Fig. 2

Participants’ skin parameters. (A) Skin hydration was assessed using a corneometer. Basic values for erythema and melanin were measured using a pigmentation probe (mexameter). A skin elastic meter was used to detect total skin elastic. All values are presented as mean ± SD. Participants were divided into the RG group and control (C) group. Red box: female participants, green box: male participants. All data were analyzed using SPSS version 18.0. A p value of less than 0.05 was considered to indicate statistical significance. *p < 0.05, **p < 0.01. (B) Advanced skin elasticity assay. Skin was subjected to constant negative pressure of 350 mbar in the time–strain mode for 18 s followed by relaxation for 2 s. (C) Elasticity parameters (R0–R9 and F0–F1) were calculated from the deformation curve and in accordance with the suction applied using the Cutometer MPA580. Bars represent the mean ± SD. (N = 5; each test was performed at least 5 times). R1 indicates skin total deformation; R2, skin gross elasticity; R3, skin amplitude; R4, last minute amplitude; R5, pure elasticity of the skin; R6, skin sagginess; R7, biological elasticity; R8, skin pliability; and R9, skin tiring effect. The black column represents the control group, and the white column represents the RG group. *p < 0.05; **p < 0.01, compared with other groups