Enhancement of Interleukin-1α Mediated Autocrine Growth of Cultured Human Keratinocytes by Sho-saiko-to

抄録

We investigated the effects of Sho-saiko-to, the most commonly used herbal medicine in Japan, on the production of interleukin (IL)-la by cultured human epidermal keratinocytes. IL-lα production was significantly promoted by treatment with 100 or 500 μg/ml Sho-saiko-to for 24 or 48 hr. Expression of IL-lα receptors was the most markedly upregulated after treatment with 500 μg/ml Sho-saiko-to for 24 hr and with 100 or 500 μg/ml for 48 hr; these cells showed the characteristics of multilayered differentiated keratinocytes. The presence of an anti-IL-lα antibody during the treatment with 500 μg/ml of Sho-saiko-to for 24 or 48 hr or with 100 μg/ml for 48 hr significantly down-regulated the synthesis by the keratinocytes and induced damages in them. Keratinocytes treated with Sho-saiko-to might produce IL-lα and express IL-lα receptors. IL-lα may regulate the proliferation and differentiation of keratinocytes after Sho-saiko-to treatment. These findings suggest that Sho-saiko-to enhances the autocrine growth mediated by IL-lα.