ABSTRACT
Objective:To study the mechanism of Taoren Chengqitang in regulating intestinal myoelectric activity and microenvironment homeostasis in intestinal sepsis rats based on high mobility group protein 1(HMGB1)/Toll-like receptor 4(TLR4)/nuclear factor -κB(NF-κB) pathway. Method:The 60 SD rats were randomly divided into sham operation group, model group, glycyrrhizic acid (HMGB1 inhibitor, 0.03 g·kg-1) group, Taoren Chengqitang group (10 g·kg-1), glycyrrhizic acid+Taoren Chengqitang group (0.03 g·kg-1+10 g·kg-1), with 12 rats in each group. Except the sham operation group, the other groups established intestinal sepsis rat models, each group was treated with medicine, hematoxylin-eosin (HE) staining was used to detect the histopathological changes of small intestinal mucosa in rats of each group, the changes of mucosal thickness and villus height were compared, the levels of secretory immunoglobulin A (sIgA), diamine oxidase (DAO) and D-lactic acid in intestinal mucosa of rats were detected by kit, the intestinal myoelectrical activity of rats in each group was measured, the slow wave frequency and amplitude of small intestinal smooth muscle were compared, the intestinal flora of rats in each group was detected, the contents of E. coli, Bifidobacterium and Lactobacillus were compared, and the expressions of HMGB1/TLR4/NF-κB pathway proteins HMGB1, TLR4, MyD88 and NF-κB p65 in small intestinal tissues were detected by Western blot. Result:Compared with sham operated group, the villus height, mucosal thickness, sIgA content, slow wave frequency and amplitude of smooth muscle, Bifidobacterium and Lactobacillus contents in intestinal mucosa of model group rats were significantly decreased, and serum DAO and D-lactic acid levels, intestinal E. coli content, intestinal tissue HMGB1, TLR4, MyD88 and NF-κB p65 proteins were significantly increased (P<0.05). Compared with the model group, the villus height, mucosal thickness, sIgA content, slow wave frequency and amplitude of smooth muscle, Bifidobacterium and Lactobacillus contents in intestinal mucosa of the Taoren Chengqitang group, glycyrrhizic acid group, and glycyrrhizic acid + Taoren Chengqitang group were significantly increased, and serum DAO and D-lactic acid levels, intestinal E. coli content, intestinal tissue HMGB1, TLR4, MyD88 and NF-κB p65 proteins were significantly decreased (P<0.05). Compared with the Taoren Chengqitang group and the glycyrrhizic acid group, the villus height, mucosal thickness, sIgA content, slow wave frequency and amplitude of smooth muscle, Bifidobacterium and Lactobacillus contents in intestinal mucosa of glycyrrhizic acid+Taoren Chengqitang group were significantly increased, and serum DAO and D-lactic acid levels, intestinal E. coli content, intestinal tissue HMGB1, TLR4, MyD88 and NF-κB p65 proteins were significantly decreased, the differences were statistically significant (P<0.05). Conclusions:Taoren Chengqitang can alleviate intestinal mucosal injury, regulate intestinal myoelectrical activity and microenvironment homeostasis, restore intestinal function and maintain flora balance in intestinal sepsis rats, which may be achieved by down-regulating HMGB1/TLR4/NF-κB pathway.
ABSTRACT
Objective: To study the protective effect of Taoren Chengqitang on intestinal mucosal barrier in septic rats and its possible mechanism. Method: Rats were divided into sham operation group, model group (replication of septic rats with cecal ligation and perforation), low, middle and high-dose Taoren Chengqitang groups (2.85,5.70,8.55 g·kg-1), and dexamethasone group (0.01 g·kg-1),with 12 rats in each group. After last administration, rats were put to death, the morphological changes of intestinal mucosa were observed under electron microscope, the bacterial translocation rates in lymphoglandulae mesentericae, liver, kidney and spleen tissues were detected; the levels of serum tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and diamine oxidase (DAO) and intestinal fatty acid binding protein (i-FABP) levels in small intestine tissues were detected by enzyme-linked immunosorbent assay (ELISA).Expressions of Toll like receptor 9 (TLR9), myeloid differentiation factor 88 (MyD88) and nuclear factor-kappa B subunit p65 in small intestine tissues were detected by Western blot and immunohistochemistry. Result: Compared with sham operated group, the bacterial translocation rate, TNF-α and IL-1β levels in model group increased significantly, DAO, i-FABP, mucosal thickness and villus height decreased significantly, and protein expressions of TLR9, MyD88 and nucleus NF-κB p65 increased significantly (PPκB p65 protein decreased significantly. Compared with model group, the bacterial translocation rate, TNF-α and IL-1β levels in organs of low, medium and high-dose Taoren Chengqitang groups and dexamethasone group decreased significantly, DAO, i-FABP, mucosal thickness and villus height increased significantly, while the protein expressions of TLR9, MyD88 and nucleus NF-κB p65 decreased significantly (PκB p65 protein increased significantly. Conclusion: Taoren Chengqitang has a certain protective effect on intestinal mucosal barrier in septic rats, which may be related to the inhibition of TLR9 signaling pathway.