Action mechanism of anti-wrinkle effect of Rhamnus yoshinoi methanol extract in human dermal fibroblast and keratinocyte cell lines

Abstract

Rhamnus yoshinoi is a deciduous broad-leaf bush and endemic species widely found in Korea. Recently, we reported that R. yoshinoi methanol extract (RYME) had excellent antioxidant activity and inhibition of collagenase and elastase activity in cell-free system. In this study, we investigated the ability of RYME to control the mRNA and protein expression levels of the known skin wrinkle-related factors in cultured human dermal fibroblast and keratinocyte cell lines. Treatment with 100 or 200 μg/mL RYME strongly blocked the UVB-induced downregulation of type 1 collagen mRNA expression (p < 0.001) and partially blocked the UVB-induced upregulation of MMP-3 mRNA expression in HaCaT human keratinocytes (p < 0.05 or p < 0.001). Treatment with RYME at 100 μg/mL considerably decreased MMP-1 mRNA expression in UVB-exposed HaCaT cells (p < 0.01). In HaCaT cells, RYME exhibited the potential to improve UV light-induced skin wrinkles. Moreover, RYME selectively inhibited the UVB-induced ERK-1/2 protein phosphorylation in CCD-986sk human dermal fibroblasts at 80 and 160 μg/mL. UV-induced ERK-1/2 protein phosphorylation is one of the major mechanisms of the generation of UV-induced skin wrinkles. Therefore, it is likely that the anti-skin wrinkling effect of RYME could be attributable to selective inhibition of UV induced ERK-1/2 protein phosphorylation.

Keywords: Anti-wrinkle effect; CCD-986sk cells; ERK-1/2 protein phosphorylation; HaCaT cells; MMP-3; Rhamnus yoshinoi.

Fig. 1

Effect of RYME or vitamin C treatment at the indicated concentrations and/or times on viability of control or UVB-irradiated CCD-986sk cells. RYME: R. yoshinoi methanol extract. Vit. C: vitamin C. Values are mean ± SD of three independent measurements

Fig. 2

Effect of RYME or vitamin C treatment on phosphorylation and expression levels of ERK-1/2, p38 MAPK, and JNK-1/2 in UVB-irradiated CCD-986sk cells. RYME: R. yoshinoi methanol extract. a p-ERK-1/2, phosphorylated ERK-1/2; T-ERK-1/2, total ERK-1/2. b p-p38 MAPK, phosphorylated p38 MAPK; T-p38 MAPK, total p38 MAPK. c p-JNK-1/2, phosphorylated JNK-1/2; T-JNK-1/2, total JNK-1/2

Fig. 3

Morphological observation in control or UVB-irradiated CCD-986sk cells treated with RYME or vitamin C for 4 h. RYME: R. yoshinoi methanol extract

Fig. 4

Effect of RYME or vitamin C treatment at the indicated concentrations on viability of control or UVB (10 mJ/cm²)-irradiated HaCaT cells. RYME: R. yoshinoi methanol extract. Values are mean ± SD of three independent measurements

Fig. 5

Morphological observation in control or UVB-irradiated HaCaT cells treated with RYME or vitamin C. RYME: R. yoshinoi methanol extract

Fig. 6

a Effect of RYME on mRNA transcript levels of type I collagen, MMP-1, and MMP-3 in control or UVB-irradiated HaCaT cells. RYME: R. yoshinoi methanol extract. b Quantification of mRNA expression levels of type I collagen, MMP-1, and MMP-3 normalized to those of β‑actin in (a). Values are presented the mean ± standard deviation of three independent experiments. **p < 0.01, ***p < 0.001 versus control HaCaT cells (no UVB irradiation), ^#p < 0.05, ^##p < 0.01, ^###p < 0.001 versus UVB-irradiated HaCaT cells