Nicholas School of the Environment, Duke University, Durham, NC, 27708, United States.
Division of Pulmonary, Allergy, and Critical Care Medicine, Duke School of Medicine, Duke University, Durham, NC, 27708, United States.
Food Chem Toxicol. 2023 Dec;182:114108. doi: 10.1016/j.fct.2023.114108. Epub 2023 Oct 25.
Azobenzene disperse dyes are the fastest-growing category of commercial dyestuffs and have been found in indoor house dust and in children's polyester apparel. Azobenzene disperse dyes are implicated as potentially allergenic; however, little experimental data is available on allergenicity of these dyes. Here, we examine the binding of azobenzene disperse dyes to nucleophilic peptide residues as a proxy for their potential reactivity as electrophilic allergenic sensitizers. The Direct Peptide Reactivity Assay (DPRA) was utilized via both a spectrophotometric method and a high-performance liquid chromatography (HPLC) method. We tested dyes purified from commercial dyestuffs as well as several known transformation products. All dyes were found to react with nucleophilic peptides in a dose-dependent manner with pseudo-first order kinetics (rate constants as high as 0.04 h). Rates of binding reactivity were also found to correlate to electrophilic properties of dyes as measured by Hammett constants and electrophilicity indices. Reactivities of polyester shirt extracts were also tested for DPRA activity and the shirt extracts with high measured abundances of azobenzene disperse dyes were observed to induce greater peptide reactivity. Results suggest that azobenzene disperse dyes may function as immune sensitizers, and that clothing containing these dyes may pose risks for skin sensitization.
偶氮分散染料是商业染料中增长最快的类别，已在室内房屋灰尘和儿童聚酯服装中被发现。偶氮分散染料被认为具有潜在的致敏性；然而，关于这些染料的致敏性的实验数据很少。在这里，我们研究了偶氮分散染料与亲核肽残基的结合情况，以此作为其作为亲电致敏原潜在反应性的替代指标。通过分光光度法和高效液相色谱法（HPLC）两种方法利用直接肽反应性测定法（DPRA）进行了测试。我们测试了从商业染料中纯化的染料以及几种已知的转化产物。所有染料均发现与亲核肽以剂量依赖的方式反应，具有准一级动力学（高达 0.04 h 的速率常数）。结合反应性的速率也被发现与染料的电子性质相关，如由哈米特常数和电子性指数测量。还对聚酯衬衫提取物的 DPRA 活性进行了测试，并且发现含有高含量偶氮分散染料的衬衫提取物可诱导更高的肽反应性。结果表明，偶氮分散染料可能作为免疫敏化剂起作用，并且含有这些染料的衣物可能对皮肤敏化构成风险。
