Green tea: A novel functional food for the oral health of older adults

Therapeutic potentialities of green tea (Camellia sinensis) in ischemic stroke: biochemical and molecular evidence

Ischemic stroke is a leading cause of disability and death in patients. Despite considerable recent advances in the treatment of ischemic stroke, only a limited number of effective neuroprotective agents are available for stroke. Green tea (Camellia sinensis) is a popular herbal plant, and numerous studies have indicated its health benefits for several diseases. Green tea is of interest due to its high content of catechin derivatives, including epicatechin, gallocatechin, epicatechin gallate, epigallocatechin, and epigallocatechin-3-gallate. This review tried to develop a feasible background for the potential effects of green tea and its bioactive derivatives concerning protection against ischemic stroke. Green tea's antioxidants, anti-inflammatory, anti-apoptotic, and neuroprotective effects are believed to be efficacious in stroke treatment. Evidence supports the idea that green tea can be used to assist in treating ischemic stroke.

Special tea products featuring functional components: Health benefits and processing strategies

The functional components in tea confer various potential health benefits to humans. To date, several special tea products featuring functional components (STPFCs) have been successfully developed, such as O-methylated catechin-rich tea, γ-aminobutyric acid-rich tea, low-caffeine tea, and selenium-rich tea products. STPFCs have some unique and enhanced health benefits when compared with conventional tea products, which can meet the specific needs and preferences of different groups and have huge market potential. The processing strategies to improve the health benefits of tea products by regulating the functional component content have been an active area of research in food science. The fresh leaves of some specific tea varieties rich in functional components are used as raw materials, and special processing technologies are employed to prepare STPFCs. Huge progress has been achieved in the research and development of these STPFCs. However, the current status of these STPFCs has not yet been systematically reviewed. Here, studies on STPFCs have been comprehensively reviewed with a focus on their potential health benefits and processing strategies. Additionally, other chemical components with the potential to be developed into special teas and the application of tea functional components in the food industry have been discussed. Finally, suggestions on the promises and challenges for the future study of these STPFCs have been provided. This paper might shed light on the current status of the research and development of these STPFCs. Future studies on STPFCs should focus on screening specific tea varieties, identifying new functional components, evaluating health-promoting effects, improving flavor quality, and elucidating the interactions between functional components.

Oolong Tea Consumption and the Risk of Oral Squamous Cell Carcinoma: A Propensity Score-Based Analysis in Southeast China

Oolong tea is one of the world's most popular non-alcoholic beverages, particularly in coastal Southeast China. Hitherto, epidemiological studies on the association between oolong tea consumption and the risk of patients with oral squamous cell carcinoma (OSCC) are very limited. This study aimed to evaluate the potential effect of oolong tea consumption on OSCC risk in Southeast China. From January 2010 to October 2020, face-to-face interviews were conducted for 744 newly diagnosed OSCC patients and 1,029 healthy controls to collect information on demographics, oolong tea consumption behaviors, and other lifestyle factors. Propensity score matching (PSM), inverse probability of treatment weight (IPTW), and stabilized inverse probability of treatment weight (SIPTW) were utilized to minimize confounding effects. Multivariate, conditional, and weighted logistic regression was used to evaluate the associations of oolong tea consumption behaviors with OSCC risk. Participants who drank oolong tea showed a lower risk of OSCC when compared to their non-drink counterparts [PSM population, OR (95%CI): 0.69 (0.49–0.97); SIPTW population, OR (95%CI): 0.74 (0.58–0.94)]. Moreover, the reduced risk was found to be significantly associated with certain tea-drinking habits (consumed amount over 500 mL per day, a duration of <20 years, age at initiation older than 30 years, and warm and moderately concentrated tea). Similar results were yielded in the sensitivity analyses (Multivariate adjustment and the IPTW analysis). Furthermore, subgroup analysis revealed that the negative association of oolong tea drinking with OSCC risk was more evident among those with poor oral hygiene. This study provides supportive evidence that oolong tea consumption may have a potentially beneficial effect in preventing OSCC, especially for those with poor oral hygiene.

Socioeconomics, health-related factors, and tooth loss among the population aged over 80 years in China

Background

The prevalence of tooth loss varies across the globe among oldest-old individuals. The presence of fewer than 20 teeth in old age was associated with a decrease in people’s health and quality of life. This paper explored the association between socioeconomics, health-related factors, and tooth loss among the population over the age of 80 in China.

Methods

The tooth loss status of older Chinese adults was collected with a structured questionnaire from the 8^th wave of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). A total of 6716 individuals aged 80 years and above were included. Logistic regression was used to assess the association between socioeconomic statuses, dietary intake at approximately 60 years old, health-related factors, and tooth loss.

Results

Of the 6716 individuals aged 80 years and above, the composition of the group with fewer teeth for both men and women was statistically significant in many ways. Multivariate logistic regression analyses show that for men, being older than 90 years and being ADL disabled (adjusted OR: 1.71, 95% CI: 1.01–2.89) are factors that are significantly and consistently associated with a higher risk of having fewer than 20 teeth, while having a higher household income per capita (adjusted OR: 0.56, 95% CI: 0.32–0.99) decreases the risk. For women, an age of above 95 years, brushing teeth less than once per day (adjusted OR: 1.96, 95% CI: 1.26–3.03), consuming sugar some of the time as opposed to less than once per month at approximately 60 years old (adjusted OR = 1.74, 95% CI: 1.15–2.62), and being ADL disabled (adjusted OR: 1.70, 95% CI: 1.04–2.77) are factors that are significantly associated with the risk of having fewer than 20 teeth.

Conclusion

The analysis suggests that socioeconomic status, dietary intake in early old age, and ADL capacity are associated with the risk of having fewer teeth for the population aged 80 years and above, and the risk factors vary between sexes.

