Saccharomyces cerevisiae-based probiotic as novel anti-fungal and anti-inflammatory agent for therapy of vaginal candidiasis.

Previously we demonstrated that the treatment with live Saccharomyces cerevisiae exerts beneficial therapeutic effects against vaginal candidiasis. Here, we address potential mechanisms particularly examining the probiotic capacity to modulate both fungus and host-related factors. We show that the S. cerevisiae-based probiotic markedly affects the expression of virulence traits of Candida albicans such as aspartyl proteinases (SAPs) as well as hyphae-associated proteins Hwp1 and Ece1 in the vaginal cavity. On the host side, the probiotic suppression of the influx of neutrophils caused by the fungus into the vaginas of the mice is likely related to: (1) lower production of interleukin-8; and (2) inhibition of SAPs expression. However, these neutrophils displayed reactive oxygen species hyperproduction and increased killing activity as compared to the neutrophils of placebo-treated mice. There was no evidence of any cytotoxic effect by the probiotic, either when used in vivo on vaginal epithelial cell and organ architecture, or in in vitro in human vaginal epithelium. Inactivated yeast cells did not affect any of the factors above. In summary, the data suggest that the beneficial effect exerted by this S. cerevisiae-based probiotic is the result of its interference with the expression of fungus virulence factors coupled with the modulation of the inflammatory response of the host.

A purified capsular polysaccharide markedly inhibits inflammatory response during endotoxic shock.

Capsular material of the opportunistic fungus Cryptococcus neoformans is composed mainly of a polysaccharide named glucuronoxylomannan (GXM). In this study, the effects of GXM were analyzed in an in vivo experimental system of lipopolysaccharide (LPS)-induced shock. Endotoxic shock was induced in mice by a single intraperitoneal injection of LPS from Escherichia coli. GXM treatment reduced the mortality of mice at early stages. Mice treated with LPS alone showed markedly increased plasma levels of tumor necrosis factor alpha (TNF-α), interleukin-1ß (IL-1ß), and IL-6, whereas mice that were also treated with GXM showed significantly lower plasma levels of these cytokines. This effect was related to a marked suppression of Akt and IκBα activation. Importantly, the inhibitory effect of GXM on proinflammatory cytokine secretion was reproduced by treatment with wortmannin, an inhibitor of the Akt transcription pathway. Our results indicate that GXM has a beneficial effect on endotoxic shock, resulting in a significant increase in the rate of survival by dampening the hyperinflammatory response.