Anti-inflammatory activities of Dangyuja (Citrus grandis Osbeck) in concanavalin A stimulated murine splenocytes and 12-O-tetradecanoylphorbol-13-acetate-induced murine skin edema.

Dangyuja (Citrus grandis Osbeck), a citrus cultivated in southern Korea, has been used in traditional medicine for its anti-inflammatory effect. In this study, we investigated the anti-inflammatory potential of extract of Citrus grandis Osbeck (ECGO). In in vitro assays, ECGO treatment of concanavalin A (10μg/ml, for 24h) stimulated splenocytes showed significant reduction in CD44/CD62L+ T cell population and a marked decrease in the production of inflammatory cytokines IL-2, IFN-γ and IL-4. Interestingly, in vivo assays of ECGO topical treatment (100μg/20μl/ear) significantly mitigated the TPA (4μg/20μl/ear) induced edema induction and Myeloperoxidase activity. Anti-inflammatory potential of ECGO were further evidenced through its potent decrease in expression of inducible nitric oxide, cyclooxygenase-2, IL-1β and TNF-α and suppressed homing of CD3+ T cells and F4/80+ macrophages to site of inflammation. This study emphasizes the possibility of developing ECGO as an alternative natural topical agent to combat inflammatory diseases.