Inhibitory activity of green tea (Camellia sinensis) extract on some clinically isolated cariogenic and periodontopathic bacteria

Association between tea types and number of teeth: a cross-sectional study of the Chinese Longitudinal Healthy Longevity Survey

BACKGROUND

Previous studies have suggested that tea consumption may have a positive impact on oral health. However, the effects of different tea types on oral health remain unclear. Therefore, this study aimed to determine the association between residual teeth and consumption habits of different types of tea (green tea, black tea, oolong tea, and scented tea) in older adults.

METHODS

We conducted a secondary analysis using data from the Chinese Longitudinal Healthy Longevity Survey in 2018. In a sample of 6,387 older adults, we performed logistic regression analysis to examine the relationship between persistent tea consumption and oral health according to sex and brushing frequency. The indices for particularly healthy oral health and relative health were set at more than 20 teeth and more than 10 teeth, respectively.

RESULTS

The study included 2,725 males and 3,662 females, both aged 65 and older. Among individuals with more than 20 teeth, drinking green tea significantly improved oral health in men (adjusted odds ratio [ORs]: 1.377; 95% confidence interval [CI]: 1.082-1.752) and drinking black tea significantly improved the oral health of women (ORs: 2.349, 95%CI: 1.028-5.366). In the daily brushing group, green tea had a significant beneficial effect on increasing the number of teeth in men and black tea had a significant beneficial effect in women. Among individuals with more than 10 teeth, drinking green tea significantly improved oral health in men (ORs: 1.539; 95% CI: 1.209-1.959) and drinking green tea and scented tea significantly improved the oral health of women (ORs: 1.447, 95%CI: 1.052-1.991; ORs: 1.948, 95%CI: 1.137-3.340). In the daily brushing group, consumption of green tea and black tea had significant beneficial effects on increasing the number of teeth in men, whereas that of green tea, black tea, and scented tea had significant beneficial effects in women.

CONCLUSION

Long-term green tea consumption in males and black tea consumption in females were significantly associated with maintaining functional dentition (≥20 teeth). Similarly, long-term green tea consumption in males and green tea and scented tea consumption in females were associated with avoiding severe tooth loss (≥10 teeth). Furthermore, in the daily tooth brushing group, long-term consumption of black tea was associated with avoiding severe tooth loss in both sexes. However, tea consumption alone had no effect on oral health without good brushing habits.

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.

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.

Potential applications of medicinal herbs and phytochemicals in oral and dental health: Status quo and future perspectives

OBJECTIVE

Herbal therapies are utilized to treat a broad diversity of diseases all over the globe. Although no clinical studies have been conducted to demonstrate the antibacterial, antimicrobial, and antiplaque characteristics of these plants, this does not imply that they are ineffectual as periodontal treatments or anti-cariogenic drugs. However, there is a scarcity of research confirming their efficacy and worth.

SUBJECT

Herbs are utilized in dentistry as antimicrobial, antineoplastic, antiseptic, antioxidant, and analgesics agents as well as for the elimination of bad breath. In addition, the application of herbal agents in tissue engineering improved the regeneration of oral and dental tissues. This study reviews the application of medicinal herbs for the treatment of dental and oral diseases in different aspects.

METHODS

This article focuses on current developments in the use of medicinal herbs and phytochemicals in oral and dental health. An extensive literature review was conducted via an Internet database, mostly PubMed. The articles included full-text publications written in English without any restrictions on a date.

CONCLUSION

Plants have been suggested, as an alternate remedy for oral-dental problems, and this vocation needs long-term dependability. More research on herbal medicine potential as pharmaceutical sources and/or therapies is needed.

A comparative evaluation of the antimicrobial effect of chamomile, Aloe vera-green tea, and chlorhexidine mouthwashes on some oral bacterial species

Background

Plant compounds such as Aloe vera, green tea, and chamomile have been increasingly used in recent years to achieve oral health. This study aimed to determine the antimicrobial effect of chamomile (Matrika), A. vera-green tea, and chlorhexidine (CHX) mouthwashes on some oral bacterial species.

Materials and Methods

This prospective experimental study investigated the antimicrobial properties of three mouthwashes, including chamomile (Matrika), A. vera -green tea, and CHX as well as distilled water as control on five bacterial species, including Streptococcus Oralis, Streptococcus sanguis, and Streptococcus mutans as primary colonizers and Porphyromonas gingivalis and Eikenella corrodens as secondary colonizers. Colony-forming unit was used to count the colonies and disc diffusion and well diffusion methods were used to measure the diameter of zone of inhibition. Data were analyzed by SPSS (version 22) software using descriptive statistics, ANOVA, Tukey, Kruskal-Wallis, and Mann-Whitney tests (α = 0.05).

Results

CHX had a significantly higher antibacterial effect than the other two mouthwashes in all three methods (P < 0.001). Further, the herbal mouthwashes in all three methods had a statistically significant effect on the bacterial species (P < 0.001). A. vera-green tea mouthwash had a significantly higher effect than chamomile mouthwash (Matrika) on all bacterial species except for S. sanguis (P < 0.05).

Conclusion

The findings showed that herbal mouthwashes had potentially antibacterial effects, but these effects were significantly lower than that of CHX. However, more clinical studies are needed to prove the current findings.

Evaluating the Effects of Camellia Sinensis (Green Tea) and Teucrium Polium Extracts on Salivary Streptococcus Mutans Levels in Children

STATEMENT OF THE PROBLEM

Camelia Sinenis or green tea (GT) and Teucrium polium (TP) are known to have a great antimicrobial potential on salivary Streptococcus mutans (S. mutans). Their efficacy should be examined compared to the gold standard antimicrobial agents.

PURPOSE

To evaluate the effects of Camelia Sinenis or green tea (GT) and Teucrium polium (TP) extracts in comparison with chlorhexidine gluconate (CHG) on salivary S. mutans levels.

