Multi-omics techniques to compare the potential of raw and processed licorice as food supplements for ameliorating chronic fatigue syndrome

Abstract

Licorice is the dried root or rhizome of Glycyrrhiza uralensis Fisch., Glycyrrhiza inflata Bat., and Glycyrrhiza glabra L., which has attracted considerable interest as a well-known dietary and medicinal plant. Licorice possesses a number of biological activities, including anti-inflammatory and antitumor, and is used as a major ingredient in various healthy food products. According to traditional Chinese medicine, raw licorice effectively eliminates heat and detoxifies, and processed licorice is effective in regulating the spleen and qi. Thus, we compared the effectiveness of raw and processed licorice in treating chronic fatigue syndrome (CFS) and found that processed licorice is more effective than raw licorice. The mechanisms underlying the effects of raw and processed licorice in the treatment of CFS were clarified in this study through multi-omics analysis. Results demonstrated that processed licorice increased the expression levels of the pyruvate kinase, acetyl coenzyme A acetyltransferase, and cytochrome P-450 4A2 genes, which in turn promoted glycolytic processes, cholesterol metabolism, and glycerolipid metabolism. After processing, licorice's total flavone and saponin content decreased, and the decrease in flavonoid content was more pronounced. This finding is in line with the findings of plant metabolomics, which showed that the content of saponins in the total licorice extract increased, possibly accounting for the majority of the enhanced effects. In conclusion, processed licorice is more suitable as a raw material or ingredient for medicines and functional food for CFS than raw licorice.