Inhibitory effect of tea catechins on collagenase activity

Oral treatment with catechin isolated from Japanese green tea significantly inhibits the growth of periodontal pathogen Porphyromonas gulae and ameliorates the gingivitis and halitosis caused by periodontal disease in cats and dogs

It has been postulated that 90 % of cats and dogs develop periodontal disease by 1 year of age. Periodontal disease develops because of infection by multiple bacteria, including Porphyromonas gulae (P. gulae) and Porphyromonas gingivalis (P. gingivalis), resulting in severe gingivitis, halitosis, and bone lysis. Because periodontal disease is an irreversible disorder, preventive dentistry in veterinary medicine has become pertinent. This study examined the efficacy of catechin isolated from green tea by focusing on its bactericidal effects against P. gulae and P. gingivalis, inhibition of inflammation, and reduction in halitosis in dogs and cats with periodontal disease. The viability of P. gulae and P. gingivalis was significantly inhibited by catechin in a dose-dependent manner in vitro. P. gulae- and P. gingivalis-associated biofilm formation was also significantly suppressed by catechin, but the effect was not as drastic as the bactericidal effect. Hydrogen sulfide and methyl mercaptan generated by P. gulae and P. gingivalis were significantly decreased by catechin, even after a short exposure. Pro-inflammatory cytokine production and phosphorylation of P-38 and JNK induced by P. gulae were inhibited by catechin treatment in a dose-dependent manner. Treatment with 0.01892 % catechin-contained wet food for 1 month (30-35 days) significantly ameliorated halitosis and P. gulae activity, but had no impact on dental plaque and gingivitis. Our findings indicate that oral treatment with catechin can prevent periodontal diseases in both dogs and cats.

Characterizing Curing Efficiency of EGCG-Encapsulated Halloysite Nanotube Modified Adhesives for Durable Dentin-Resin Interfaces

Matrix metalloproteinase (MMP)-induced collagen degradation at the resin-dentin interface remains a significant challenge for maintaining the longevity of dental restorations. This study investigated the effects of epigallocatechin-3-gallate (EGCG), a potent MMP inhibitor, on dental adhesive curing efficiency when encapsulated in halloysite nanotubes (HNTs). EGCG-loaded HNTs were incorporated into a commercial dental adhesive (Adper Scotchbond Multi-Purpose) at 7.5% and 15% w/v concentrations. To isolate the effects of each component, the study included three control groups: unmodified adhesive (negative control), adhesive containing only HNTs, and adhesive containing only EGCG (0.16% and 0.32%, equivalent to the EGCG content in EGCG-HNT groups). Degree of conversion (DC), polymerization conversion (PC), and Vickers micro-hardness (VHN) were assessed to evaluate curing efficiency. The addition of 7.5% EGCG-encapsulated HNTs maintained curing properties similar to the control, showing no significant differences in DC (80.97% vs. 81.15%), PC (86.59% vs. 85.81%), and VHN (23.55 vs. 24.12) (p > 0.05). In contrast, direct incorporation of EGCG at 0.32% significantly decreased DC (73.59%), PC (80.63%), and VHN (20.56) values compared to both control and EGCG-HNT groups (p < 0.05). Notably, HNT encapsulation mitigated these negative effects on polymerization, even at higher EGCG concentrations. These findings demonstrate that EGCG encapsulation in HNTs can maintain the curing efficiency of dental adhesives while potentially preserving the MMP-inhibitory benefits of EGCG.

Exploring the Impact of Catechins on Bone Metabolism: A Comprehensive Review of Current Research and Future Directions

Background/Objectives: Degenerative musculoskeletal diseases represent a global health problem due to the progressive deterioration of affected individuals. As a bioactive compound, catechins have shown osteoprotective properties by stimulating osteoblastic cells and inhibiting bone resorption. Thus, this review aimed to address the mechanism of action of catechins on bone tissue. Methods: The search was applied to PubMed without limitations in date, language, or article type. Fifteen articles matched the topic and objective of this review. Results: EGCG (epigallocatechin gallate) and epicatechin demonstrated action on the osteogenic markers RANKL, TRAP, and NF-κβ and expression of BMPs and ALP, thus improving the bone microarchitecture. Studies on animals showed the action of EGCG in increasing calcium and osteoprotegerin levels, in addition to regulating the transcription factor NF-ATc1 associated with osteoclastogenesis. However, it did not show any effect on osteocalcin and RANK. Regarding human studies, EGCG reduced the risk of fracture in a dose-dependent manner. In periodontal tissue, EGCG reduced IL-6, TNF, and RANKL in vitro and in vivo. Human studies showed a reduction in periodontal pockets, gingival index, and clinical attachment level. The action of EGCG on membranes and hydrogels showed biocompatible and osteoinductive properties on the microenvironment of bone tissue by stimulating the expression of osteogenic growth factors and increasing osteocalcin and alkaline phosphate levels, thus promoting new bone formation. Conclusions: EGCG stimulates cytokines related to osteogenes, increasing bone mineral density, reducing osteoclastogenesis factors, and showing great potential as a therapeutic strategy for reducing the risk of bone fractures.

Exploring the therapeutic potential of medicinal plants and their active principles in dental care: A comprehensive review

Since the human population realized how important it was to maintain overall health and the weight of disease, they have been looking for therapeutic qualities in natural environments. The use of plants having medicinal qualities for the treatment and prevention of illnesses that may have an impact on general health is known as herbal medicine. There has been a noticeable increase in interest lately in the combination of synthetic contemporary medications and traditional herbal remedies. About 80 % of people rely on it for healthcare, particularly in developing nations. One important aspect of overall health is said to be oral healthcare. The World Health Organization views oral health as a crucial component of overall health and well-being. Because they are more readily available, less expensive, and have fewer adverse effects than pharmaceutical treatments, using natural medicines to treat pathologic oro-dental disorders can make sense. The current evaluation of the literature sought to investigate the range and scope of the use of herbal products and their secondary metabolites in maintaining oral health, encompassing several oral healthcare domains such as halitosis, gingivitis, periodontitis, and other oral disorders. Therefore, there are many herbs discussed in this work and their mechanism in the treatment and improvement of many oral ailments. Besides, compounds that are useful in oral treatment with their natural sources and the cases where they can be used. To prevent any possible side effects or drug interactions, a doctor's consultation is necessary before using dental medicine. Although herbal therapy is safe and with minimum side effects, it is also strongly advised to do a more thorough preclinical and clinical evaluation before using herbal medicines officially.

