Figure 3. Andrographolide alleviates experimental colitis induced by DSS in mice. Mice were treated with 2.5% DSS in their drinking water for 7 d to induce acute colitis. Andro was administered daily via i.p. injection. Mice were sacrificed on d 10 after colitis induction. (A) The body weight of the mice was measured and presented as a percentage of the original body weight. (B) The disease activity index was calculated. (C) The length of the colon was measured when the mice were sacrificed. (D) The colon was photographed. (E and F) Paraffin-embedded colon sections were stained with H&E for light microscopy assessment of epithelial damage. (G) MPO activity in colonic tissues was detected. (H) RNA was extracted from colonic tissues, and mRNA expressions of Il17a, Ifng, Il1b, and Tnf were determined by real-time PCR. (I) Protein levels of various cytokines in colon homogenates were examined by ELISA. (J) Expression of p-RELA was analyzed by immunochemical staining of paraffin-embedded colon sections. (K) Expression of p-RELA among colonic proteins was examined by western blotting. Values are mean ± SEM of 6 mice/group. *P < 0.05, **P < 0.01 vs. DSS-treated group. Andro, andrographolide. Sulfa, Sulfasalazine.