Sagittaria sagittifolia polysaccharides regulates Nrf2/HO-1 to relieve liver injury caused by multiple heavy metals in vivo and in vitro / 中国中药杂志

This study explored whether Sagittaria sagittifolia polysaccharides(SSP) activates the nuclear factor erythroid-2-related factor2(Nrf2)/heme oxygenase-1(HO-1) signaling pathway to protect against liver damage jointly induced by multiple heavy metals. First, based on the proportion of dietary intake of six heavy metals in rice available in Beijing market, a heavy metal mixture was prepared for inducing mouse liver injury and HepG2 cell injury. Forty male Kunming mice were divided into five groups: control group, model group, glutathione positive control group, and low-and high-dose SSP groups, with eight mice in each group. After 30 days of intragastric administration, the liver injury in mice was observed by HE staining. In the in vitro experiment, MTT assay was conducted to detect the effects of SSP at 0.25, 0.5, 1, and 2 mg·mL~(-1) on HepG2 cell survival at different time points. The content of alanine transaminase(ALT) and aspartate aminotransferase(AST) in the 48-h cell culture fluid was measured using micro-plate cultivation method, followed by the detection of the change in reactive oxygen species(ROS) content by flow cytometry. The mRNA expression levels of Nrf2 and HO-1 in cells were determined by RT-PCR, and their protein expression by Western blot. HE staining results showed that compared with the model group, the SSP administration groups exhibited significantly alleviated inflammatory cell infiltration and fatty infiltration in the liver, with better outcomes observed in the high-dose SSP group. In the in vitro MTT assay, compared with the model group, SSP at four concentrations all significantly increased the cell survival rate, decreased the ALT, AST, and ROS content(P<0.05), and down-regulated Nrf2 and HO-1 mRNA and protein expression(P<0.05). SSP significantly improves inflammatory infiltration in the liver tissue of mice exposed to a variety of heavy metals and corrects the liver fat degeneration, which may be related to its regulation of the Nrf2/HO-1 signaling pathway, reduction of ROS, and alleviation of oxidative damage.

Gegen Qinliantang Regulates MMP-9/p38 MARK Pathway to Repair Intestinal Mucosal Barrier Function in Mice with Ulcerative Colitis / 中国实验方剂学杂志

Objective:To explore the protective effect of Gegen Qinliantang on the intestinal mucosal epithelial barrier function of ulcerative colitis （UC） mice， and to explore its mechanism of action in the treatment of ulcerative colitis via matrix metallopeptidase-9 （MMP-9）/p38 mitogen-activated protein kinase （p38 MAPK） signaling pathway. Method:The 48 female C57BL/6 mice were randomly divided into normal group， model group， sulfasalazine group （0.3 g·kg^-1） and Gegen Qinliantang high， medium and low dose groups （2.84，1.42，0.71 g·kg^-1）. The UC murine model was established by 3% dextran sulfate sodium （DSS）. Gegen Qinliantang and sulfasalazine were intragastrically administered on the 8^th day after the model was established for 7 days， and the normal group was treated with the same amount of normal saline. Colon tissues were collected after the last administration， and the pathological changes of colon tissues were detected by hematoxylin-eosin （HE） staining. The expression of tight junction （TJ） proteins such as Occludin and zonula occludens-1（ZO-1） in colon tissues was detected by immunohistochemistry （IHC）， and the expression levels of tumor necrosis factor-alpha （TNF-<italic>α</italic>）， interleukin-1<italic>β</italic> （IL-1<italic>β</italic>）， and MMP-9 mRNA in colon tissues were detected by Real-time polymerase chain reaction （Real-time PCR）. The expression of phosphorylated p38 MAPK （p-p38 MAPK）， p38 MAPK and MMP-9 protein in colon tissues was detected by Western blot. Result:Compared with normal group， the body weight of mice decreased （<italic>P</italic><0.01） and disease activity index （DAI） score increased significantly （<italic>P</italic><0.01） in model group， the colon tissues of the model group were damaged more obviously， the expression of occludin and ZO-1 proteins in model group was significantly reduced （<italic>P</italic><0.01）， and the relative expression levels of TNF-<italic>α</italic>， IL-1<italic>β</italic>， and MMP-9 mRNA in model group were significantly increased （<italic>P</italic><0.01）， the expression of p-p38 MAPK and MMP-9 in model group was significantly increased （<italic>P</italic><0.01）. Compared with model group， the body mass and DAI score of the sulfasalazine group and Gegen Qinliantang group were significantly improved （<italic>P</italic><0.05，<italic>P</italic><0.01）， the colonic tissues damage were significantly improved， and the expression of Occludin and ZO-1 protein was significantly increased （<italic>P</italic><0.05，<italic>P</italic><0.01）， the relative expression levels of TNF-<italic>α</italic>， IL-1<italic>β</italic>， and MMP-9 mRNA were significantly decreased （<italic>P</italic><0.01）， and the expression of p-p38 MAPK and MMP-9 was significantly decreased （<italic>P</italic><0.01）. The changes in the middle dose group were the most obvious among the various dose groups of Gegen Qinliantang. Conclusion:Gegen Qinliantang repairs the intestinal mucosal barrier function by inhibiting the expressions of MMP-9 and inflammatory cytokines such as TNF-<italic>α</italic> and IL-1<italic>β</italic>， blocking the activation of the p38 MAPK signaling pathway， and increasing the expressions of tight junction protein.