Many plants, especially those of the Compositae family, are responsible for allgeric contact dermatitis (ACD). As a number of plant extracts used in the perfume and cosmetics industry contain significant amounts of allergenic components, it becomes very important to develop a mild procedure for the removal of these undesirable substances. We describe here one such method in which the allergens are removed by selective binding to insoluble polymer gels.
Previous studies with natural extracts
Laurel oil has been known for a long time as a contact sensitizer. Early work on Strasbourg showed that its allergenic properties could be completely suppressed by treating the oil with sodium borohydride. The activity of laurel oil (extracted from the leaves of Laurus Nobilis L., fam. Lauraccae) has been attributed to the α-methylene-γ-butyrolactones it contains. Sodium borohydride reacts with these unsaturated lactones and completely suppresses their sensitizing activity as the α-methylene group is reduced with formation of innocuous α-methyl-γ-lactones. In other cases, a loss of sensitizing activity was observed upon addition of an amino acid such as cystein to sesquiterpene lactones.
