Glycyrrhizic acid, active component from Glycyrrhizae radix, prevents toxicity of graphene oxide by influencing functions of microRNAs in nematode Caenorhabditis elegans.

We investigated effects of pretreatment with Glycyrrhizae radix (GR) or its specific components on toxicity of graphene oxide (GO) in Caenorhabditis elegans. GR pretreatment prevented GO toxicity on function of both primary and secondary targeted organs. Among active components in GR, the beneficial effects of GR were attributable to presence of glycyrrhizic acid. Glycyrrhizic acid pretreatment suppressed translocation of GO into secondary targeted organs through intestinal barrier. Glycyrrhizic acid pretreatment recovered expression patterns of dysregulated microRNAs (miRNAs) induced by GO, and genes required for oxidative stress control acted as targeted genes for some of these miRNAs. Among these miRNAs, mir-360 mutation enhanced beneficial effects of glycyrrhizic acid. We hypothesize that glycyrrhizic acid may prevent GO toxicity and translocation by influencing functions of miRNAs which upstream regulate functions of their targeted genes. Furthermore, glycyrrhizic acid had potential to extend lifespan, and to suppress accelerated aging process induced by GO. FROM THE CLINICAL EDITOR: Exposure to graphene oxide may pose toxic effects to health, as suggested in animal studies. In this article, the authors showed that the use of glycyrrhizae radix (GR) prevented toxicity of graphene oxide in Caenorhabditis elegans. These results may provide novel strategies in the reducing potential side effects of nanoparticles.