The potential of EGCG in modulating the oral-gut axis microbiota for treating inflammatory bowel disease

Inflammatory bowel disease (IBD) is a recurrent chronic intestinal disorder that includes ulcerative colitis (UC) and Crohn's disease (CD). Its pathogenesis involves intricate interactions between pathogenic microorganisms, native intestinal microorganisms, and the intestinal immune system via the oral-gut axis. The strong correlation observed between oral diseases and IBD indicates the potential involvement of oral pathogenic microorganisms in IBD development. Consequently, therapeutic strategies targeting the proliferation, translocation, intestinal colonization and exacerbated intestinal inflammation of oral microorganisms within the oral-gut axis may partially alleviate IBD. Tea consumption has been identified as a contributing factor in reducing IBD, with epigallocatechin gallate (EGCG) being the primary bioactive compound used for IBD treatment. However, the precise mechanism by which EGCG mediates microbial crosstalk within the oral-gut axis remains unclear. In this review, we provide a comprehensive overview of the diverse oral microorganisms implicated in the pathogenesis of IBD and elucidate their colonization pathways and mechanisms. Subsequently, we investigated the antibacterial properties of EGCG and its potential to attenuate microbial translocation and colonization in the gut, emphasizing its role in attenuating exacerbations of IBD. We also elucidated the toxic and side effects of EGCG. Finally, we discuss current strategies for enhancing EGCG bioavailability and propose novel multi-targeted nano-delivery systems for the more efficacious management of IBD. This review elucidates the role and feasibility of EGCG-mediated modulation of the oral-gut axis microbiota in the management of IBD, contributing to a better understanding of the mechanism of action of EGCG in the treatment of IBD and the development of prospective treatment strategies.

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.

Vegetal Compounds as Sources of Prophylactic and Therapeutic Agents in Dentistry

Dental pathology remains a global health problem affecting both children and adults. The most important dental diseases are dental caries and periodontal pathologies. The main cause of oral health problems is overpopulation with pathogenic bacteria and for this reason, conventional therapy can often be ineffective due to bacterial resistance or may have unpleasant side effects. For that reason, studies in the field have focused on finding new therapeutic alternatives. Special attention is paid to the plant kingdom, which offers a wide range of plants and active compounds in various pathologies. This review focused on the most used plants in the dental field, especially on active phytocompounds, both in terms of chemical structure and in terms of mechanism of action. It also approached the in vitro study of active compounds and the main types of cell lines used to elucidate the effect and mechanism of action. Thus, medicinal plants and their compounds represent a promising and interesting alternative to conventional therapy.

Local Oral Delivery Agents with Anti-Biofilm Properties for the Treatment of Periodontitis and Peri-Implantitis. A Narrative Review

Despite many discoveries over the past 20 years regarding the etiopathogenesis of periodontal and peri-implant diseases, as well as significant advances in our understanding of microbial biofilms, the incidence of these pathologies continues to rise. For this reason, it was clear that other strategies were needed to eliminate biofilms. In this review, the literature database was searched for studies on locally delivered synthetic agents that exhibit anti-biofilm properties and their potential use in the treatment of two important oral diseases: periodontitis and peri-implantitis.

Different applications forms of green tea (Camellia sinensis (L.) Kuntze) for the treatment of periodontitis: a systematic review and meta-analysis

BACKGROUND

Scaling and root planning (SRP) is the gold standard for non-surgical periodontal treatment. Green tea as a supporting alternative in non-surgical periodontal treatment has been suggested as a therapeutic option in the treatment of periodontitis.

OBJECTIVE

To analyse the comparative effectiveness of green tea (Camellia sinensis) in its different forms and applications for the treatment of periodontitis.

METHODS

We included randomized clinical trials evaluating green tea as an adjuvant therapeutic agent to scaling and root planning (SRP) in the treatment of periodontitis. For the meta-analysis, we calculated standardized mean difference (SMD) and 95%CI comparing green tea and control (only SRP). We subgrouped by types of application forms of green tea. The certainty of the evidence was assessed through GRADE.

RESULTS

Nine studies were included. The follow-up time of treatments varied from 21 days to 6 months. The subgroup meta-analysis showed that the green tea as sachet reduced probing bleeding (SMD = -0.71; 95%CI) and the gingival index (SMD = -0.78; 95%CI) compared to SRP with very low certainty of evidence. The sachet (SMD = -0.29; 95%CI) and dentifrice (SMD = -1.31; 95%CI) reduced plaque index with very low certainty compared to the control. All forms of application of green tea showed very low certainty of evidence (SMD = -0.27; 95% CI) in reducing the probing depth, as well as for the loss of clinical insertion (SMD = -0.42; 95% CI) with low certainty of evidence.

CONCLUSION

There was not a difference in the effectiveness of green tea isolated or in combination with SRP to reduce probing depth. Green tea adjunct to periodontal therapy showed very low certainty of effectiveness for the treatment of periodontal disease.

Proanthocyanidins and Flavan-3-ols in the Prevention and Treatment of Periodontitis-Immunomodulatory Effects, Animal and Clinical Studies

This paper continues the systematic review on proanthocyanidins and flavan-3-ols in the prevention and treatment of periodontal disease and covers the immunomodulatory effects, and animal- and clinical studies, while the other part discussed the direct antibacterial properties. Inflammation as a major response of the periodontal tissues attacked by pathogenic microbes can significantly exacerbate the condition. However, the bidirectional activity of phytochemicals that simultaneously inhibit bacterial proliferation and proinflammatory signaling can provide a substantial alleviation of both cause and symptoms. The modulatory effects on various aspects of inflammatory and overall immune response are covered, including confirmed and postulated mechanisms of action, structure activity relationships and molecular targets. Further, the clinical relevance of flavan-3-ols and available outcomes from clinical studies is analyzed and discussed. Among the numerous natural sources of flavan-3-ols and proanthocyanidins the most promising are, similarly to antibacterial properties, constituents of various foods, such as fruits of Vaccinium species, tea leaves, grape seeds, and tannin-rich medicinal herbs. Despite a vast amount of in vitro and cell-based evidence of immunomodulatory there are still only a few animal and clinical studies. Most of the reports, regardless of the used model, indicated the efficiency of these phytochemicals from cranberries and other Vaccinium species and tea extracts (green or black). Other sources such as grape seeds and traditional medicinal plants, were seldom. In conclusion, the potential of flavan-3-ols and their derivatives in prevention and alleviation of periodontal disease is remarkable but clinical evidence is urgently needed for issuing credible dietary recommendation and complementary treatments.

