Induction of nociceptive stimulus in TMJ region: minimum effective concentration of piperine in normality, local chronic inflammation and chronic stress conditions

Author(s)

Ana Paula Varela Brown Martins

• Document type: Doctoral Thesis
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2013-07-08

Examining board members

Celia Marisa Rizzatti Barbosa; Cinara Maria Camparis Bussadori; Luciano Castellucci Barbosa; Eduardo Dias de Andrade; Antônio Pedro Ricomini Filho

• Advisor: Celia Marisa Rizzatti Barbosa

Abstract

Temporomandibular Dysfunction may affect the masticatory muscles, temporomandibular joint (TMJ) or both, has high prevalence in women and most common symptoms is pain. It was proposed to determine minimal effective concentration of piperine to activate the transient receptor potential vanilloid subfamily 1 (TRPV1) in the right TMJ in Wistar female rats under the conditions: normal, chronic inflammation in the TMJ, chronic stress and inflammation and stress combination. It was developed two randomized double-blind experimental studies (n. 2633-1). In study I, 48 animals were randomly divides into six groups, each group received 30 ?l into the TMJ one of this solutions: standard solution (80% sterile saline, 10% Tween 80 and 10% ethyl alcohol) or 1, 2, 3, 4 and 5 ?g of piperine diluted in 100 ml of standard solution. In study II, 144 rats were randomly divided into groups: A - chronic inflammation in the right TMJ induced by Freund's Complete Adjuvant; B - chronic stress caused by chronic stress model; C - association of these conditions. These groups were divided (n = 8), and it was injected into the TMJ 30 ?l of the same solutions as previously describe. In both studies, rats in diestrous phase of the hormonal cycle, after injection of the solution, were assessed for nociceptive behavior, which consisted in quantify how many times the rats flinched its head and the time spent, in seconds (s), to rub the orofacial region. Each head flinch followed uniform pattern of 1 second duration, and the behaviors were expressed as time function, allowing the sum. For statistical comparison, it was used variance analysis and Tukey-Kramer (P<0.05). In study I, there was a significant difference for rubbing orofacial region between groups of 2 ?g and 5 ?g (100,37 ± 63,81 s, 100 ± 60,5 s, respectively) and control (33,37 ± 18,48 s), and the sum of the behaviors between 2?g (130,87 ± 257,88 s) and control (62,75 ± 14,81 s). In study II, in group A, there were statistical differences for head flinch behavior between 5?g (69,5 ± 16,44 s) and control (41,13 ± 15,06 s) groups; for rubbing orofacial region between 4?g (51,5 ± 28,73 s) and control (14,71 ± 7,54 s), and for the sum, among 4 and 5?g (105,37 ± 22,64 s, 115,50 ± 35,14 s, respectively) and controls (52,86 ± 17,46 s). In group B, for head flinching behavior there was significant difference between 4 ?g (85,87 ± 19,21 s) and control (49,87 ± 10,7 s); rubbing orofacial region, between 5 ?g (48,25 ± 27,25 s) and control (3,.75 ± 12,69 s). In group C, there was no significant difference in the subgroups. Thus, 0,02 ?g/ml of piperine showed the lowest concentration effective to cause noxious stimulation in normal condition, the solution of 0,04 ?g/ml of piperine, for groups of chronic joint inflammation and chronic stress and for association conditions group there was not statistical significant difference (AU)

• FAPESP's process: 12/07964-2 - Nociceptive behavior of Female Rats using Piperine in the region of Temporomandibular Joint in the presence of local chronic inflammation and stress
• Grantee: Ana Paula Varela Brown Martins
• Support Opportunities: Scholarships in Brazil - Doctorate