Eugenia brasiliensis leaves extract attenuates visceral and somatic inflammatory pain in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Eugenia brasiliensis Lam. (Myrtaceae) is a Brazilian tree distributed throughout Atlantic rain forest, since Bahia until Santa Catarina state, and is popularly known as "grumixaba, grumixameira, cumbixaba, ibaporoiti, and cereja-brasileira". The bark and leaves of Eugenia brasiliensis are used in folk medicine as adstringent, diuretic, energizing, anti-rheumatic and anti-inflammatory. This study aimed at investigating the chemical composition, antinociceptive and anti-inflammatory effect of the hydroalcoholic extract of Eugenia brasiliensis (HEEb). MATERIAL AND METHODS: Chemical composition of the HEEb was determined by High Performance Liquid Chromatography/ESI-Mass Spectrometry (HPLC-ESI-MS/MS). The antinociceptive and anti-inflammatory effects of HEEb (30-300 mg/kg) was verified in mice after oral administration by intra-gastric gavage (i.g.) 60 min prior to experimentation. It was investigated whether HEEb decreases visceral pain and leukocyte migration induced by an intraperitoneal (i.p.) injection of acetic acid (0.6%). We also evaluated whether HEEb decreases nociceptive behavior induced by formalin (including paw edema and temperature), prostaglandin E2 (PGE2), histamine, and compound 48/80. Finally, we evaluated the effect of HEEb in the chronic inflammatory (mechanical and thermal hypersensitivity) pain induced by complete Freund's adjuvant (CFA), as well as quantifying the concentration of the pro-inflammatory cytokines TNF-α and IL-6 in the paw by ELISA method. RESULTS: Seven polyphenols were identified in HEEb by HPLC-ESI-MS/MS analysis. HEEb treatment alleviated nocifensive behavior and leukocyte migration caused by acetic acid. Moreover, HEEb also reduced the inflammatory pain and paw temperature induced by formalin, as well as it decreased nociceptive behavior induced by histamine and compound 48/80. Finally, acute and repeated treatment of animals with HEEb (100 mg/kg, i.g.) markedly reduced the mechanical and thermal (heat) hypersensitivity, besides decrease paw edema and temperature induced by CFA, and this effect was evident until the day 7. Moreover, repeated treatment with HEEb (100 mg/kg, i.g.) significantly reduced the levels of IL-6 and TNF-α in the paw when compared to the CFA group. CONCLUSIONS: This is the first report showing that HEEb presents antinociceptive and anti-inflammatory effects in the visceral and somatic inflammatory pain in mice, possibly involving the inhibition of histamine receptors and pro-inflammatory cytokines activated pathways. Our results are of interest because they support the use of Eugenia brasiliensis as a potential source of phytomedicine for inflammatory diseases and pain.

Determination of phenolic profile by HPLC-ESI-MS/MS and anti-inflammatory activity of crude hydroalcoholic extract and ethyl acetate fraction from leaves of Eugenia brasiliensis

ABSTRACT Eugenia brasiliensis Lam., Myrtaceae, is used in folk medicine for anti-inflammatory diseases such as arthritis and rheumatism. This study investigated the anti-inflammatory activity and phenolic profile of the crude hydroalcoholic extract and ethyl acetate fraction from E. brasiliensis leaves. Crude hydroalcoholic extract and the ethyl acetate fraction were analyzed by HPLC-ESI-MS/MS in comparison to standard phenolic compounds. The anti-inflammatory activity of the crude hydroalcoholic extract (1, 10 and 25 mg kg-1) and the ethyl acetate fraction (10, 25 and 50 mg kg-1) was evaluated in a swiss mouse model of acute pleurisy induced by carrageenan, being the total cell count, exudation and analysis of nitrite/nitrate the inflammation parameters. HPLC-ESI-MS/MS analysis revealed apigenin, catechin, galangin, isoquercetin, myricetin, quercetin and rutin. Crude hydroalcoholic extract and ethyl acetate fraction were effective in inhibiting cell migration in all tested doses. Crude hydroalcoholic extract was effective in inhibiting exudation only at the 10 mg kg-1 dose; ethyl acetate fraction was effective in all tested doses. Results for nitrite/nitrate levels reveals that only the ethyl acetate fraction was effective at the tested doses. This is the first report of the presence of isoquercetin, galangin and apigenin in this species. Results from the phytochemical analysis enhance the chemical knowledge of this species. In the future, together with more studies, validation of its popular use in inflammatory diseases is possible.