Anti-inflammatory effect of Pycnocycla spinosa extract and its component isoacetovanillone on acetic acid induced colitis in rats.

Colitis is an inflammatory disease of the intestine with unknown etiology involving multiple immune, genetic and environmental factors. We were interested to examine the effect of total extract from Pycnocycla spinosa Boiss. on the treatment of experimental colitis. Mediators involved in colonic inflammation are prostaglandins, interleukins, leukotriene as well as an increase in myeloperoxidase (MPO) activity. Therefore, MPO activity was also determined in this research. P. spinosa hydroalcoholic extract (5, 10 and 20 mg/kg) or isoacetovanillone (2, 5 and 10 mg/kg) were administered orally, started 2 h before induction of colitis by intrarectal administration of acetic acid (3%) in rats. Prednisolone (4 m/kg) was used as the standard drug for comparison. Biochemical evaluation of inflamed colon was done using assay of MPO activity. After 5 days treatments, mucosal ulceration was evaluated. Intrarectal instillation of acetic acid caused significant inflammatory reactions as indicated by macroscopic and microscopic changes. The activity of MPO increased in vehicle treated groups while recovered to normal level by pretreatment of animals with P. spinosa extract, isoacetovanillone and prednisolone. P. spinosa and isoacetovanillone-treated groups showed significantly lower score values of macroscopic and microscopic characters when compared with the vehicle treated negative control group. The beneficial effect of P. spinosa was comparable with that of prednisolone. This research has shown the anti-inflammatory potential of P. spinosa extract and isoacetovanillone in experimentally induced colitis.