Abstract：
This study aims to compare six commercial adult toothpaste (labeled as A, B, C, D, E, and F) for cytotoxicity and melanocyte function alterations in vitro using primary human epidermal melanocytes from a Caucasian donor (HEMn-LP cells) as a model of oral melanocytes. Cells were incubated with toothpaste extracts (50% w/v) in culture media at dilutions (1:25, 1:50, 1:100, 1:200, 1:500, 1:800, and 1:1000) for 24 h. MTS and LDH assays were used to assess cytotoxicity. The effects of noncytotoxic toothpaste concentrations on melanocyte functional endpoints were then examined using spectrophotometric methods. All toothpaste showed concentration-dependent cytotoxicity that was heterogeneous across toothpaste containing SLS detergent. IC50 values of cytotoxicity followed the order: A = E > C > B > D > F. To compare toothpaste, they were tested at 1:800 and 1:1000 dilutions that were noncytotoxic after 24 h. None of the toothpaste affected cellular melanin production. However, toothpaste A, C, and D suppressed tyrosinase activity at both dilutions, while toothpaste B suppressed tyrosinase activity only at 1:800 dilution. Toothpaste A, C, E, and F elevated ROS production at 1:800 dilution, with no change at 1:1000 dilution. Toothpaste has a heterogeneous effect on melanocytes. Toothpaste B, E, and F at 1:1000 dilution were the safest as they did not alter melanocyte functions at this dilution, although toothpaste F is the least cytotoxic of these. Future studies are necessary to expand these results in a physiological environment of oral tissue. The findings of this study provide novel insight into the biocompatibility studies of toothpaste on oral melanocytes. They can aid dental practitioners and consumers in selecting noncytotoxic toothpaste that do not contribute to ROS generation by melanocytes in the oral cavity or lead to cytotoxicity and impaired cellular function.
摘要：
这项研究旨在比较六种商业成人牙膏(标记为A，B,C,D,E,和F）使用来自高加索人供体的原代人表皮黑素细胞（HEMn-LP细胞）作为口腔黑素细胞模型，在体外进行细胞毒性和黑素细胞功能改变。将细胞与牙膏提取物(50%w/v)在培养基中以稀释度(1:25、1:50、1:100、1:200、1:500、1:800和1:1000)孵育24小时。MTS和LDH测定用于评估细胞毒性。然后使用分光光度法检查非细胞毒性牙膏浓度对黑素细胞功能终点的影响。所有牙膏均显示浓度依赖性细胞毒性，在含有SLS洗涤剂的牙膏中具有异质性。细胞毒性的IC50值依次为：A=E>C>B>D>F。它们在24小时后无细胞毒性的1:800和1:1000稀释度进行测试。没有牙膏影响细胞黑色素的产生。然而,牙膏A,C,和D抑制酪氨酸酶活性在两个稀释，而牙膏B仅在1:800稀释时抑制酪氨酸酶活性。牙膏A,C,E,和F在1:800稀释时提高了ROS的产生，在1:1000稀释时没有变化。牙膏对黑素细胞具有异质性作用。牙膏B,E,和F在1:1000稀释是最安全的，因为他们没有改变黑素细胞的功能在这个稀释，虽然牙膏F是这些中细胞毒性最小的。未来的研究有必要在口腔组织的生理环境中扩展这些结果。这项研究的发现为牙膏对口腔黑素细胞的生物相容性研究提供了新的见解。它们可以帮助牙科医生和消费者选择不促进口腔中黑素细胞产生ROS或导致细胞毒性和细胞功能受损的非细胞毒性牙膏。