Ethanol- and Cigarette Smoke-Related Alternations in Oral Redox Homeostasis

Alcohol abuse as well as smoking cigarettes has been proven to negatively affect the oral environment. The aim of this work was to provide a systematic review of the literature on the influence of ethanol and cigarette smoking on oral redox homeostasis. A search was performed for scientific articles indexed in the PubMed, Medline and Web of Science databases. We identified 32,300 articles, of which 54 were used for the final review, including the results from 2000 to 2021. Among the publications used to write this article, n = 14 were related to the influence of alcohol consumption (clinical studies n = 6, experimental studies n = 8) and n = 40 were related to the influence of smoking (clinical studies n = 33, experimental studies n = 7) on oral redox homeostasis. The reviewed literature indicates that alcohol abusers and smokers are more likely to suffer from salivary gland dysfunction, as well as develop precancerous lesions due to DNA damage. Compared to alcohol abstainers and non-smokers, alcohol drinkers and smokers are also characterized by a deterioration in periodontal health measured by various indicators of periodontal status. In summary, alcohol abuse and smoking are associated with disrupted oral redox homeostasis, which may lead not only to tooth loss, but also contribute to various adverse effects related to mental health, digestive processes and chronic inflammation throughout the human body.

Biological Approaches for Extraction of Bioactive Compounds From Agro-industrial By-products: A Review

Bioactive compounds can provide health benefits beyond the nutritional value and are originally present or added to food matrices. However, because they are part of the food matrices, most bioactive compounds remain in agroindustrial by-products. Agro-industrial by-products are generated in large quantities throughout the food production chain and can—when not properly treated—affect the environment, the profit, and the proper and nutritional distribution of food to people. Thus, it is important to adopt processes that increase the use of these agroindustrial by-products, including biological approaches, which can enhance the extraction and obtention of bioactive compounds, which enables their application in food and pharmaceutical industries. Biological processes have several advantages compared to nonbiological processes, including the provision of extracts with high quality and bioactivity, as well as extracts that present low toxicity and environmental impact. Among biological approaches, extraction from enzymes and fermentation stand out as tools for obtaining bioactive compounds from various agro-industrial wastes. In this sense, this article provides an overview of the main bioactive components found in agroindustrial by-products and the biological strategies for their extraction. We also provide information to enhance the use of these bioactive compounds, especially for the food and pharmaceutical industries.

Beverages Containing Plant-Derived Polyphenols Inhibit Growth and Biofilm Formation of Streptococcus mutans and Children’s Supragingival Plaque Bacteria

Objectives: Polyphenols in edible berries and tea plant (Camellia sinensis) suppressed virulence factors of oral pathogens. We investigated if the commercially marketed plant polyphenols-containing beverages inhibited growth and biofilm formation of Streptococcus mutans and children’s dental plaque. Methods: Supragingival plaque collected from 16 children (7–11 years) were suspended in TSB for testing. Test beverages included 26 marketed packaged teas, ready-to-drink bottled raspberry flavored teas and cranberry juice cocktails with and without added sugars. Their effects on in vitro growth and biofilm formation of S. mutans and children’s plaque bacteria were determined after 24–48 h at 37 °C anaerobically in CDM with or without sucrose. Results: Brewed infusions from black, green and cinnamon or raspberry flavored teas bags inhibited growth and biofilm formation of children’s plaque bacteria. Compared to controls, bottled raspberry flavored teas and cranberry juice cocktails significantly inhibited growth and biofilm formation of test bacteria. Added sugar did not significantly impact the inhibition (p > 0.05). Biofilms formed in these beverages were loosely attached and easily dislodged from surfaces. Conclusions: Beverages rich in antimicrobial plant polyphenols reduce plaque adherence, may benefit oral health and are preferred over other sugary beverages. The concept of oral diseases prevention using natural foods/diet is innovative, practical and acceptable.

The Sensory Quality and the Textural Properties of Functional Oolong Tea-Infused Set Type Yoghurt with Inulin

Set type yoghurts are characterised by a semi-solid texture, which is created during the fermentation process. The tea infusion in this type of yoghurt production can influence the quality of the final product. Therefore, the aim of the experiment was to evaluate the influence of the addition of 3, 6 and 9% inulin to oolong tea-infused yoghurts on the sensory quality. It has been evaluated by trained experts using a Quantitative Descriptive Profile analysis and by consumers using hedonic scaling, as well as on instrumentally evaluated features such as texture, stability and visual parameters. The addition of oolong tea to yoghurt resulted in positive changes in the perception of sweet, peach and nectar odours and flavours, and also creaminess, as well as negative changes in the presence of a bitter taste, the whey presence and a colour intensification towards dark cream (p ≤ 0.05). The addition of inulin to the tested oolong tea yogurts caused a decrease in the whey presence and brightened the yoghurt's colour (6% and 9%, p ≤ 0.05, respectively), as well as an improved creaminess and an increase in the sweet taste of the yoghurt. It was also observed that the addition of oolong tea deteriorated the instrumentally evaluated texture of the set yoghurts, while inulin at a higher concentration (9%, p ≤ 0.05) increased the firmness and adhesiveness. Moreover, the addition of inulin also had a positive effect on the yoghurt's stability. The addition of inulin to oolong tea-infused set yoghurts may be valuable both as a source of prebiotic fibre in functional products and as a factor improving the quality of these products.

Effectiveness of green tea mouthwash for improving oral health status in oral cancer patients: A single-blind randomized controlled trial

BACKGROUND

Painful oral mucositis or trismus, caused by cancer therapy, reduces patients' willingness to maintain basic oral hygiene and eventually results in a poor oral health status. Using mouth rinses and cleaning the tongue are popular ways to improve the oral health status.

OBJECTIVES

To evaluate the effectiveness of green tea mouthwash for improving the oral health status in oral cancer patients undergoing cancer treatment.

DESIGN

This was a prospective, single-blind, randomized, controlled trial.

