Comparison of Aqueous and Lactobacterial-Fermented Mercurialis perennis L. (Dog’s Mercury) Extracts with Respect to Their Immunostimulating Activity

Abstract

Lactic acid (LA) fermentation of dog’s mercury (M. perennis L.) herbal parts was investigated in samples inoculated with either Lactobacteria (Lactobacillus plantarum and Pediococcus pentosaceus, LBF) or whey (WF). Depending on fermentation time, LA concentrations were monitored in a range of 3.4–15.6 g/L with a concomitant pH decline from 6.5 to 3.9. A broad spectrum of cinnamic acids depsides containing glucaric, malic and 2-hydroxyglutaric acids along with quercetin and kaempferol glycosides were detected by LC-DAD-ESI-MSn. Moreover, in this study novel constituents were also found both in unfermented and fermented extracts. Furthermore, amino acids and particular Lactobacteria metabolites such as biogenic amines (e.g., putrescine, 4-aminobutyric acid, cadaverine) and 5-oxoproline were assigned in WF extracts by GC-MS analysis after silylation. Enhanced NFκB and cytokine expression (IL-6, TNFα, IL-8 and IL-1β) was induced by all extracts, both non-fermented and fermented, in NFκB-THP1 reporter cells, showing a concentration-dependent immunostimulatory effect. The WF extracts were tested for micronuclei formation in THP1 cells and toxicity in luminescent bacteria (V. fischeri), whereby no mutagenic or toxic effects could be detected, which corroborates their safe use in pharmaceutical remedies.

Biological Activity of Fermented Plant Extracts for Potential Dermal Applications

“…Fermented Paeoniae alba extract with plant-derived Lactobacillus brevis 174A suppressed inflammatory cytokines interleukin (IL)—6, tumor necrosis factor-α (TNF-α), while simultaneously downregulating the gene expressions of inducible nitric oxide synthase (iNOS), IL-6, TNF-α, and IL-1 compared to the unfermented extract [ 32 ]. Fermented Mercurialis perennis extract with Lactobacteria ( Lactobacillus plantarum and Pediococcus pentosaceus ) and non-fermented extract enhanced NFκB and cytokine expression (IL-6, TNF, IL-8, and IL-1) in NFκB-THP-1 reporter cells, showing a concentration-dependent immunostimulatory effect [ 31 ]. Fermented Chenopodium formosanum leaf extract with Aspergillus oryzae increases anti-inflammatory activity via reduced nitric oxide (NO), IL-6, and TNF-α production in lipopolysaccharide (LPS)-stimulated RAW264.7 cells in a dose-dependent manner [ 23 ].…”

“…Laminaria japonica fermented freeze-dried powder is non-irritating to the eyes, has high safety, and can be added to skin care products as a functional raw material [ 26 ]. The aqueous and Lactobacterial-fermented Mercurialis perennis extracts were tested for micronuclei formation in THP-1 cells and toxicity in luminescent bacteria ( V. fischeri ), whereby no mutagenic or toxic effects were detected, which corroborates their safe use in pharmaceutical remedies [ 31 ]. Unfortunately, most of the studies presented in this paper do not include toxicological tests, which should be crucial for FPE and their use in cosmetics and drugs applied topically to the skin.…”