Photoageing and skin cancer are major causes of morbidity and are a high cost to society. Interest in the development of photoprotective agents for inclusion in topical cosmetic and sunscreen products is profound. Recently, amino acids with a sulfinic group, notably hypotaurine, have been included as ingredients in cosmetic preparations. However, the mechanism of action of hypotaurine as a possible anti-ageing agent is unknown, despite its use as a free radical scavenger. To address this issue, we investigated hypotaurine uptake in a human keratinocyte model and examined its effect on UVR-induced cytotoxicity. Hypotaurine was taken up by keratinocytes in a time- and concentration-dependent manner, with levels remaining significantly above baseline 48 h after washout. A cytoprotective effect of pre-incubation with 2.5-5 mM hypotaurine was shown as indicated by increased cell viability when keratinocytes were irradiated with UVA at 5 or 10 Jcm-2 , with the level of hypotaurine also significantly reduced. These findings indicate a potential cytoprotective effect of hypotaurine against the deleterious effects of UVA irradiation. This provides support for further studies to evaluate the potential photoprotective benefits of hypotaurine supplementation of topical cosmetic and sunscreen products.

中文翻译：

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次牛磺酸在保护角质形成细胞免受 UVA 诱导的损伤中的作用

光老化和皮肤癌是发病的主要原因，对社会造成高昂的代价。对开发用于局部化妆品和防晒产品的光保护剂的兴趣是深远的。最近，具有亚磺酸基团的氨基酸，特别是亚牛磺酸，已被用作化妆品制剂的成分。然而，尽管亚牛磺酸用作自由基清除剂，但其作为一种可能的抗衰老剂的作用机制尚不清楚。为了解决这个问题，我们研究了人类角质形成细胞模型中亚牛磺酸的摄取，并检查了其对 UVR 诱导的细胞毒性的影响。角质形成细胞以时间和浓度依赖性方式吸收次牛磺酸，冲洗后 48 小时，其水平仍显着高于基线。2. 预孵育的细胞保护作用。当用 5 或 10 Jcm-2 的 UVA 照射角质形成细胞时，细胞活力增加表明 5-5 mM 亚牛磺酸，亚牛磺酸的水平也显着降低。这些发现表明亚牛磺酸对 UVA 辐射的有害影响具有潜在的细胞保护作用。这为进一步研究评估局部化妆品和防晒产品补充亚牛磺酸的潜在光保护益处提供了支持。