SETTINGS

Patients were recruited from a major regional teaching hospital that provides specialist cancer care services in Chia-Yi, Taiwan, from July 2018 to June 2020.

PARTICIPANTS

A total of 63 patients met the following criteria: > 20 years old; newly diagnosed with oral cancer by a physician; treated with oral surgery within one month prior; and completion of follow-up, with or without chemotherapy or radiation therapy. The exclusion criteria were mental illness; an acute and severe illness; complete edentulism; and inability to open the mouth more than 1 cm.

METHODS

Patients were randomly assigned to 2 groups: the mouthwash with green tea (intervention) group or the tap water (control) group. After each teeth-brushing procedure, those in the intervention group rinsed the mouth with 100 ml of a green tea solution for 60 seconds, and those in the control group rinsed the mouth with 100 ml of tap water for 60 seconds. The primary outcome was the oral health status, which was evaluated according to the Oral Assessment Guide and measured at baseline and at every monthly outpatient follow-up until six months by the same nurse.

RESULTS

There were 31 subjects in the intervention group and 30 subjects in the control group in the final analysis. The results of t-test showed that compared with baseline, the improvement in the oral health status in the intervention group was significantly better than that in the control group at 4 months after the intervention began. At 4 to 6 months after the intervention began, the oral health status score in the intervention group significantly decreased, by 1.71, 2.97 and 2.93 points, respectively, compared with that in the control group.

CONCLUSIONS

The oral health status can be improved and maintained for a long time with the continuous use of green tea mouthwash. Green tea mouthwash is a simple, natural, effective and safe intervention that should be recognized as a nonpharmacological treatment option for protecting the oral mucosa.

TRIAL REGISTRATION

clinicaltrials.gov identifier NCT04615780.

High-resolution taxonomic examination of the oral microbiome after oil pulling with standardized sunflower seed oil and healthy participants: a pilot study

OBJECTIVES

We aimed at the high-resolution examination of the oral microbiome depending on oil pulling, compared it with saline pulling, and analyzed whether the method is capable of reducing the overall microbial burden of the oral cavity.

MATERIALS AND METHODS

The study was a cohort study with three healthy subjects. Oil pulling samples, saline pulling samples, and saliva samples were microscoped and cultured under microaerophilic and anaerobic conditions; colony-forming units were counted; and cultivated bacteria were identified employing MALDI-TOF MS. The oral microbiomes (saliva) and the microbiota incorporated in oil and saline pulling samples were determined in toto by using 16S rDNA next-generation sequencing (NGS) and bioinformatics.

RESULTS

Microscopy revealed that oral epithelial cells are ensheathed with distinct oil droplets during oil pulling. Oil pulling induced a higher production of saliva and the oil/saliva emulsion contained more bacteria than saline pulling samples. Oil pulling resulted in a significant and transient reduction of the overall microbial burden in comparison to saliva examined prior to and after pulling. Both oil and saline pulling samples mirrored the individual oral microbiomes in saliva.

CONCLUSIONS

Within the limitations of this pilot study, it might be concluded that oil pulling is able to reduce the overall microbial burden of the oral cavity transiently and the microbiota in oil pulling samples are representative to the oral microbiome.

CLINICAL RELEVANCE

Within the limitations of this pilot study, it might be concluded that oil pulling can be considered as an enlargement of standard oral hygiene techniques since it has the characteristic of an oral massage, enwrapping epithelial cells carrying bacteria in oil vesicles and reaching almost all unique habitats in oral cavity.

A green tea extract and epigallocatechin-3-gallate attenuate the deleterious effects of irinotecan in an oral epithelial cell model

OBJECTIVE

To investigate the ability of a green tea extract and epigallocatechin-3-gallate (EGCG) to protect oral epithelial cells against the deleterious effects of the chemotherapeutic agent irinotecan, with respect to cytotoxicity; reactive oxygen species (ROS) generation; cytokine and matrix metalloproteinase (MMP) production; and cell proliferation and migration.

METHODS

The B11 oral keratinocyte and GMSM-K oral epithelial cell lines were used in this study. Cell viability was determined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. A fluorometric assay was used to quantify ROS production. Cell proliferation was assessed using a fluorescent cell tracker dye, while a migration assay kit was used to monitor cell migration. Cytokine and MMP secretion was quantified by an enzyme-linked immunosorbent assay.

RESULTS

The green tea extract and EGCG reduced the cytotoxicity of irinotecan toward oral keratinocyte and epithelial cell lines. Irinotecan-induced intracellular ROS generation by oral keratinocytes was reduced by the green tea extract and EGCG. Irinotecan negatively affected the proliferation and migration of oral keratinocytes in a dose-dependent manner. However, these effects were not neutralized by the green tea extract, while EGCG showed a trend to attenuate the irinotecan-induced decrease in cell migration. The green tea extract and EGCG also had a dose-dependent inhibitory effect on irinotecan-induced secretion of interleukin-6 and interleukin-8 by oral epithelial cells. Lastly, the irinotecan-induced decrease in the secretion of MMP-2 and MMP-9 by oral epithelial cells was partially restored by the green tea extract and EGCG.

CONCLUSIONS

The green tea extract and EGCG, through anti-cytotoxic, anti-oxidative, and anti-inflammatory properties, may protect the oral mucosa against the deleterious effects of the chemotherapeutic agent irinotecan and may be of interest for treating oral mucositis.

