Sensitization Properties of Propolis and Balsam of Peru in Guinea Pig Maximization Test(GPMT)

Introduction: Propolis is used in Poland as an active ingredient of some drugs administered externally, dietary supplements and cosmetics. According to the literature, propolis is a non-toxic and safe substance, although it may cause allergic contact dermatitis. Aim: The aim of this study was to assess the allergenic properties of propolis and Balsam of Peru. Material and methods: The study was conducted according to the OECD Guideline for testing of chemicals-Skin sensitization with use of Guinea pig maximization test (GPMT). Guinea pigs have similar sensitivity to allergens as human body. Sensitization properties of propolis were tested in comparison with sensitization properties of Balsam of Peru because of the possibility of cross-reaction between those two substances. Results: The skin of guinea pigs in the propolis group showed no visible change compared to the control group during the first (48 h) and second observation (72 h). The skin of guinea pigs from Balsam of Peru group showed discrete erythema in only one case at the first observation (8.33% of the animals). During the second observation, no visible changes were observed compared to the control group. Conclusions: Guinea pig maximization test showed no sensitizing properties of propolis and weak sensitizing properties of Balsam of Peru in concentration of 5%.

Guinea Pig Maximization Test for Trichloroethylene and Its Metabolites

Objectives To study the contact allergenic activities of trichloroethylene (TCE) and its three metabolites trichloroacetic acid, trichloroethanol and chloral hydrate. Methods A modified guinea pig maximization test (GPMT) was adopted. The skin sensitization (edema and erythema) was observed in trichloroethylene, trichloroacetic acid, trichloroethanol, chloral hydrate and 2,4-dinitrochlorobenzene. Results The allergenic rate of TCE, trichloroacetic acid and 2,4-dinitrochlorobenzene was 71.4%, 58.3% and 100.0% respectively, and that of trichloroethanol and chloral hydrate was 0%. The mean response score of TCE, trichloroacetic acid and 2,4-dinitrochlorobenzene was 2.3, 1.1, 6.0 respectively. The histopathological analysis also showed an induction of allergenic transfomation in guinea pig skin by both TCE and trichloroacetic acid. Conclusion TCE appears to be a strong allergen while trichloroacetic acid a moderate one. On the other hand, both trichloroethanol and chloral hydrate are weak sensitization potentials. Immunologic reaction induced by TCE might be postulated as the pathological process of this illness. Consequently, it is suggested that in the mechanism of Occupational Dermatitis Medicamentose-Like (ODML) induced by TCE, the chemical itself might be the main cause of allergy. As one of its metabolic products, trichloroacetic acid might be a subordinate factor.

几种壳聚糖类产品的致敏试验研究

目的通过豚鼠最大剂量试验(GPMT)、小鼠局部淋巴结试验(LLNA)、人细胞系激发试验(h-CLAT)探究几种壳聚糖类产品的致敏性。方法将羧甲基壳聚糖、壳聚糖止血粉、羧甲基壳聚糖愈创膏、羧甲基壳聚糖止血纱作为试验样品,按GB/T 16886.12规定的比例浸提制备受试液,按GB/T 16886.10-2017进行GPMT、LLNA试验,按OECD442(E)进行h-CLAT试验,对样品进行致敏性检测。结果羧甲基壳聚糖、壳聚糖止血粉、羧甲基壳聚糖愈创膏、羧甲基壳聚糖止血纱的GPMT、LLNA试验结果均为阴性。h-CLAT试验中,羧甲基壳聚糖、羧甲基壳聚糖愈创膏、羧甲基壳聚糖止血纱的综合判定结果为阴性;壳聚糖止血粉100%、50%、25%浓度受试液CD54的相对荧光强度(RFI)均高于2.00,CD86的RFI均高于1.50,综合判定结果为阳性。结论采用作为皮肤致敏评价体外替代方法之一的h-CLAT评估壳聚糖止血粉的致敏反应风险有待于进一步研究。