Inhibitory role of silk cocoon extract against elastase, hyaluronidase and UV radiation-induced matrix metalloproteinase expression in human dermal fibroblasts and keratinocytes

Topical delivery of potent antioxidants maintain the redox balance of the skin, which leads to the downregulation of matrix metalloproteinase (MMP) expression and prevents UV radiation-induced photoaging. In this study, we aimed at investigating the inhibitory role of silk cocoon extract (SCE) isolated from the Antheraea assamensis (AA), Bombyx mori (BM), and Philosamia ricini (PR) silk varieties against UV radiation-induced MMP expression. Incubation of elastase and hyaluronidase with Antheraea assamensis silk cocoon extract (AASCE) caused 50% inhibition of activity. The assessment of total collagen content using the Sirius red assay showed that AASCE (10 μg mL-1) and Philosamia ricini silk cocoon extract (PRSCE at 100 μg mL-1 concentration) post-treatment significantly enhanced the total collagen content in UVA1 and UVB irradiated HDF cells, whereas BM silk cocoon extract (BMSCE at 100 μg mL-1 concentration) post-treatment significantly enhanced the total collagen content in UVA1-irradiated HDF cells. Gene expression studies revealed AASCE and PRSCE post-treatment downregulated the expression of interleukin (IL)-6, MMP-1 and upregulated procollagen genes in UV irradiated HDF cells. Gelatin zymography studies with AASCE post-treatment downregulated the release of MMP-2 and MMP-9 by HaCaT cells. The overall results validate AASCE efficiently shielding UV radiation-induced collagen and elastin degradation by downregulation of MMP expression, substantiating its further use as a potent antioxidant complement in skin care formulations.

Activity evaluation on Ribes species, traditionally used to speed up healing of wounds: With special focus on Ribes nigrum

ETHNOPHARMACOLOGICAL RELEVANCE

Ribes species are usually evergreen shrubs, represented by eight species in Turkey. Although they are known for their fruits with commercial importance, their leaves have been used as folk remedy in various areas in Turkey by rural population owing to their wound healing potential.

AIM OF THE STUDY

In the present study we aimed to assess the wound healing activity of the leaves of Ribes species growing in Turkey, namely, Ribes alpinum L., R. anatolica Behçet, R. petraeum Wulfen, R. multiflorum Kit. ex Romer & Schultes, R. nigrum L., R. orientale Desf., R. rubrum L., R. uva-crispa L.

MATERIALS AND METHODS

Wounds were surgically induced on the dorsal parts of the rats and mice. Prepared herbal ointments were topically applied onto the wounds once daily. The effects of the extracts were evaluated by measuring the breaking strength and percentage of reduction in wounded area by comparing the results with the registered reference ointment, FITO Krem^®. Histopathological and antioxidant assays were also conducted. Since, R. nigrum was determined to be the most active species, we further investigated the wound healing potential of the subextracts of the methanol extract of R. nigrum leaves.

RESULTS

R. nigrum and R. multiflorum extracts significantly increased wound breaking strength. Significant reduction in the areas was determined for the wounded tissues treated with the ointments of R. nigrum and R. multiflorum extracts. Oxidative Stress Index was found to be lowest for R. orientale, R. nigrum and R. multiflorum. Among the subextracts of R. nigrum, ethyl acetate subextract was found to have promising effect.

CONCLUSIONS

Methanol extracts of leaves of R. nigrum and R. multiflorum demonstrated significant wound healing effect. We can suggest that ethyl acetate subextract of R. nigrum may be a potential candidate to be used for the development of a wound healing agent.

Induction and inhibition of oral malodor

Volatile sulfur compounds (VSCs) such as hydrogen sulfide (H₂ S) and methyl mercaptan (CH₃ SH) are the main components of oral malodor, and are produced as the end products of the proteolytic processes of oral microorganisms. The main pathway of proteolysis is the metabolism of sulfur-containing amino acids by gram-negative anaerobic bacteria. Gram-positive bacteria may promote VSC production by gram-negative anaerobes by cleaving sugar chains from glycoproteins and thus providing proteins. A large variety of bacteria within the oral microbiota are thought to be involved in the complex phenomenon of halitosis. Oral microbiota associated with a lack of oral malodor, oral microbiota associated with severe and H₂ S-dominant oral malodor, and oral microbiota associated with severe and CH₃ SH-dominant oral malodor have been distinguished through molecular approaches using the 16S rRNA gene. Pathological halitosis may primarily be addressed through treatment of causative diseases. In all cases, plaque control is the basis of oral malodor control, and dentifrices, mouthwashes, and functional foods play a supplementary role in addition to brushing. Recently, the use of natural ingredients in products tends to be favored due to the increase in antibiotic-resistant strains and the side effects of some chemical ingredients. In addition, probiotics and vaccines are expected to offer new strategies for improving the oral conditions through mechanisms other than antibacterial agents.

Novel Approaches to the Control of Oral Microbial Biofilms

Effective management of biofilm-related oral infectious diseases is a global challenge. Oral biofilm presents increased resistance to antimicrobial agents and elevated virulence compared with planktonic bacteria. Antimicrobial agents, such as chlorhexidine, have proven effective in the disruption/inhibition of oral biofilm. However, the challenge of precisely and continuously eliminating the specific pathogens without disturbing the microbial ecology still exists, which is a major factor in determining the virulence of a multispecies microbial consortium and the consequent development of oral infectious diseases. Therefore, several novel approaches are being developed to inhibit biofilm virulence without necessarily inducing microbial dysbiosis of the oral cavity. Nanoparticles, such as pH-responsive enzyme-mimic nanoparticles, have been developed to specifically target the acidic niches within the oral biofilm where tooth demineralization readily occurs, in effect controlling dental caries. Quaternary ammonium salts (QAS) such as dimethylaminododecyl methacrylate (DMADDM), when incorporated into dental adhesives or resin composite, have also shown excellent and durable antimicrobial activity and thus could effectively inhibit the occurrence of secondary caries. In addition, custom-designed small molecules, natural products and their derivatives, as well as basic amino acids such as arginine, have demonstrated ecological effects by modulating the virulence of the oral biofilm without universally killing the commensal bacteria, indicating a promising approach to the management of oral infectious diseases such as dental caries and periodontal diseases. This article aims to introduce these novel approaches that have shown potential in the control of oral biofilm. These methods may be utilized in the near future to effectively promote the clinical management of oral infectious diseases and thus benefit oral health.

Catechin-mediated restructuring of a bacterial toxin inhibits activity

BACKGROUND

Catechins, polyphenols derived from tea leaves, have been shown to have antibacterial properties, through direct killing of bacteria as well as through inhibition of bacterial toxin activity. In particular, certain catechins have been shown to have bactericidal effects on the oral bacterium, Aggregatibacter actinomycetemcomitans, as well as the ability to inhibit a key virulence factor of this organism, leukotoxin (LtxA). The mechanism of catechin-mediated inhibition of LtxA has not been shown.