Sunflower seed byproduct and its fractions for food application: An attempt to improve the sustainability of the oil process

The sunflower (Helianthus annus L.) is one of the main oil crops in the world grown for the production of edible and biodiesel oil. Byproducts of the extraction of sunflower oil constitute a raw material with potential for several applications in the food area due to its chemical composition, including the high content of proteins and phenolic compounds. Thoughtful of a consumer increasingly concerned with the environmental impact, we try to clarify in this review the potential of using sunflower seed byproducts and their fractions to enhance the production of potentially functional foods. The applications of sunflower seed byproduct include its transformation into flours/ingredients that are capable of improving the nutritional and functional value of foods. In addition, the protein isolates obtained from sunflower seed byproduct have good technological properties and improve the nutritional value of food products. These protein isolates can be used to obtain protein hydrolysates with technological and bioactive properties and as matrices for the development of edible, biodegradable, and active films for food. The sunflower seed byproduct is also a source of phenolic compounds with bioactive properties, mainly chlorogenic acid, which can be extracted by different methods and applied in the development of functional foods and active and bioactive food packaging. The use of sunflower seed byproduct and its fractions are promising ingredients for the development of healthier and less expensive foods as well as the alternative to decrease the environmental problems caused by the sunflower oil industry.

Impact of Green Tea (Camellia Sinensis) on periodontitis and caries. Systematic review and meta-analysis

Background

The oral health-promoting effects of green tea are attributed to its polyphenol components. Aim of this work was to systematically review the literature in search for clinical trials assessing green tea for managing periodontitis and caries.

Methods

Randomized clinical trials comparing the efficacy of green tea versus control groups in oral hygiene and gingival health; periodontitis; caries; periodontal pathogens number; Streptococcus mutans, Lactobacillus spp. Meta-analysis and meta-regression analysis were performed.

Literature searches were carried out using MedLine (PubMed), Scopus, and the Cochrane Library. Eighteen studies (870 subjects) were included.

Results

Green tea treatment had medium positive effect size in reducing GI (SMD: 0.50; 95%CI: −0.02/1.01); PI (SMD: 0.54; 95%CI: 0.14/0.95); GBI (SMD: 0.58; 95%CI: −0.41/1.56) and BOP (SMD: 0.52; 95%CI: −0.57/1.60) in respect to the control group. Splitting to subgroups, green tea showed a small negative effect in the chlorhexidine control groups. Green tea treatment had medium positive effect size in reducing CAL (SMD 0.58; 95%CI: −0.49/1.65) and large positive effect size in reducing PPD (SMD:1.02; 95%CI: 0.45/1.59).

Conclusion

Even if the results are encouraging, there is insufficient evidence to recommend the use of green tea formulation as first choice treatment for gingivitis, periodontitis and caries.

Functional Tea-Infused Set Yoghurt Development by Evaluation of Sensory Quality and Textural Properties

In the present study, the potential to design natural tea-infused set yoghurt was investigated. Three types of tea (Camellia sinensis): black, green and oolong tea as well as lemon balm (Melissa officinalis L.) were used to produce set yoghurt. The sensory quality (using Quantitative Descriptive Profile analysis and consumer hedonic test) and texture analysis, yield stress, physical stability and colour analysis were assessed to describe the profile of the yoghurt and influence of quality attributes of the product on the consumer acceptability of infused yoghurts in comparison with plain yoghurt. Among the analyzed plant additives for yoghurt, addition of 2% oolong tea to the yoghurt allows a functional food to be obtained with satisfactory texture and sensory properties, accepted by consumers at the same level as for control yoghurt. Both types of yoghurt were also characterised by high consumer willingness to buy, which confirms the legitimacy of using oolong tea as a natural, functional yoghurt additive that improves the sensory quality of the product. The high overall quality of yoghurt with oolong tea in comparison to other plant extracts was associated with the intensive peach flavour and odour, nectar and sweet odour and flavour, and the highest creaminess and thickness. That was confirmed by principal component analysis (PCA) where the overall sensory quality of yoghurts was mainly positively correlated with peach flavour and odour, sweet odour and yoghurt odour, while it was negatively correlated with herbs flavor and odour, and green tea flavour and odour. The sensory profile confirmed no differences in textural profile between plain yoghurt and the tea-infused one measured in the mouth, which corresponds to the result of textural properties such as firmness and adhesiveness.

In vitro antimicrobial and antipro-inflammation potential of honokiol and magnolol against oral pathogens and macrophages

BACKGROUND/PURPOSE

Honokiol and magnolol are natural components isolated from Magnolia bark that is used in traditional Chinese and Japanese herbal medicine. These two isomers are used as a component of dietary supplements and cosmetic products. In this study, we investigated the antimicrobial effect of honokiol and magnolol on pathogens causing oral diseases, their mechanism of action in biofilm formation and drug resistance of oral pathogens, and inflammatory regulation in mammalian cells.

METHODS

We determined the minimum inhibitory concentration and minimum bactericidal concentration of honokiol and magnolol, and their stability at different temperatures and pH. We also evaluated their effect on biofilm formation, antibiotic-resistance gene expression in MRSA, and pro-inflammatory gene expression in mammalian cells.

RESULTS

Honokiol showed better antimicrobial activity than magnolol. Both honokiol and magnolol showed stable bacterial inhibitory activity over a wide range of temperature and pH, reduced biofilm formation, and antibiotic resistance in oral pathogens. The biofilm formation- and antibiotic resistance-related gene expression was consistent with the respective phenotypes. Furthermore, these two isomers repressed the expression of pro-inflammatory genes in RAW264.7 cells.

CONCLUSION

Our study provides evidence of the potential application of honokiol and magnolol in dental medicine to cure or prevent oral diseases.

Effect of storage temperature on the antioxidant activity and catechins stability of Matcha (Camellia sinensis)

This study was conducted to evaluate the storage conditions of matcha (Camellia sinensis) according to temperature during 2 months. The moisture content of matcha tend to decrease with increasing temperature. To evaluate the brightness and green value of matcha, changes in L* and G* values were examined. These values decreased with increasing temperature and time. Total phenolic content and total flavonoid content also decreased with increasing temperature and time. ABTS and DPPH radical scavenging activities decreased with the increase in storage temperature and time. The content of catechins such as epicatechin, epigallocatechin, epicatechin gallate and epigallocatechin gallate showed a tendency to decrease gradually according to the storage temperature and time. Also, caffeine and rutin content in matcha significantly decreased according to storage temperature and time. This study could be used as basic data to determine optimal storage conditions by measuring physiological changes according to the temperature conditions of matcha.