MATERIALS AND METHOD

This double-blinded randomized clinical trial study was conducted on 90 preschool children aged 4 to 6 years and assigned randomly (simple randomization) to three groups as GT, TP, and CHG. Unstimulated saliva samples were then collected in three times as before application of agents, after half an hour, and after one week. To determine S. mutans levels, quantitative polymerase chain reaction (qPCR) technique was additionally utilized. Statistical analysis was also fulfilled using Shapiro-Wilk test, Friedman test, Chi-square test, paired sample t-test, repeated measures analysis of variance (ANOVA), and Mann-Whitney U test at a significance level of 0.05.

RESULTS

The results of this study established a significant difference between mean salivary S. mutans levels after administration of the three compounds. Although the mean of S. mutans levels reduced significantly following the application of CHG and TP after half an hour, the mean salivary S. mutans levels in the group receiving GT declined in a significant manner only one week later (p< 0.05).

CONCLUSION

The results of this study indicated that GT and TP extracts had considerable effects on salivary S. mutans levels compared with CHG.

Anticancer Therapeutic Effects of Green Tea Catechins (GTCs) When Integrated with Antioxidant Natural Components

After decades of research and development concerning cancer treatment, cancer is still at large and very much a threat to the global human population. Cancer remedies have been sought from all possible directions, including chemicals, irradiation, nanomaterials, natural compounds, and the like. In this current review, we surveyed the milestones achieved by green tea catechins and what has been accomplished in cancer therapy. Specifically, we have assessed the synergistic anticarcinogenic effects when green tea catechins (GTCs) are combined with other antioxidant-rich natural compounds. Living in an age of inadequacies, combinatorial approaches are gaining momentum, and GTCs have progressed much, yet there are insufficiencies that can be improvised when combined with natural antioxidant compounds. This review highlights that there are not many reports in this specific area and encourages and recommends research attention in this direction. The antioxidant/prooxidant mechanisms of GTCs have also been highlighted. The current scenario and the future of such combinatorial approaches have been addressed, and the lacunae in this aspect have been discussed.

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.

Therapeutic Potential of Flavonoids and Tannins in Management of Oral Infectious Diseases-A Review

Medicinal plants are rich sources of valuable molecules with various profitable biological effects, including antimicrobial activity. The advantages of herbal products are their effectiveness, relative safety based on research or extended traditional use, and accessibility without prescription. Extensive and irrational usage of antibiotics since their discovery in 1928 has led to the increasing expiration of their effectiveness due to antibacterial resistance. Now, medical research is facing a big and challenging mission to find effective and safe antimicrobial therapies to replace inactive drugs. Over the years, one of the research fields that remained the most available is the area of natural products: medicinal plants and their metabolites, which could serve as active substances to fight against microbes or be considered as models in drug design. This review presents selected flavonoids (such as apigenin, quercetin, kaempferol, kurarinone, and morin) and tannins (including oligomeric proanthocyanidins, gallotannins, ellagitannins, catechins, and epigallocatechin gallate), but also medicinal plants rich in these compounds as potential therapeutic agents in oral infectious diseases based on traditional usages such as Agrimonia eupatoria L., Hamamelis virginiana L., Matricaria chamomilla L., Vaccinium myrtillus L., Quercus robur L., Rosa gallica L., Rubus idaeus L., or Potentilla erecta (L.). Some of the presented compounds and extracts are already successfully used to maintain oral health, as the main or additive ingredient of toothpastes or mouthwashes. Others are promising for further research or future applications.

Antimicrobial Effect of Tea Polyphenols against Foodborne Pathogens: A Review

ABSTRACT

Food contamination by foodborne pathogens is still widespread in many countries around the world, and food safety is a major global public health issue. Therefore, novel preservatives that can guarantee safer food are in high demand. Contrary to artificial food preservatives, tea polyphenols (TPs) are getting wide attention as food additives for being "green," "safe," and "healthy." TPs come from many sources, and the purification technology is sophisticated. Compared with other natural antibacterial agents, the antibacterial effect of TPs is more stable, making them excellent natural antibacterial agents. This review includes a systematic summary of the important chemical components of TPs and the antibacterial mechanisms of TPs against various foodborne pathogens. The potential applications of TPs are also discussed. These data provide a theoretical basis for the in-depth study of TPs.

HIGHLIGHTS

Green tea extract rich in epigallocatechin gallate impairs alveolar bone loss in ovariectomized rats with experimental periodontal disease

Periodontal disease and osteoporosis are characterized by bone resorption, and researchers have shown an association between these two diseases through increasing loss of systemic bone mass and triggering alveolar bone loss. Green tea is a common and easily accessible beverage, and evidences show that flavonoid epigallocatechin gallate (EGCG) could decrease bone loss in pathologies such as osteoporosis and periodontal disease. In order to verify its possible effects and apply them in the treatment and prevention of these diseases, this investigation aimed to evaluate the influence of green tea extract (GTE) on bone metabolism of ovariectomized rats after experimental periodontal disease (EPD) by histological, morphological and microtomographic parameters. Wistar female rats were divided into Sham, Sham + EPD, Sham + EPD + GTE, OVX, OVX + EPD and OVX + EPD + GTE groups. Immediately after surgery, gavage administration of 50 mg/kg of green tea extract (GTE) was performed for 60 days, with subsequent induction of periodontal disease by ligature 15 days before euthanasia. Mandible and femur samples were collected for histological, morphometric and microtomographic analysis. The results were analysed by means of statistical software with significance set at 5%. Histological and morphometric analysis showed a significant decrease in alveolar and femoral trabecular bone loss in groups that received GTE. Microtomographic results showed that trabecular thickness and bone surface density values in alveolar bone interradicular septum of the OVX + EPD + GTE groups were similar to the Sham group. The results obtained suggest that green tea extract may improve bone metabolism in osteoporotic rats with periodontal disease.

