皮肤老化是一个复杂的过程，当受到紫外线辐射的强烈影响，会刺激表皮和真皮中活性氧（ROS）的产生，继而导致皮肤损伤。其中主要的后果是胶原蛋白降解的增加和胶原合成的减少。以前的报告已经证明了多酚对健康皮肤的有益作用。其中西番莲果（Coppens＆V.E.） Barney是西番莲科的一个种，广泛分布于南美洲，且富含类黄酮。我们证明了UVB辐射增加了金属蛋白酶（mmp-1），降低了人类真皮成纤维细胞（HDF）细胞中的原胶原蛋白的生成。我们研究了苦瓜提取物及其部位的抗氧化和抗衰老作用。通过ORAC（4097 μmol ET/g）和ABTS（2992 μmol ET/g）测定，所述级分显示高多酚含量（620 mg EAG / g）和抗氧化剂活性。另外，含水部分显着地抑制胶原酶（IC 500.43 μg/ mL）。苦瓜提取物及其部位通过减少UVB诱导的MMP-1产生，增加UVB抑制的前胶原产生以及降低HDF中UVB辐射后的ROS产生而呈现光保护作用。最后用高效液相色谱-电喷雾电离质谱（HPLC-DAD-ESI-MSn）分析苦瓜提取物及其部位的多酚含量，鉴定原花青素和糖化黄酮。
(英文原文)Passiflora tarminiana fruits reduce UVB-induced photoaging in human skin fibroblasts
Skin aging is a complex process that is strongly affected by UV radiation, which stimulates the production of reactive oxygen species (ROS) in the epidermis and dermis and subsequently causes skin damage. Among the major consequences are increased collagen degradation and reduced collagen synthesis. Previous reports have demonstrated the beneficial effects of polyphenols for healthy skin. Passiflora tarminiana Coppens & V.E. Barney, a species of the Passifloraceae family, is widely distributed in South America and is rich in flavonoids. We show that UVB radiation increases metalloproteinase 1 (MMP-1) and reduces procollagen production in human dermal fibroblast (HDF) cells in a dose- and time-dependent manner. We examined the antioxidant and antiaging effects of the extract and fractions of P. tarminiana fruits. The fractions showed high polyphenol content (620 mgEAG/g) and antioxidant activity, asmeasured by ORAC (4097 μmol ET/g) and ABTS (2992 μmol ET/g) assays. The aqueous fraction drastically inhibited the collagenase enzyme (IC50 0.43 μg/mL).。The extract and fractions presented photoprotective effects by reducing UVB induced MMP-1 production, increasing UVB-inhibited procollagen production, and decreasing ROS production after UVB irradiation in HDF. Finally, the polyphenol contents of the extracts and fractions from P. tarminiana were analyzed by HPLC-DAD-ESI-MSn, and procyanidins and glycosylated flavonoids were identified.
(英文原文)Protective effects of grape stem extract against UVB-induced damage in C57BL mice skinAbstract
Humans have become exposed to another form of a trait which is ultraviolet B (UVB) radiation reaching the earth's surface. This has become a major source of oxidative stress that ultimately leads to inflammation, DNA damage, photoaging and pigmentation disorders etc. Although several studies have shown the photo-protective role of different grape parts like the fruits and seeds, little or no data demonstrating the in vivo photo-protective role of grape stem, which is the most discarded part of the grape are available. We evaluated the protective influence of grape stem extract against UVB-induced oxidative damage in C57BL mice characterized by epidermal hyperplasia, pigmentation, collagen degradation and inflammation. Grape stem extract was administered topically 1 week before UVB irradiation (120 mJ/cm2) and continued until the termination of the experiment. A group of non-irradiated mice and a group of irradiated mice topically administered with propylene were used as a negative and positive control. Epidermal thickness, pigmentation, erythema, mast cell and neutrophil infiltration, collagen degradation and COX-2, Nrf2, and HO-1 expressions were evaluated. Grape stem extract markedly recovered skin damage induced by the UVB radiation through the prevention of epidermal hyperplasia, pigmentation, erythema, mast cell and neutrophil infiltrations, collagen degradation and COX-2, Nrf2, and HO-1 expressions. Our study demonstrated for the first time in C57BL mice that grape stem extract reduces UVB-induced oxidative damage and hence can play a protective role in skin photo-damage.