Sabinene suppresses growth, biofilm formation, and adhesion of Streptococcus mutans by inhibiting cariogenic virulence factors

Inhibition of the Biofilm Formation of Plant Streptococcus mutans

This review is devoted to a systematic analysis of studies aimed at investigating plant extracts, essential oils and phytochemical compounds capable of inhibiting Streptococcus mutans biofilm formation. This paper investigates the effect of extracts, essential oils and individual plant compounds on inhibiting the biofilm formation of Streptococcus mutans, one of the major pathogens responsible for the development of dental caries. Using cultural microbiology and molecular biology techniques, the authors describe the mechanisms by which plant samples reduce Streptococcus mutans adhesion and growth. The results show that several plant components have antibacterial properties, contributing to the reduction of Streptococcus mutans colony numbers and inhibiting the synthesis of extract-exopolysaccharide matrices required for biofilm formation. This work highlights the potential of botanicals in inhibiting Streptococcus mutans biofilm formation, which can be applied as natural antimicrobial agents in the prevention and treatment of dental diseases. Views on the use of these plant extracts and their components in dental preparations such as toothpastes, rinses and gels aimed at preventing dental caries are evaluated. The review shows the relevance of the research to optimizing the use of plant extracts, essential oils, individual compounds and their active actions in the control of Streptococcus mutans biofilms.

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.

Comparison of autoclaving and γ-radiation impact on four spices aroma profiles and microbial load using HS-SPME GC-MS and chemometric tools

Herbal spices are widely consumed as food additives owing to their distinct aroma and taste as well as a myriad of economic and health value. The aroma profile of four major spices including bay leaf, black pepper, capsicum, and fennel was tested using HS-SPME/GC-MS and in response to the most widely used spices´ processing methods including autoclaving and γ-radiation at low and high doses. Additionally, the impact of processing on microbial contamination of spices was tested using total aerobic count. GC-MS analysis led to the identification of 22 volatiles in bay leaf, 34 in black pepper, 23 in capsicum, and 24 in fennel. All the identified volatiles belonged to oxides/phenols/ethers, esters, ketones, alcohols, sesquiterpene and monoterpene hydrocarbons. Oxides/phenol/ethers were detected at high levels in all tested spices at ca. 44, 28.2, 48.8, 61.1%, in bay leaves, black pepper, capsicum, and fennel, respectively of the total blend and signifying their typical use as spices. Total oxides/phenol/ethers showed an increase in bay leaf upon exposure to γ-radiation from 44 to 47.5%, while monoterpene hydrocarbons were enriched in black pepper upon autoclaving from 11.4 in control to reach 65.9 and 82.6% for high dose and low dose of autoclaving, respectively. Cineole was detected in bay leaf at 17.9% and upon exposure to autoclaving at high dose and γ-radiation (both doses) its level increased by 29-31%. Both autoclaving and γ-radiation distinctly affected aroma profiles in examined spices. Further, volatile variations in response to processing were assessed using multivariate data analysis (MVA) revealing distinct separation between autoclaved and γ-radiated samples compared to control. Both autoclaving at 115 °C for 15 min and radiation at 10 kGy eliminated detected bioburden in all tested spices i.e., reduced the microbial counts below the detection limit (< 10 cfu/g).

Investigating the Wound-Healing Potential of a Nanoemulsion-Gel Formulation of Pituranthos tortuosus Essential Oil

This study explores a nanoemulsion (NE)-based gel incorporating Tunisian Pituranthos tortuosus essential oil, with a focus on its wound-healing potential. The essential oil, extracted via hydrodistillation, underwent GC-MS analysis for compositional verification. The physicochemical characterization included dynamic light scattering (DLS), transmission electron microscopy (TEM), zeta potential measurement, pH, and viscosity. The gelification of the NE facilitated topical application. The results revealed an average extraction yield of 0.45% and identified 38 compounds in the essential oil. The NE exhibited a particle size of 27 ± 0.4 nm, a polydispersity index (PDI) of 0.3, and a zeta potential of -22.8 ± 1.4 mV. The stability of the gelified preparation was confirmed through thermodynamic stability studies, TEM observations, and zeta and size results. In vivo experiments confirmed significant wound-healing effects, highlighting the promising role of the NE-based gel in healthcare advancements. This research underscores the potential of novel phyto-based delivery systems in wound care.