Gut/Oral Bacteria Variability May Explain the High Efficacy of Green Tea in Rodent Tumor Inhibition and Its Absence in Humans

Consumption of green tea (GT) and GT polyphenols has prevented a range of cancers in rodents but has had mixed results in humans. Human subjects who drank GT for weeks showed changes in oral microbiome. However, GT-induced changes in RNA in oral epithelium were subject-specific, suggesting GT-induced changes of the oral epithelium occurred but differed across individuals. In contrast, studies in rodents consuming GT polyphenols revealed obvious changes in epithelial gene expression. GT polyphenols are poorly absorbed by digestive tract epithelium. Their metabolism by gut/oral microbial enzymes occurs and can alter absorption and function of these molecules and thus their bioactivity. This might explain the overall lack of consistency in oral epithelium RNA expression changes seen in human subjects who consumed GT. Each human has different gut/oral microbiomes, so they may have different levels of polyphenol-metabolizing bacteria. We speculate the similar gut/oral microbiomes in, for example, mice housed together are responsible for the minimal variance observed in tissue GT responses within a study. The consistency of the tissue response to GT within a rodent study eases the selection of a dose level that affects tumor rates. This leads to the theory that determination of optimal GT doses in a human requires knowledge about the gut/oral microbiome in that human.

Antibacterial activity of plant species used for oral health against Porphyromonas gingivalis

Porphyromonas gingivalis is the keystone pathogen of periodontitis, a chronic inflammatory disease which causes tooth loss and deterioration of gingiva. Medicinal plants have been traditionally used for oral hygiene and health and might play a role as antibacterial agents against oral pathogens. In this work, we aimed to evaluate the antibacterial activity of plants used for oral hygiene or symptoms of periodontitis against P. gingivalis. We first reviewed the literature to identify plant species used for oral hygiene or symptoms of periodontitis. Then, we cross-checked this species list with our in-house library of plant extracts to select extracts for testing. Antibacterial activity tests were then performed for each plant extract against P. gingivalis, and their cytotoxicity was assessed on HaCaT cells. The selectivity index (SI) was then calculated. A total of 416 plant species belonging to 110 families and 305 genera were documented through our literature search, and 158 plant species were noted as being used by North American Native peoples Once cross-checked with the extracts contained in our library of natural products, 30 matches were identified and 21 were defined as high priority. Of the 109 extracts from 21 plant species selected and tested, 21 extracts from 11 plants had higher than 90% inhibition on P. gingivalis at 64 μg/mL and were further selected for MIC (Minimum Inhibitory Concentration) assays. Out of 21 plant extracts, 13 extracts (7 plant species) had a SI > 10. Pistacia lentiscus fruits showed the best MIC with value of 8 μg/mL, followed by Zanthoxylum armatum fruits/seeds with a MIC of 16 μg/mL. P. lentiscus fruits also showed the highest SI of 256. Most of the extracts tested present promising antibacterial activity and low cytotoxicity. Further testing for biofilm eradication and examination of activity against other dental pathogens and oral commensals should be performed to confirm the potential of these extracts as antibacterial agents. Future work will focus on application of a bioassay-guided fractionation approach to isolating and identifying the most active natural products in the top performing extracts. This study can serve as a basis for their future development as ingredients for oral hygiene products.

The Porphyromonas gingivalis inhibitory effects, antioxidant effects and the safety of a Sri Lankan traditional betel quid - an in vitro study

Background

The Sri Lankan traditional betel quid (TBQ) which had been extensively used in the country before its colonization is claimed to have antiperiodontopathic effects in the Sri Lankan folklore. However, there is no reported scientific evidence to support the claimed antiperiodontopathic effects mediated by this TBQ. The present study was carried out to investigate the protective effect of the Sri Lankan TBQ in the pathogenesis of periodontitis.

Methods

We investigate the ethyl acetate extract of the Sri Lankan TBQ for its antibacterial effects against the keystone periodontopathic bacterium, P. gingivalis and also its antioxidant potential, which is important to protect the periodontium from oxidative stress. Further, its safety was analyzed using the cytokinesis block micronucleus assay on human peripheral blood lymphocytes (PBLs).

Results

Ethyl acetate extract of this TBQ inhibited the growth of P. gingivalis with a minimum bactericidal concentration (MBC) of 125 μg/ml. It was found to be a rich source of polyphenols and displayed considerable DPPH and ABTS radical scavenging activities and a strong ferric reducing antioxidant power. This extract could protect the cultured human gingival fibroblasts from H₂O₂ induced oxidative stress. In addition, this TBQ extract was not genotoxic to human PBLs even at a concentration of 2.5 mg/ml. Moreover, it exhibited protective effects against bleomycin induced genotoxicity in PBLs.

Conclusion

Ethyl acetate extract of the Sri Lankan TBQ is a source of natural antibacterial compounds against P. gingivalis. It is also a source of natural antioxidants which can protect human gingival fibroblasts from H₂O₂ induced oxidative stress. These properties of the TBQ may have contributed to its claimed antiperiodontopathic effects. Besides, it was found to be relatively non-toxic to human cells. Thus this TBQ extract has a huge potential to be developed as a novel adjunctive therapeutic lead against periodontitis.

Inhibitory effects on Streptococcus mutans of antibacterial agents mixed with experimental fluoride varnish

We investigated the inhibitory effect of antibacterial agents mixed with experimental fluoride varnish (EFV) on Streptococcus mutans. The antibacterial agents used were (1 and 10) mM of xanthorrhizol, bakuchiol, bavachalcone, isobavachromene, and bavachromene. Agar diffusion tests were performed on S. mutans (1.1×10¹⁰ CFU/mL), using antibacterial agents without and with EFV. Bavachalcone showed the highest inhibition zone without and with EFV at both (1 and 10) mM (p<0.05). All EFV with antibacterial agents showed greater inhibition and semi-inhibition zones than EFV alone (p<0.05). The cell viability of each antibacterial agent was not significantly different from the vehicle controls (p>0.05), except xanthorrhizol and bakuchiol at 1 mM. All antibacterial agents were effective, while antibacterial agents with EFV co-formulations were more effective than EFV alone. Bavachalcone was the most effective agent against S. mutans, indicating its potential usefulness with fluoride varnish in preventing dental caries.

