Gastroprotective Effects ofPiper carpunyaAgainst Diclofenac-Induced Gastric Lesions in Rats

Piper carpunya Ruiz & Pav. (Piper lenticellosum C. DC.), a member of the Piperaceae family, is a remedy with anti-inflammatory and antiulcer properties that is used in folk medicine in Ecuador. The present work determined the gastroprotective effects of this plant in a model of diclofenac-induced ulcers in rats and studied the mechanism involved. The aqueous suspension of the ethanol extract of the leaves of P carpunya was administered twice orally to three groups of Wistar rats at doses of 62.5, 125, and 250 mg/kg, with a 24-h interval between doses. Diclofenac (100 mg/kg) was given I h after the last administration of the extract. Pretreatment with P carpunya decreased the ulcerated area, prevented neutrophil infiltration induced by NSAID administration in vivo, and inhibited the release of the proteolytic enzyme myeloperoxidase by neutrophils stimulated with the calcium ionophore A23187. Superoxide dismutase activity demonstrated a marked increase at the two lowest doses of the extract versus diclofenac group and glutathione peroxidase activity was reverted near to sham levels. On the other hand, P carpunya treatment did not prevent the increased levels of lipoperoxides in gastric mucosa caused by diclofenac. Furthermore, P carpunya did not affect PGE(2) levels, which were depicted by diclofenac treatment. These results suggest that the gastroprotective effect of P carpunya in this experimental model appears through anti-inflammatory and antiradical mechanisms.