The protective effects of total phenols in magnolia officinalix rehd. et wils on gastrointestinal tract dysmotility is mainly based on its influence on interstitial cells of cajal

Abstract

Magnolia officinalix Rehd. et Wils is a kind of herb which is widely used for gastrointestinal tract mobility disorder in Asian countries. In this study, we investigated whether the total phenols of Magnolia officinalix Rehd. et Wils (TPM) treatment improves gastrointestinal tract dysmobility induced by intraperitoneal injection of atropine (5 mg/kg) in rats. Rats were randomly grouped into three units: TPM-pretreated/atropine-treated group, atropinetreated group and control group. TPM were administrated for 7 days. Gastric residual rate and intestinal transit were measured 20 min after atropine injected, and gastrointestinal hormones (including: gastrin (GAS), motilin (MTL), somatostatin (SS) and p substance (PS) levels in serum were also measured by ELISA kits. The number and distribution of interstitial cells of Cajal (ICCs) in stomach were detected by immunohistochemistry analysis, while c-kit and stem cell factor (SCF) expressions in stomach were also measured by western blotting. We found that TPM pretreatment significantly improved atropine-induced gastric residual rate increase, while had no significantly effects on intestinal transit; it also significantly normalized GAS, MTL and PS serum levels. Atropine-induced ICCs numbers decreased in both sinuses ventriculi and body of stomach, which is improved by TPM pretreatment. Western blotting results showed the expressions of c-kit and SCF were down-regulated after atropine injection, which can be reversed with TPM pretreatment. These results above indicates that TPM treatment can significantly protected atropine-induced gastric dysmoblility, which may owed to its regulation on c-kit/SCF signing pathway.

Keywords: Magnolia officinalix Rehd. et Wils; gastrointestinal tract; interstitial cells of Cajal (ICCs); mobility disorder.

Figure 1

The HPLC profile of total phenols of Magnolia officinalix Rehd. et Wils (TPM). A. HPLC chromatogram for the standard substances of magnolol and honokiol; B. HPLC chromatogram for total phenols of Magnolia officinalix Rehd. et Wils (TPM).

Figure 2

The protective effects of TPM on atropine-induced gastric and intestinal dysmobility in rats. Gastric residual rate (A) and intestinal transit (B) were measured in control (Ctrl), atropine-treated (Atropine) and TPM-pretreated/atropine-treated (TPM+atropine) rats via the method described above. Data are shown as mean ± SD (n = 8). *: P < 0.05, **: P < 0.01.

Figure 3

The regulation of TPM on gastrointestinal hormones which were interrupted by atropine-treatment in rats. The serum levels of gastrointestinal hormones, which including gastrin (GAS) (A), motilin (MTL) (B), somatostatin (SS) (C) and p substance (PS) (D), were measured in control (Ctrl), atropine-treated (Atropine) and TPM-pretreated/atropine-treated (TPM + atropine) rats via ELISA method. Data are shown as mean ± SD (n = 8). *: P < 0.05, **: P < 0.01.

Figure 4

The protective effects of TPM on atropine-induced ICCs damage in rats’ stomach. The distribution and amount of ICCs in sinuses ventriculi and body of stomach were evaluated by immunohistochemistry analysis in control (Ctrl), atropine-treated (Atropine) and TPM-pretreated/atropine-treated (TPM + atropine) rats. Optical density value (A) and representative immunohistochemistry photos (×400 magnification) (B) of each group are presented. Data are shown as mean ± SD (n = 6). *: P < 0.05.

Figure 5

TPM reversed atropine-induced down-regulation of c-kit and SCF expressions. The c-kit and SCF expressions in control (Ctrl), atropine-treated (Atropine) and TPM-pretreated/atropine-treated (TPM + atropine) rats’ stomach were measured via western blotting method. The variation folds of c-kit (A) and SCF (B) expressions and protein bands (C) of each group are presented. Data are shown as mean ± SD (n = 6). **: P < 0.01.