Therapeutic Effects of Pinus koraiensis on 1-Fluoro-2,4-Dinitrofluorobenzene-induced Contact Dermatitis in Mice

Background: Korean pine nuts (Semen Pinus koraiensis (P. koraiensis)) have been a valuable ingredient in Korean cuisine since ancient times, and the classical literature on traditional medicine states that pine nuts can moisturize skin. Aims: To confirm the therapeutic efficacy of the ethanol extract of these pine nuts in an animal contact dermatitis (CD) model. Materials and Methods: Korean pine nuts were extracted using 70% ethanol, and the crude extract obtained was condensed and lyophilized to produce EEPK (the 70% ethanol extract of P. koraiensis). A DNFB (1-fluoro-2,4-dinitrofluorobenzene)-induced BALB/c mouse model of CD was used to investigate the effects of EEPK on skin symptoms, histopathological abnormalities, and cytokine secretion in inflamed tissues. Results: EEPK reduced skin color changes, lesion severities, and dorsal skin thickening and inhibited epidermis hyperplasia and immune cell infiltration into inflamed tissues. In addition, EEPK suppressed the productions of tumor necrosis factor-alpha, interferon-gamma, interleukin-6, and monocyte chemoattractant protein-1 but did not affect body weights or spleen/body weight ratios. Conclusion: P. koraiensis has potential as a therapeutic agent for CD and as a treatment for inflammatory skin disease management products. Furthermore, the mechanism underlying its therapeutic effects differs from that of corticosteroids.