Comparison of antimicrobial efficacy of aqueous ozone, green tea, and normal saline as irrigants in pulpectomy procedures of primary teeth

AIM

Sodium hypochlorite, though considered an ideal root canal irrigant, cannot be used at required concentrations in children, due to its undesirable effects. Hence, it is imperative to search for an ideal root canal irrigant to avoid these undesirable effects which we hope to achieve with this study. The antimicrobial efficacy of aqueous ozone, green tea, and normal saline as irrigants in pulpectomy procedures of the primary teeth has been compared.

MATERIALS AND METHODS

Sixty patients between 4 and 8 years of age with a single-rooted deciduous tooth indicated for pulpectomy were included. The infected teeth were randomly allocated to one of the three treatment groups based on the irrigating agents used, namely normal saline, green tea extract, or ozonated water. Specimens for anaerobic culture were collected three times from the teeth: before irrigation, after initial irrigation, and on the 3^rd day after final irrigation.

RESULTS AND CONCLUSION

Mean colony forming unit (CFU) count after both initial and final irrigation with ozonated water was significantly lower when compared with green tea and normal saline. Further, it was observed that the mean CFU count with green tea was significantly lower than the counts obtained with normal saline on the 3^rd day after final irrigation. Hence, both ozonated water and green tea could be considered a good alternative to conventional root canal irrigants in the primary teeth. Larger sample sizes with a larger variety of irrigants are recommended.

Dose-dependent green tea effect on decrease of inflammation in human oral gingival epithelial keratinocytes: in vitro study

Objectives

This in vitro study aimed to analyze the anti-inflammatory and wound healing potential of green tea extract (GTE) in human gingival epithelial keratinocytes (HGEK) treated with lipopolysaccharides (LPS).

Materials and methods

A cell viability assay was conducted using MTT to determine nontoxic levels of GTE on immortalized HGEK. Cells were concomitantly treated with LPS (1 μg/ml) and GTE (1 mg/ml, 2.5 mg/ml, 5 mg/ml, and 10 mg/ml) to assess inflammation. Gene expression levels of inflammatory markers IL-β1, IL-6, and TNFα were measured by RT-PCR and their protein production was assessed by ELISA. The scratch wound healing assay was used to investigate the effects of different concentrations of GTE on cell migration. We also explored the effect of GTE on the induction of the Nrf2/HO-1 pathway in the cells with or without LPS.

Results

GTE at concentrations of 2.5 mg/ml, 5 mg/ml, and 10 mg/ml significantly enhanced cell viability (p < 0.05). And IL-β1, IL-6, and TNFα gene expression presented up to 10-fold decrease compared with LPS-treated cells, which was also similarly found on the protein levels. At the same concentrations, cell migration increased.

Conclusions

The mechanism results showed that GTE produced the anti-inflammatory response by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway and increasing the level of anti-oxidant protein heme oxygenase-1 (HO-1).

Clinical relevance

GTE may be potentially used as oral rinse anti-inflammatory drug for treatment and prevention of oral inflammatory diseases, which is shown here by the ability to reduce the inflammation and increase in cell migration in a dose-dependent manner.

Polyphenols in the prevention and treatment of periodontal disease: A systematic review of in vivo, ex vivo and in vitro studies

Plant-derived polyphenols with antimicrobial and immunomodulatory characteristics appear to provide a variety of oral health benefits. Thus, the aim of the present study was to review the scientific literature to identify these effects of polyphenols on periodontal pathogens and inflammation. A MEDLINE search from 1st January 2013 to 18th January 2018 was performed to identify studies reporting polyphenol-containing plant extracts. Reports regarding pure compounds and essential oils, as well as effects on bacteria that are not defined as periodontal pathogens, were excluded. Thirty-eight studies matched the selection criteria. Studies on immunomodulatory effects included in vitro, ex vivo, and in vivo studies (n = 23), whereas studies reporting antibacterial effects against periodontal pathogens included only in vitro studies (n = 18). Three studies were included in both groups. The antibacterial effects were characterised by inhibition of bacterial growth, adhesion to oral cells, and enzymatic activity. Decreased secretion of pro-inflammatory and increased secretion of anti-inflammatory cytokines were demonstrated. Higher attachment levels, lower inflammation, and bone loss were reported by in vivo studies. Due to the high heterogeneity, it is difficult to draw clear conclusions for applicability; nevertheless, polyphenols have great potential as antimicrobial and immunomodulatory substances in the treatment and prevention of periodontal disease.

Green Tea Catechins: Their Use in Treating and Preventing Infectious Diseases

Green tea is one of the most popular drinks consumed worldwide. Produced mainly in Asian countries from the leaves of the Camellia sinensis plant, the potential health benefits have been widely studied. Recently, researchers have studied the ability of green tea to eradicate infectious agents and the ability to actually prevent infections. The important components in green tea that show antimicrobial properties are the catechins. The four main catechins that occur in green tea are (-)-epicatechin (EC), (-)-epicatechin-3-gallate (ECG), (-)-epigallocatechin (EGC), and (-)-epigallocatechin-3-gallate (EGCG). Of these catechins, EGCG and EGC are found in the highest amounts in green tea and have been the subject of most of the studies. These catechins have been shown to demonstrate a variety of antimicrobial properties, both to organisms affected and in mechanisms used. Consumption of green tea has been shown to distribute these compounds and/or their metabolites throughout the body, which allows for not only the possibility of treatment of infections but also the prevention of infections.

