Embelin reduces cutaneous TNF-α level and ameliorates skin edema in acute and chronic model of skin inflammation in mice

Tumor necrosis factor-α (TNF-α) is known to play a crucial role in the pathogenesis of psoriasis. The present study was designed to investigate the effects of embelin on lipopolysachharide induced TNF-α production in mice and in human keratinocytes in vitro and also to study the effect of embelin on acute and chronic skin inflammation in mice. Production of pro-inflammatory cytokines (TNF-α and IL-1β), activation of myeloperoxidase and histological assessment were examined in acute and chronic skin inflammation using 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced mouse ear edema. Embelin inhibited topical edema in the mouse ear, leading to substantial reductions in skin thickness and tissue weight, inflammatory cytokine production, neutrophil-mediated myeloperoxidase activity, and various histopathological indicators. Furthermore, embelin was effective at reducing inflammatory damage induced by chronic TPA exposure. Our data indicate that embelin has anti-inflammatory activities in both acute and chronic irritant contact dermatitis in vivo and this effect of embelin may be due, at least in part, to the inhibition of IL-1β and TNF-α and to the subsequent blockade of leukocyte accumulation.