Sustainability arises as a challenge in the last decades and the cosmetic field is not an exception. The search for new cosmetic active principles extracted from food byproducts through eco-innovative technologies has emerged as a novel concept. However, the European Regulation is very restrictive and different assays should be performed to guarantee the products' efficacy and safety. Considering a multidisciplinary approach, this paper aims to compare chestnut shells extracts prepared by three different green techniques – Subcritical Water Extraction (SWE), Ultrasound-Assisted Extraction (UAE) and Supercritical Fluids Extraction (SFE) – regarding antimicrobial activity, hyaluronidase and elastase inhibitory activities, in-vitro cytotoxicity on dermal cells (HaCaT and HFF-1) and skin permeation (using Franz cells coupled to human skin). The best extract was tested on skin and ocular 3D models and through an in-vivo patch test to evaluate its irritancy and safety. The results demonstrated the antimicrobial properties of the extracts (particularly against Staphylococcus aureus) as well as the capacity to inhibit the hyaluronidase (IC₅₀ = 0.76–54.36 mg/mL) and elastase (33.56–82.70% at 0.4 mg/mL) activities. Regarding in-vitro cell assays, UAE and SWE extracts revealed the best outcomes. Between 0.1 and 100 μg/mL, none of the extracts conducted to a decrease of cell viability in both cell lines (HaCaT and HFF-1). The ex-vivo assay proved that SWE extract led to a higher polyphenol's permeation (1061.6 μg/g dw), being selected for further assays. Ellagic acid was the major polyphenol that permeated the human skin (732.1–847.0 μg/g dw). The 3D skin and ocular models evidenced absence of irritation by SWE extract, without decreasing cell viability and releasing IL-1α. Finally, an in-vivo patch test confirmed the absence of irritation in humans based on the acute irritation index of 0.50 achieved 24 h after the patch removal. To the best of our knowledge, this is the first study that validated by in-vitro and in-vivo assays, and in accordance with the European Regulation 1223/2009, a new cosmetic ingredient extracted from chestnut shells.

在过去的几十年里，可持续性成为一项挑战，化妆品领域也不例外。寻找通过生态创新技术从食品副产品中提取的新化妆品活性成分已成为一个新概念。然而，欧洲法规非常严格，应进行不同的检测以保证产品的有效性和安全性。考虑到多学科方法，本文旨在比较通过三种不同的绿色技术——亚临界水提取 (SWE)、超声辅助提取 (UAE) 和超临界流体提取 (SFE)——制备的板栗壳提取物的抗菌活性、透明质酸酶和弹性蛋白酶抑制体外活动对真皮细胞（HaCaT 和 HFF-1）和皮肤渗透（使用与人皮肤偶联的 Franz 细胞）的细胞毒性。最好的提取物在皮肤和眼部 3D 模型上进行了测试，并通过体内贴片测试来评估其刺激性和安全性。结果证明了提取物的抗菌特性（特别是对金黄色葡萄球菌）以及抑制透明质酸酶（IC ₅₀  = 0.76–54.36 mg/mL）和弹性蛋白酶（0.4 mg/mL 时为 33.56–82.70%）活性的能力。关于体外细胞测定，UAE 和 SWE 提取物显示出最好的结果。在 0.1 和 100 μg/mL 之间，没有任何提取物导致两种细胞系（HaCaT 和 HFF-1）中细胞活力的降低。在离体测定证明 SWE 提取物导致更高的多酚渗透率 (1061.6 μg/g dw)，被选择用于进一步测定。鞣花酸是渗透人体皮肤的主要多酚（732.1–847.0 μg/g dw）。3D 皮肤和眼部模型证明 SWE 提取物没有刺激性，没有降低细胞活力和释放 IL-1α。最后，根据贴片去除后 24 小时达到的 0.50 的急性刺激指数，体内贴片测试证实了对人体没有刺激。据我们所知，这是第一项通过体外和体内试验验证的研究，并符合欧洲法规 1223/2009，这是一种从板栗壳中提取的新化妆品成分。