豚鼠最大值试验的方法学改进探讨

目的对豚鼠最大值试验(GPMT)的试验方法进行改进,提高GPMT法的可操作性和重复性。方法对试验剂量的确定、试剂的选择、试验动物与分组、受试物前处理、去毛方法、十二烷基硫酸钠(SLS)的应用、动物固定以及试验结果观察8个方面进行改进及完善。使用改进后的GPMT法对三氯乙烯(TCE)进行致敏试验2次。结果细化了试验剂量的确定方法和试剂、实验动物、受试物前处理和SLS的使用方法。明确了电动剃毛刀的去毛效果。确定了无刺激胶布法作为受试物固定的有效方法。皮肤过敏反应情况应在去除激发斑贴后5h开始进行观察。重复激发的致敏率和致敏强度均下降。TCE两次致敏率分别为52%和48%,且差异无显著性(P>0.05)。结论改进后的GPMT法提高了操作性,重复性好。

三氯乙烯致豚鼠皮肤变态反应和血清免疫球蛋白水平改变

目的:探讨三氯乙烯(TCE)对豚鼠皮肤变态反应和血清免疫球蛋白水平的改变。方法:采用豚鼠最大值试验GPMT,动物分成阴性对照组、阳性对照组和TCE实验组,每组6只豚鼠,分别皮内注射橄榄油、2,4-二硝基氯苯(DNCB)和TCE。实验结束后观察动物皮肤改变,应用自动生化分析仪检测致敏动物血清免疫球蛋白水平。结果:阳性对照组和TCE实验组动物出现明显皮肤损害,阳性对照组动物致敏率为100%,TCE实验组致敏率为83.3%。TCE致敏豚鼠血清总IgG含量明显高于阴性对照组(P<0.05)。结论:三氯乙烯属于强致敏物,可诱导豚鼠产生皮肤变态反应,引起血清免疫球蛋白改变。

低收缩性树脂封闭剂的研制及其生物相容性研究

目的探讨以双甲基丙烯酸酯类新单体为基质单体的低收缩树脂封闭剂(LSRCS)的合成及其生物相容性。方法将单体以特定比例混合,按配方设计加入无机填料,以封闭剂的流动性和溶解性为标准优化填料比例,以双键转化率、聚合收缩、流动性和溶解性优化有机与无机组分比例,获得性能最优的LSRCS。按照ISO10993标准通过细胞毒性试验、急性全身毒性试验、溶血试验和致敏试验,系统评价LSRCS生物相容性。结果通过优化配比获得填料含量为50%的LSRCS,其填料配方BaSO4∶ZnO∶HA=9∶3∶2。细胞毒性试验毒性等级随时间延长而增大,毒性顺序为Epiphany>LSRCS>AHPlus;急性毒性试验两组小鼠活动、体重、呼吸及组织病理学均无明显差异;LSRCS溶血率0.20%,无溶血性;致敏豚鼠试验组无红斑及水肿。结论本课题组合成LSRCS,经检验其具有良好的生物相容性。

豚鼠最大值试验法研究二氯乙酰氯皮肤致敏作用的初步报告

目的探讨二氯乙酰氯(DCAC)是否在三氯乙烯药疹样皮炎发病过程中起到半抗原的作用。方法按豚鼠最大值试验(GPMT)法,用DCAC对白色豚鼠进行皮内和涂皮结合法致敏试验,并设阳性对照组(二硝基氯苯)、阴性对照组(橄榄油和福氏完全佐剂),观察各组动物皮肤的红斑和水肿等情况,求出致敏率和平均反应值,并且检测ALT和AST以及计算各脏器系数。结果 DCAC实验组、阳性对照组和阴性对照组的致敏率分别为0%、100%和0%;平均反应值分别为0、6.0和0;各实验组豚鼠的ALT和AST以及脏器系数差异无统计学意义。结论 DCAC可能在三氯乙烯药疹样皮炎发病过程中没有起到半抗原的作用,并且对实验动物没有明显肝功能损害。