Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, 77515, Olomouc, Czech Republic.
Department of Histology and Embryology, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, 77900, Olomouc, Czech Republic.
Photochem Photobiol Sci. 2022 Jan;21(1):59-75. doi: 10.1007/s43630-021-00140-9. Epub 2021 Nov 27.
The ultraviolet (UV) part of solar radiation can permanently affect skin tissue. UVA photons represent the most abundant UV component and stimulate the formation of intracellular reactive oxygen species (ROS), leading to oxidative damage to various biomolecules. Several plant-derived polyphenols are known as effective photoprotective agents. This study evaluated the potential of quercetin (QE) and its structurally related flavonoid taxifolin (TA) to reduce UVA-caused damage to human primary dermal fibroblasts (NHDF) and epidermal keratinocytes (NHEK) obtained from identical donors. Cells pre-treated with QE or TA (1 h) were then exposed to UVA light using a solar simulator. Both flavonoids effectively prevented oxidative damage, such as ROS generation, glutathione depletion, single-strand breaks formation and caspase-3 activation in NHDF. These protective effects were accompanied by stimulation of Nrf2 nuclear translocation, found in non-irradiated and irradiated NHDF and NHEK, and expression of antioxidant proteins, such as heme oxygenase-1, NAD(P)H:quinone oxidoreductase 1 and catalase. For most parameters, QE was more potent than TA. On the other hand, TA demonstrated protection within the whole concentration range, while QE lost its protective ability at the highest concentration tested (75 μM), suggesting its pro-oxidative potential. In summary, QE and TA demonstrated UVA-protective properties in NHEK and NHDF obtained from identical donors. However, due to the in vitro phototoxic potential of QE, published elsewhere and discussed herein, further studies are needed to evaluate QE safety in dermatological application for humans as well as to confirm our results on human skin ex vivo and in clinical trials.
太阳辐射的紫外线（UV）部分会对皮肤组织造成永久性影响。UVA 光子代表最丰富的 UV 成分，会刺激细胞内活性氧（ROS）的形成，导致各种生物分子的氧化损伤。几种植物来源的多酚被认为是有效的光保护剂。本研究评估了槲皮素（QE）及其结构相关的类黄酮紫杉素（TA）降低来自同一供体的人原代真皮成纤维细胞（NHDF）和表皮角质形成细胞（NHEK）的 UVA 引起的损伤的潜力。用太阳模拟器照射细胞前用 QE 或 TA（1 小时）预处理，然后暴露于 UVA 光下。两种类黄酮都能有效防止氧化损伤，如 ROS 生成、谷胱甘肽耗竭、单链断裂形成和 caspase-3 在 NHDF 中的激活。这些保护作用伴随着 Nrf2 核易位的刺激，在未照射和照射的 NHDF 和 NHEK 中都有发现，以及抗氧化蛋白的表达，如血红素加氧酶-1、NAD(P)H：醌氧化还原酶 1 和过氧化氢酶。对于大多数参数，QE 比 TA 更有效。另一方面，TA 在整个浓度范围内都具有保护作用，而 QE 在测试的最高浓度（75 μM）下失去了其保护能力，表明其具有促氧化潜力。总之，QE 和 TA 在来自同一供体的 NHEK 和 NHDF 中表现出 UVA 保护特性。然而，由于 QE 在体外具有光毒性潜力，这在其他地方发表过，并在本文中讨论过，需要进一步研究以评估 QE 在皮肤科应用于人类的安全性，以及确认我们在人体皮肤离体和临床试验中的结果。
