The purpose this study was to develop mouthwash product with solid-state fermented oriental medicinal herb (OMH). And an extra emphasis was laid on the potential effect of root of Taraxacum, known to have anti-inflammatory efficacy, on amelioration of oxidative stress induced by lipopolysaccharide (LPS). Solid-state fermentation of fresh root of Taraxacum and dried silver magnolia, licorice, and cnidium were carried out with Phellinus linteus mycelium. Fresh root of Taraxacum was successfully fermented by liquid spawn of Phellinus linteus mycelium (10% w/v). For dried OMHs such as silver magnolia, licorice, and cnidium, additional water at 30% (final w/v concentration) was needed for the fermentation, while brown rice powder was required as an extra nutrient at 10% (w/w) to the dried leaves of mint. The amount of total phenolic compounds and DPPH scavenging activities of OMH increased significantly (p<0.05) by solid-state fermentation. Anti-microbial activities of the fermented OMH also increased, which were approximately 100-fold greater than those of the unfermented samples. When the ethanol extracts of the fermented OMHs including silver magnolia, licorice, cnidium, and root of Taraxacum were mixed together in the ratio of 5:3:2:1, the mouthwash product had the maximum anti-microbial effect against oral pathogenic bacteria. Hot water extracts of mint and clove, as base components, were mixed in the ratio of 100:15. In the sensory evaluation, scores for the overall preference and the purchase intention were higher compared to those of commercially available OMH-based mouthwash product (p<0.05).
In animal study, potential effect of Taraxacum herba, known to have anti-inflammatory efficacy, on amelioration of oxidative stress induced by LPS were first studied. Different amount of hot water extracts of fresh root of Taraxacum was orally administrated to the mice, the elevated level of reactive oxygen species (ROS), peroxinitrite, thiobarbituric acid related substances (TBARS) in the plasma and/or liver by LPS injection decreased in dose-dependent manner (p<0.05) via suppression of inducible nitric oxide synthase (iNOS) and cyclo-oxygenase 2 (COX-2) expression through inhibition of nuclear factor-κB (NF-κB) activation. Tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) concentrations in plasma for the fermented Taraxacum coreanum Nakai group decreased compared to those of LPS control group informing that production of inflammatory cytokines were reduced by Taraxacum coreanum Nakai administration (p<0.05).
In second part of animal study, anti-oxidant and anti-inflammatory effects of fresh root of Taraxacum, fermented Taraxacum coreanum Nakai, mycelium of Phellinus linteus were compared. Protein expression of iNOS, and COX-2 elevated in LPS control group decreased with the administration of fresh root of Taraxacum, fermented Taraxacum coreanum Nakai, and the mycelium of Phellinus linteus, respectively with the greatest suppression from mice group fed the fermented Taraxacum coreanum Nakai (p<0.05). Superoxide dismutase protein expressions in Taraxacum coreanum Nakai and the mycelium of Phellinus linteus groups increased compared to that in LPS control group. The protein expressions of catalase and glutathione peroxidase demonstrated the highest level in mice group fed the fermented root of Taraxacum. Fifteen and seventeen compounds were isolated from fresh and fermented root of Taraxacum, respectively by liquid chromatography. The major compound identified by mass chromatography in fresh root of Taraxacum was taraxinic acid β-D glucopyranosyl ester with molecular weight of 424, followed by taraxinic acid with molecular weight of 262. In the fermented root of Taraxacum, taraxinic acid appeared as the most active compound. Accordingly, it is highly probable that more taraxinic acid was produced from the taraxinic acid β-D glucopyranosyl ester in the process of solid-state fermentation. After fermentation, the amount of taraxinic acid showed a notable increase by about 400%.
In this study, the Taraxacum herba, known to have anti-inflammatory effect, was found having specific effects in treating LPS-induced inflammation once it was fermented and accordingly had increased anti-oxidant and anti-inflammatory efficacy. It is conclusive that, in the process of fermentation, the taraxinic acid β-D glucopyranosyl ester was bio-converted to low-molecule taraxinic acid by mycelium of Phellinus linteus and became more effective in amelioration of oxidative stress.