Inhibitory activity of a green and black tea blend on Streptococcus mutans

Through the years, tea consumption has been associated with good health, and some publications are related to oral health. The bioactive components of green tea are thought to be able to influence the process of caries formation through inhibition of proliferation of the streptococcal agent, interference with the process of bacterial adhesion to tooth enamel, and inhibition of glucosyl transferase and amylase; however, little is known about black tea and oral health. The aim of the present in-vitro study was to determine the inhibitory activity of a novel, patent-pending and proprietary blend of green and black tea aqueous extracts on Streptococcus mutans, a bacterium widely associated with plaque development and tooth decay. A minimum inhibitory concentration (MIC) of 12.5 mg/mL and a minimum bactericidal concentration (MBC) of 12.5 mg/mL was established against S. mutans, meaning that at concentrations of 12.5 mg/mL and higher, the proprietary tea blend is effective against the growth of S. mutans. This MIC concentration is lower than the ones reported in the literature for alcoholic black tea and green tea extracts tested separately. As a promising natural ingredient for oral health, this finding is a good indicator for the use of this proprietary blend of black and green tea water extracts.

Development and preparation of active starch films carrying tea polyphenol

Starch films incorporated with tea polyphenol (TP) were developed to produce active food packaging. The effect of the incorporation of TP with different content on the structure, physicochemical properties, antioxidant activity and antimicrobial activity of the starch films was systematically evaluated. Results showed that TP was well dispersed in the starch matrix, which induced a slight influence on the surface and barrier properties of the films. TP addition led to an important improvement in antioxidant capability, as well as inhibition efficiency against the microorganisms of S. aureus and E. coli. However, a decrease in mechanical properties of films was observed. Moreover, a new automatic counting method which combined the computer vision and machine learning algorithm was developed to identify and count the colonies, and the method performed much faster without subjective uncertainty.

Effects of green tea on miRNA and microbiome of oral epithelium

Consumption of green tea (GT) extracts or purified catechins has shown the ability to prevent oral and other cancers and inhibit cancer progression in rodent models, but the evidence for this in humans is mixed. Working with humans, we sought to understand the source of variable responses to GT by examining its effects on oral epithelium. Lingual epithelial RNA and lingual and gingival microbiota were measured before and after 4 weeks of exposure in tobacco smokers, whom are at high risk of oral cancer. GT consumption had on average inconsistent effects on miRNA expression in the oral epithelium. Only analysis that examined paired miRNAs, showing changed and coordinated expression with GT exposure, provided evidence for a GT effect on miRNAs, identifying miRNAs co-expressed with two hubs, miR-181a-5p and 301a-3p. An examination of the microbiome on cancer prone lingual mucosa, in contrast, showed clear shifts in the relative abundance of Streptococcus and Staphylococcus, and other genera after GT exposure. These data support the idea that tea consumption can consistently change oral bacteria in humans, which may affect carcinogenesis, but argue that GT effects on oral epithelial miRNA expression in humans vary between individuals.

Effect of Green Tea Varnish on Depth of Root Caries

AIM

Root caries is a common, debilitating condition particularly in the elderly population, which can lead to tooth loss. Evidence shows that green tea has cariostatic effects. Considering the gap of information on green tea varnish, this study aimed to assess the efficacy of green tea varnish in the prevention of root caries.

MATERIALS AND METHODS

This in vitro experimental study was performed on 42 sound premolars. Two layers of acid-resistant nail varnish were applied on root surfaces except for a window of 1 × 4 mm. The teeth were randomly divided into three groups (n = 14). Group I (control) received no intervention. Group II received green tea varnish applied on the roots every 48 hours for 21 days. Group III received green tea varnish every 24 hours for 21 days. Sections of 40 μ thickness were prepared from the center of the window, and the depth of carious lesion was measured in three points with 500 μ distance from each other using polarized light microscope. Data were analyzed using Statistical Package for the Social Sciences (SPSS) version 16 and non-parametric Kruskal-Wallis and Mann-Whitney U tests (α = 0.05).

RESULTS

The mean (and standard deviation) depth of carious lesion was 54.30 ± 28.64 (μm), 0, and 0 in groups I, II, and III respectively. Control group showed the highest depth of caries. Groups II and III were not significantly different in this respect, but significant differences were noted in depth of caries between groups I and II and also groups I and III (p < 0.001).

CONCLUSION

Based on the results, the green tea varnish may possess anticariogenic effects on root caries when applied every 24 or 48 hours over a 21-day period. Application of green tea varnish every 24 or 48 hours for 21 days may prevent root caries.

CLINICAL SIGNIFICANCE

Application of green tea varnish can prevent root caries.

Effect of Camellia sinensis plant on decreasing the level of halitosis: A systematic review

Tea is the second most consumed beverage. Polyphenolic catechins of green tea have a number of beneficial effects in oral cavity. This study aims to evaluate the clinical effects of green tea on halitosis through a systematic review of available literature. All available randomized, clinical trials - with a relevant subject that met the inclusion criteria - were included by searching PubMed, Cochrane, ProQuest, and Google Scholar, and Scopus databases. To score the selected articles, 27 items of CONSORT 2010 checklist were considered. Each article was reviewed by all the authors. Searching the PubMed database yielded 42 articles, 2 of which met the inclusion criteria. None of the 12 articles were obtained through Cochrane library, and 85 articles retrieved from ProQuest database met the inclusion criteria. Three hundred and five articles were obtained from Google Scholar, three of which fulfilled the inclusion criteria. Two articles were omitted because they were duplicated, and the rest were excluded. Searching the Scopus database yielded 270 articles, 2 of which met the inclusion criteria, but they were also duplicated. Finally, two studies were selected according to the inclusion criteria of the study. In both of the included articles, the early effect of green tea use was statistically significant in comparison with baseline. One of the studies showed the long-term effect of green tea mouthwash. Green tea can reduce halitosis through rinsing and antimicrobial effect.

