Research Center of Traditional Chinese Medicine, The Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, 130021, China.
Jilin Ginseng Academy, Changchun University of Chinese Medicine, Changchun, 130117, China.
J Ethnopharmacol. 2023 Feb 10;302(Pt A):115883. doi: 10.1016/j.jep.2022.115883. Epub 2022 Oct 31.
Long-wave ultraviolet A (UVA) causes skin aging by damaging the fine structures of the skin, such as elastic fibers and collagen fibers, through oxidation. Currently, the use of plant extracts to protect skin from photoaging is a popular method. Panax ginseng C.A. Meyer exerts commendable anti-photoaging and antioxidant effects. P. ginseng Meyer cv. Silvatica, also known as forest ginseng (FG), is a type of ginseng cultivated by artificially simulating the growth environment of wild ginseng aged >15 years. However, there are only a few reports on its anti-photoaging effect on the skin caused by UVA stimulation.
To investigate whether isolated and extracted FG can inhibit skin photoaging as well as to explore its action mechanism.
The FG extract (FGE) was obtained from the supernatant of FG after water extraction and alcohol precipitation with the D101 resin. The composition and content of phenolic acids in FGE were determined by high-performance liquid chromatography (HPLC). The MTT assay was performed to detect cell viability. The ratio of SA-β-GAL-positive cells, CoL-I level, 8-OHdG concentration, MDA, GSH, GPx, SOD, and CAT activity were measured using relevant kits. Furthermore, cell cycle alterations and ROS accumulation were assessed by flow cytometry. The expressions of p53, p21, p16, and Keap1 protein were detected by Western blotting. The Nrf2 translocation was monitored by immunofluorescence staining.
The findings revealed that FGE significantly restored UVA injury-induced cell viability, reduced the proportion of SA-β-GAL-positive cells, and increased the level of CoL-I secretion in a dose-dependent manner, where the main ingredients were chlorogenic acid, protocatechuic acid, salicylic acid, p-hydroxybenzoic acid, vanillic acid, ferulic acid, and caffeic acid. Further studies indicated that this phenolic acid mixture (PAM) could alleviate UVA-induced HFF-1 cell cycle arrest and protect the DNA from oxidative damage caused by UVA stimulation. Moreover, the expressions of cell cycle regulatory proteins p53, p21, and p16 and the accumulation of ROS were inhibited, the translocation of Nrf2 into the nucleus was promoted, the expression of Keap1 protein was inhibited, the activity of intracellular antioxidant indicators GSH, GPx, SOD, and CAT was enhanced, and the expression of malondialdehyde (MDA) was inhibited.
Collectively, our results demonstrated that FG phenolic acids protect DNA from oxidative damage by activating Nrf2 to safeguard the skin from photoaging induced by UVA stimulation.
长波紫外线 A（UVA）通过氧化破坏皮肤的弹性纤维和胶原蛋白纤维等精细结构，导致皮肤老化。目前，使用植物提取物保护皮肤免受光老化是一种流行的方法。人参 Panax ginseng C.A. Meyer 具有令人称赞的抗光老化和抗氧化作用。人参 Panax ginseng Meyer cv. Silvatica，也称为森林人参（FG），是一种通过人工模拟野生人参生长环境 15 年以上培育的人参。然而，关于其对 UVA 刺激引起的皮肤光老化的抗老化作用的报道较少。
研究 FG 提取物（FGE）是否能抑制皮肤光老化，并探讨其作用机制。
采用 D101 树脂从 FG 水提醇沉后的上清液中提取 FG 提取物（FGE）。采用高效液相色谱法（HPLC）测定 FGE 中酚酸的组成和含量。采用 MTT 法检测细胞活力。采用相关试剂盒测定 SA-β-GAL 阳性细胞比例、CoL-I 水平、8-OHdG 浓度、MDA、GSH、GPx、SOD 和 CAT 活性。此外，通过流式细胞术评估细胞周期改变和 ROS 积累。采用 Western blot 检测 p53、p21、p16 和 Keap1 蛋白的表达。通过免疫荧光染色监测 Nrf2 易位。
结果表明，FGE 能显著恢复 UVA 损伤诱导的细胞活力，降低 SA-β-GAL 阳性细胞比例，增加 CoL-I 分泌水平，呈剂量依赖性，主要成分有绿原酸、原儿茶酸、水杨酸、对羟基苯甲酸、香草酸、阿魏酸和咖啡酸。进一步研究表明，这种酚酸混合物（PAM）可减轻 UVA 诱导的 HFF-1 细胞周期阻滞，并保护 DNA 免受 UVA 刺激引起的氧化损伤。此外，抑制细胞周期调节蛋白 p53、p21 和 p16 的表达和 ROS 的积累，促进 Nrf2 向核内易位，抑制 Keap1 蛋白的表达，增强细胞内抗氧化指标 GSH、GPx、SOD 和 CAT 的活性，抑制丙二醛（MDA）的表达。
综上所述，我们的研究结果表明，FG 酚酸通过激活 Nrf2 来保护 DNA 免受氧化损伤，从而防止 UVA 刺激引起的皮肤光老化。