METHODS

In this work, we studied the ability of six catechins to inhibit LtxA-mediated cytotoxicity in human white blood cells, using Trypan blue staining, and investigated the mechanism of action using a combination of techniques, including fluorescence and circular dichroism spectroscopy, confocal microscopy, and surface plasmon resonance.

RESULTS

We found that all the catechins except (-)-catechin inhibited the activity of this protein, with the galloylated catechins having the strongest effect. Pre-incubation of the toxin with the catechins increased the inhibitory action, indicating that the catechins act on the protein, rather than the cell. The secondary structure of LtxA was dramatically altered in the presence of catechin, which resulted in an inhibition of toxin binding to cholesterol, an important initial step in the cytotoxic mechanism of the toxin.

CONCLUSIONS

These results demonstrate that the catechins inhibit LtxA activity by altering its structure to prevent interaction with specific molecules present on the host cell surface.

GENERAL SIGNIFICANCE

Galloylated catechins modify protein toxin structure, inhibiting the toxin from binding to the requisite molecules on the host cell surface.

3,5,6,7,8,3',4'-Heptamethoxyflavone, a Citrus Flavonoid, Inhibits Collagenase Activity and Induces Type I Procollagen Synthesis in HDFn Cells

Citrus fruits contain various types of flavonoids with powerful anti-aging and photoprotective effects on the skin, and have thus been attracting attention as potential, efficacious skincare agents. Here, we aimed to investigate the chemical composition of Citrus unshiu and its protective effects on photoaging. We isolated and identified a bioactive compound, 3,5,6,7,8,3',4'-heptamethoxyflavone (HMF), from C. unshiu peels using ethanol extraction and hexane fractionation. HMF inhibited collagenase activity and increased type I procollagen content in UV-induced human dermal fibroblast neonatal (HDFn) cells. HMF also suppressed the expression of matrix metalloproteinases 1 (MMP-1) and induced the expression of type I procollagen protein in UV-induced HDFn cells. Additionally, HMF inhibited ultraviolet B (UVB)-induced phosphorylation of the mitogen-activated protein kinases (MAPK) cascade signaling components-ERK, JNK, and c-Jun-which are involved in the induction of MMP-1 expression. Furthermore, HMF affected the TGF-β/Smad signaling pathway, which is involved in the regulation of type I procollagen expression. In particular, HMF induced Smad3 protein expression and suppressed Smad7 protein expression in UV-induced HDFn cells in a dose-dependent manner. These findings suggest a role for Citrusunshiu in the preparation of skincare products in future.

Anti-aging potential of extracts from Sclerocarya birrea (A. Rich.) Hochst and its chemical profiling by UPLC-Q-TOF-MS

Background

Degradation of components of the extracellular matrix such as elastin and collagen by elastase and collagenase accelerates skin aging. Phytochemicals that inhibit the activity of these enzymes can be developed as anti-aging ingredients. In this study, an investigation of the anti-aging properties of Sclerocarya birrea (A. Rich.) Hochst (Marula) extracts was conducted in vitro with the aim of developing chemically characterized anti-aging ingredients.

Methods

Marula stems, leaves and fruits were extracted using methanol:dichloromethane (DCM) (1:1). The stems were later extracted using acetone, ethanol, methanol:DCM (1:1) and sequentially using hexane, DCM, ethyl acetate and methanol. The stem ethanol extract was defatted and concentrated. Elastase and collagenase inhibition activities of these extracts and Marula oil were determined using spectrophotometric methods. The chemical profile of the ethanolic stem extract was developed using Ultra-performance-liquid chromatography quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS) with MassLynx software. Pure standards were used to confirm the identity of major compounds and were screened for anti-elastase and anti-collagenase activity.

Results

Marula stems extracts were the most active as they exhibited anti-elastase activity comparable to that of elafin (> 88%) and anti-collagenase activity as potent as EDTA (> 76%). The leaf extract had moderate anti-elastase activity (54%) but was inactive agains collagenase. Marula fruits and oil exhibited limited activity in both assays. The ethanolic extract of Marula stems was the most suitable based on its acceptability to the cosmetic industry and its anti-collagenase activity (99%). Defatting and concentration improved its antiaging activity and lowered the colour intensity. Six compounds have been tentatively identified in the chemical profile of the ethanolic extract of Marula stems of which four; quinic acid, catechin, epigallocatechin gallate and epicatechin gallate have been confirmed using pure standards. Epigallocatechin gallate and epicatechin gallate were as potent (p < 0.05) as EDTA at 5 μg/ml in the anti-collagenase assay.

Conclusions

The ethanolic extract of Marula stems can be developed into an anti-aging ingredient as it exhibited very good in vitro anti-aging activity and its chemical profile has been developed. Epicatechin gallate and epigallocatechin gallate contribute to the anti-aging activity of Marula stem ethanol extract.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2112-1) contains supplementary material, which is available to authorized users.

Molecular mechanisms of green tea polyphenols with protective effects against skin photoaging

Whereas green tea has historically been consumed in high quantities in Northeast Asia, its popularity is also increasing in many Western countries. Green tea is an abundant source of plant polyphenols exhibiting numerous effects that are potentially beneficial for human health. Accumulating evidence suggests that green tea polyphenols confer protective effects on the skin against ultraviolet (UV) irradiation-induced acceleration of skin aging, involving antimelanogenic, antiwrinkle, antioxidant, and anti-inflammatory effects as well as prevention of immunosuppression. Melanin pigmentation in the skin is a major defense mechanism against UV irradiation, but pigmentation abnormalities such as melasma, freckles, senile lentigines, and other forms of melanin hyperpigmentation can also cause serious health and aesthetic issues. Furthermore, UV irradiation initiates the degradation of fibrillar collagen and elastic fibers, promoting the process of skin aging through deep wrinkle formation and loss of tissue elasticity. UV irradiation-induced formation of free radicals also contributes to accelerated photoaging. Additionally, immunosuppression caused by UV irradiation plays an important role in photoaging and skin carcinogenesis. In this review, we summarize the current literature regarding the antimelanogenic, antiwrinkle, antioxidant, and immunosuppression preventive mechanisms of green tea polyphenols that have been demonstrated to protect against UV irradiation-stimulated skin photoaging, and gauge the quality of evidence supporting the need for clinical studies using green tea polyphenols as anti-photoaging agents in novel cosmeceuticals.

