RESUMEN
This study was aimed to evaluate the anti-inflammatory potential of triterpene alpha, beta-amyrin in rats on acute phase periodontitis. Periodontitis was induced by ligature placement around the maxillary right second molar tooth. Rats (n = 8/group) were pretreated with alpha, beta-amyrin (5 and 10 mg/kg, p. o.), two hours before the induction of periodontal inflammation. Sham-operated and positive controls (lumiracoxib and dexamethasone) were included. Six hours later, plasma levels of TNF-alpha were analysed. Rats were sacrificed at 24 h, and the gingival tissue analysed for myeloperoxidase (MPO) and thiobarbituric acid-reactive substances (TBARS), as measures of neutrophil influx and lipid-peroxidation, respectively alpha, beta-Amyrin as well as dexamethasone significantly inhibited the periodontitis-associated increases of TNF-alpha, and the gingival MPO and TBARS. alpha, beta-Amyrin effect was more prominent at 5 mg/kg. Lumiracoxib manifested varied influence on the studied parameters. These results provide evidence to show that alpha, beta-Amyrin retards acute inflammation in rat model of periodontitis and warrant further study on its efficacy to prevent chronic periodontitis-associated bone loss.
Asunto(s)
Antiinflamatorios/farmacología , Burseraceae/química , Ácido Oleanólico/análogos & derivados , Periodontitis/prevención & control , Enfermedad Aguda , Administración Oral , Animales , Antiinflamatorios/administración & dosificación , Antiinflamatorios/química , Dexametasona/administración & dosificación , Dexametasona/farmacología , Diclofenaco/administración & dosificación , Diclofenaco/análogos & derivados , Diclofenaco/farmacología , Modelos Animales de Enfermedad , Encía/efectos de los fármacos , Encía/metabolismo , Encía/patología , Gingivitis/metabolismo , Gingivitis/patología , Gingivitis/prevención & control , Isomerismo , Masculino , Estructura Molecular , Infiltración Neutrófila/efectos de los fármacos , Ácido Oleanólico/administración & dosificación , Ácido Oleanólico/química , Ácido Oleanólico/farmacología , Estrés Oxidativo/efectos de los fármacos , Triterpenos Pentacíclicos/administración & dosificación , Triterpenos Pentacíclicos/química , Triterpenos Pentacíclicos/farmacología , Periodontitis/metabolismo , Periodontitis/patología , Peroxidasa/metabolismo , Ratas , Ratas Wistar , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
The effects of alpha,beta-amyrin, a pentacyclic triterpene isolated from Protium heptaphylum was investigated on rat model of orofacial pain induced by formalin or capsaicin. Rats were pretreated with alpha,beta-amyrin (10, 30, and 100mg/kg, i.p.), morphine (5mg/kg, s.c.) or vehicle (3% Tween 80), before formalin (20 microl, 1.5%) or capsaicin (20 microl, 1.5 microg) injection into the right vibrissa. In vehicle-treated controls, formalin induced a biphasic nociceptive face-rubbing behavioral response with an early first phase (0-5 min) and a late second phase (10-20 min) appearance, whereas capsaicin produced an immediate face-rubbing (grooming) behavior that was maximal at 10-20 min. Treatment with alpha,beta-amyrin or morphine significantly inhibited the face-rubbing response in both test models. While morphine produced significant antinociception in both phases of formalin test, alpha,beta-amyrin inhibited only the second phase response, more prominently at 30 mg/kg, in a naloxone-sensitive manner. In contrast, alpha,beta-amyrin produced much greater antinociceptive effect at 100mg/kg in the capsaicin test, which was also naloxone-sensitive. These results provide first time evidence to show that alpha,beta-amyrin attenuates orofacial pain at least, in part, through a peripheral opioid mechanism but warrants further detailed study for its utility in painful orofacial pathologies.