Fig 3. Effects of the addition of berberine to 5-ASA on colon tissue injury and mRNA expressions of mucin genes of DSS-induced chronic relapsing colitis mice.

Experimental colitis was induced by giving mice three cycles of DSS. Each cycle consisted of 2% DSS for five days followed by drinking water for 14 days. The first and last day of DSS treatment were designated as days 0 and 43, respectively. From day 13, experimental mice were treated daily with 5-ASA (200 mg/kg) alone or 5-ASA plus berberine hydrochloride (20 mg/kg) through gavage of 0.2 ml of the respective solution during the 30 days of concomitant DSS-colitis induction. Control mice received water alone. At the end of treatment, mice were killed and the colon sections were collected and subjected to paraffin embedding and later hematoxylin and eosin (H&E) staining for light microscopic assessment (A) and colon injury/inflammation scoring (B). Scale bar = 50 or 100 μm. The colonic mRNA expression of MUC1 (C), MUC2 (D), MUC4 (E) and the housekeeping gene Gapdh in colitis mice was determined by RT-qPCR. The cytokine mRNA expression level in the water group was set as 100%, and mRNA expression levels in treated mice were compared with the water group. ^b P < 0.01 versus water; ^e P < 0.05, ^f P < 0.01 versus DSS; ^h P < 0.05 versus 5-ASA alone (n = 4 mice per treatment group).