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Lactic acid bacteria (LAB) &ldquo, fermentates&rdquo, confer a beneficial effect on intestinal function. However, the ability of new fermentations to improve LAB broth activity in preventing pathogen-induced intestinal inflammation and barrier dysfunction has not yet been studied. The objective of this study was to determine if broths of LAB fermented with Eruca sativa or Barbarea verna seed extracts prevent gut barrier dysfunction and interleukin-8 (CXCL8) release in vitro in human intestinal Caco-2 cells infected with enterohemorrhagic Escherichia coli (EHEC) O157:H7. LAB broths were assayed for their effects on EHEC growth and on Caco-2 viability, thereafter, their biological properties were analysed in a co-culture system consisting of EHEC and Caco-2 cells. Caco-2 cells infected with EHEC significantly increased CXCL8 release, and decreased Trans-Epithelial Electrical Resistance (TEER), a barrier-integrity marker. Notably, when Caco-2 cells were treated with LAB broth enriched with E. sativa seed extract and thereafter infected, both CXCL8 expression and epithelial dysfunction reduced compared to in untreated cells. These results underline the beneficial effect of broths from LAB fermented with E. sativa seed extracts in gut barrier and inflammation after EHEC infection and reveal that these LAB broths can be used as functional bioactive compounds to regulate intestinal function.

Herpes simplex virus types 1 (HSV-1) and 2 (HSV-2) cause several clinically relevant syndromes in both adults and neonates. Despite the availability of efficient anti-HSV agents, the search for new therapeutic approaches is highly encouraged due to the increasing drug resistance of virus strains. Medicinal plants represent a source of potential bioactive compounds. In this context we evaluated the anti-herpetic activity of Hemidesmus indicus (L.) R. Br., a plant widely used in traditional Indian medicine. The hydroalcoholic extract prepared from roots was characterized by NMR and HPLC analysis and assayed in vitro by CPE reduction and virus infectivity assays to define its anti-viral effect. The extract's mechanism of action was investigated by virucidal and time-of-addition assays and by in vitro α-glucosidase inhibitory assay. The extract exhibited a remarkable anti-herpetic activity at 100 mg/mL, at non-cytotoxic concentration, through multiple mechanisms: it reduced the infectivity of viral particles released from infected cells possibly through its anti-ER α-glucosidase inhibitory activity and it inhibited the beginning stage of HSV infection acting as a virucide agent and/or preventing virus attachment to the host cell surface.

Background Alkaloids present in plants of the Amaryllidaceae family are secondary metabolites of high biological interest, possessing a wide range of pharmacological activities. In the search for new plant-derived compounds with antimicrobial activities, two alkaloid extracts obtained from bulbs and leaves of Pancratium illyricum L., a plant of the Amarillydaceae family, were tested for their effect on bacterial and yeast growth. Methods The broth microdilution susceptibility test was applied to study the effect of plant extracts on the growth of reference bacterial strains and Candida albicans reference and clinical isolates strains. Extracts obtained from the different parts of the plant were tested and compared with the pure components identified in the extracts. Since matrix metalloproteinase enzymes play a role in the dissemination process of Candida albicans, the effect of the bulb extract and pure alkaloids on in vitro collagenase activity was tested. Cell viability test was carried out on human embryo lung fibroblasts (HEL 299). Results Whilst both extracts did not show any inhibitory activity against neither Gram positive nor Gram negative bacteria, a strong antifungal activity was detected, in particular for the bulb extract. All clinical isolates were susceptible to the growth inhibitory activity of the bulb extract, with endpoint IC50 values ranging from 1.22 to 78 μg/mL. The pure alkaloids lycorine and vittatine, identified as components of the extract, were also assayed for their capacity of inhibiting the yeast growth, and lycorine turned very active, with endpoint IC50 values ranging from 0.89 to 28.5 μg/mL. A potent inhibition of the in vitro collagenase activity was found in the presence of the bulb extract, and this effect was much higher than that exerted by the pure alkaloids. Viability of cell lines tested was not affected by the extract. Conclusions Taken together, results suggest that the extract of Pancratium illyricum may act as antifungal agent both directly on the yeast growth and by altering the tissue invasion process. Electronic supplementary material The online version of this article (doi:10.1186/1472-6882-14-409) contains supplementary material, which is available to authorized users.