Antagonistic Potential against Pathogenic Microorganisms and Hydrogen Peroxide Production of Indigenous Lactobacilli Isolated from Vagina of Chinese Pregnant Women

Objective To investigate the indigenous lactobacilli from the vagina of pregnant women and to screen the isolates with antagonistic potential against pathogenic microorganisms. Methods The strains were isolated from pregnant women＇s vagina and identified using the API50CH system. The ability of the isolates to produce hydrogen peroxide was analyzed semi-quantitatively using the TMB-HRP-MRS agar. The antagonistic effects of the isolates on pathogenic microorganisms were determined with a double layer agar plate. Results One hundred and three lactobacilli strains were isolated from 60 samples of vaginal secretion from healthy pregnant women. Among them, 78 strains could produce hydrogen peroxide, in which 68%, 80%, 80%, and 88% had antagonistic effects against Candida albicans CMCC98001, Staphylococcus aureus CMCC26003, Escherichia coli CMCC44113, and Pseudomonas aeruginosa CMCC10110, respectively. Conclusion The recovery of hydrogen peroxide-producing lactobacilli decreases with the increasing pregnant age and time. The most commonly isolated species from vagina of Chinese pregnant women are Lactobacillus acidophilus and Lactobacillus crispatus. Most of L. acidophilus and L. crispatus produce a high H2O2 level.

Cycloastragenol induces apoptosis and protective autophagy through AMPK/ULK1/mTOR axis in human non-small cell lung cancer cell lines

Objective:Studies have demonstrated that cycloastragenol induces antitumor effects in prostate,colorectal and gastric cancers;however,its efficacy for inhibiting the proliferation of lung cancer cells is largely unexplored.This study explores the efficacy of cycloastragenol for inhibiting non-small cell lung cancer(NSCLC)and elucidates the underlying molecular mechanisms.Methods:The effects of cycloastragenol on lung cancer cell proliferation were assessed using an adenosine triphosphate monitoring system based on firefly luciferase and clonogenic formation assays.Cycloastragenol-induced apoptosis in lung cancer cells was evaluated using dual staining flow cytometry with an annexin V-fluorescein isothiocyanate/propidium iodide kit.To elucidate the role of cycloastragenol in the induction of apoptosis,apoptosis-related proteins were examined using Western blots.Immunofluorescence and Western blotting were used to determine whether cycloastragenol could induce autophagy in lung cancer cells.Genetic techniques,including small interfering RNA technology,were used to investigate the underlying mechanisms.The effects against lung cancer and biosafety of cycloastragenol were evaluated using a mouse subcutaneous tumor model.Results:Cycloastragenol triggered both autophagy and apoptosis.Specifically,cycloastragenol promoted apoptosis by facilitating the accumulation of phorbol-12-myristate-13-acetate-induced protein 1(NOXA),a critical apoptosis-related protein.Moreover,cycloastragenol induced a protective autophagy response through modulation of the adenosine 5'-monophosphate-activated protein kinase(AMPK)/unc-51-like autophagy-activating kinase(ULK1)/mammalian target of rapamycin(mTOR)pathway.Conclusion:Our study sheds new light on the antitumor efficacy and mechanism of action of cycloastragenol in NSCLC.This insight provides a scientific basis for exploring combination therapies that use cycloastragenol and inhibiting the AMPK/ULK1/mTOR pathway as a promising approach to combating lung cancer.