The impact of mangiferin from Belamcanda chinensis on experimental colitis in rats

Abstract

Background: Inflammatory bowel disease (IBD) [including Crohn's disease (CD) and ulcerative colitis (UC)] constitutes an important clinical problem. The pathogenesis of IBD remains unclear. It is believed that immune dysfunction, inflammatory mediators and oxidative damage play crucial roles in development of IBD. The condition is clinically associated with symptoms ranging from mild to severe during relapses, depending on the affected segment of the gastrointestinal tract. Bloody diarrhea with mucus, abdominal pain, weight loss and anemia are initial symptoms of both CD and UC. Differences between diseases become more evident in time, along with the development of intestinal and extraintestinal complications. Mangiferin (1,3,6,7-tetrahydroxyxanthone-C-2-β-D-glucoside), a natural polyphenol in plants, exerts antioxidant and anti-inflammatory effects making it an interesting option for the treatment of inflammatory pathologies associated with oxidative stress in humans, such as IBD.

Purpose: The aim of the current study was to elucidate the impact of mangiferin on colon tissues in 2,4,6-trinitrobenzensulfonic acid (TNBS)-induced colitis in rats.

Methods: Mangiferin was obtained from Belamcanda chinensis rhizomes by a multistage process. Groups of rats were pre-treated with 10, 30 or 100 mg/kg of mangiferin, or with distilled water administered intragastrically for 16 days. An ethanol solution of TNBS or saline was given rectally on the day 15 of the experiment. The experiment was terminated on the day 17. The colon was removed, cleaned, weighed and examined macro- and microscopically. Determination of tumor necrosis factor α (TNF-α), interleukin 17 (IL-17), malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity were performed spectrophotometrically in homogenates of colon tissues.

Results: Rats in the TNBS group developed symptoms of colitis, including: body weight loss, colon mass index increase and damage of intestinal tissues with concomitant increase in TNF-α, IL-17, MDA levels and decreased SOD activity. In non-TNBS-treated rats mangiferin did not cause any changes of studied parameters. Pre-treatment with mangiferin exerted a protective effect, reducing the intensity of damage caused by TNBS. Mangiferin at the doses of 30 and 100 mg/kg reduced the macro- and microscopic damage score and the MDA level in colon tissues. Only at the dose of 100 mg/kg, mangiferin decreased TNF-α and IL-17 concentrations, and SOD activity in colon tissues.

Conclusion: Mangiferin attenuates inflammatory changes of colon tissues in experimental, TNBS-induced colitis in rats. Protective effect exerted by mangiferin depends primarily on its anti-inflammatory activity and secondarily on its antioxidant properties.

Keywords: Experimental colitis; Inflammatory bowel disease; Interleukin-17; Mangiferin; Trinitrobenzensulfonic acid; Tumor necrosis factor α.

Fig. 1

Multiple reaction monitoring (MRM) chromatograms recorded during the analysis of the methanol extract of mangiferin standard (a) and obtained mangiferin (b). In the whole range of peak there is only one mass 421.1 m/z

Fig. 2

The impact of mangiferin on rat: body weight (a), colon mass index (b), macroscopic damage of colon tissues (c), microscopic damage of colon tissues (d), colon tissues TNF-α concentration (e), colon tissues IL-17 concentration (f), colon tissues MDA concentration (g), SOD activity in colon tissues (h) in experimental groups; K—the control group, M₁₀, M₃₀, M₁₀₀—groups receiving, respectively, 10, 30 or 100 mg/kg of mangiferin intragastrically, C—the group receiving only TNBS rectally, CM₁₀, CM₃₀, CM₁₀₀—groups receiving 10, 30 or 100 mg/kg of mangiferin with TNBS, respectively. Macroscopic evaluation of colonic tissue damage according to the criteria described by Galvez et al.: score 0 (no damage); score 1 (hyperemia, no ulcers); score 2 (linear ulcer with no significant inflammation); score 3 (linear ulcer with inflammation at one site); score 4 (two or more sites of ulceration or inflammation and ulceration or inflammation extending <1 cm); score 5 (two or more major sites of ulceration or inflammation extending >1 cm along the length of the colon) Microscopic evaluation of colonic tissue damage: in mucosal epithelium and lamina propria: ulceration (0–4), mononuclear cell infiltration (0–3), polymorphonuclear cell infiltration (0–3); in submucosa: edema (0–3), mononuclear cell infiltration (0–3), polymorphonuclear cell infiltration (0–3); in muscular layer: mononuclear cell infiltration (0–3), polymorphonuclear cell infiltration (0–3). Scoring scale: 0—none, 1—mild, 2—moderate, 3—severe, 4—full-thickness; maximum score: 25. Results are presented as mean values ± SD. Differences ***p < 0.001 vs the control group; **p < 0.01 vs the control group; *p < 0.05 vs the control group; ^### p < 0.001 vs the TNBS group; ^## p < 0.01 vs the TNBS group; ^# p < 0.05 vs the TNBS group were deemed statistically significant

Fig. 3

Microscopic appearance of colon tissues after hematoxylin-eosin staining showed that mangiferin reduces histological damage; control group (K), groups receiving mangiferin at the doses of 10 or 30 or 100 mg/kg (M₁₀, M₃₀, M₁₀₀, respectively), group receiving only TNBS (C), groups receiving mangiferin at the doses of 10 or 30 or 100 mg/kg with TNBS (CM₁₀, CM₃₀, CM₁₀₀, respectively); magnification 200×

Fig. 4

Microscopic appearance of colon tissues after Giemsa staining showed that mangiferin reduces the inflammatory cells infiltration (a); and after Alcian blue staining showed that mangiferin prevents loss of mucus layer (b); control group (K), group receiving only TNBS (C), groups receiving mangiferin at the doses of 10 or 30 or 100 mg/kg with TNBS (CM₁₀, CM₃₀, CM₁₀₀, respectively); magnification 200×