Epigallocatechin gallate (EGCG) alleviates the inflammatory response and recovers oral microbiota in acetic acid-induced oral inflammation mice.

The oral microbiota, the second largest microbiome in the human body, plays an integral role in maintaining both the local oral and systemic health of the host. Oral microecological imbalances have been identified as a potential risk factor for numerous oral and systemic diseases. As a representative component of tea, epigallocatechin gallate (EGCG) has demonstrated inhibitory effects on most pathogens in single-microbial models. In this study, the regulatory effect of EGCG on more complex oral microbial systems was further explored through a mouse model of acetic acid-induced oral inflammation. Acetic acid induces histological damage in the cheek pouch, tongue, and throat, such as broken mucosa, submucosal edema, and muscular disorders. These detrimental effects were ameliorated significantly following EGCG treatment. Additionally, EGCG reduced the levels of the inflammatory cytokines interleukin-6 and tumor necrosis factor-α to alleviate the inflammation of the tongue, cheek pouch, and throat. According to the 16S rDNA gene sequencing data, EGCG treatment contributed to increased diversity of the oral microbiota and the reversal of oral microecological disorder. This study demonstrates the regulatory effect of EGCG on dysregulated oral microbiota, providing a potential option for the prevention and treatment of oral-microbiota-associated diseases.

Green tea extracts alleviate acetic acid-induced oral inflammation and reconstruct oral microbial balance in mice.

Oral cavity contains the second largest microbial community in the human body. Due to the highly vascularized feature of mouth, oral microbes could directly access the bloodstream and affect the host healthy systemically. The imbalance of oral microbiota is closely related to various oral and systemic diseases. Green tea extracts (GTE) mainly contain tea polyphenols, alkaloids, amino acid, flavones, and so on, which equipped with excellent anti-inflammatory activities. Previous studies have demonstrated the beneficial effects of GTE on oral health. However, most researches used in vitro models or focused on limited microorganisms. In this study, the regulatory effect of GTE on oral microbiome and the alleviative effect on oral inflammation in vivo were evaluated. The results showed that GTE could efficiently alleviate the inflammations of the tongue, cheek pouch, as well as throat. GTE effectively inhibited the activation of NF-κB through the upregulation of the anti-inflammatory cytokine interleukin (IL)-10, consequently leading to reduced expression of pro-inflammatory cytokines IL-6 and tumor necrosis factor-α. The indexes of spleen and thymus were also elevated by GTE in stomatitis mice. Moreover, GTE promoted the growth of probiotics Lactobacillus and Bacillus, inhibited the reproduction of pathogens Achromobacter, reversing the microbiota disorders in oral cavity. This study not only presents a novel approach for enhancing oral microecology but also facilitates the wider adoption of tea consumption.

Another thread to uncover the aging mystery of white tea: Focusing on the natural nanoparticles in tea infusion.

Aged white tea (WT) has promising medicinal potential, but how to accurately identify aged white tea is still a difficult problem. Inspired by tea cream, the relationship between the characteristics of nanoparticles in tea infusion and aging time was studied. The results showed that with the increase of aging time, the particle size of white tea nanoparticles (WTNs) decreased gradually. Microscopic images showed that the surface structure of WTNs was changed in three aspects: the waxy layer, the cuticle layer and the palisade tissue. Additional in vitro modeling demonstrated a strong correlation between nanoparticle size and protein and tea polyphenol content. The correlation between nanoparticle sizes and aging time was further verified in aged Pu'er raw tea. Starting with the tea infusion's nanoparticles, this study showed that the aging time of WT would impact the nanoparticles' properties, offering a unique way to determine the aging period of WT.

Characterization of Thermally Induced Flavor Compounds from the Glucosinolate Progoitrin in Different Matrices via GC-TOF-MS.

As important flavor precursors, glucosinolates are ubiquitous in the plant family of Brassicaceae. Glucosinolate degradation products are the major volatile flavor compounds of rapeseed oil, accounting for up to 80% of the total volatiles. However, up to now, little attention has been paid to the volatile flavor products of the nonenzymatic thermal degradation of glucosinolates. One of the most important factors that determine the flavor of hot-pressed rapeseed oil is the roasting process, where the thermal degradation of glucosinolates mainly occurs. The thermal degradation behavior and volatile products of progoitrin (the main glucosinolate of rapeseed) in different matrices (phosphate buffer at a pH value of 5.0, 7.0, or 9.0, sea sand, and rapeseed powder) at different temperatures (150-200 °C) and times (0-60 min) were studied using HPLC and GC-TOF-MS. Thereby, the degradation rate of progoitrin decreased in the following order: pH 9.0 > sea sand > rapeseed powder > pH 7.0 > pH 5.0. Further, a higher degradation was observed with increasing temperature and time. Under the applied conditions in this study, 2,4-pentadienenitrile was the major nitrile and thiophenes were the major sulfur-containing volatile compounds formed. Possible formation pathways of main sulfur-containing and nitrogen-containing volatiles were proposed.