Probable benefits of green tea with genetic implications

Tea is produced from the Camellia sinensis plant and can generally be divided into categories based on how they are processed. In general, green tea that is unfermented C. sinensis has been considered superior to black tea in health benefits. It contains a unique set of catechins that possess biological activity as antioxidant, anti-inflammatory and antiproliferative, which is potentially significant to the prevention and treatment of various forms of diseases. Oral cavity oxidative stress and inflammation, consequent cigarettes due to nicotine and acrolein, may be reduced in the presence of green tea polyphenols. In addition, green tea polyphenols can close down halitosis through modification of odorant sulfur components. Usually, green tea defends healthy cells from malignant transformation and locally has the ability to induce apoptosis in oral cancer cells. In unison, there is an increasing implication in the health benefits of green tea in the field of oral health. This review will cover recent findings on the therapeutic properties and anticancer health benefits of green tea.

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.

Green Tea (Camellia Sinensis): Chemistry and Oral Health

Green tea is a widely consumed beverage worldwide. Numerous studies have suggested about the beneficial effects of green tea on oral conditions such as dental caries, periodontal diseases and halitosis. However, to date there have not been many review articles published that focus on beneficial effects of green tea on oral disease. The aim of this publication is to summarize the research conducted on the effects of green tea on oral cavity. Green tea might help reduce the bacterial activity in the oral cavity that in turn, can reduce the aforementioned oral afflictions. Furthermore, the antioxidant effect of the tea may reduce the chances of oral cancer. However, more clinical data is required to ascertain the possible benefits of green tea consumption on oral health.

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.

Dietary antioxidants and their indispensable role in periodontal health

Periodontitis is an increasing area of interest due to its global prevalence. This inflammatory condition results due to the loss of the critical balance between the virulence factors produced by microorganisms and the inflammatory host response. A number of efforts have been made in the past to address this condition and regain periodontal health. Targeting the root cause by nonsurgical debridement has been considered the gold standard. However, research has shown the possible effects of nutrient deficiency and an imbalanced diet on the periodontium. Therefore, an effort toward the maintenance of optimal conditions as well as improvement of the oral health necessities the introduction of adjunctive nutritional therapy, which can benefit the patients. Antioxidants in the diet have some remarkable benefits and valuable properties that play an irreplaceable role in the maintenance of periodontal health. These have emerged as excellent adjuncts that can enhance the outcomes of conventional periodontal therapy. The aim of this review article is to highlight some of these dietary antioxidants that can make a notable difference by striking a balance between health and disease.

Thermoreversible gel for intrapocket delivery of green tea catechin as a local drug delivery system: An original research

The periodontal therapies along with systemic antibiotic therapy aim at eliminating the subgingival microbiota to arrest the progression of periodontal diseases. The complete elimination is often difficult, and thus the probability of repopulation after periodontal therapy is also high. The objectives of the study are to develop in situ thermoreversible gelling system of green tea catechins suitable for periodontal pocket administration, which would act as an adjunct to mechanical periodontal therapy. Gel is prepared on a weight basis using a cold process. In vitro drug release pattern is observed through spectrophotometer analysis at 277 nm. The gel is subjected to serial dilution analysis to determine the minimum inhibitory concentration (MIC) and disc diffusion analysis to determine the in vitro antibacterial effectiveness. Release pattern studies showed a complete release of drug from gel occurred by 36 h. A volume of 1.25 mg/ml was determined as MIC required against the periodontal pathogens. Disc diffusion analysis showed a 14 mm zone of inhibition is present around the 75 µl well for all the four species and 12 mm zone of inhibition around the 50 µl well. The advantage of F-127 is its thermoreversible nature that used for in situ gel formulation. Pluronic gel proved to be a promising carrier for prolong and effective release of green tea catechin.

Efficacy of chlorhexidine and green tea mouthwashes in the management of dental plaque-induced gingivitis: A comparative clinical study

Background:

The intake of green tea has been increased recently due to its medicinal values. The antibacterial and antioxidant properties of green tea were found to be beneficial in the treatment of gingival and periodontal diseases. The aim of this comparative study was to compare the efficacy of the mouthwash containing green tea and chlorhexidine in the management of dental plaque-induced gingivitis.

Materials and Methods:

Thirty patients who participated in the study were divided randomly into two groups, each group of 15 patients was prescribed with either chlorhexidine or green tea mouthwash. Turesky modification of Quigley-Hein plaque index, Löe and Silness gingival index, Ainamo and Bay bleeding index, tooth stain, and tongue stain (TS) were recorded at baseline, 15 days, and 1 month. The subjects were asked to report any discomfort or alteration in taste.

Results:

There was a significant decrease in plaque index, gingival index, and bleeding index in both the groups. However, green tea mouthwash resulted in a statistically significant decrease in bleeding index compared to chlorhexidine group. There was no significant difference in tooth stain and TS in both the groups.

Conclusion:

The green tea-containing mouthwash is equally effective in reducing the gingival inflammation and plaque to chlorhexidine.

A natural therapeutic approach for the treatment of periodontitis by MK615

Periodontitis is a chronic inflammatory disease that affects the tooth-supporting tissues. Gingival fibroblasts are the most abundant cells in periodontal tissues and they participate actively in the host inflammatory response to periodontal pathogens that is known to mediate local tissue destruction in periodontitis. The Japanese apricot, known as Ume in Japanese, has been a traditional Japanese medicine for centuries and is a familiar and commonly consumed food. The health benefits of Ume are widely recognized and have been confirmed in recent studies showing that MK615, an extract of compounds from Ume, has strong anticancer and anti-inflammatory effects. However, the potential role of MK615 in oral health is unknown. We hypothesized that the anti-inflammatory activities of MK615 could be exploited to inhibit the effects of lipopolysaccharide (LPS) produced by periodontal bacterial pathogens, such as Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis. Here, we show that LPS-induced interleukin (IL)-6 and IL-8 production by gingival fibroblasts was dose-dependently inhibited by MK615. As a potent inhibitor of the inflammatory responses induced by periodontal pathogens, MK615 merits further testing as a therapeutic agent in inflammatory diseases such as periodontitis.

Non-Nutrient, Naturally Occurring Phenolic Compounds with Antioxidant Activity for the Prevention and Treatment of Periodontal Diseases

One of the main factors able to explain the pathophysiological mechanism of inflammatory conditions that occur in periodontal disease is oxidative stress. Given the emerging understanding of this relationship, host-modulatory therapies using antioxidants could be interesting to prevent or slow the breakdown of soft and hard periodontal tissues. In this context, non-nutrient phenolic compounds of various foods and plants have received considerable attention in the last decade. Here, studies focusing on the relationship between different compounds of this type with periodontal disease have been collected. Among them, thymoquinone, coenzyme Q (CoQ), mangiferin, resveratrol, verbascoside and some flavonoids have shown to prevent or ameliorate periodontal tissues damage in animal models. However evidence regarding this effect in humans is poor and only limited to topical treatments with CoQ and catechins. Along with animal experiments, in vitro studies indicate that possible mechanisms by which these compounds might exert their protective effects include antioxidative properties, oxygen and nitrogen scavenging abilities, and also inhibitory effects on cell signaling cascades related to inflammatory processes which have an effect on RNS or ROS production as well as on antioxidant defense systems.

