Department of Pharmacy, National University of Singapore, 18 Science Drive 4, 117543, Singapore.
3M Innovation Singapore, 100 Woodlands Avenue, 738205, Singapore.
Sci Rep. 2016 Nov 28;6:37664. doi: 10.1038/srep37664.
Copper is an essential mineral and plays important roles in skin growth and activity. Copper delivery through skin can provide beneficial effects but its potential to induce skin irritation reactions is often overlooked. Data on dermal toxicity caused by copper compounds is scant. Some recognized in vitro skin toxicity methods are unsuitable for all metal compounds. Here, we employ a keratinocyte-based model and evaluated the skin irritation potential of copper compounds at cellular, genomic and proteomic levels. We determined cell viability and cytotoxicity by using tetrazolium reduction assay and Lactate Dehydrogenase (LDH) assay, performed real-time PCR and protein quantification to assess the expression of biomarkers after treating cells with copper peptide (GHK-Cu), copper chloride (CuCl) and copper acetate (Cu(OAc)). These copper compounds exhibited different irritancy potentials at the same treatment concentrations. GHK-Cu was not cytotoxic and did not induce any significant change in the expression levels of various skin irritation-related biomarkers. IL-1α and IL-8, HSPA1A and FOSL1 were significantly upregulated following 24-h treatment with CuCl and Cu(OAc) at 58 and 580 μM without concomitant inhibition in cell viability. GHK-Cu has a low potential of inducing skin irritation and therefore provides a safer alternative for the delivery of copper through skin.
铜是一种必需的矿物质，在皮肤生长和活动中发挥着重要作用。铜通过皮肤输送可以带来有益的效果，但它引起皮肤刺激反应的潜力往往被忽视。关于铜化合物引起的皮肤毒性的数据很少。一些公认的体外皮肤毒性方法并不适用于所有金属化合物。在这里，我们使用角质形成细胞模型，在细胞、基因组和蛋白质组水平上评估了铜化合物的皮肤刺激性潜力。我们通过使用噻唑蓝还原试验和乳酸脱氢酶（LDH）试验来确定细胞活力和细胞毒性，通过实时 PCR 和蛋白质定量来评估细胞用铜肽（GHK-Cu）、氯化铜（CuCl）和醋酸铜（Cu（OAc））处理后生物标志物的表达。这些铜化合物在相同的处理浓度下表现出不同的刺激性潜力。GHK-Cu 没有细胞毒性，也没有引起与各种皮肤刺激相关的生物标志物表达水平的任何显著变化。IL-1α 和 IL-8、HSPA1A 和 FOSL1 在 58 和 580 μM 的 CuCl 和 Cu（OAc）处理 24 小时后显著上调，而细胞活力没有同时受到抑制。GHK-Cu 引起皮肤刺激的潜力较低，因此为通过皮肤输送铜提供了更安全的选择。
