alpha,beta-amyrin, a natural triterpenoid ameliorates L-arginine-induced acute pancreatitis in rats.

AIM: To study the beneficial effects of triterpene alpha,beta-amyrin and the underlying mechanisms in an experimental pancreatitis model. METHODS: Acute pancreatitis was induced in five groups of rats (n = 8) by L-arginine (2 x 2.5 g/kg, intraperitoneal, 1 h apart) and 1 h later, they received a single oral dose of alpha,beta-amyrin (10, 30 and 100 mg/kg), methylprednisolone (30 mg/kg) and vehicle (3% Tween 80). A saline (0.9% NaCl) treated group served as a normal control. Efficacy was assessed at 24 h by determination of serum levels of amylase, lipase and pro-inflammatory cytokines [tumor necrosis factor (TNF)-alpha and interleukin (IL)-6], pancreatic myeloperoxidase (MPO) activity, lipid peroxidation [thiobarbituric acid reactive substances (TBARS)], nitrate/nitrite levels, and the wet weight/body weight ratio. Tissue histology and the immunoreactivity for TNF-alpha and inducible nitric oxide synthetase (iNOS) were performed. RESULTS: alpha,beta-amyrin and methylprednisolone treatments significantly (P < 0.05) attenuated the L-arginine-induced increases in pancreatic wet weight/body weight ratio, and decreased the serum levels of amylase and lipase, and TNF-alpha and IL-6, as compared to the vehicle control. Also, pancreatic levels of MPO activity, TBARS, and nitrate/nitrite were significantly lower. Histological findings and TNF-alpha and iNOS immunostaining further confirmed the amelioration of pancreatic injury by alpha,beta-amyrin. CONCLUSION: alpha,beta-amyrin has the potential to combat acute pancreatitis by acting as an anti-inflammatory and antioxidant agent.

Estudo do efeito farmacológico da a,ß-amirina, uma mistura de triterpenos isolada de protium heptaphyllum, na pancreatite aguda experimental / Study of the pharmacological effect of a, ß-amyrin, a mixture of triterpene isolated heptaphyllum protium in the experimental acute pancreatitis

Os triterpenos pentacíclicos são compostos naturais com atividade antiinflamatória e citoprotetora e são relativamente atóxicos. A pancreatite aguda, uma inflamação aguda do pâncreas, pode levar a síndrome da resposta inflamatória sistêmica (SRIS) e a síndrome da disfunção múltipla de órgãos (MODS), condições que podem levar o paciente ao óbito. Neste trabalho, a mistura de triterpenos pentacíclicos α,ß-amirina, isolada do Protium hepthaphyllum, foi investigada quanto aos seus efeitos nos modelos de pancreatite aguda induzida por L-arginina em ratos e por ceruleína em camundongos. No modelo de pancreatite aguda induzida por L-arginina, ratos Wistar machos foram tratados com a mistura de α,ß-amirina (10, 30 e 100 mg/kg, v.o.) ou com o veículo (2% de Tween 80 em água destilada, 10 ml/kg) 48, 24, 1,5h antes da administração de L-arginina (2 x 2,5 g/kg; i h de intervalo) ou com metilprednisolona (30 mg/kg, i.m.) 30 min antes da administração de L-arginina. Na pancreatite induzida por ceruleína, camundongos Swiss machos foram tratados com a mistura α,ß-amirina (10, 30 e 100 mg/kg, v.o.) ou com o veículo (2% de Tween 80 em água destilada, 10 ml/kg) 48, 24 e 1,5h antes da administração de ceruleína (5 x 50 μg/kg/ 1 h de intervalo) ou com talidomida (200 mg/kg, v.o.) 1h antes da administração de ceruleína...