[Bletilla striata polysaccharide improves toxic and side effects induced by 5-FU: an untargeted metabolomics study].

This study aimed to analyze the effect of Bletilla striata polysaccharide(BSP) on endogenous metabolites in serum of tumor-bearing mice treated with 5-fluorouracil(5-FU) by untargeted metabolomics techniques and explore the mechanism of BSP in alleviating the toxic and side effects induced by 5-FU. Male BALB/C mice were randomly divided into a normal group, a model group, a 5-FU group, and a 5-FU + BSP group, with eight mice in each group. Mouse colon cancer cells(CT26) were transplanted into the mice except for those in the normal group to construct the tumor-bearing mouse model by subcutaneous injection, and 5-FU chemotherapy and BSP treatment were carried out from the second day of modeling. The changes in body weight, diarrhea, and white blood cell count in the peripheral blood were recorded. The mice were sacrificed and sampled when the tumor weight of mice in the model group reached approximately 1 g. TUNEL staining was used to detect the cell apoptosis in the small intestine of each group. The proportions of hematopoietic stem cells and myeloid progenitor cells in bone marrow were measured by flow cytometry. Five serum samples were selected randomly from each group for untargeted metabolomics analysis. The results showed that BSP was not effective in inhibiting colon cancer in mice, but diarrhea, leukopenia, and weight loss caused by 5-FU chemotherapy were significantly improved after BSP intervention. In addition, apoptotic cells decreased in the small intestinal tissues and the percentages of hematopoietic stem cells and myeloid progenitor cells in bone marrow were significantly higher after BSP treatment. Metabolomics results showed that the toxic and side effects of 5-FU resulted in significant decrease in 29 metabolites and significant increase in 22 metabolites in mouse serum. Among them, 19 disordered metabolites showed a return to normal levels in the 5-FU+BSP group. The results of pathway enrichment indicated that metabolic pathways mainly involved pyrimidine metabolism, arachidonic acid metabolism, and steroid hormone biosynthesis. Therefore, BSP may ameliorate the toxic and side effects of 5-FU in the intestinal tract and bone marrow presumably by regulating nucleotide synthesis, inflammatory damage, and hormone production.

Management of haemorrhoids: protocol of an umbrella review of systematic reviews and meta-analyses.

INTRODUCTION: The prevalence of haemorrhoidal diseases was high in general population, and many treatments are proposed for the management of haemorrhoids. The treatments include conservative and surgical interventions; the credibility and strength of current evidence of their effectiveness are not comprehensively evaluated. We aim to evaluate the credibility of systematic reviews and meta-analyses that assess the effectiveness of the treatments for haemorrhoidal diseases through an umbrella review. METHODS AND ANALYSIS: We will search Ovid Medline, Embase, Cochrane library and Web of Science from inception to March 2020 without any language restriction. We will include meta-analyses that examine the effectiveness of treatments in the management of haemorrhoids. Two reviewers will independently screen the titles and abstracts of retrieved articles, and they will extract data from the included meta-analyses. For each meta-analysis, we will estimate the effect size of a treatment through the random-effect model and the fixed-effect model, and we will evaluate between-study heterogeneity (Cochrane's Q and I2 statistics) and small-study effect (Egger's test); we will also estimate the evidence of excess significance bias. Evidence of each treatment will be graded according to prespecified criteria. Methodological quality of each meta-analysis will be evaluated by using Assessment of Multiple Systematic Reviews 2. The corrected cover area method will be used to assess the impact of overlap in reviews on the findings of the umbrella review. ETHICS AND DISSEMINATION: We will present the results of the umbrella review at conferences and publish the final report in a peer-reviewed journal. The umbrella review does not require ethical approval. PROSPERO REGISTRATION NUMBER: CRD42019140702.