Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, 141/143 Pomorska, 90-236 Lodz, Poland.
Department of Pharmacognosy, Faculty of Pharmacy, Medical University of Lodz, 1 Muszynskiego, 90-151 Lodz, Poland.
Molecules. 2022 Aug 12;27(16):5144. doi: 10.3390/molecules27165144.
Leaves of are a by-product of the olive oil industry and a dietary supplement with acknowledged antioxidant and anti-inflammatory activity but underestimated photoprotective potential. We investigated the protective effects of the LC-PDA-MS/MS standardized ethanol-water extract of olive leaves (OLE), containing 26.2% total phenols and 22.2% oleuropein, with underlying mechanisms against the UVA-induced oxidative damage in human dermal fibroblasts. Hs68 cells were pre-treated (24 h) with OLE (2.5-25 μg/mL) or the reference antioxidants, quercetin and ascorbic acid (25 μg/mL), followed by irradiation (8 J/cm). OLE significantly reduced the UVA-induced DNA damage and reactive oxygen species (ROS) overproduction and increased the thioredoxin reductase (TrxR) expression and post-radiation viability of fibroblasts by inhibiting their apoptosis. Both intrinsic and extrinsic apoptotic signaling pathways appeared to be inhibited by OLE, but the activity of caspase 9 was the most reduced. We hypothesized that the TrxR up-regulation by OLE could have prevented the UVA-induced apoptosis of Hs68 cells. In addition, a significant decrease in UVA-induced secretion levels of tumor necrosis factor (TNF-α) and interleukin-2 (IL-2) was shown in human lymphocyte culture in response to OLE treatment. In summary, our results support the beneficial effect of OLE in an in vitro model and indicate its great potential for use in the cosmetic and pharmaceutical industry as a topical photoprotective, antioxidant, and anti-inflammatory agent.
橄榄叶是橄榄油工业的副产品，作为一种膳食补充剂，具有公认的抗氧化和抗炎活性，但光保护潜力被低估。我们研究了橄榄叶 LC-PDA-MS/MS 标准化乙醇-水提取物（OLE）的保护作用，该提取物含有 26.2%的总酚和 22.2%的橄榄苦苷，其对人皮肤成纤维细胞的 UVA 诱导氧化损伤具有潜在的作用机制。Hs68 细胞先用 OLE（2.5-25 μg/mL）或参考抗氧化剂槲皮素和抗坏血酸（25 μg/mL）预处理 24 小时，然后进行辐照（8 J/cm）。OLE 显著降低了 UVA 诱导的 DNA 损伤和活性氧（ROS）的过度产生，并通过抑制细胞凋亡增加了成纤维细胞的硫氧还蛋白还原酶（TrxR）表达和辐照后活力。OLE 似乎抑制了内在和外在的凋亡信号通路，但 caspase 9 的活性降低最明显。我们假设 OLE 上调 TrxR 可能防止了 Hs68 细胞的 UVA 诱导凋亡。此外，在用 OLE 处理时，在人淋巴细胞培养中还显示出 UVA 诱导的肿瘤坏死因子（TNF-α）和白细胞介素-2（IL-2）分泌水平显著降低。总之，我们的结果支持 OLE 在体外模型中的有益作用，并表明其在化妆品和制药行业中作为局部光保护剂、抗氧化剂和抗炎剂的巨大潜力。