Molecular weight and galloylation affect grape seed extract constituents' ability to cross-link dentin collagen in clinically relevant time

OBJECTIVE

To investigate the relationship between the structures of polyphenolic compounds found in grape seed extract (GSE) and their activity in cross-linking dentin collagen in clinically relevant settings.

METHODS

Representative monomeric and dimeric GSE constituents including (+)-catechin (pCT), (-)-catechin (CT), (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin gallate (EGCG), procyanidin B2 and a pCT-pCT dimer were purchased or synthesized. GSE was separated into low (PALM) and high molecular weight (PAHM) fractions. Human molars were processed into dentin films and beams. After demineralization, 11 groups of films (n=5) were treated for 1min with the aforementioned reagents (1wt% in 50/50 ethanol/water) and 1 group remained untreated. The films were studied by Fourier transform infrared spectroscopy (FTIR) followed by a quantitative mass spectroscopy-based digestion assay. Tensile properties of demineralized dentin beams were evaluated (n=7) after treatments (2h and 24h) with selective GSE species that were found to protect dentin collagen from collagenase.

RESULTS

Efficacy of GSE constituents in cross-linking dentin collagen was dependent on molecular size and galloylation. Non-galloylated species with degree of polymerization up to two, including pCT, CT, EC, EGC, procyanidin B2 and pCT-pCT dimer were not active. Galloylated species were active starting from monomeric form, including ECG, EGCG, PALM, GSE and PAHM. PALM induced the best overall improvement in tensile properties of dentin collagen.

SIGNIFICANCE

Identification under clinically relevant settings of structural features that contribute to GSE constituents' efficacy in stabilizing demineralized dentin matrix has immediate impact on optimizing GSE's use in dentin bonding.

Green tea catechin inhibits the activity and neutrophil release of Matrix Metalloproteinase-9

Green tea (Camellia sinensis; 綠茶 lǜ chá) extracts have been shown to possess anti-oxidant and anti-inflammatory effects in various cell types. Green tea extract (GTX) has been shown to significantly inhibit the activity of collagenase-3 (matrix metalloproteinase-13 (MMP-13)) in vitro. MMPs, such as MMP-9, are known to be involved in many inflammatory diseases including periodontal disease. GTX and a major catechin, epigallocatechin-gallate (EGCG), were examined for their ability to inhibit purified MMP-9 activity and its release from stimulated neutrophils.

Methanol extract of Green tea and commercially purchased EGCG (>95 % purity) were tested in vitro for their ability to inhibit MMP-9 activity and/or its release from neutrophils using a β-casein cleavage assay and gelatin zymography, respectively. Statistical analysis was performed by Student's t-test.

GTX and EGCG at 0.1% (w/v) completely inhibited the activity of MMP-9. In addition, GTX and EGCG (0.1 %) significantly inhibited (p < 0.001) the release of MMP-9 from formyl-Met-Leu-Phe (FMLP)-stimulated human neutrophils by 62.01% ± 6.717 and 79.63% ± 1.308, respectively. The inhibitory effects of GTX and EGCG occurred in unstimulated neutrophils (52.42% ± 3.443 and 62.33% ± 5.809, respectively). When the inhibitory effect of EGCG was further characterized, it significantly inhibited the release of MMP-9 from the FMLP-stimulated human neutrophils in a dose-dependent manner.

The effects of GTX and EGCG on MMPs could be extrapolated to clinical/in vivo studies for the development of oral care products to prevent or treat chronic inflammatory diseases including periodontal diseases.

Stevia rebaudiana Bert. leaf extracts as a multifunctional source of natural antioxidants

The aim of the presented study was to characterize the content and biological activity of extracts prepared from dried Stevia rebaudiana leaves with potential application in the food or cosmetic industry. Aqueous (A), ethanolic (E) and glycol-aqueous (GA) extracts were analyzed for the content of polyphenols and proteins, showing that the highest amount of phenols (15.50 mg/g) and flavonoids (3.85 mg/g) contained GA. All extracts contained significant amount of protein (69.40–374.67 mg/g). Between analyzed stevia extracts (HPLC) GA contained the highest amount of polyphenols, especially ferulic (5.50 mg/g) and rozmaric (4.95 mg/g) acids derivates. The highest antiradical activity against DPPH^• and ABTS^•+ was noted for GA and E (IC₅₀ = 0.38 and 0.71 µg flavonoids/mL). The highest ability to chelate Fe²⁺ was observed for E (IC₅₀ = 2.08 µg flavonoids/mL). Stevia extracts were also analyzed for their cytotoxicity and fibroblast irritation potential in vitro. E and GA were the most cytotoxic and irritating, probably due to the high content of biologically active phytochemicals. On the other hand, a extract was the most tolerable by the cells. To summarize, the presented study evaluated the potential application of A, E and GA stevia extracts as natural source of antioxidants in the food and cosmetic industry.

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).

Paclitaxel/epigallocatechin gallate coloaded liposome: a synergistic delivery to control the invasiveness of MDA-MB-231 breast cancer cells

Matrix metalloproteinases (MMPs) have been investigated as a potential target for treating invasive breast cancers. The chemotherapy for breast cancer is often prescribed as a combination of drugs. The present study investigates a novel strategy of combining a MMP inhibitor, Epigallocatechin gallate (EGCG), along with an anticancer drug, Paclitaxel (PTX), in the form of a liposomal co-delivery system. The developed PTX/EGCG co-loaded liposomes showed an entrapment of 77.11±2.30% and 59.11±3.51% for PTX and EGCG, respectively. The in vitro efficacy of the liposomes was assessed by their ability to promote apoptosis and curtail cell invasion. On all parameters, namely cytotoxicity and caspase-3 activity that are indicators of apoptosis, and MMP-2 and - 9 inhibition and invasion assays that are indicators of cell invasion, the PTX/EGCG co-loaded liposomes showed better results than each of the individual drug loaded liposomes. These findings demonstrate the synergistic outcome of PTX/EGCG combination and indicate the suitability of PTX/EGCG co-loaded liposomes for the treatment of invasive breast cancer.