Polyphenols in Dental Applications

(1) Background: polyphenols are a broad class of molecules extracted from plants and have a large repertoire of biological activities. Biomimetic inspiration from the effects of tea or red wine on the surface of cups or glass lead to the emergence of versatile surface chemistry with polyphenols. Owing to their hydrogen bonding abilities, coordination chemistry with metallic cations and redox properties, polyphenols are able to interact, covalently or not, with a large repertoire of chemical moieties, and can hence be used to modify the surface chemistry of almost all classes of materials. (2) Methods: the use of polyphenols to modify the surface properties of dental materials, mostly enamel and dentin, to afford them with better adhesion to resins and improved biological properties, such as antimicrobial activity, started more than 20 years ago, but no general overview has been written to our knowledge. (3) Results: the present review is aimed to show that molecules from all the major classes of polyphenolics allow for low coast improvements of dental materials and engineering of dental tissues.

Catechin inhibiting the H1N1 influenza virus associated with the regulation of autophagy

BACKGROUND

The influenza virus is a highly infectious disease, with a notably rapid transmission rate. Autophagy is triggered by viral infection and is a survival mechanism exerted to maintain cellular homeostasis. Catechin is a representative phenolic acid which exerts anti-inflammatory responses against influenza A virus infection. The aim of this study is to explore the anti-H1N1 influenza virus effects by catechin associated with the restoration of autophagy.

METHODS

XTT assay was used to detect cellular viability. The inhibitory effects on the H1N1 influenza virus were assessed by hemagglutination assay, neuraminidase activity, and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The protein levels of H1N1 influenza virulence and autophagic markers were detected by Western blot.

RESULTS

We herein demonstrated that catechin had no cytotoxic effect on both infected and noninfected A549 cells and exerted protective effects on infected A549 cells. The results of the hemagglutination assay, neuraminidase activity, and qRT-PCR to examine viral load demonstrated that catechin effectively inhibited the replication of the H1N1 influenza virus. The virulent M2 protein and viral nucleoprotein were also inhibited after treatment with catechin. As for the autophagic markers, the LC3B protein was notably decreased by catechin in a dose-dependent manner, while the amount of autophagic vacuoles in H1N1 influenza virus-infected cells also decreased after catechin treatment in a dose-dependent manner.

CONCLUSION

Collectively, the autophagy activated by the H1N1 influenza virus could be reversed after catechin treatment. This study indicates that catechin effectively inhibits H1N1 viral proliferation and thus may be applied as an adjuvant in future clinical application.

The Potential Role of Tea in Periodontal Therapy: An Updated Review

Periodontal diseases are highly prevalent and can affect high percentage of the worlds' population. Oxidative stress and inflammation play an important role in the pathogenesis of periodontal diseases. Nowadays, more attention has been focused on the herbal remedies in the field of drug discovery. Green tea is an important source of polyphenol antioxidants. It has long been used as a beverage worldwide. The most interesting polyphenol components of green tea leaves that are related with health benefits are the catechins. Taken together, this review suggested that green tea, with its wide spectrum of activities, could be a healthy alternative for controlling the damaging reactions seen in periodontal diseases.

Effects of a blend of green tea and curcuma extract supplementation on lipopolysaccharide-induced inflammation in horses and ponies

Background

In horses and ponies numerous medical conditions are known to be linked with inflammation in different tissues, especially in the liver. Besides affecting other metabolic pathways such as the expression of certain interleukins (IL), inflammation is associated with stress of the endoplasmic reticulum (ER). In particular, ER stress leads to adaptive stress response and can be measured by several markers of inflammatory and stress signalling pathways, like nuclear factor κB (NF-kB).

Objectives

To investigate lipopolysaccharide (LPS)-induced inflammatory reactions and their modulation in horses and ponies by feeding a polyphenol-rich supplement consisting of green tea and curcuma.

Methods

In a cross-over study, 11 animals were allocated to either a placebo or a supplement group and supplemented with 10 g of a blend of green tea and curcuma extract (GCE) or a placebo (calcium carbonate) once daily. After 21 days of supplementation, all animals underwent a LPS challenge to induce moderate systemic inflammation. Blood samples and liver biopsies were taken at standardized time points: 24 hours before and 12 hours after LPS challenge. Inflammatory blood parameters such as serum amyloid A (SAA), haptoglobin and retinol binding protein 4 (RBP4) were measured in serum. Hepatic mRNA levels of selected markers of inflammation such as haptoglobin, tumor necrosis factor α (TNF-α), IL-1β, IL-6, cluster of differentiation 68 (CD68), fibroblast growth factor 21 (FGF-21), NF-κB, activating transcription factor 4 (ATF4) were quantified by RT-qPCR. In addition, liver biopsies were examined histologically for inflammatory alterations.

Results

Blood markers of acute inflammatory response increased after LPS challenge. In the liver, the proinflammatory cytokine IL-1β showed significantly lower mRNA levels after LPS challenge in the supplemented group (P = 0.04) compared to the placebo group. Levels of the hepatic CD68 mRNA increased significantly in the placebo group (P = 0.04). There were no significant differences between supplemented and placebo groups concerning other markers of inflammation and markers of ER stress within the liver. The number of hepatic macrophages were not different after LPS challenge in both feeding groups.

Conclusion

LPS was able to induce inflammation but seemed less suitable to induce ER stress in the horses and ponies. The polyphenol-rich supplement showed some potential to reduce inflammatory responses. Nevertheless, the supplementation did not exert an overall anti-inflammatory effect in horses and ponies.

