Licorice extract and its active fraction Gly1 promote Treg cells in vivo.
(a) C57BL/6 mice were orally administrated with licorice or water, Foxp3+CD4+ Treg cells in peripheral blood were monitored every three days (n = 5 mice per group). (b) Analysis of Foxp3 protein expression of a per-cell basis in (a). Data are shown as mean fluorescence intensity (MFI). (c–f) C57BL/6 mice were orally administrated with licorice (c) or Gly1 fraction (d), Foxp3+CD4+ Treg cells in colonic lamina propria and spleen were analyzed after two weeks (n = 5 mice per group). (e) Quantification of the result in (c) (n = 5 mice per group). (f) Quantification of the result in (d). (g,h) Mice were treated with Gly1 fraction and induced colitis using dextran sulfate sodium and the body weight (g) and colon shortness (h) were analyzed (n = 6 mice per group). Results are expressed as means ± SEM and are representative of three experiments. *P < 0.05, **P < 0.01 and ***P < 0.001, as determined by Man-Whitney U test (e,f), one-way ANOVA followed by Bonferroni’s test (b), or two-way ANOVA (a,g).