Yoshinari Matsumoto (1), Masashi Kato (2), Yasuhiko Tamada (3), Hijiri Mori (1) and Masaru Ohashi (1)
(1) Department of Dermatology and (2) Department of Immunology, Nagoya
University, School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya 466, Japan
(3) Department of Dermatology, Aichi Medical University, Nagakute, Aichi 480-11, Japan
Abstract: We investigated the effects of Sho-saiko-to, the most commonly used herbal medicine in Japan, on the production of interleukin (IL)-1alpha by cultured human epidermal keratinocytes. IL-1alpha production was significantly promoted by treatment with 100 or 500 microg/ml Sho-saiko-to for 24 or 48 hr. Expression of IL-1alpha receptors was the most markedly upregulated after treatment with 500 microg/ml Sho-saiko-to for 24 hr and with 100 or 500 microg/ml for 48 hr; these cells showed the characteristics of multilayered differentiated keratinocytes. The presence of an anti-IL-1alpha antibody during the treatment with 500 microg/ml of Sho-saiko-to for 24 or 48 hr or with 100 microg/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-1alpha and express IL-1alpha receptors. IL-1alpha 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-1alpha.
Keywords: Sho-saiko-to, Cultured keratinocyte, Interleukin-1alpha, Autocrine growth