White Tea is More Effective in Preservation of Bone Loss in Adult Rats Co-Exposed to Lead and Cadmium Compared to Black, Red or Green Tea

Lead (Pb) and cadmium (Cd) are toxic metals occurring commonly in the human environment that show mutagenic, genotoxic and carcinogenic effects. Dietary components could prevent heavy metals intoxication by reducing their accumulation in the body. The purpose of the study was to check possible protective effect of regular consumption of white, black, red, or green tea on bone metabolism during long-term exposure to Pb and Cd in adult rats. The 12 week-long exposure to Pb and Cd (50 mg Pb and 7 mg Cd/kg of the diet) in a rat model was studied. Twelve-week-old adult male Wistar rats were randomly divided into a negative control group (Pb and Cd exposure without tea), a control (without Pb and Cd and teas), and groups co-exposed to Pb and Cd and supplemented with green, red, black, or white tea (n=12 each group). The experiment lasted for 12 weeks. The co-exposure to Pb and Cd led to the increase of bone resorption depending on the tea treatment, which was confirmed by the mechanical testing and histomorphometrical examination of cancellous bone. Pb and Cd influenced mechanical strength, reduced the densitometric and geometric parameters and the thickness of growth plate and articular cartilages. Concluding, white tea exerted the best protective effect on bone tissue and hyaline cartilage against heavy metal action.

Sour cherry extract inhibits human salivary α-amylase and growth of Streptococcus mutans (a pilot clinical study)

The purpose of this study was to determine whether cherry extract has any effect on salivary α-amylase activity (sAA) or on the level of Streptococcus mutans in human saliva. 70 patients (45 females and 25 males) in three age groups (22 children, 25 young adults, and 23 adults) were examined. All participants completed a questionnaire to obtain information on their oral health behaviour and life style. Clinical examination was performed to record the number of decayed, missing and filled teeth (DMF-T). Saliva samples were collected for the measurement of sAA and the salivary S. mutans level before and after chewing a gum with or without cherry extract. Statistical evaluation of data was performed. S. mutans and the sAA level of unstimulated saliva samples did not depend on either age or gender. The basal sAA value of adult patients was in linear correlation with the dental caries status. Habitual chewing-gum use decreased the resting sAA and the mean of DMF-T. The number of S. mutans cells was significantly lower in the resting saliva of allergic patients. The applied mechanical and gustatory stimuli by chewing gum resulted in higher sAA and S. mutans levels and a slow decrease of values was observed in the control group for the next 30 min. Thereafter, sAA and S. mutans levels decreased earlier in the presence of sour cherry extract than those of control cases. Chewing gum with sour cherry extract may be useful for the prevention of dental caries.

Comparative studies on the hypolipidemic, antioxidant and hepatoprotective activities of catechin-enriched green and oolong tea in a double-blind clinical trial

This study aimed to compare the beneficial effect of catechin-enriched green tea and oolong tea on mildly hypercholesterolemic subjects. Sixty mildly hypercholesterolemic subjects (180-220 mg dL^-1) were enrolled and divided into three groups as catechin-enriched green tea (CEGT), catechin-enriched oolong tea (CEOT) or placebo. The subjects were instructed to drink 2 × 300 mL of CEGT (780.6 mg of catechin), CEOT (640.4 mg of catechin) or placebo beverage for 12 weeks. Drinking CEGT and CEOT significantly decreased (p < 0.05) the body weight, fat, and BMI, lipid peroxidation as well as lipid profile (TC, LDL-c, HDL-c, and TG). Also, intervention with CEGT and CEOT significantly improved (p < 0.05) the oxidative indices (TEAC and GSH) and antioxidant enzymes (SOD, CAT, GPx, and GR). Moreover, ultrasound examination endorsed the hepatoprotective activity of CEGT and CEOT by reverting mild fatty liver to the normal hepatic condition because of antioxidant and hypolipidemic activities. To summarize, both CEGT and CEOT showed similar antioxidant and hepatoprotective activities. However, CEOT displayed superior lipid-lowering activity compared to CEGT or placebo, and hence it could be used to amend the wellness condition of mildly hypercholesterolemic subjects.

Consumption of green tea but not coffee is associated with the oral health-related quality of life among an older Japanese population: Kyoto-Kameoka cross-sectional study

BACKGROUND/OBJECTIVES

The consumption of both green tea and coffee is known to induce positive health effects; however, it remains unclear whether there is an association between the consumption of these beverages and oral health-related quality of life (OHRQoL). Thus, the present study investigated the relationship between the consumption of green tea and coffee and OHRQoL.

SUBJECTS/METHODS

We analyzed cross-sectional baseline data in 2012. The subjects were 7514 Japanese participants (3563 men, 3951 women; ≥65 years of age). Each subject completed a validated self-administered questionnaire that included items on the frequency of the consumption of green tea and coffee. OHRQoL was evaluated using the self-reported General Oral Health Assessment Index (GOHAI), which assesses oral health problems in older adults. A GOHAI score <50 points was defined as a poor OHRQoL.

RESULTS

Following adjustment for age, body mass index, total energy intake, alcohol, smoking, medication use, coffee, and fruit and vegetable consumption, increased consumption of green tea showed a strong positive association with the GOHAI score in both men and women (P_trend < 0.001 in both). In contrast, after adjusting for all factors, no statistically significant association was observed between coffee consumption and the GOHAI score in men (P_trend = 0.538) or women (P_trend = 0.607). The respective multivariate-odds ratios (95% confidence intervals) for a poor OHRQoL associated with green tea consumption frequencies of none, <1 cup/day, 1-2 cups/day, and ≥3 cups/day were 1.00, 1.01 (0.80-1.27), 0.95 (0.74-1.21), and 0.78 (0.61-0.99) (P_trend = 0.024) in men, and 1.00, 1.19 (0.90-1.57), 0.98 (0.74-1.29), and 0.86 (0.67-1.12) (P_trend = 0.014) in women.

