Therapeutic effects of green tea as an antioxidant on oral health- A review

Engineering of zeolitic imidazolate frameworks based on magnetic three-dimensional graphene as effective and reusable adsorbent to enhance the adsorption and removal of caffeine from tea samples

As more and more adverse health effects of caffeine are being discovered, decaffeinated drinks are receiving increasing attention. In this work, a magnetic imidazole zeolite backbone compounded with three-dimensional graphene was successfully synthesized as a solid adsorbent using a layer-by-layer self-assembly technique, which can rapidly and effectively adsorb caffeine from tea. Meanwhile, the structure and properties of caffeine in tea were investigated by various physicochemical characterization tools. The analytical data showed that Fe3O4@3DGA@ZIF-8 had a specific surface area of 162.9754 m2/g and an adsorption capacity of up to 19.57 mg/g with a maximum adsorption rate of 96.55%, which could be maintained with good adsorption repeated utilization three times. The adsorption isotherm and the adsorption kinetic better fit with the Langmuir model and the preudo-second order kinetic model, respectively. Therefore, Fe3O4@3DGA@ZIF-8 is a good magnetic adsorbent for the separation and the effective removal of caffeine from tea sample.

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.

Antimicrobial Effects of Edible Mixed Herbal Extracts on Oral Microorganisms: An In Vitro Study

Background and Objectives: The oral cavity is inhabited by pathogenic bacteria, whose growth can be inhibited by synthetic oral drugs, including antibiotics and other chemical compounds. Natural antimicrobial substances that elicit fewer negative side effects may serve as alternatives to synthetic agents for long-term use. Thus, the aim of this study was to evaluate the effects of edible mixed herbal extracts on the growth of oral pathogenic bacteria. Materials and Methods: The yield of each herbal extract was as follows: 5% Schizonepeta tenuifolia Briq (STB), 10.94% Mentha piperascens (MP), 5.47% Acanthopanax sessiliflorus Seem (AS), and 10.66% Glycyrrhiza uralensis (GU). The herbal extracts used included 0.5 mg/mL STB, 1.5 mg/mL MP, 1.5 mg/mL AS, and 2.0 mg/mL GU. Antimicrobial tests, morphological analyses (using scanning electron microscopy), microbial surface hydrophobicity measurements, and oral malodor reduction tests were performed using each extract. Statistical analyses were performed with IBM® SPSS® (version 24), using paired t-tests. Results: The mixed herbal extracts significantly inhibited the growth of Streptococcus mutans, Enterococcus faecalis, Candida albicans, and Porphyromonas gingivalis compared to the control (p < 0.001). Scanning electron microscopy results further revealed altered cellular morphology in the groups treated with the mixed herbal extracts. Additionally, the hydrophobicity assay results showed that the mixed herbal extracts reduced the oral adhesion capacities of bacteria (p < 0.001). Administration of the mixed herbal extracts also reduced the levels of volatile sulfur compounds, the main contributors to oral malodor (p < 0.001). Conclusions: Edible mixed herbal extracts can effectively eliminate oral pathogens and may be useful for improving oral health. The herbal extracts used were effective against all species of oral pathogens studied in this report.

Effects of green tea extract epigallocatechin-3-gallate (EGCG) on oral disease-associated microbes: a review

For thousands of years, caries, periodontitis and mucosal diseases, which are closely related to oral microorganisms, have always affected human health and quality of life. These complex microbiota present in different parts of the mouth can cause chronic infections in the oral cavity under certain conditions, some of which can also lead to acute and systemic diseases. With the mutation of related microorganisms and the continuous emergence of drug-resistant strains, in order to prevent and treat related diseases, in addition to the innovation of diagnosis and treatment technology, the development of new antimicrobial drugs is also important. Catechins are polyphenolic compounds in green tea, some of which are reported to provide health benefits for a variety of diseases. Studies have shown that epigallocatechin-3-gallate (EGCG) is the most abundant and effective active ingredient in green tea catechins, which acts against a variety of gram-positive and negative bacteria, as well as some fungi and viruses. This review aims to summarize the research progress on the activity of EGCG against common oral disease-associated organisms and discuss the mechanisms of these actions, hoping to provide new medication strategies for the prevention and treatment of oral infectious diseases, the future research of EGCG and its translation into clinical practice are also discussed.

Are Dental Caries Associated with Oxidative Stress in Saliva in Children and Adolescents? A Systematic Review

Background: This systematic review aimed to assess whether dental caries is associated with oxidative salivary stress. Methods: The searches were carried out in electronic databases, including PubMed, Scopus, Web of Science, the Cochrane Library, LILACS, OpenGrey, and Google Scholar, without restrictions on the date of publication and language. The acronym PECO was used, in which the participants (P) were children and adolescents exposed (E) to dental caries compared (C) to those without dental caries, with the outcome (O) of modulation of oxidative biochemical parameters. After the search retrieval, the duplicates were removed, and the articles were evaluated by title and abstract, following the inclusion and exclusion criteria. Then, the papers were read and thoroughly assessed. After selection, the risk of bias assessment and qualitative synthesis were performed using the Newcastle-Ottawa Scale (NOS) for observational studies. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool was used to assess the level of evidence. Results: A total of 5790 studies were found, and 30 articles were considered eligible and were included for the qualitative synthesis and the level of evidence assessment. The studies showed an imbalance of the antioxidant and pro-oxidant parameters in individuals with dental caries, with primarily increases in both total antioxidant capacity and lipid peroxidation. Most articles showed a low risk of bias, having comparability as the main issue. When exploring through GRADE, a very low level of evidence was found. Conclusions: It was possible to observe an association between oxidative stress and dental caries, showing a disbalance of antioxidants and pro-oxidants, but the evidence level was still very low.

Camellia sinensis L. Alleviates Pulmonary Inflammation Induced by Porcine Pancreas Elastase and Cigarette Smoke Extract

Cigarette smoke (CS) is the major factor in the development of chronic obstructive pulmonary disease (COPD), the third leading cause of death worldwide. Furthermore, although Camellia sinensis (CN) has been known as an anti-inflammatory material, the effect of CN has not yet been known on pulmonary inflammation in COPD. Thus, we investigated the protective effects of Camellia sinensis L. extract (CLE) against pulmonary inflammation in porcine pancreas elastase (PPE) and a cigarette smoke extract (CSE)-induced COPD mouse model. Oral administration of CLE suppressed the symptoms such as infiltration of immune cells, cytokines/chemokines secretion, mucus hypersecretion, and injuries of the lung parenchyma. Increased inflammatory responses in COPD are mediated by various immune cells such as airway epithelial cells, neutrophils, and alveolar macrophages. Thus, we investigated the effect and mechanisms of CLE in H292, HL-60, and MH-S cells. The CLE inhibited the expression of IL-6, IL-8, MUC5AC and MUC5B on CSE/LPS-stimulated H292 cells and also suppressed the formation of neutrophil extracellular traps and secretion of neutrophil elastase by inhibiting reactive oxygen species in PMA-induced HL-60 cells. In particular, the CLE suppressed the release of cytokines and chemokines caused by activating the nuclear factor kappa-light-chain-enhancer of activated B via the activation of nuclear factor erythroid-2-related factor 2 and the heme oxygenase-1 pathway in CSE/LPS-stimulated MH-S cells. Therefore, we suggest that the CLE administration be the effective approach for treating or preventing chronic pulmonary diseases such as COPD induced by CS.