The Suppressive Effect of Evening Primrose Oil on Murine Contact Sensitivity

ABSTRACT

BACKGROUND: Evening primrose oil(EPO) is a rich source of cis-linoleic acid and gammalinolenic acid(GLA) and has been used as a therapeutic agent in various skin diseases such as atopic dermatitis. OBJECTIVE: The purpose of this study was to evaluate the suppressive effect of EPO on murine contact sensitivity. METHODS: BALB/c mice were divided into 3 groups, positive control, experimental and negative control groups the positive control group represents a group of mice which were sensitized and challenged with DNFB, the experimental group represents EPO-pretreated positive control group and the negative control group represents a group of mice which were challenged only. The changes of ear thickness were measured, and H & E staining and immunohistochemical staining for ICAM-1 expression of ear skin were performed to evaluate the histological changes of each group. RESULTS: The Pretreatment of mice with EPO resulted in suppression of contact sensitivity by more than 82%. On H & E staining, only a mild inflammatory reaction was observed in the dermis. Also ICAM-1 expression of keratinocytes, the intensity of the staining was significantly decreased in the experimental group compared with positive group. CONCLUSIONS: Our study indicates that EPO was able to suppress the induction of contact sensitivity.