Protective effect of homogeneous polysaccharides of Wuguchong (HPW) on intestinal mucositis induced by 5-fluorouracil in mice

Abstract

Background: In hospitalized patients, drug side effects usually trigger intestinal mucositis (IM), which in turn damages intestinal absorption and reduces the efficacy of treatment. It has been discovered that natural polysaccharides can relieve IM. In this study, we extracted and purified homogenous polysaccharides of Wuguchong (HPW), a traditional Chinese medicine, and explored the protective effect of HPW on 5-fluorouracil (5-FU)-induced IM.

Methods and results: First, we identified the physical and chemical properties of the extracted homogeneous polysaccharides. The molecular weight of HPW was 616 kDa, and it was composed of 14 monosaccharides. Then, a model of small IM induced by 5-FU (50 mg/kg) was established in mice to explore the effect and mechanism of HPW. The results showed that HPW effectively increased histological indicators such as villus height, crypt depth and goblet cell count. Moreover, HPW relieved intestinal barrier indicators such as D-Lac and diamine oxidase (DAO). Subsequently, western blotting was used to measure the expression of Claudin-1, Occludin, proliferating cell nuclear antigen, and inflammatory proteins such as NF-κB (P65), tumour necrosis factor-α (TNF-α), and COX-2. The results also indicated that HPW could reduce inflammation and protect the barrier at the molecular level. Finally, we investigated the influence of HPW on the levels of short-chain fatty acids, a metabolite of intestinal flora, in the faeces of mice.

Conclusions: HPW, which is a bioactive polysaccharide derived from insects, has protective effects on the intestinal mucosa, can relieve intestinal inflammation caused by drug side effects, and deserves further development and research.

Keywords: 5-Fluorouracil; Drug side effects; Intestinal barrier; Intestinal mucositis; Polysaccharide; Wuguchong.

Fig. 1

Purification and identification of HPW. A Elution curves of crude polysaccharides and the position of HPW. The abscissa is the number of elution tubes, and the ordinate is the absorbance value of the tracking sugar levels at 490 nm by the phenol–sulfuric acid method. B Ion chromatogram of the monosaccharide composition of HPW samples. The abscissa is the retention time (Time, min), and the ordinate is the response value of the ion detection (Response, nC). C Aggregated table of properties and monosaccharide composition of HPW

Fig. 2

Effect of HPW on the physiological manifestations of mice. A Body weight change analysis. (Weight/initial weight) × 100%. B The diarrhoea scores of the mice. C Food intake of mice in each group. The data are presented as the means ± SEM and were analysed using one-way ANOVA followed by Dunnett’s test (n = 8). “*” represents the comparison with the model group (water + 5-FU), and “#” represents the comparison with the control group (water + saline). One tag means p < 0.05, two tokens represent p < 0.01, and three indicates p < 0.001

Fig. 3

Microhistological examination of the small intestine. A HE staining of intestine tissues (scale bar = 100 μm). B Villus height. C Crypt depth. D The ratio of V/C. E PAS staining of goblet cells (scale bar = 50 μm). F Analysis of goblet cell counts. The data are presented as the means ± SEM and were analysed using one-way ANOVA followed by Dunnett’s test (n = 8). “*” represents the comparison with the model group (water + 5-FU), and “#” represents the comparison with the control group (water + saline). One tag means p < 0.05, two tokens represent p < 0.01, and three is p < 0.001

Fig. 4

Effect of HPW on small intestinal barrier indices. A D-lactic acid (D-LA), B DAO and E total antioxidant capacity (T-AOC) in serum. C SIgA in tissue homogenate. D Contrast diagram showing Occludin, Claudin-1, PCNA and GAPDH protein bands. F–H Analysis of their respective greyscale values. The data are presented as the means ± SEM and were analysed using one-way ANOVA followed by Dunnett’s test (n = 8). The “*” represents the comparison with the model group (water + 5-FU), and “#” represents the comparison with the control group (water + saline). One tag means p < 0.05, two tokens represent p < 0.01, and three are p < 0.001

Fig. 5

Effect of HPW on the inflammatory pathway and inflammatory factors. Greyscale value analysis of A COX-2, B NF-κB and D TNF-α. C Contrast diagram showing these three molecules and GAPDH protein bands. Analysis of E IL-1β, F IL-10 in tissue homogenate. The data are presented as the means ± SEM and were analysed using one-way ANOVA followed by Dunnett’s test (n = 8). “*” represents the comparison with the model group (water + 5-FU), and “#” represents the comparison with the control group (water + saline). One tag means p < 0.05, two tokens represent p < 0.01, and three are p < 0.001

Fig. 6

Effect of HPW on SCFAs. Analysis of A total SCFAs, B acetic acid, C propionic acid, and D butyric acid. The data are presented as the means ± SEM and were analysed using one-way ANOVA followed by Dunnett’s test (n = 8). “*” represents the comparison with the model group (water + 5-FU), and “#” represents the comparison with the control group (water + saline). One tag means p < 0.05, two tokens represent p < 0.01, and three are p < 0.001