Effects of red ginseng on the elastic properties of human skin

Abstract

Background: Red ginseng contains components, including microelements, vitamins, essential oils, and fatty acids, that can be used in skincare to delay the aging process. We investigated the effects of red ginseng treatment on skin elasticity by assessing cellular stiffness and measuring collagen protein synthesis.

Methods: Human dermal fibroblasts were treated with red ginseng, and the resulting changes in stiffness were investigated using atomic force microscopy. Cytoskeletal changes and mRNA expression of biomarkers of aging, including that of procollagens I and VII, elastin, and fibrillin-1, were investigated. Collagen in a human skin equivalent treated with red ginseng was visualized via hematoxylin and eosin staining, scanning electron microscopy, and atomic force microscopy.

Results and conclusion: The stiffness of fibroblasts was significantly reduced by treatment with red ginseng concentrations of ≥ 0.8 mg/mL. The ratio of F-actin to G-actin decreased after treatment, which corresponded to a change in fibroblast stiffness. The storage modulus (G') and loss modulus (G″) of the skin equivalent were both lowered by red ginseng treatment. This result indicates that the viscoelasticity of the skin equivalent can be restored by red ginseng treatment.

Keywords: Atomic force microscopy; Cellular stiffness; Collagen; Red ginseng; Skin elasticity.

Fig. 1

A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate the cytotoxicity of (A) various concentrations of red ginseng and (B) different treatment durations.

Fig. 2

(A) Representative topographical atomic force microscopy (AFM) image of a fibroblast. (B) The force–distance curve plotted as a function of load force and indentation depth and (C) the approach curve fitted to the Sneddon model. (D) Distribution of Young's modulus values for control fibroblasts. (E) Changes in Young's modulus for fibroblasts as a function of the red ginseng concentration and (F) treatment duration at 0.8 mg/mL.

Fig. 3

(A) G-actin and F-actin protein expression according to red ginseng concentration. (B) Changes in the F-actin:G-actin ratio according to red ginseng concentration. (C) G-actin and F-actin protein expression according to treatment duration at 0.8 mg/mL red ginseng. (D) Changes in the F-actin:G-actin ratio according to treatment duration at 0.8 mg/mL red ginseng. *p < 0.05 and **p < 0.01 compared with the control.

Fig. 4

Expression of (A) collagen type I, (B) collagen type VII, (C) elastin, and (D) fibrillin 1 mRNA according to red ginseng concentration. Expression of (E) collagen type I, (F) collagen type VII, (G) elastin, and (H) fibrillin 1 mRNA with different red ginseng treatment durations. *p < 0.05, **p < 0.01, and ***p < 0.001 compared with the control.

Fig. 5

(A) Collagen type I protein expression according to red ginseng concentration and (B) treatment duration. (C) Western blot of collagen type I protein in cells. (D) Collagen type VII protein expression according to red ginseng concentration and (E) treatment durations. (F) Western blot of collagen type VII protein in cells. (G–I) Collagen type I protein expression according to red ginseng concentration and treatment duration; (J–L) are the results for collagen type VII in the skin equivalent. *p < 0.05, **p < 0.01, and ***p < 0.001 compared with the control.

Fig. 6

(A) Human skin equivalent stained with hematoxylin and eosin. Collagen is stained red. (B) Collagen fiber density in the sample according to red ginseng concentration and (C) treatment duration. (D) Collagen was visualized using scanning electron microscopy (SEM). (E) Collagen fiber thickness measured in SEM images according to concentration and (F) treatment duration. (G) Collagen nanostructure in the sample treated with red ginseng (0.8 mg/mL) for 0, 6, 12, and 24 h visualized using atomic force microscopy.

Fig. 7

Log profile of strain-dependent storage modulus (G′) and loss modulus (G″) for the skin equivalent. (A) G′ and (B) G″ curves according to red ginseng concentration. (C) G′ and (D) G″ curves according to treatment duration at 0.8 mg/mL red ginseng.