Fig 1.
Effect of GL administration on spleen weight in AOM/DSS-induced colorectal cancer (CC) model mice.
**p < 0.01. AOM, azoxymethane; DSS, dextran sodium sulfate; GL, glycyrrhizin.
Fig 2.
Murine splenic tissue with HE staining (A) and its areas (B). White asterisk: white pulp (WP); yellow triangle: red pulp (RP); white dotted line: marginal zone (MZ); Original magnification—20×. Graphs (B) represent the average area (bar: SD; *p < 0.05; **p < 0.01; ***p < 0.001). CC, colorectal cancer; GL, glycyrrhizin; HE, hematoxylin and eosin.
Fig 3.
Immunohistochemical analysis of FoxP3 expression in the splenic tissues of the four groups of mice.
Staining for FoxP3 (A, C) and its percentage of FoxP3-positive area (Tregs) (B, D) in the splenic tissues: RP (A, B) and WP (C, D). Brown color indicates specific immunostaining. Arrow indicates splenic capsule (Ca); Original magnification—200×. Graphs (B, D) represent the average percentage of positive area (bar: SD; **p < 0.01; *p < 0.05). CC, colorectal cancer; GL, glycyrrhizin.
Fig 4.
Immunohistochemical analysis of CD8 expression in the splenic tissues of the four groups of mice.
Staining for CD8 (A, C) and its percentage of positive area (B, D) in the splenic tissues: RP (A, B) and WP (C, D). Brown color indicates specific immunostaining. Arrow indicates splenic capsule (Ca); Original magnification—200×. Graphs (B, D) represent the average percentage of positive area (bar: SD; *p < 0.05; **p < 0.01; ***p < 0.001). RP, red pulp; WP, white pulp; CC, colorectal cancer; GL, glycyrrhizin.
Fig 5.
Immunohistochemical analysis of CD11c expression in the splenic tissues of the four groups of mice.
Staining for CD11c (A, C) and its percentage of positive area (B, D) in the splenic tissues: RP (A, B) and WP (C, D). Brown color indicates specific immunostaining. Arrow indicates splenic capsule (Ca); Original magnification—200×. Graphs (B, D) represent the average percentage of positive area (bar: SD; *p < 0.05; **p < 0.01; ***p < 0.001). RP, red pulp; WP, white pulp; CC, colorectal cancer; GL, glycyrrhizin.
Fig 6.
Immunohistochemical analysis of FoxP3 expression in the colon tissues of the four groups of mice.
Staining for FoxP3 (A-E) and its percentage of positive area (F). Brown color indicates specific immunostaining. Original magnification—200× (A, B, D, E) and 100× (C). (C) Arrows indicate non-cancer tissues (CC1) surrounding cancer area, and dotted square indicates cancer tissue (CC2). (D) Enlarged picture of dotted square in (C). Graphs (F) represent the average percentage of positive area (bar: SD; ***p < 0.001). CC, colorectal cancer; GL, glycyrrhizin.
Fig 7.
Immunohistochemical analysis of RAGE expression in the colon tissues of the four groups of mice.
Staining for RAGE (A-E) and its percentage of positive area (F). Brown color indicates specific immunostaining of RAGE. Original magnification—200× (A, B, D, E) and 100× (C). (C) Arrows indicate non-cancer tissues (CC1) surrounding cancer area, and dotted square indicates cancer tissue (CC2). (D) Enlarged picture of dotted square in (C). Graphs (F) represent the average percentage of positive area (bar: SD; *p < 0.05; **p < 0.01). CC, colorectal cancer; GL, glycyrrhizin.
Fig 8.
A possible mechanism of the role of Treg cells and its suppression by GL.
GL has been demonstrated to inhibit a series of HMGB1-TLR4-NF-κB signaling pathways and leaning to the suppression of carcinogenesis via DNA damage. As mechanisms of splenomegaly 1) DCs that have taken up cancer antigens activate CD8+ and CD4+ T cells in the spleen, and the accumulation of CTL and Treg cells in the spleen is the cause of splenomegaly. 2) Treg cells accumulated in the spleen migrate to cancer tissues and promote cancer growth by suppressing immune action by activated CTLs. Ag, antigen; AOM, azoxymethane; CTL, cytotoxic T lymphocytes; DC, dendritic cell; DSS, dextran sodium sulfate; GL, glycyrrhizin; nT, naïve T.