CONCLUSIONS

Regardless of sex, green tea consumption was positively associated with the GOHAI score. Therefore, ≥3 cups/day of green tea may reduce the risk of a poor OHRQoL, especially in men.

Growth Media Affect Assessment of Antimicrobial Activity of Plant-Derived Polyphenols

This study aimed to investigate the effects of different microbial growth media on the laboratory assessment of antimicrobial activity of natural polyphenolic compounds. The inhibition of the tea polyphenol EGCG on growth of selected oral microorganisms was evaluated in complex media and a protein-free chemically defined medium (CDM). Other antimicrobial agents (polyphenolic grape seed extract, plant alkaloid berberine, methyl salicylate, and chlorhexidine gluconate) were also tested in the study. The presence of proteins and their effects on the antimicrobial activity of EGCG were investigated by the addition of BSA to the CDM. The MICs of EGCG against test oral microorganisms were 4 to 64 times higher in complex media than in CDM. The polyphenolic grape seed extract exhibited similar discrepancies. However, the MICs of the nonpolyphenolic compounds (berberine, methyl salicylate, and chlorhexidine) were not significantly different between the two growth media. The MIC of EGCG against S. mutans UA159 in CDM with added BSA was 16 times higher than that in CDM alone. Therefore, nonproteinaceous CDM should be used to avoid interference of proteins with the active ingredients when testing the antimicrobial activity of plant-derived polyphenolic compounds against microorganisms. This will also minimize the discrepancies noted in results obtained by different investigators.

A review of diagnosis and treatment of acne in adult female patients

This review focuses on the treatment options for adult female patients with acne. Acne in adult female patients may start during adolescence and persist or have an onset in adulthood. Acne has various psychosocial effects that impact patients’ quality of life. Treatment of acne in adult women specifically has its challenges due to the considerations of patient preferences, pregnancy, and lactation. Treatments vary widely and treatment should be tailored specifically for each individual woman. We review conventional therapies with high levels of evidence, additional treatments with support from cohort studies and case reports, complementary and/or alternative therapies, and new agents under development for the treatment of patients with acne.

Treatment Modalities for Acne

Acne is a common inflammatory skin disease which affects the pilosebaceous units of the skin. It can have severe psychological effects and can leave the patient with severe skin scarring. There are four well-recognized pathological factors responsible for acne which is also the target for acne therapy. In this review, different treatment options are discussed, including topical (i.e., retinoids, and antibiotics) and systemic (i.e., retinoids, antibiotics, and hormonal) treatments. Since the general public has been showing an increasing interest in more natural and generally safer treatment options, the use of complementary and alternative medicines (CAM) for treating acne was also discussed. The use of physical therapies such as comedone extraction, cryoslush therapy, cryotherapy, electrocauterization, intralesional corticosteroids and optical treatments are also mentioned. Acne has been extensively researched with regards to the disease mechanism as well as treatment options. However, due to the increasing resistance of Propionibacterium acnes towards the available antibiotics, there is a need for new treatment methods. Additionally, the lack of necessary evidence on the efficacy of CAM therapies makes it necessary for researchers to investigate these treatment options further.

Excessive Consumption of Green Tea as a Risk Factor for Periodontal Disease among Korean Adults

This study was performed to assess the relationship between the amount of green tea that is consumed and periodontitis. It is based on data obtained from the Korea National Health and Nutrition Examination Survey, conducted between 2008 and 2010. A community periodontal index equal to code 3 was defined as moderate periodontitis, and code 4 was defined as severe periodontitis (n = 16,726). Consumption of green tea less than one cup per day was associated with a decreased prevalence of periodontal disease among Korean adults. The association between the consumption of green tea and periodontal disease was independent of various potential confounding factors, such as age, sex, body mass index, smoking, drinking, exercise, metabolic syndrome, frequency of tooth brushing per day, use of secondary oral products, the number of dental examination per year, diabetes, hypertension, and white blood cell count. Adjusted odds ratio and 95% confidence interval of no consumption was 1.360 (1.156, 1.601) when participants with consumption of two times per week ≤ x < 7 times per week was considered as a reference. However, consumption of one or more cups per day increased the prevalence of moderate and severe periodontitis. In conclusion, excessive consumption of green tea may be considered as a risk factor for periodontal disease among Korean adults.

Odontonutraceuticals: Pleiotropic Phytotherapeutic Agents for Oral Health

This brief commentary aims to focus on the urgency of further clinical research on phytotherapy in dentistry, and, noteworthy, to propose, for the first time, to the best of our knowledge, the term "odontonutraceuticals" to identify those phytochemicals relevant for the prevention and the treatment of oral diseases. A valuable impact is expected on nutritional, dental and biomedical sciences, suggesting the use of the suffix "odonto-" to define a specific field of nutraceutical research.

Green tea catechins potentiate the effect of antibiotics and modulate adherence and gene expression in Porphyromonas gingivalis

OBJECTIVES

A number of studies have brought evidence that green tea catechins may contribute to periodontal health. The objective of this study was to investigate the ability of a green tea extract and its principal constituent epigallocatechin-3-gallate (EGCG) to potentiate the antibacterial effects of antibiotics (metronidazole, tetracycline) against Porphyromonas gingivalis, and to modulate the adherence to oral epithelial cells and expression of genes coding for virulence factors and the high temperature requirement A (HtrA) stress protein in P. gingivalis.

METHODS

A broth microdilution assay was used to determine the antibacterial activity of the green tea extract and EGCG. The synergistic effects of either compounds in association with metronidazole or tetracycline were evaluated using the checkerboard technique. A fluorescent assay was used to determine bacterial adherence to oral epithelial cells. The modulation of gene expression in P. gingivalis was evaluated by quantitative RT-PCR. The Vibrio harveyi bioassay was used for monitoring quorum sensing inhibitory activity.