Strategies for the inhibition of gingipains for the potential treatment of periodontitis and associated systemic diseases

Gingipains are the major virulence factors of Porphyromonas gingivalis, the main periodontopathogen. It is expected that inhibition of gingipain activity in vivo could prevent or slow down the progression of adult periodontitis. To date, several classes of gingipain inhibitors have been recognized. These include gingipain N-terminal prodomains, synthetic compounds, inhibitors from natural sources, antibiotics, antiseptics, antibodies, and bacteria. Several synthetic compounds are potent gingipain inhibitors but inhibit a broad spectrum of host proteases and have undesirable side effects. Synthetic compounds with high specificity for gingipains have unknown toxicity effects, making natural inhibitors more promising as therapeutic gingipain blockers. Cranberry and rice extracts interfere with gingipain activity and prevent the growth and biofilm formation of periodontopathogens. Although the ideal gingipain inhibitor has yet to be discovered, gingipain inhibition represents a novel approach to treat and prevent periodontitis. Gingipain inhibitors may also help treat systemic disorders that are associated with periodontitis, including cardiovascular disease, rheumatoid arthritis, aspiration pneumonia, pre-term birth, and low birth weight.

Association of tea consumption and the risk of oral cancer: a meta-analysis

OBJECTIVES

Epidemiological studies evaluating the association of tea consumption and the risk of oral cancer risk have produced inconsistent results. Thus, we conducted a meta-analysis to assess the relationship between tea consumption and oral cancer risk.

METHODS

Pertinent studies were identified by a search in PubMed, Web of Knowledge and Wan Fang Med Online. The fixed or random effect model was used based on heterogeneity test. Publication bias was estimated using Egger's regression asymmetry test.

RESULTS

Finally, 14 articles with 19 studies comprising 4675 oral cancer cases were included in this meta-analysis. The relative risk (95% confidence interval) of oral cancer for the highest versus the lowest category of tea consumption was 0.853 (0.779-0.934), and the association was significant between oral cancer risk and green tea consumption [0.798 (0.673-0.947)] but not in the black tea consumption [0.953 (0.792-1.146)]. The associations were also significant in Asian and Caucasian.

CONCLUSIONS

Our analysis indicated that tea consumption may have a protective effect on oral cancer, especially in green tea consumption.

Green tea extract as a local drug therapy on periodontitis patients with diabetes mellitus: A randomized case-control study

Background:

The green tea extract is a naturally occurring product having beneficial effects that counteract with the pathobiological features of periodontitis and diabetes mellitus. Hence, the present study was aimed at incorporation of green tea extract into hydroxylpropyl methylcellulose and investigates its efficacy in chronic periodontitis patients associated with and without diabetes mellitus.

Materials and Methods:

For the in vitro study, formulation of green tea strips and placebo strips, and analysis of drug release pattern from the green tea strips at different time intervals were performed. For the in vivo study, 50 patients (20-65 years), including 25 systemically healthy patients with chronic periodontitis (group 1) and 25 diabetic patients with chronic periodontitis (group 2) were enrolled. In each patient, test and control sites were identified for the placement of green tea and placebo strips, respectively. Gingival Index (GI), Probing Pocket Depth (PPD), and Clinical Attachment Level (CAL) were examined at baseline, first, second, third, and fourth weeks. Microbiological analysis for Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans was performed at baseline and fourth week.

Results:

The in vitro study showed 10.67% green tea release at 30 min; thereafter, a slow release was noted till 120 min.

In vivo study:

Both groups showed significant reduction in GI scores at the test sites. Group 1 showed significant (P < 0.001) PPD reduction at different time intervals at the test sites. However, group 2 showed significant reduction from baseline (5.30 ± 0.70) to fourth week (3.5 ± 0.97). Statistically significant gain in CAL at the test sites was observed both in group 1 (1.33 mm) and group 2 (1.43 mm). The prevalence of P. gingivalis in group 1 test sites was significantly reduced from baseline (75%) to fourth week (25%).

Conclusions:

Local drug delivery using green tea extract could be used as an adjunct in the treatment of chronic periodontitis in diabetic and non-diabetic individuals.

The effect of orally administered epigallocatechin-3-gallate on ligature-induced periodontitis in rats

BACKGROUND AND OBJECTIVE

Epigallocatechin-3-gallate (EGCG) is known for its beneficial properties, including anti-inflammatory and anti-oxidative activities. Recently, reports have suggested that EGCG plays a pivotal role in regulating cytokine expression and osteoclastic activity. In the present study, we investigated whether orally administered EGCG has a therapeutic effect on ligature-induced periodontitis.

MATERIALS AND METHODS

Forty-eight Sprague-Dawley rats were treated with EGCG or phosphate-buffered saline. Periodontitis was induced by tying a ligature for 7 d. After removing ligation, EGCG (200 mg/kg) or phosphate-buffered saline was administered via oral gavage on a daily basis. Rats were killed after 1, 2 and 4 wk of administration. Histologic and histomorphometric analyses, tartrate resistant acid phosphatase staining and immunohistochemistry were carried out.

RESULTS

In the control group, bone loss did not recover even after the causative factor of periodontitis was eliminated. On the other hand, distance from cemento-enamel junction to alveolar bone crest, long junctional epithelium and collagen destruction were reduced in the EGCG group. Decreased interleukin (IL)-6 expression was shown from the early stage of EGCG administration, followed by reduced tumor necrosis factor (TNF) expression at week 4 EGCG group. The CT area showed a higher decrease of IL-6 expression between the control and EGCG group than alveolar bone area. Downregulation of TNF and IL-6 expression led to a decrease in osteoclast number and activity, which resulted in reduced bone loss.

CONCLUSIONS

Systemic administration of EGCG could have a therapeutic effect on damaged periodontal tissue. Inhibited cytokine expression, including TNF and IL-6 is responsible for the reduction in osteoclast formation, osteoclastic activity and collagen destruction.

Effect of green tea mouthwash on oral malodor

This study aimed to determine the effect of green tea mouthwash on oral malodor, plaque, and gingival inflammation. Gingivitis subjects who had over 80 parts per billion of volatile sulfur compounds (VSC) in the morning breath were randomly assigned into green tea or placebo mouthwash group. At baseline, VSC, Plaque Index (PI) and Papillary Bleeding Index (PBI) were recorded. Participants were rinsed with the assigned mouthwash, and VSC level was remeasured at 30 minutes and 3 hours postrinsing. For the following 4 weeks, participants were asked to rinse with the assigned mouthwash twice daily. VSC, PI and PBI were remeasured at day 28. It was found that, at 30 minutes and 3 hours postrinsing, VSC was reduced by 36.76% and 33.18% in the green tea group and 19.83% and 9.17% in the placebo group, respectively. At day 28, VSC was reduced by 38.61% in the green tea group and 10.86% in the placebo group. VSC level in the green tea group was significantly different when compared to the placebo. PI and PBI were significantly reduced in both groups. However, no significant difference was found between groups. In conclusion, green tea mouthwash could significantly reduce VSC level in gingivitis subjects after rinsing for 4 weeks.

