Anti-inflammatory analgesic and anti-oedematous effects of Lafeonsia pacari extract and ellagic acid

Latoensia pacari St. Hil. (Lythraceae) is used in traditional medicine to treat inflammation. Previously, we demonstrated the anti-inflammatory effect that the ethanolic extract of L. pacari has in Toxocara canis infection (a model of systemic eosinophilia). In this study, we tested the anti-inflammatory activity of the same L. pacari extract in mice injected intraperitoneally with ss-glucan present in fraction 1 (F1) of the Histoplasma capsulatum cell wall (a model of acute eosinophilic inflammation). We also determined the anti-oedematous, analgesic and anti-pyretic effects of L. pacari extract in carrageenan-induced paw oedema, acetic acid writhing and LPS-induced fever, respectively. L. pacari extract significantly inhibited leucocyte recruitment into the peritoneal cavity induced by ss-glucan. In addition, the L. pacari extract presented significant analgesic, anti-oedematous and anti-pyretic effects. Bioassay-guided fractionation of the L. pacari extract in the F1 model led us to identify ellagic acid. As did the extract, ellagic acid presented anti-inflammatory, anti-oedematous and analgesic effects. However, ellagic acid had no anti-pyretic effect, suggesting that other compounds present in the plant stem are responsible for this effect. Nevertheless, our results demonstrate potential therapeutic effects of L. pacari extract and ellagic acid, providing new prospects for the development of drugs to treat pain, oedema and inflammation.