Angelica acutiloba Kitagawa Extract Attenuates DSS-Induced Murine Colitis

Abstract

We examined the protective effects of Angelica acutiloba Kitagawa (AAK) extract on a murine model of acute experimental colitis. Colitis was induced by 4% dextran sulfate sodium (DSS) in the drinking water of male C57BL/6 mice, for 7 consecutive days. Oral administration of AAK extract (500 mg/kg/day) significantly alleviated DSS-induced symptoms such as anorexia, weight loss, events of diarrhea or bloody stools, and colon shortening. Histological damage was also ameliorated, as evidenced by the architectural preservation and suppression of inflammatory cell infiltration in colonic samples. Treatment improved the colonic mRNA expression of different inflammatory markers: cytokines, inducible enzymes, matrix metalloproteinases, and tight junction-related proteins. In the isolated serum, IgE levels were downregulated. Collectively, these findings indicate the therapeutic potentials of AAK as an effective complementary or alternative modality for the treatment of ulcerative colitis.

Figure 1

HPLC-PDA profiles of the index compound decursin, decursinol angelate, and the ethanol extract of AAK. Chromatograms of (a) decursin, decursinol angelate, and (b) AAK were monitored at 330 nm. Quantitative content of decursin and decursinol angelate in AAK was <0.001%.

Figure 2

Effects of AAK extract on the symptoms of DSS-induced colitis. (a) Daily changes of food intake. Average food intake per mouse was calculated by dividing total consumption of chow on a specific day with the number of mice per cage. (b) Daily changes of body weight. Body weight was calculated by dividing weight on a specific day with the initial weight of each mouse. Stool samples were monitored daily for scoring of (c) consistency and (d) occult blood. Data represent the percentage or mean ± SD (n = 4–6 per group). ^∗ p < 0.05; ^∗∗ p < 0.01; ^∗∗∗ p < 0.001 versus DSS.

Figure 3

Effects of AAK extract on the colon length and spleen weight of DSS-induced colitis. Mice colon and spleen samples were collected on the day of sacrifice. (a) Colon length of each group. (b) Macroscopic images of the colon. (c) Spleen weight of each group. Data represent the mean ± SD (n = 4–6 per group). ^### p < 0.001 versus control; ^∗∗∗ p < 0.001 versus DSS.

Figure 4

Effects of AAK extract on the colonic histological property of DSS-induced colitis. (a) Representative microscopic images of hematoxylin and eosin (H&E) stained colon sections in each group. Scale bars indicate 400 μm for transverse sections (100x) and 100 μm for longitudinal sections (400x). (b) Cumulative histology scores for each group. Data represent the mean ± SD (n = 4–6 per group). ^### p < 0.001 versus control; ^∗ p < 0.05 and ^∗∗∗ p < 0.001 versus DSS.

Figure 5

Effects of AAK extract on the gene expression levels of inflammatory mediators in DSS-induced colitis. (a–f) mRNA expression of TNF-α, IFN-γ, IL-1β, IL-6, IL-12, and IL-10 was measured by real-time PCR, and GAPDH was used as an endogenous control. Fold-changes are expressed as the mean ± SD (n = 4–6 per group). ^# p < 0.05, ^## p < 0.01, and ^### p < 0.001 versus control; ^∗ p < 0.05, ^∗∗ p < 0.01, and ^∗∗∗ p < 0.001 versus DSS.

Figure 6

Effects of AAK extract on the gene expression levels of inducible enzymes and MMPs in DSS-induced colitis. (a–d) mRNA expression of COX-2, iNOS, MMP-9, and MMP-14 was measured by real-time PCR, and GAPDH was used as an endogenous control. Fold-changes are expressed as the mean ± SD (n = 4–6 per group). ^# p < 0.05 and ^## p < 0.01 versus control; ^∗ p < 0.05 and ^∗∗ p < 0.01 versus DSS.

Figure 7

Effects of AAK extract on the gene expression levels of tight junction-related proteins in DSS-induced colitis. (a–c) mRNA expression of occludin, ZO-1, and ICAM-1 was measured by real-time PCR, and GAPDH was used as an endogenous control. Fold-changes are expressed as the mean ± SD (n = 4–6 per group). ^## p < 0.01 and ^### p < 0.001 versus control; ^∗ p < 0.05 versus DSS.

Figure 8

Effects of AAK extract on the concentrations of serum IgE in DSS-induced colitis. Total serum IgE levels were measured by ELISA. Values are expressed as the mean ± SD (n = 4–6 per group). ^# p < 0.05 versus control; ^∗ p < 0.05 versus DSS.