Efficacy of Japanese Maca Powder Against Aging Stress in Human Dermal Fibroblasts

The aim of this study was to identify and examine materials that have a long history of use in folk medicine and exhibit biological activity but have not been fully utilized. This study evaluated the reactivity of Japanese maca powder in cultured human dermal cells subjected to aging stress (UV irradiation, AGE treatment, or H₂O₂ treatment). The mRNA levels of three stress parameters (collagen, elastin, and hyaluronic acid synthase) were measured using quantitative reverse transcription polymerase chain reaction. The activity of a prototype Japanese maca powder sample was compared with that of samples subjected to fermentation, room-temperature enzyme, and rapid freeze-drying treatments. Inhibitory effects on reactive oxygen species (ROS) were measured, and the expression of genes involved in senescent cell removal (JAG1) and regeneration promotion (EGF) was examined. Finally, the expression of molecules involved in senescent cell phagocytosis (STAB1) and stem cell phagocytosis signaling and regeneration promotion (FGF2) in macrophages was evaluated. The four types of maca samples altered the mRNA levels of the three stress parameters, conferred resistance to various aging stresses, and delayed suppressed intracellular ROS accumulation. These findings suggest that Japanese maca may help to protect skin cells from age-related stress.