Effects of dietary restriction on spontaneous dermatitis in NC/Nga mice

In laboratory animals, dietary restriction prolongs life span, improves physiologic function, and prevents or lessens severity of several diseases including some experimental inflammatory states. We investigated the effect of dietary restriction on a spontaneously occurring mouse model of atopic dermatitis, an inflammatory skin disease. NC/Nga mice were assigned to a group fed ad libitum or to a restricted diet group receiving 60% of the amount of food consumed by the other group. Dermatitis was characterized according to extent, intensity, and scratching time. We then used computer-assisted image analysis to quantify immunologic findings in skin sections. Extent, intensity score, and scratching time in mice with restriction increased more gradually than in mice fed ad libitum. Infiltrating inflammatory cells (CD4-positive T cells, CD8-positiveT cells, eosinophils, and mast cells) as well as interleukin-4 and -5 secreted into tissue were reduced in mice with restriction. In conclusion, dietary restriction delayed onset and progression of spontaneous dermatitis in NC/Nga mice, an effect possibly involving inhibition of inflammatory infiltration cell and cytokine secretion.