Shishihakuhito, a Kampo medicine for atopic dermatitis, suppresses NGF-induced neurite extension by inhibition of MEK/ERK signaling in PC12D cells

Accumulating evidence obtained from clinical studies as well as animal studies suggests that nerve growth factor (NGF) may play a crucial role in the pathogenic mechanism of atopic dermatitis (AD), involving severe scratching due to itching. Shishihakuhito is a Kampo medicine for AD. In the current study, we for the first time report that shishihakuhito extract has the activity to prevent NGF-induced stimulation of phoshorylation of MEK and ERK which has been demonstrated to mediate neurite outgrowth induced by this neurotrophic factor, and actually inhibit NGF-induced neurite extension in PC12D cells, a cellular model of peripheral sensory neurons. These findings suggest that shishihakuhito might prevent NGF signaling, thereby reducing the induction of severe itching and scratching in AD.