Vitreoscilla filiformis Extract for Topical Skin Care: A Review

Abstract

The term probiotic has been defined by experts as live microorganisms, which when administered in adequate amounts, confer a health benefit on the host. Probiotics are, thus, by definition, live microorganisms, and the viability of probiotics is a prerequisite for certain benefits, such as the release of metabolites at the site or adhesion properties, for example. However, some semi-active or non-replicative bacterial preparations may retain a similar activity to the live forms. On cosmetic, lysates or fractions are generally used. Topically applied Vitreoscilla filiformis extract has shown to have some similar biological activity of probiotics in the gut, for example, regulating immunity by optimisation of regulatory cell function, protecting against infection, and helping skin barrier function for better recovery and resistance. Due to their mode of action and efficacy, V. filiformis extract (lysate including membrane and cytosol) may be considered as non-replicative probiotic fractions, and this review article presents all its properties.

Keywords: Vitreoscilla; immunity; microbiome; skin barrier; skin defences.

Figure 1

Stimulatory effect of Vitreoscilla filiformis extract (Vfe) on cytokines in monocytes (mean ± SEM). The effect of Vfe 0.2% (black circles) on cytokine stimulation in vitro was evaluated in monocytes isolated from peripheral blood mononuclear cells and compared with lipopolysaccharide (dark grey circle). Monocytes were incubated with the test compounds for 36 h, and the supernatant was collected and assayed for cytokines (IL-6, IL-8, and IL-10 and IL-12p40) using the Milliplex assay kit and Luminex LX100 apparatus. *p < 0.05 compared with lipopolysaccharide (LPS).

Figure 2

Vitreoscilla filiformis extract (Vfe) induces growth enhancement of Staphylococcus epidermidis (mean ± SD). In an in vitro method based on growth kinetics, bacteria were incubated with Vfe in a liquid culture of a minimal medium composed of glucose, potassium phosphate, ammonium sulfate, heptahydrate magnesium sulfate, and NaCl, at pH 6. The presence of Vfe at 0.2% significantly enhanced the growth of S. epidermidis compared with the conditions without Vfe. *p < 0.05 compared with medium alone.

Figure 3

Inhibitory effect of Vitreoscilla filiformis extract (Vfe) on the inflammasome. In an in vitro model of the NLRP3 inflammasome on monocytes (THP-1 cell line), the inflammasome was activated by uncoupling the mitochondrial respiratory chain, causing the production of reactive oxygen species (ROS). ROS were induced by nigericin, rotenone, or the control lipopolysaccharide. The percentage of ROS+ cells was defined according to flow cytometry mitotracker markers. The addition of Vfe decreased the percentage of ROS+ cells. *p < 0.05 compared with control.

Figure 4

Stimulatory effect of Vitreoscilla filiformis extract (Vfe) on skin cell renewal rate in vivo (mean ± SD). In 22 women, volunteers aged from 24 to 55 years, the effect of Vfe 1% versus a control formula on the cell renewal rate after 2 weeks of pre-treatment and 10 days of treatment was evaluated by the decrease in skin colour after staining using 10% dihydroxyacetone (DHA) cream, as measured by Chroma meter CR400. Parameter b* values before and after treatment showed that the DHA-induced colour decreased significantly more rapidly on the arm treated with the formula containing Vfe 1% than on the arm treated with the vehicle cream. *p < 0.05 compared with vehicle cream.

Figure 5

Vitreoscilla filiformis extract (Vfe) decreased the diffusion rate of caffeine through reconstructed skin (mean ± SD). A 13-day culture of EPISKIN™ was incubated for a total of 5 days with Vfe, vitamin C reference, or the control. The epidermis was then washed and 100 μl of 2 μCi/ml (0.04 mM) radioactive caffeine (14C-caffeine, Perkin Elmer Ref. NEC41205UC) and 0.35 mM of cold caffeine (Sigma C8960), corresponding to around 500,000 cpm in total, was applied to the surface of each epidermis before media sampling kinetic measurements. The treatment by Vfe 0.2% and 0.04% decreased the rate of caffeine diffusion by 40% to 50% compared with the control. *p < 0.05 compared with control.

Figure 6

Vitreoscilla filiformis extract (Vfe) increased skin barrier recovery rates after tape stripping (mean ± SD). To evaluate skin barrier recovery rates in female volunteers aged 25 to 55 years, test areas on the inner forearm were subject to barrier damage by tape stripping using D-Squames^® on day 1. Vfe was then applied twice daily to the test area for 4 days or left untreated (control). Skin barrier recovery was assessed by measuring on days 1 to 5. As expected, tape stripping impaired the skin barrier, as shown by increased TEWL. Natural barrier recovery was observed for the untreated control area between days 2 and 5 compared with day 1. TEWL, transepidermal water loss. *p < 0.05 compared with control zone.

Figure 7

Stimulatory effect of Vitreoscilla filiformis extract (Vfe) on collagen IV expression in human fibroblasts. Representative high-resolution images of in situ immunolabelling demonstrating the significant effect of Vfe (0.017% and 0.05%) on collagen IV expression in human fibroblasts.