The aim of the present study was to investigate the anti-inflammatory action of the hydroalcoholic extract of Sapium glandulatum (EHSG) leaves in mouse models of acute or chronic skin inflammation.
Topical effects of EHSG were evaluated in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced edema in the ear. Systemic effects of the extract were studied in a TPA-induced ear edema model, as well as in a carrageenan-induced paw edema model. To gain insight into the mechanism by which EHSG blocked inflammation, we evaluated the role of glucocorticoid receptors (GR) using the TPA-induced ear edema model and also measured specific binding in a glucocorticoid assay. Possible adverse effects of EHSG were evaluated after multiple treatments with the extract in the skin atrophy model on the ear and with the alkaline comet assay.
EHSG presented potent anti-inflammatory activity when applied topically in acute and chronic models, inhibiting edema formation and leukocyte migration as well as expression pro-inflammatory cytokines IL-1β, IL-6 and TNF-α in the tissue. Similar anti-inflammatory effects were found following oral treatment in both ear and paw edema models. Strikingly, the EHSG-induced blockade of leukocyte migration was reversed by mifepristone, a GR antagonist. Additionally, a specific binding assay revealed that ESGH interacts with GR. Multiple treatments with EHSG failed to induce adverse effects when evaluated in the skin atrophy model and bone marrow genotoxicity test.
Taken together, our data suggest that EHSG is a potential source of anti-inflammatory tool compounds for the treatment of pro-inflammatory-derived skin diseases, and its mechanism of action may be, at least in part, via the GR pathway.