化妆品安全性评价中小鼠局部淋巴结试验方法的改进

目的改进小鼠局部淋巴结实验(LLNA),建立既可检测化学物致敏性也可同时检测刺激性的LLNA替代方法。方法选取一种阴性物质:4-氨苯甲酸;三种致敏阳性物:2,4-二硝基氯苯(DNCB)、己基肉桂醛(HCA)和2-氨基酚(2-APC);以及两种刺激阳性物:氢氧化钾(KOH)、十二烷基硫酸钠(SLS)。按常规LLNA方法对雌性Balb/c小鼠进行染毒,测量小鼠耳缘厚度并称量耳廓重量,于第6天获取耳引流淋巴结进行称重,制备单细胞悬液计数并用CCK-8试剂盒检测淋巴细胞增殖活性。结果受试剂量氢氧化钾、十二烷基硫酸钠和2,4-二硝基氯苯在0.5%以上剂量,可引起耳缘厚度和耳廓重量增加,与对照组相比差异有显著性(P<0.05),可判定为对皮肤有刺激性,2-氨基酚和己基肉桂醛均无刺激性。三种致敏物在致敏试验中均呈阳性,但三指标的敏感性略有不同。己基肉桂醛,2,4-二硝基氯苯,2-氨基酚均可引起淋巴结重量增加和淋巴细胞计数增加(P<0.05);中剂量以上组己基肉桂醛和2,4-二硝基氯苯和高剂量2-氨基酚的CCK-8检测均见淋巴细胞增殖明显。结论以耳缘厚度和耳廓重量作为刺激性观察指标,以淋巴结重量和淋巴细胞增殖作为致敏性观察指标的改良小鼠淋巴结实验可有效地同时评价化学物的皮肤致敏性和刺激性。

Improvement of local lymph node assay for cosmetics safety evaluation

Objective To improve the local lymph node assay (LENA) as an alternative method to detect chemicals for both sensitization and irritation. Methods The following chemicals: one negative control: 4-Aminobenzoie Acid, three sensitizers: 2, 4-dinitrochlorobenzene (DNCB), Hexyl cinnamic aldehyde (HCA), 2-Aminophenol (2-APC) and two irritations: potassium hydroxide (KOH), sodium lauryl sulphate (SLS) were selected. According to the normal LENA, groups of female Balb/c mice were treated with test solutions. The thickness of each ear was measured and each auricle was weighed. On the sixth day, the bilateral draining auricular lymph nodes were excised and weighed. The single cell suspensions were prepared, the lymphocyte were counted and the proliferations of lymph cells were detected by cell counting kit-8(CCK-8). Results Significant increase in ear thickness and weight were found in groups of KOH, SLS and DNCB (above 0.5%) (P < 0.05), which could be considered as irritants, whereas irritation were not found in 2-APC and HCA. In the allergic test, three sensitizers showed positive, but different sensitivity were found among each index. HCA, DNCB and 2-APC could all obviously augment the weight of lymph node and the lymphocyte count in different groups (P < 0.05). Conspicuous proliferation of lymphocyte were found in DNCB(all group), HCA (above the middle dose) and 2-APC (high dose) by CCK-8. Conclusion The reformed LENA using auricle thickness and weighing as observed markers for irritation, and using lymph nodes weighing and proliferation of lymphocyte as observed markers for sensitization, could evaluate both sensitization and irritation at the same time.