Comparative Study of Anti-Inflammatory Effect on DSS-Induced Ulcerative Colitis Between Novel Glycyrrhiza Variety and Official Compendia

Abstract

Glycyrrhizae radix (GR), a plant commonly referred to as licorice, is used as a medicine and food worldwide. However, the utilization of GR from wild areas has caused desertification and a depletion of natural resources. Environmental restrictions and low productivity have limited plant cultivation. For this reason, an improved Glycyrrhiza variety, Wongam (WG), in cultivation and quality has been developed by Korea Rural Development Administration. To evaluate the equivalence of efficacy, several comparative studies between already-registered species and new cultivars have been conducted. This study evaluated the anti-inflammatory effect of WG extracts in a dextran sulfate sodium (DSS)-induced colitis model, in comparison to that of GR extracts. WG extract significantly improved the clinical signs of DSS-induced ulcerative colitis, including disease activity index, body weight loss, and colon length shortening, which was equivalent to the effect of GR. Furthermore, the fecal microbiota was analyzed by terminal restriction fragment length polymorphism. The composition of the fecal microbiota did not show a specific pattern based on experimental groups; however, a tendency toward an increase in the proportion of Lactobacillales was observed. These findings showed an equivalence of efficacy and the possible utilization of WG as a medicinal resource with already-registered species.