Anti-inflammatory and immunomodulatory properties of Pistacia lentiscus extracts

Abstract

This study aimed to evaluate the anti-inflammatory activity of alcoholic and aqueous extracts of Pistacia lentiscus leaves. Croton oil-induced ear edema in mice, acetic acid-induced vascular permeability in mice and carrageenan induced-pleurisy in rats were conducted as acute inflammation models. Chemotaxis and elastase activity of human neutrophils were assayed in vitro. Results showed that local treatment with 2 mg/ear of alcoholic extract decreased significantly the ear edema (65%), while the aqueous extract exerted a lower inhibitory effect (51%). Moreover, the oral treatment with 200 mg/kg of alcoholic extract inhibited the vascular permeability by 46%, whereas the aqueous extract caused only 28% of inhibition. Furthermore, both extracts reduced significant the carrageenan induced-pleurisy. Indeed, at 400 mg/kg, the extracts inhibited the neutrophil migration by 29% and 38%, respectively, and reduced the number of the PMNS migrated into the pleural exudates by 49% and 43%, respectively. At 100 μg/mL, the methanolic and aqueous extracts inhibited neutrophil chemataxis by 81% and 71%, respectively, and reduced significantly the elastase activity with maximum values of 82% and 90%, respectively. These findings provide valuable evidence for the potential anti-inflammatory of Pistacia lentiscus leaves, suggesting that this plant can be exploited as a natural source of anti-inflammatory agents.