Quantum curcumin mediated inhibition of gingipains and mixed-biofilm of Porphyromonas gingivalis causing chronic periodontitis

Periodontitis is a biofilm-associated irreversible inflammation of the periodontal tissues. Reports suggest the role of Porphyromonas gingivalis specific Arg- and Lys-specific proteinases in the orchestration of the initiation and progression of periodontal diseases. These proteinases are precisely termed as gingipains R and K. Curcumin is an active polyphenol that is extracted from the rhizomes of Curcuma longa. However, the molecule curcumin owing to its high hydropathy index and poor stability has not been able to justify its role as frontline drug modality in the treatment of infectious and non-infectious diseases as claimed by several investigators. In the present study, at first, we synthesized and characterized quantum curcumin, and investigated its biocompatibility. This was subsequently followed by the evaluation of the role of quantum curcumin as an antimicrobial, anti-gingipains and antibiofilm agent against Porphyromonas gingivalis and select reference strains. We have successfully synthesized the quantum curcumin utilizing a top-down approach with the average size of 3.5 nm. Apart from its potent antimicrobial as well as antibiofilm properties, it also significantly inhibited the gingipains in a dose-dependent manner. At the minimal concentration of 17.826 μM, inhibition up to 98.7% and 89.4% was noted for gingipain R and K respectively. The data was also supported by the in silico docking experiments which revealed high exothermic enthalpies (−7.01 and −7.02 cal mol⁻¹). Besides, the inhibition constant was found to be 7.24 μM and 7.1 μM against gingipains R and K respectively. The results suggest that quantum curcumin is a potential drug candidate which needs further clinical validation.

Periodontitis is a biofilm-associated irreversible inflammation of the periodontal tissues.

Antimicrobial activity of aqueous extracts from four plants on bacterial isolates from periodontitis patients

Four aqueous extracts of different plant organs are the following: Artemisia herba-alba, Opuntia ficus-indica, Camellia sinensis and Phlomis crinita were evaluated against two bacterial strains: Porphyromonas gingivalis and Prevotella intermedia, which are implicated in periodontal diseases. By using a disc method, these plant extracts demonstrated powerful bacterial activity against these Gram-negative strains. The minimum inhibitory concentration values of the four plant extracts varied between 0.03 and 590.82 mg/ml for the microbes. Another assay using commercial antibiotics and antibacterials as positive controls was also conducted. Values obtained after statistical analysis of inhibition diameters of all plant extracts demonstrated that for P. gingivalis, the aqueous extracts of A. herba-alba and O. ficus-indica were most effective, followed by those of C. sinensis and P. crinita. For P. intermedia, aqueous extracts of O. ficus-indica and C. sinensis appeared to be more efficient with significantly different (P > 0.05) inhibition diameters, followed by those of O. ficus-indica and P. crinita. In summary, the statistical results reveal that these plant extracts exert stronger antibacterial activity on P. intermedia germ as compared to P. gingivalis.

In Vitro Antimicrobial Activity of Thymus vulgaris Essential Oil Against Major Oral Pathogens

The objective of present investigation was to determine antimicrobial activity of Thymus vulgaris oil on some oral pathogens. Thymus vulgaris oil was prepared by hydrodistillation and tested against 30 clinical isolates of each of Streptococcus pyogenes, Streptococcus mutans, Candida albicans, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans, prepared from related oral infections using agar disk diffusion and broth microdilution methods. Thymus vulgaris oil at concentrations of 16 to 256 μg/mL exhibited strong inhibitory activity on all clinical isolates producing inhibition zones of 7.5 to 42 mm as measured by agar disk diffusion method. Streptococcus pyogenes and Streptococcus mutans were the most sensitive isolates with minimum inhibitory concentrations of 1.9 and 3.6 μg/mL, respectively. The minimum inhibitory concentration values for C albicans, A actinomycetemcomitans, and P gingivalis were 16.3, 32, and 32 μg/mL, respectively.

Herbs as an antioxidant arsenal for periodontal diseases

Herbal medicines have long been used as a traditional mode of therapy for various ailments in India. They are being used increasingly as dietary supplements to ward off common diseases. Periodontal diseases are highly prevalent and can affect up to 90% of the world population. Gingivitis is the mild form whereas periodontitis results in an irreversible loss of supporting structures of the teeth. Even though periodontal pathogens form a crucial component in the etiopathogenesis of periodontitis, there is a growing body of evidence suggesting oxidative stress playing a pivotal role in the disease initiation and progression. Studies have shown a direct correlation between increased levels of biomarkers for tissue damage induced by reactive oxygen species (ROS) to the severity of periodontal disease. Thus, the focus of attention has revolved back to herbal medicines due to their wide spectrum of biological and medicinal activities, lower costs, and higher safety margin. Internet databases Pubmed and Google Scholar were searched, and the most relevant articles were considered for review. This review briefly describes the various herbs with antioxidant capacity and their potency in the treating periodontal disease.

