Topical anti-inflammatory activity of Eugenia brasiliensis Lam. (Myrtaceae) leaves

Eugenia brasiliensis Lam., a plant from the south of Brazil, is used in the popular medicine for rheumatism treatment. This study reports that topical application of hydroalcoholic extract, fractions and isolated compounds from E. brasiliensis caused an inhibition of ear oedema in response to topical application of croton oil on the mouse ear. For oedema inhibition, the estimated ID50 values (dose reducing the inflammatory response by 50% relative to the control value) for hydroalcoholic extract and fractions (hexane, ethyl acetate and dichloromethane) were 0.17, 0.29, 0.13 and 0.14 mg/ear, respectively, with inhibition of 79+/-7%, 87+/-6%, 88+/-5% and 96+/-2%, respectively. Isolated phenolic compounds (quercetin, catechin and gallocatechin) were also effective in inhibiting the oedema (inhibition of 61+/-5%, 66+/-2% and 37+/-9%, respectively). Moreover, both extract and isolated compounds caused inhibition of polymorphonuclear cells influx (inhibition of 85+/-6%, 81+/-5%, 73+/-6% and 76+/-6%, respectively). The histological analysis of the ear tissue clearly confirmed that the extract and compounds of E. brasiliensis inhibited the influx of polymorphonuclear cells to mouse ear skin after application of croton oil. Furthermore, hydroalcoholic extract was also effective in inhibiting the arachidonic acid-mediated mouse ear oedema (ID50 value was 1.94 mg/ear and inhibition of 60+/-7%). Therefore, these results consistently support the notion that E. brasiliensis possesses topical anti-inflammatory activity.