Abstract：
Consumer products containing botanicals or natural substances (BNS) are often preferred because there is a perception that \'natural\' is safe. As with any product ingredient, a thorough safety assessment must be conducted, including a determination of skin sensitization potential. A modification of the Peroxidase Peptide Reactivity Assay (PPRA) was explored for screening BNS (B-PPRA) for their reactivity to a model cysteine peptide. The PPRA incorporates a horseradish peroxidase‑hydrogen peroxide (+HRP/P) oxidation system for the activation of potential pre- and pro-haptens. BNS test materials contained <2% botanical constituent in either glycerin/water or propylene glycol/water. Stock solutions prepared in acetonitrile were diluted to 8 working concentrations. Direct reactivity was determined in reaction mixtures containing peptide and deferoxamine in potassium phosphate buffer. Enzyme-mediated reactivity determinations were performed with addition of +HRP/P. Initial studies demonstrated that results were reproducible and impact of carrier low. To determine the sensitivity of the assay, experiments were conducted with chamomile extract spiked with three sensitizers. Peptide depletion was observed in the +HRP/P reaction mixtures with isoeugenol spikes as low as 0.05%. The B-PPRA shows promise as a screening method for skin sensitization potential and could become part of a framework for the skin sensitization safety assessment of BNS.
摘要：
含有植物药或天然物质（BNS）的消费品通常是首选，因为人们认为“天然”是安全的。与任何产品成分一样，必须进行全面的安全评估，包括皮肤致敏潜力的测定。探索了过氧化物酶肽反应性测定(PPRA)的改进,用于筛选BNS(B-PPRA)对模型半胱氨酸肽的反应性。PPRA包含辣根过氧化物酶-过氧化氢（HRP/P）氧化系统，用于激活潜在的前半抗原和前半抗原。BNS测试材料在甘油/水或丙二醇/水中含有<2%的植物成分。将在乙腈中制备的储备溶液稀释至8个工作浓度。在磷酸钾缓冲液中含有肽和去铁胺的反应混合物中测定直接反应性。添加+HRP/P进行酶介导的反应性测定。初步研究表明，结果是可重复的，载体的影响低。为了确定测定的灵敏度，实验是用洋甘菊提取物掺入三种敏化剂进行的。在具有低至0.05%的异丁香酚尖峰的+HRP/P反应混合物中观察到肽耗尽。B-PPRA有望作为皮肤致敏潜力的筛选方法，并可能成为BNS皮肤致敏安全性评估框架的一部分。