Indicience of bacteria nad antibacterial activity of selected types of tea

The purpose of this study was to determine in vitro antibacterial activity of selected teas (Assam: Indian black tea from Camellia sinensis, Pu-erh: darkpu-erh (shu) from Camellia sinensis, Sencha: Japanese green tea from Camellia sinensis) against five species of pathogenic microorganisms. In our study, we determined the total viable count (TVC), yeasts (Y) andEnterobacteriaceae counts (E). MALDI-TOF MS Biotyper was used for identification of colonies after cultivation. Evaluation of the antimicrobial activity was performed by disc diffusion method, well diffusion method and detection of minimum inhibitory concentration (MIC). For antibacterial activity against Escherichia coli CCM 2024, Yersinia enterocolitica CCM 5671, Klebsiella pneumonie CCM 2318, Staphylococus aureus CCM 2461 and Bacillus thurigiensis CCM19 were detected. The inhibition zones were measured in mm in disc diffusion method and well diffusion method. The MIC of the individual extracts was measured spectrophotometrically. The high number of total viable count was found in Pu-erh tea (2.1 log CFU.g-1) and lowest number was found in Assam tea (0.7 log CFU.g-1). The high number of Enterobacteriacea was found in Pu-erh tea (2.03 log CFU.g-1) and lowest in Assam tea (0 log CFU.g-1). The higher number of yeasts was found in Pu-erh tea (1.83 log CFU.g-1) and lowest in Assam tea (0.3 log CFU.g-1). Mass spectrometry revealed the presence of seven Gram positive bacteria Bacillus cereus, B. mycoides, B. pumilus, Enterococcus durans, Staphylococcus epidermis, S. hominis, S. warneri, four Gram negative bacteriaAcinetobacter junii, Hafnia alvei, Klebsiella pneumoniae, Sphingomonas spp. and two yeast - Candida glabrata, Cryptococcus albidus. The results show that certain tea extracts are particularly active against various pathogenic bacteria. Tea extracts (Sencha, Rooibos, Mate, Assam) were found to have the strongest antibacterial activity against Staphylococcus aureus CCM 2461.

Natural Antimicrobials and Oral Microorganisms: A Systematic Review on Herbal Interventions for the Eradication of Multispecies Oral Biofilms

Oral diseases such as caries and periodontitis are mainly caused by microbial biofilms. Antibiotic therapy has reached its limits with regard to antimicrobial resistance, and new therapeutic measures utilizing natural phytochemicals are currently a focus of research. Hence, this systematic review provides a critical presentation of the antimicrobial effects of various medicinal herbs against in vitro, ex vivo, and in situ formed multispecies oral biofilms. Searches were performed in three English databases (PubMed, EMBASE, CAMbase) and the electronic archives of five German journals from the times of their establishment until October 10th, 2014, with the search terms “(plant extracts OR herbal extracts OR plant OR herb) AND (oral biofilm OR dental biofilm OR dental plaque OR oral disease OR dental disease).” The pooled data were assessed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA). Initially, 1848 articles were identified, out of which 585 full-text articles were screened, 149 articles were reevaluated for eligibility and finally, 14 articles met all inclusion criteria. The data of 14 reports disclosed enhanced antiadhesive and antibiofilm activity by the plant extracts obtained from Vitis vinifera, Pinus spp., Coffea canephora, Camellia sinensis, Vaccinium macrocarpon, Galla chinensis, Caesalpinia ferrea Martius, Psidium cattleianum, representative Brazilian plants and manuka honey. Overall, a positive correlation was revealed between herb-based therapies and elimination rates of all types of multispecies oral biofilms. In that context, integrating or even replacing conventional dental therapy protocols with herbal-inspired treatments can allow effective antimicrobial control of oral biofilms and thus, dental diseases.

Traditionally used herbal medicines with antibacterial effect on Aggegatibacter actinomycetemcomitans: Boswellia serrata and Nigella sativa

Background:

Since bacterial strains developed resistance against commonly used antibiotics and side effects became more serious, other alternatives have been postulated. There is an answer for this issue in ancient medicine. Many plants have been proved to provide antibacterial effect. In this study, Boswellia serrata (BS) and Nigella sativa (NS) were assessed to evaluate the antibacterial effect on Aggregatibacter actinomycetemcomitans (A.a) known as main pathogen of aggressive periodontitis.

Materials and Methods:

Broth microdilution method was used to obtain minimum inhibitory concentration (MIC) of crude extract of BS and NS. Furthermore, the logarithm of colony forming units grown in fresh brain heart infusion bacterial culture was assessed. Three groups including BS+ (containing only BS), NS+ (containing only NS), and BS-NS− (control group) were defined. For each group, the experiment was repeated 12 times.

Results:

MIC of BS and NS were 512 μg/mL and 128 μg/mL, respectively. No growth was observed in our negative control group. The mean ± standard deviation of logarithm of CFU/mL for BS, NS, and control group was 4.32 ± 0.36, 3.61 ± 0.3, and 5.57 ± 0.19, respectively. ANOVA test revealed significant difference (P values < 0.0001) of these groups which was later confirmed using the post hoc test of Tukey's honest significant difference (all P < 0.0001).

Conclusions:

Both BS and NS are effective against A.a which should be taken into account as appropriate ingredient for oral hygiene products.

Natural products and caries prevention

Dental caries is considered as the most common polymicrobial oral disease in the world. With the aim of developing alternative approaches to reduce or prevent the decay, numerous papers showed the potential anticaries activity of a number of natural products. The natural products with anticaries effects are selected from e.g. food, beverages, flowers or traditional herbs. Most of the effective components are proven to be polyphenol compounds. Many of the natural products are studied as antibacterial agents, while some of them are found to be effective in shifting the de-/remineralization balance. However, the mechanisms of the anticaries effects are still unclear for most of the natural products. In the future, more efforts need to be made to seek novel effective natural products via in vitro experiment, animal study and in situ investigations, as well as to enhance their anticaries effects with the help of novel technology like nanotechnology.

Drug resistance of bacterial dental biofilm and the potential use of natural compounds as alternative for prevention and treatment

Oral diseases, such as dental caries and periodontal disease are directly linked with the ability of bacteria to form biofilm. The development of dental caries involves acidogenic and aciduric Gram-positive bacteria colonizing the supragingival biofilm (Streptococcus, Lactobacillus and Actinomycetes). Periodontal diseases have been linked to anaerobic Gram-negative bacteria forming a subgingival plaque (Porphyromonas gingivalis, Actinobacillus, Prevotella and Fusobacterium). Cells embedded in biofilm are up to 1000-fold more resistant to antibiotics compared to their planctonic ones. Several mechanisms have been proposed to explain biofilms drug resistance. Given the increased bacterial resistance to antibiotics currently used in dentistry, a great importance is given to natural compounds for the prevention of oral bacterial growth, adhesion and colonization. Over the past decade, interest in drugs derived from medicinal plants has markedly increased. It has been well documented that medicinal plants and natural compounds confer considerable antibacterial activity against various microorganisms including cariogenic and periodontal pathogens. This paper provides a review of the literature focusing on the studies on (i) biofilm in the oral cavity, (ii) drug resistance of bacterial biofilm and (iii) the potential use of plant extracts, essential oils and natural compounds as biofilm preventive agents in dentistry, involving their origin and their mechanism of biofilm inhibition.

