In the process of searching for antioxidants in plants, the methylene chloride fraction of guzeungupo-processed Curcuma longa L. was observed to have a strong scavenging effect on DPPH radicals. In the study using Caenorhabditis elegans, the methylene chloride fraction reduced the level of reactive oxygen species (ROS), while the oxidative stress resistances of superoxide dismutase (SOD) and catalase were improved. The methylene chloride fraction was also found to cause the transgenic strain CF1553 to produce resistant proteins that resist oxidative stress.
Choi et al. (Tue,) studied this question.