The effect of Camellia Sinensis (green tea) mouthwash on plaque-induced gingivitis: a single-blinded randomized controlled clinical trial

Background and the purpose of the StudyComplementary medicine received high attention during last decades. We aimed to assess the efficacy of Green tea mouthwash on plaque-induced gingivitis as the most common form of periodontal disease.

METHODS AND MATERIALS

We designed a single blinded placebo controlled clinical trial. High school female students with chronic generalized plaque-induced gingivitis were distributed to receive either 5 ml of Green tea 5% two times/day or normal saline with the same dosage. Gingival index (Sillness & Loe), plaque index (Sillness & Loe) and bleeding index (Barnett) were recorded at baseline and five consecutive weeks. Comparisons were made by a general linear model, repeated measure ANOVA and a Bonferroni test applied for multiple comparisons.

RESULTS

Twenty five students were recruited in each arm of the study. A significant improvement was observed in all periodontal indices during the study (P < 0.001). Two groups were contrasted by changing patterns of alteration of indices (P < 0.05). Although total amount of improvement was higher in mouthwash group, the differences did not reach a statistically significant level (P > 0.05, observed power for GI: 0.09, PI: 0.11 and BI: 0.07).

CONCLUSION

Green tea mouthwash may be a safe and feasible adjunct treatment for inflammatory periodontal diseases. A future larger scale study is warranted for better evaluating the effect of green tea.

Myricetin suppresses LPS-induced MMP expression in human gingival fibroblasts and inhibits osteoclastogenesis by downregulating NFATc1 in RANKL-induced RAW 264.7 cells

OBJECTIVE

Periodontitis is an inflammatory disease that affects connective tissue attachments and the supporting bone that surrounds the teeth. Gingival fibroblasts induce the overexpression of matrix metalloproteinase (MMP), which is involved in inflammatory progression in periodontitis. Osteoclasts are responsible for skeletal modeling and remodeling but may also destroy bone in several bone diseases, including osteoporosis and periodontitis. This study examined the anti-destructive effects of myricetin on human gingival fibroblasts (HGF) under lipopolysaccharide- (LPS-) induced inflammatory conditions, and the anti-osteoclastogenetic effect of myricetin on the receptor activator of NF-κB ligand (RANKL) induced RAW264.7 cells was also investigated.

DESIGN

The effects of myricetin on HGF were determined by measuring the cell viability and mRNA expression and enzyme activity of tissue-destructive proteins, including MMP-1, MMP-2 and MMP-8. The effects of myricetin on osteoclasts were examined by measuring the following: (1) the cell viability, (2) the formation of tartrate-resistant acid phosphatase (TRAP)(+) multinucleated cells, (3) MAPK signalling pathways (4) mRNA expression of osteoclast-associated genes and (5) tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) secretion.

RESULTS

The myricetin had no effects on the cell viability of the HGF and decreased the mRNA expression and enzyme activity of MMP-1, MMP-2 and MMP-8 in the HGF. Myricetin inhibited the formation of RANKL-stimulated TRAP(+) multinucleated cells. Myricetin also inhibited the RANKL-stimulated activation of p-38, ERK and cSrc signaling, and inhibited the RANKL-stimulated degradation of I(k)B in the RAW264.7 cells. In addition, the RANKL-stimulated induction of NFATc1 transcription factors was abrogated by myricetin. Myricetin decreased the mRNA expression of osteoclast-associated genes, including cFOS, TRAP and cathepsin K in the RAW264.7 cells. Myricetin inhibited the secretion of LPS-induced TNF-α and IL-1β in the RAW264.7 cells.

CONCLUSIONS

These findings suggest that myricetin has therapeutic effects on bone-destructive processes, such as those that occur in periodontal diseases.

MK615: a new therapeutic approach for the treatment of oral disease

The oral cavity is inhabited by over 500 different bacterial species. Dental caries and periodontitis are major bacterial infectious diseases in the oral cavity. Prunus mume Sieb. et Zucc., which is a variety of Japanese apricot known as Ume in Japanese, has been a traditional Japanese medicine for centuries, and is a familiar and commonly consumed food. The health benefits of Ume are now being widely recognized. Recent studies showed that MK615, an extract of compounds from Ume, has strong anticancer and anti-inflammatory effects. However, the potential role of MK615 in the antimicrobial field remains unknown. Therefore, we hypothesize that MK615 has antimicrobial activities against a range of oral bacterial pathogens. Here, we show that MK615 may be a potent inhibitor of the growth of some oral bacteria and an inhibitor of biofilm formation by Streptococcus mutans, the principal etiological agent of human dental caries. Our findings suggest that MK615 has potential as a therapeutic agent for treating and preventing oral diseases such as dental caries and periodontitis.

Inhibition of host- and bacteria-derived proteinases by natural anthocyanins

BACKGROUND AND OBJECTIVES

Host- and bacteria-derived proteinases are considered to play critical roles in periodontitis progression. This study investigated the ability of a blackcurrant extract and its major anthocyanins (cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside and delphinidin-3-O-rutinoside) to inhibit the activity of matrix metalloproteinases (MMPs), neutrophil elastase and periodontopathogen (Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola) proteinases.

MATERIAL AND METHODS

Enzyme inhibition was detected using fluorometric and colorimetric assays after incubating blackcurrant extract and its major anthocyanins (at concentrations of 6.25, 12.5, 25 and 50 μg/mL) with MMPs, elastase or bacterial proteinases, along with their specific substrates. Substrate degradation was recorded every hour for up to 4 h.

RESULTS

The blackcurrant extract (50 μg/mL) inhibited all proteinases tested. MMP-1 and MMP-9 were significantly inhibited by pure anthocyanins at concentrations ranging from 6.25 to 50 μg/mL. Elastase activity was inhibited by cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside in the range of 6.25-50 μg/mL and by delphinidin-3-O-rutinoside at 50 μg/mL. P. gingivalis, T. forsythia and T. denticola proteinases were also significantly inhibited by pure anthocyanins. In all cases, enzyme inhibition was time-dependent.

CONCLUSION

Our study showed that a blackcurrant extract and its major anthocyanins were able to inhibit the activity of host- and bacteria-derived proteinases. This suggests that such natural compounds may represent promising agents for use in adjunctive treatments for periodontitis.