EGCG ameliorates colitis in DSS-induced UC mice
The typical features in the DSS-induced mice model of UC have sustained
body weight loss, diarrhea, and rectal bleeding16. The
colitis was induced in mice by administration of 3% DSS for 8days as
described in methods. We found that the bodyweight of mice in DSS group
continued to decrease significantly from day6 (figure2A) and EGCG
administration could dramatically improve body weight loss in mice by
treat with high dose (figure1A, p<0.05). The colon shortening
was restored by EGCG therapy compared with DSS treatment group (figure2B
and 2C). The spleen weight was generally measured as an indirect marker
of inflammation in all experiment groups. Different concentrations EGCG
could significantly reversed the DSS-mediated increase in the spleen
index (P<0.05, Figure 2D). Furthermore, the DAI score, which
is used as indicator to assessing the severity of colitis, increased
distinctly after DSS treatment and it was markedly lower in the HE group
(figure2E and 2F). In addition, we also observed epithelial crypt
damage, mucosa edema, disappearance of intestinal crypts and goblet
cells, and inflammatory cell infiltration by histopathological analysis
using H&E staining to assessing severity of colonic ulceration and
inflammation during experiment groups. The DSS group was sharp contrast
to the normal group (figure 2G) and EGCG could exhibited obvious
protection of mucosa damage and less histological inflammation (figure
2G), which showed a lower histopathological score (figure 2H). Thus,
these data confirm that EGCG exerts therapeutic effects on DSS-induced
colitis.