Effects of green tea on Escherichia coli as a uropathogen

Escherichia coli is the most common cause of urinary tract infections. The development of antibiotic resistance in E. coli is an important problem. Finding alternative antimicrobial agents from plant extracts has received growing interest. Camellia sinensis is a safe, nontoxic, cheap beverage that has been reported to have antimicrobial effects against various pathogenic bacteria including E. coli. Polyphenolic components of green tea ( lǜ chá) have antibacterial activity. Catechins also have synergistic effect with antibiotics such as chloramphenicol, amoxicillin, sulfamethoxazole, azithromycin, levofloxacin, gentamycin, methicillin, naldixic acid, and, especially ciprofloxacin. In this review, all experimental studies that evaluated the effect of green tea on E. coli were collected. Data from in vitro studies on the antimicrobial effects of green tea are promising, but human data are currently lacking. In vivo studies on antibacterial effects of green tea and evaluating the efficacy of its catechins in the treatment of urinary tract infection are needed.

The antimicrobial possibilities of green tea

Green tea is a popular drink, especially in Asian countries, although its popularity continues to spread across the globe. The health benefits of green tea, derived from the leaves of the Camellia sinensis plant, have been studied for many years. Fairly recently, researchers have begun to look at the possibility of using green tea in antimicrobial therapy, and the potential prevention of infections. The particular properties of catechins found in the tea have shown promise for having antimicrobial effects. There are four main catechins (polyphenols) found in green tea: (-)-epicatechin (EC), (-)-epicatechin-3-gallate (ECG), (-)-epigallocatechin (EGC), and (-)-epigallocatechin-3-gallate (EGCG). Three of these, ECG, EGC, and EGCG have been shown to have antimicrobial effects against a variety of organisms. These catechins have exhibited a variety of antimicrobial mechanisms. The results of studies on the antimicrobial effects of green tea have shown that the potential for preventive and therapeutic purposes is present. Further data collection on studies performed with human consumption during the course of infections, and studies on the occurrence of infections in populations that consume regular amounts of green tea will be necessary to complete the picture of its antimicrobial possibilities.

Inhibitory activity of Myrtus communis oil on some clinically isolated oral pathogens

OBJECTIVES

To determine the antimicrobial activities of Myrtus communis oil (MCO) on some oral pathogens.

MATERIAL AND METHODS

Thirty strains of Streptococcus mutans, Aggregatibacteractinomycetemcomitans, Porphyromonas gingivalis and 20 strains of Streptococcus pyogenes and Candida albicans isolated from patients with dental caries, periodontal diseases, pharyngitis and oral lesions associated with artificial dentures were used for the antimicrobial activity of MCO. The oil was prepared by hydrodistillation procedures using a Clevenger apparatus. Agar disk diffusion and broth microdilution methods were performed on various concentrations of MCO (3.9-1,000 µg/ml) using all the pathogens isolated.

RESULTS

All isolates were sensitive to MCO at 125-1,000 µg/ml by agar disk diffusion producing inhibition zones of 8.1-41.25 mm in diameter. All of the S. pyogenes, S. mutans and C. albicans strains were sensitive to 62.5 µg/ml while 70% (21/30) of A. actinomycetemcomitans and 66.6% (20/30) of P. gingivalis were resistant to these concentrations. All S. pyogenes and S. mutans strains were sensitive to 31.25 µg/ml. All S. pyogenes strains were sensitive to 15.6 and 7.8 µg/ml of MCO. None of the clinical isolates in this study were sensitive to 3.9 µg/ml or to a lower concentration of oil. The minimum inhibitory concentrations of MCO for S. pyogenes, S. mutans, C. albicans, A.actinomycetemcomitans and P. gingivalis were 29.68 ± 4.8, 31.25 ± 0, 46.9 ± 16, 62.5 ± 0 and 62.5 ± 0 µg/ml, respectively.

CONCLUSIONS

Data obtained in this study revealed a strong antimicrobial activity of MCO on the tested oral pathogens, and MCO could therefore be useful in the prevention of the related oral infections.

The benefits and risks of consuming brewed tea: beware of toxic element contamination

Background. Increasing concern is evident about contamination of foodstuffs and natural health products. Methods. Common off-the-shelf varieties of black, green, white, and oolong teas sold in tea bags were used for analysis in this study. Toxic element testing was performed on 30 different teas by analyzing (i) tea leaves, (ii) tea steeped for 3-4 minutes, and (iii) tea steeped for 15-17 minutes. Results were compared to existing preferred endpoints. Results. All brewed teas contained lead with 73% of teas brewed for 3 minutes and 83% brewed for 15 minutes having lead levels considered unsafe for consumption during pregnancy and lactation. Aluminum levels were above recommended guidelines in 20% of brewed teas. No mercury was found at detectable levels in any brewed tea samples. Teas contained several beneficial elements such as magnesium, calcium, potassium, and phosphorus. Of trace minerals, only manganese levels were found to be excessive in some black teas. Conclusions. Toxic contamination by heavy metals was found in most of the teas sampled. Some tea samples are considered unsafe. There are no existing guidelines for routine testing or reporting of toxicant levels in "naturally" occurring products. Public health warnings or industry regulation might be indicated to protect consumer safety.