The ethanolic extract of domesticated Amauroderma rugosum alleviated DSS-induced ulcerative colitis via repairing the intestinal barrier

Abstract

Amauroderma rugosum (Blume and T. Nees) Torrend (Ganodermataceae) (A. rugosum) has been found to have anti-inflammatory ability in previous studies. The present study aimed to verify the therapeutic benefits of A. rugosum in the treatment of ulcerative colitis and to investigate its underlying mechanism of action. Acute experimental ulcerative colitis was induced by feeding the mice drinking water supplemented with dextran sodium sulfate (DSS). The findings indicated that the ethanolic extract of domesticated A. rugosum exhibited therapeutic efficacy comparable to Salazosulfapyridine (SASP) in mitigating clinical symptoms and the pathological score of the colon. Furthermore, A. rugosum exhibited the capacity to enhance the expression of tight junction (TJ) proteins, while concurrently decreasing the levels of TNF-ɑ and IL-6. A noteworthy finding is that it exhibited the capability to diminish the nuclear translocation of NF-κB p65. In conclusion, A. rugosum attenuates DSS-induced ulcerative colitis by enhancing intestinal barrier function and inhibiting mucosal inflammation.

Supplementary information: The online version contains supplementary material available at 10.1007/s10068-024-01565-5.

Keywords: Amauroderma rugosum; Intestinal barrier; NF-κB p65; Ulcerative colitis.

Fig. 1

Oral administration of A. rugosum attenuates the severity of DSS-induced colitis. A Mouse body weight change as a percentage. B DAI scores. C, D The length of the mice colon. E Histopathologic score of colon (n = 6). F H&E staining of colon tissue in mice (scale bars: 100 μm). G The experimental scheme. Results are expressed as means ± SD (n = 10). ^##P < 0.01 and ^###P < 0.001vs. Control group, *P < 0.05, **P < 0.01 and ***P < 0.001 vs. DSS group

Fig. 2

Amauroderma rugosum restores the expression of colonic tight junction protein in UC mice. A The expressions of ZO-1 and Claudin5 in colon tissue were detected by immunohistochemistry (n = 4, scale bars: 50 μm). B The expression of ZO-1 and Occludin in mouse colon tissue was detected by western blotting. Results are expressed as means ± SD (n = 4). ^#P < 0.05 vs. Control group, **P < 0.01 and ***P < 0.001 vs. DSS group

Fig. 3

Amauroderma rugosum promotes the recovery of Occludin expression in colon tissue of UC mice. The localization of occludin in the mouse colon was determined by immunofluorescence staining, n = 4, scale bars: 100 μm

Fig. 4

The effect of Amauroderma rugosum on goblet cells and sIgA. A Representative Alcian Blue staining images of colonic sections (n = 6, scale bars: 100 μm). B SIgA level was examined by ELISA. Results are expressed as means ± SD (n = 6). ^###P < 0.001 vs. Control group, **P < 0.01 and ***P < 0.001 vs. DSS group

Fig. 5

Amauroderma rugosum attenuates inflammation in the colon. A Western blotting banding pictures of NF-κB p65. B, C Statistic analysis of NF-κB p65 protein expression (n = 4). D TNF-ɑ levels were detected in the colon homogenates with ELISA (n = 6). E IL-6 levels were detected in the colon homogenates with ELISA (n = 6). Results are expressed as means ± SD, ^###P < 0.001 vs. Control group, ^**P < 0.01 and ^***P < 0.001 vs. DSS group