Hair growth effect of <i>Sasa veitchii</i> extract in mice

Abstract Aim Kumazasa leaves have long been used in Japan as a folk remedy to treat anorexia, fatigue, bad breath, body odor, and stomatitis. In this study, we investigated whether kumazasa extract has a hair growth effect. Methods Using human hair follicle dermal papilla cells (HFDPC), we investigated the cell proliferation effect of kumazasa extract and the expression induction effect of aquaporin 1 ( AQP1 ). We also used minoxidil as a positive control, applied kumazasa extract to mice that had been depilated, and investigated whether it had a hair growth effect and a side effect of causing inflammation. Results Kumazasa extract was found to promote HFDPC proliferation and increase AQP1 expression per cell. This effect was similar to that of epidermal growth factor (EGF). When kumazasa extract was applied to a mouse model, it showed a hair growth effect equivalent to that of minoxidil. Meanwhile, an inflammatory response was observed in the minoxidil group but not in the kumazasa group. Conclusion Kumazasa Kumazasa extract has a hair growth effect without causing inflammation. It was suggested that this effect may be related to the proliferation‐promoting effect of kumazasa extract on HFDPC. The causal relationship between the proliferation‐promoting effect of kumazasa extract on HFDPC and the AQP1 expression‐enhancing effect could not be clarified in this study.