Oral lichen planus (OLP) is a chronic inflammatory mucosal disease, and an apparent cause has not been identified. OLP is refractory to treatment, and malignant transformation has been reported. Therefore, discovering effective drugs with few adverse effects over long-term administration is crucial. In this study, we established an in vitro OLP model to investigate the effects of Cepharanthin®, an alkaloid mixture derived from Stephania cephalantha Hayata. Four alkaloids from Cepharanthin® suppressed the expression of cytokine genes at various degrees in activated T cells. However, the effect of Cepharanthin® was limited. On the other hand, Cepharanthin® and four alkaloids suppressed the expression of various cytokine genes in human oral epithelial cells when stimulated with IL-β. In the OLP model, activated T cells increased the inflammatory gene expression in the epithelial cells, while Cepharanthin® suppressed their gene expression. Anti-inflammatory effect of Cepharanthin® was observed by protein dot blot. The effects of Cepharanthin®️ might be expressed through two aspects: its effect of mildly suppressing the activation of T lymphocytes and strongly suppressing the response of epithelial cells to inflammatory stimuli. The in vitro model established in this study could be a tool for elucidating the mechanisms of OLP pathogenesis and disease persistence.