P48 DIETARY SOY OIL CONTENT AFFECTS SUSCEPTIBILITY TO ALOPECIA AREATA IN C3H/HeJ MICE

¹McElwee KJ., ¹Niiyama S., ¹Wenzel E., ¹Freyschmidt-Paul P., ²Sundberg JP., ¹Hoffmann R. ¹Dept. Dermatology, Philipp University, Marburg, Germany; ²The Jackson Laboratory, Bar Harbor, ME, USA.

Alopecia areata (AA) is a suspected autoimmune disease expressed in humans and rodent models. While oligogenetic susceptibility to AA is likely, epi-genetic factors may also affect AA expression. Diet as a susceptibility and severity modifier of AA in C3H/HeJ mice was examined.

Prior to the experiment, all mice received a standard commercial diet of 1% soy oil (4% total fat). Normal haired C3H/HeJ mice were grafted with AA affected skin, a method previously shown to successfully induce AA. Grafted mice were given one of three diets. Twenty eight mice continued to receive a 1% soy oil diet. Twenty eight mice received a commercially available diet with 5% soy oil (7.5% total fat). Eleven mice received an athrogenic diet with 20% soy oil (23% total fat) formulated by the animal diet manufacturer using the 1% soy oil diet as a base and additional soy oil from the same source. Mice were monitored for at least 20 weeks after skin grafting and then necropsied.

Twenty of 28 mice (71%) on the diet containing 1% soy oil developed AA hair loss by the time of necropsy whereas 11 of 28 mice (39%) on a 5% soy oil diet developed AA. Two of 11 mice (18%) fed a 20% soy oil diet had hair loss. Mice that failed to develop AA typically regrew white hair from their skin grafts and histology revealed no apparent inflammation. Of those mice that expressed AA, no significant association was observed between the extent of hair loss and diet. Mice with AA had hair follicle inflammation consistent with observations for spontaneous mouse AA.

The results suggest that soy oil may contain compounds with indirect or direct immunomodulatory properties that modify susceptibility to AA in mice.