RESULTS

The MIC values of the green tea extract on P. gingivalis ranged from 250 to 1000 μg/ml, while those of EGCG ranged from 125 to 500 μg/ml. A marked synergistic effect on P. gingivalis growth was observed for the green tea extract or EGCG in combination with metronidazole. Both the green tea extract and EGCG caused a dose-dependent inhibition of P. gingivalis adherence to oral epithelial cells. On the one hand, green tea extract and EGCG dose-dependently inhibited the expression of several P. gingivalis genes involved in host colonization (fimA, hagA, hagB), tissue destruction (rgpA, kgp), and heme acquisition (hem). On the other hand, both compounds increased the expression of the stress protein htrA gene. The ability of the green tea extract and EGCG to inhibit quorum sensing may contribute to the modulation of gene expression.

CONCLUSIONS

This study explored the preventive and therapeutic potential of green tea catechins against periodontal disease. In addition to inhibit growth and adherence of P. gingivalis, a green tea extract and its main constituent EGCG was found to decrease the expression of genes coding for the major virulence factors.

Green tea extract and its major constituent epigallocatechin-3-gallate inhibit growth and halitosis-related properties of Solobacterium moorei

Background

Solobacterium moorei is a volatile sulfide compound (VSC)-producing Gram-positive anaerobic bacterium that has been associated with halitosis. The aim of this study was to investigate the effects of green tea extract and its major constituent epigallocatechin-3-gallate (EGCG) on growth and several halitosis-related properties of S. moorei.

Methods

A microplate dilution assay was used to determine the antibacterial activity of green tea extract and EGCG against S. moorei. Their effects on bacterial cell membrane integrity were investigated by transmission electron microscopy and a fluorescence-based permeability assay. Biofilm formation was quantified by crystal violet staining. Adhesion of FITC-labeled S. moorei to oral epithelial cells was monitored by fluorometry. The modulation of β-galactosidase gene expression in S. moorei was evaluated by quantitative RT-PCR.

Results

The green tea extract as well as EGCG inhibited the growth of S. moorei, with MIC values of 500 and 250 μg/ml, respectively. Transmission electron microscopy analysis and a permeabilization assay brought evidence that the bacterial cell membrane was the target of green tea polyphenols. Regarding the effects of green tea polyphenols on the S. moorei colonization properties, it was found that biofilm formation on EGCG-treated surfaces was significantly affected, and that green tea extract and EGCG can cause the eradication of pre-formed S. moorei biofilms. Moreover, both the green tea extract and EGCG were found to reduce the adherence of S. moorei to oral epithelial cells. The β-galactosidase activity of S. moorei, which plays a key role in VSC production, was dose-dependently inhibited by green tea polyphenols. In addition, EGCG at ½ MIC significantly decreased the β-galactosidase gene expression.

Conclusion

Our study brought evidence to support that green tea polyphenols possess a number of properties that may contribute to reduce S. moorei-related halitosis. Therefore, these natural compounds may be of interest to be used to supplement oral healthcare products.

Clinical effect of locally delivered gel containing green tea extract as an adjunct to non-surgical periodontal treatment

Green tea catechins had an in vitro antibacterial effect against periodontopathic bacteria and were able to inhibit destruction of the periodontal tissue. In this study, we aimed to evaluate the effect of locally delivered gel containing green tea extract as an adjunct to non-surgical periodontal treatment. Forty-eight subjects who had teeth with probing pocket depth of 5-10 mm were randomly allocated into the test or control group. Probing pocket depth, clinical attachment level, gingival index (GI), bleeding on probing (BOP) and full mouth plaque score were measured at baseline. Subjects received oral hygiene instruction, single episode of scaling and root planing and subgingival application of the green tea gel (test group) or the placebo gel (control group). The gel was repeatedly applied at 1 and 2 weeks later. The parameters were recorded again at the 1st, 3rd and 6th month after the last gel application. The results showed that all parameters were improved in both groups compared to baseline. The test group exhibited significantly higher reduction in BOP at the 3rd month (p = 0.003) and significantly lower GI at the 1st month (p < 0.001) and 3rd month (p < 0.001) when compared with the control group. Thus, green tea gel could provide a superior benefit in reducing bleeding on probing and gingival inflammation when used as an adjunct to non-surgical periodontal treatment. (

TRIAL REGISTRATION

MU-IRB 2008/153.0511, ClinicalTrials.gov NCT00918060).

Antiallodynic effect of intrathecal epigallocatechin-3-gallate due to suppression of reactive oxygen species

Background

Green tea modulates neuropathic pain. Reactive oxygen species (ROS) are suggested as a key molecule in the underlying mechanism of neuropathic pain in the spinal cord. We examined the effect of epigallocatechin-3-gallate (EGCG), the major catechin in green tea, in neuropathic pain and clarified the involvement of ROS on the activity of EGCG.

Methods

Neuropathic pain was induced in male Sprague-Dawley rats by spinal nerve ligation (SNL). A polyethylene tube was intrathecally located. Nociceptive degree was estimated by a von Frey filament and expressed as a paw withdrawal threshold (PWT). To determine the role of ROS on the effect of EGCG, a free radical donor (tert-BuOOH) was pretreated before administration of EGCG. ROS activity was assayed by xanthine oxidase (XO) and malondialdehyde (MDA).

Results

SNL decreased the PWT compared to sham rats. The decrease remained during the entire observation period. Intrathecal EGCG increased the PWT at the SNL site. Intrathecal tert-BuOOH significantly decreased the effect of EGCG. The levels of both XO and MDA in the spinal cord were increased in SNL rats compared to sham. Intrathecal EGCG decreased the level of XO and MDA.

Conclusions

EGCG may reduce neuropathic pain by SNL due to the suppression of ROS in the spinal cord.