Inhibitors of the secretion of cancer exosomes, which promote cancer progression and metastasis, may not only accelerate exosome biology research but also offer therapeutic benefits for cancer patients. Here we identify sulfisoxazole (SFX) as an inhibitor of small extracellular vesicles (sEV) secretion from breast cancer cells through interference with endothelin receptor A (ETA). SFX, an FDA-approved oral antibiotic, showed significant anti-tumor and anti-metastatic effects in mouse models of breast cancer xenografts, the reduced expression of proteins involved in biogenesis and secretion of sEV, and triggered co-localization of multivesicular endosomes with lysosomes for degradation. We demonstrate the important role of ETA, as target of SFX, by gain- and loss-of-function studies of the ETA protein, through a direct binding assay, and pharmacological and genetic approaches. These findings may provide a foundation for sEV-targeted cancer therapies and the mechanistic studies on sEV biology.

Background The extended Consolidated Standards of Reporting Trials (CONSORT) Statement for Abstracts was developed to improve the quality of reports of randomized controlled trials (RCTs) because readers often base their assessment of a trial solely on the abstract. To date, few data exist regarding whether it has achieved this goal. We evaluated the extent of adherence to the CONSORT for Abstract statement for quality of reports on RCT abstracts by four high-impact general medical journals. Methods A descriptive analysis of published RCT abstracts in The New England Journal of Medicine (NEJM), The Lancet, The Journal of American Medical Association (JAMA), and the British Medical Journal (BMJ) in the year 2010 was conducted by two reviewers, independently extracting data from a MEDLINE/PubMed search. Results We identified 271 potential RCT abstracts meeting our inclusion criteria. More than half of the abstracts identified the study as randomized in the title (58.7%; 159/271), reported the specific objective/hypothesis (72.7%; 197/271), described participant eligibility criteria with settings for data collection (60.9%; 165/271), detailed the interventions for both groups (90.8%; 246/271), and clearly defined the primary outcome (94.8%; 257/271). However, the methodological quality domains were inadequately reported: allocation concealment (11.8%; 32/271) and details of blinding (21.0%; 57/271). Reporting the primary outcome results for each group was done in 84.1% (228/271). Almost all of the abstracts reported trial registration (99.3%; 269/271), whereas reports of funding and of harm or side effects from the interventions were found in only 47.6% (129/271) and 42.8% (116/271) of the abstracts, respectively. Conclusions These findings show inconsistencies and non-adherence to the CONSORT for abstract guidelines, especially in the methodological quality domains. Improvements in the quality of RCT reports can be expected by adhering to existing standards and guidelines as expressed by the CONSORT group.

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Since many glycoside compounds in natural products are hydrolyzed by intestinal microbiota when administered orally, it is of interest to know whether their pharmacological effects are derived from the glycoside itself or from the aglycone form in vivo. An interesting example is baicalin versus baicalein, the aglycone of baicalin, which is contained in some herbs from Labiatae including Scutellaria baicalensis Georgi and Scutellaria lateriflora Linne. The herbs have been extensively used for treatment of inflammatory diseases in Asia. Although there have been numerous reports regarding the pharmacological effects of baicalin and baicalein in vivo and in vitro, some reports indicated that the glycoside form would hardly be absorbed in the intestine and that it should be hydrolyzed to baicalein in advance for absorption. Therefore, the role of metabolism by intestinal microbiota should also be considered in the metabolism of baicalin. In addition, baicalin contains a glucuronide moiety in its structure, by which baicalin and baicalein show complex pharmacokinetic behaviors, due to the interconversion between them by phase II enzymes in the body. Recently, concerns about drug interaction with baicalin and/or baicalein have been raised, because of the co-administration of Scutellaria species with certain drugs. Herein, we reviewed the role of intestinal microbiota in pharmacokinetic characteristics of baicalin and baicalein, with regards to their pharmacological and toxicological effects.

Baicalin (baicalein-7-glucuronide) is a flavonoid purified from Scutellaria baicalensis Georgi that has traditionally been used for treatment of hypertension, cardiovascular diseases, and viral hepatitis. In this study, the effects of intestinal microbiota on the pharmacokinetics of baicalin were investigated in normal and antibiotic-pretreated rats following p.o. administration of 100 mg/kg baicalin by using liquid chromatography/ion trap mass spectrometry. When rats were pretreated orally with cefadroxil, oxytetracycline and erythromycin for 3 days to control the number of intestinal bacteria, the pharmacokinetic parameters of oral baicalin were significantly affected by antibiotics: Cmax, T1/2(β), Kel and AUC values were significantly changed compared to those in normal rats. These results indicate that intestinal microbiota might play a key role in the oral pharmacokinetics of baicalin.