Shenhuang Plaster Application Improves Gastrointestinal Motility in Mice with Postoperative Ileus through Intestinal Microbiota

Abstract

Postoperative ileus (POI) is a common surgical complication, and its incidence remains high. Shenhuang Plaster (SHP) is a famous traditional Chinese medicine with a definite curative effect on postoperative intestinal dysfunction; however, the mechanisms involved in these effects are unclear. Accordingly, in this study, we constructed a POI mouse model and used the intestinal flora as the target to explore the regulatory effect of SHP on gastrointestinal motility. The results illustrated that SHP applied at the Shenque acupoint promoted the recovery of gastrointestinal motility, relieved intestinal villus atrophy and basal damage caused by POI, protected the integrity of intestinal tissue morphology, and alleviated the inflammatory response in the intestinal tissue of POI model mice. In addition, we clarified the role of the intestinal flora in the occurrence and development of POI, further evaluated the changes in the intestinal flora in each group of mice, and analysed the regulatory effect of SHP on the intestinal flora in mice with POI. The results suggested that SHP might improve gastrointestinal motility disorder in POI mice by effectively regulating intestinal flora.

Figure 1

Intestinal motility evaluation. (a) Gastrointestinal transmission curves: the distribution of fluorescein-labelled dextran in the gastrointestinal tract (St, stomach; SI, small intestinal segments 1–10; Co, colon segments 1–4) of mice in each group. (b) Derived geometric centre of mice in each group. The significant differences, marked with asterisks, were in comparison with the Ctrl (^∗∗∗P < 0.001), and the significant differences, marked with triangles, were in comparison with the POI (^ΔΔΔP < 0.001). Ctrl, control group; POI, postoperative ileus group; POI + SHP, Shenhuang Plaster-treated POI group. SHP protected the integrity of intestinal morphology.

Figure 2

Histological analysis of the intestine. (a) Image of haematoxylin and eosin-stained colon and ileum of Ctrl, POI, and POI + SHP mice. (b) Average length of the intestinal villus and thickness of the mucosal layer in the colon and ileum of mice in each group as measured using NDP view software. The significant differences between the POI and Ctrl groups are indicated with asterisks (^∗∗∗P < 0.001), and the significant differences marked with triangles was in comparison between the POI + SHP and the POI groups (^ΔΔΔP < 0.001). Ctrl, control group; POI, postoperative ileus group; POI + SHP, Shenhuang Plaster-treated POI group. SHP inhibited POI-induced inflammation of intestinal tissue.

Figure 3

Measurement of inflammatory responses in intestinal tissue via immunohistochemistry. (a) The expression and distribution of COX-2 protein in the colon and ileum in each group. (b) The expression and distribution of iNOS protein in the colon and ileum in each group. (c) Relative expression of some inflammatory cytokines in the ileum and colon of mice in different groups. Data are presented as fold changes compared with that of the Ctrl group. Differences between the POI and Ctrl groups are indicated by asterisks (^∗P < 0.05, ^∗∗P < 0.01, ^∗∗∗P < 0.001), and differences between the POI + SHP and POI groups are indicated by triangles (^ΔP < 0.05, ^ΔΔP < 0.01, ^ΔΔΔP < 0.001). Ctrl, control group; POI, postoperative ileus group; POI + SHP, Shenhuang Plaster-treated POI group; IL, interleukin; TNF, tumour necrosis factor; COX, cyclooxygenase; iNOS, inducible nitric oxide synthase.

Figure 4

Changes in the intestinal flora of mice in each group. (a) Analysis of alpha diversity. (b) Analysis of beta diversity. (c) Histogram of the structure and composition of the intestinal flora at the phylum level. (d) Histogram of the structure and composition of the intestinal flora at the genus level. (e) Differential species evolutionary branch diagram of the intestinal flora. (f) Correlation analysis of the intestinal flora and intestinal function evaluation indices of POI model mice. Ctrl, control group; POI, postoperative ileus group; POI + SHP, Shenhuang Plaster-treated POI group.