induced inflammation [7,18,19]. The actual knowledge about TRPA1 channels points to a potential clinical use of TRPA1 antagonists for the control of pain states, however, the number of known selective TRPA1 inhibitors is surprisingly low [13,17]. S-(+)-Dicentrine is an aporphinic alkaloid found in several plant species, mainly from Lauraceae family. Among its biological properties, it has been reported a vasodilator and antihypertensive action [20,21,22], platelet aggregation inhibition [23,24] and even a cytostatic effect against some tumor cell lines from mice and humans [25,26,27,28]. Recently, our research group reported that S-(+)-dicentrine has an important antinociceptive effect in a model of visceral pain in mice [29], which lead us to further investigate 24195657 its effect on inflammatory models of pain, as well as possible mechanisms of action. In this context, here we investigate the antinociceptive effect of S-(+)-dicentrine in the CFA-induced inflammatory pain and show a possible involvement of TRPA1 in its mechanism of action.paw, and held in this position for 5 s with enough force to cause a slight bend in the filament. Positive responses included an abrupt withdrawal of the hindpaw or flinching behaviour immediately following removal of the stimulus. A median paw withdrawal threshold was determined using an adaptation of the Dixon’s up?down method [33].b) Measurement of thermal (heat/cold) hypersensitivity. Thermal hypersensitivity to heat was evalu-ated as previously described by Eddy and Leimbach [34] and adapted by Luszczki and Czuczwar [35]. Animals were placed in a hot plate set at 5061uC (Cold-hot Plate, AVS Projetos, Campinas, SP, Brazil) and the nociception was recorded as the latency time to withdrawal, shaking or licking the injected paw. A cut-off time of 20 s was used to avoid tissue damage. Cold hypersensitivity was evaluated as described by Flatters and Bennett [36] with minor modifications. Mice were placed in a wire mesh floor and a drop of acetone (20 mL) was gently sprayed in the ventral surface of the right hindpaw. Behavioral response was analyzed during 30 s and recorded in scores: 0?no response; 1?quick withdrawal, flick or stamp the paw; 2?prolonged withdrawal or repeated paw flicking; 3?repeated paw flicking with licking directed at the ventral side of the paw. Acetone application was repeated three times for each hindpaw, with intervals of five minutes, and the sum of the scores was used for data analysis.Methods AnimalsExperiments were conducted using adult male Swiss mice (25?35 g) obtained from the animal facility of Universidade Federal de Santa Catarina (UFSC, Florianopolis, SC, Brazil) and housed in ?collective cages at 2261uC under a 12-h light/dark cycle (lights on at 06:00 h), with free access to food and water. Animals were habituated to the laboratory conditions for at least 1 h before testing and all experiments were performed during the light phase of the cycle. All animal care and experimental procedures were carried out in accordance with the National Institutes of Health Animal Care Guidelines (NIH publications No. 80-23), and conducted following the protocol approved by the Committee for the Ethical Use of Animals of the Universidade Federal de Santa Catarina (CEUA/UFSC, protocol number PP00462, approved in December 9th, 2010). All efforts were made to demonstrate consistent effects of the drug treatments and minimize the number of animals used and their suffering [30].Capsa.
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