Anti-inflammatory effect of lemon mucilage: In vivo and in vitro studies.

The mucilage extracted from a lemon juice centrifugation pulp was studied for its anti¬inflammatory effect in rat. In vivo the lemon mucilage significantly inhibited carrageenan-induced edema in rat paw from 59% to 73.5% showing the highest effect at the third hour. In vitro, at the doses of 10−8, 10−6, 10−4 or 10−2 mg/mL the lemon mucilage stimulated the superoxide anion production in rat testing neutrophils in whole blood but inhibited it in FMLP stimulated cells at the dose of 10−2 mg/mL. The neutrophils of rats receiving p.o. the lemon mucilage for 21 days showed a significant decrease of 45.5% in O2 − generation after FMLP stimulation, and a not-significant increase after phorbol-12-myristate-13-acetate (PMA) or zymosan stimulation. Since the activity on zymosan- and PMA-induced O2 − production was not significant, the inhibition exerted by FMLP in rat neutrophils occurred mainly through the blockade of phospholipase D.