Department of Pharmacology and Pharmacotherapy, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, K-2100, Copenhagen, Denmark,
Cytotechnology. 2013 Oct;65(5):887-94. doi: 10.1007/s10616-012-9530-6. Epub 2013 Jan 18.
Cell culture systems are widely used for the investigation of in vitro immunomodulatory effects of medicines and natural products. Since many pharmacological relevant compounds are water-insoluble, solvents are frequently used in cell based assays. Although many reports describe the cellular effects of solvents at high concentrations, only a few relate the effects of solvents used at low concentrations. In this report we investigate the interference of three commonly used solvents: Dimethyl sulfoxide (DMSO), ethanol and β-cyclodextrin with five different cell culture systems. The effects of the solvents are investigated in relation to the cellular production of interleukin (IL)-6 or reactive oxygen species (ROS) after lipopolysaccharide (LPS) stimulation. We show that DMSO above 1 % reduces readout parameters in all cell types but more interestingly the 0.25 and 0.5 % solutions induce inhibitory effects in some cell types and stimulatory effects in others. We also found that LPS induced ROS production was more affected than the IL-6 production in the presence of ethanol. Finally we showed that β-cyclodextrin at the investigated concentrations did not have any effect on the LPS induced IL-6 production and only minor effects on the ROS production. We conclude that the effects induced by solvents even at low concentrations are highly relevant for the interpretation of immunomodulatory effects evaluated in cell assays. Furthermore, these results show the importance of keeping solvent concentrations constant in serial dilution of any compound investigated in cell based assays.
细胞培养系统广泛用于研究药物和天然产物的体外免疫调节作用。由于许多具有药理学相关性的化合物不溶于水，因此常在细胞实验中使用溶剂。尽管许多报告描述了高浓度溶剂对细胞的影响，但只有少数报告涉及低浓度溶剂的影响。在本报告中，我们研究了三种常用溶剂：二甲基亚砜（DMSO）、乙醇和β-环糊精对五种不同细胞培养系统的干扰。研究了溶剂的作用与脂多糖（LPS）刺激后细胞内白细胞介素（IL）-6 或活性氧（ROS）的产生的关系。我们发现 DMSO 浓度超过 1%会降低所有细胞类型的读数参数，但更有趣的是，0.25%和 0.5%的溶液在一些细胞类型中产生抑制作用，而在另一些细胞类型中产生刺激作用。我们还发现，在存在乙醇的情况下，LPS 诱导的 ROS 产生比 IL-6 产生更容易受到影响。最后，我们表明，在所研究的浓度下，β-环糊精对 LPS 诱导的 IL-6 产生没有任何影响，仅对 ROS 产生产生轻微影响。我们得出结论，即使在低浓度下，溶剂引起的影响对细胞实验中评估的免疫调节作用的解释也非常重要。此外，这些结果表明，在细胞实验中对任何化合物进行连续稀释时，保持溶剂浓度恒定非常重要。