Biofilm-mediated infections by multidrug-resistant microbes: a comprehensive exploration and forward perspectives

A biofilm is a collection of microorganisms organized in a matrix of extracellular polymeric material. Biofilms consist of microbial cells that attach to both surfaces and each other, whether they are living or non-living. These microbial biofilms can lead to hospital-acquired infections and are generally detrimental. They possess the ability to resist the human immune system and antibiotics. The National Institute of Health (NIH) states that biofilm formation is associated with 65% of all microbial illnesses and 80% of chronic illnesses. Additionally, non-device-related microbial biofilm infections include conditions like cystic fibrosis, otitis media, infective endocarditis, and chronic inflammatory disorders. This review aims to provide an overview of research on chronic infections caused by microbial biofilms, methods used for biofilm detection, recent approaches to combat biofilms, and future perspectives, including the development of innovative antimicrobial strategies such as antimicrobial peptides, bacteriophages, and agents that disrupt biofilms.

The inhibitory effect of ovomucoid from egg white on biofilm formation by Streptococcus mutans

BACKGROUND

Streptococcus mutans, the main pathogen associated with tooth decay, forms cariogenic biofilms on tooth surfaces. Therefore, controlling oral biofilm helps prevent dental caries. Hen's egg is a nutrient-dense food, and egg white is a good source of protein. Ovomucoid is one of the major proteins in egg white, with a 28 kDa molecular weight. The present study aimed to investigate the inhibitory effects of ovomucoid on the biofilm formation of S. mutans by suppressing virulence factors, including bacterial adherence, cellular aggregation and exopolysaccharide (EPS) production.

RESULTS

Crystal violet staining showed that biofilm formation by S. mutans was inhibited by ovomucoid at 0.25-1 mg mL-1 levels. Field emission scanning electron microscopy also confirmed this inhibition. In addition, ovomucoid reduced mature biofilm, water-insoluble EPS synthesis and the metabolic activity of bacterial cells in the biofilm. The bacterial adhesion and aggregation abilities of S. mutans were also decreased in the presence of ovomucoid. Ovomucoid downregulated the expression of comDE and vicR genes involved in the two-component signal transduction system and gtfA and ftf genes involved in EPS production.

CONCLUSION

Ovomucoid has the potential for use as an anti-biofilm agent for dental caries treatment because of its inhibitory effects on the virulence factors of S. mutans. © 2023 Society of Chemical Industry.

Current and Potential Applications of Monoterpenes and Their Derivatives in Oral Health Care

Plant products have been employed in medicine for centuries. As the world becomes more health-conscious, there is a growing interest in natural and minimally processed products for oral health care. This has led to an increase in research into the bioactive compounds found in plant products, particularly monoterpenes. Monoterpenes are known to have beneficial biological properties, but the specific mechanisms by which they exert their effects are not yet fully understood. Despite this, some monoterpenes are already being used in oral health care. For example, thymol, which has antibacterial properties, is an ingredient in varnish used for caries prevention. In addition to this, monoterpenes have also demonstrated antifungal, antiviral, and anti-inflammatory properties, making them versatile for various applications. As research continues, there is potential for even more discoveries regarding the benefits of monoterpenes in oral health care. This narrative literature review gives an overview of the biological properties and current and potential applications of selected monoterpenes and their derivatives in oral health care. These compounds demonstrate promising potential for future medical development, and their applications in future research are expected to expand.

Investigation on Chemical Composition, Antioxidant, Antifungal and Herbicidal Activities of Volatile Constituents from Deverra tortuosa (Desf.)

This study aims to analyze the chemical composition of the essential oils (EOs) obtained from stems and umbels of D. tortuosa as well the assessment of their biological activity. EOs were extracted by hydrodistillation and analyzed by gas chromatography coupled to mass spectrometry (GC/MS). The antioxidant properties were determined by DPPH and ABTS assays. The phytotoxic potential was assessed against dicots weeds (Sinapis arvensis and Trifolium campestre), monocots weeds (Lolium rigidum) and the crop Lepidium sativum. The antifungal activity was evaluated against four target phytopathogenic fungal strains. High diversity of compounds was detected in D. tortuosa Eos, varying among plant parts and consisting mainly of α-pinene (24.47-28.56%), sabinene (16.2-18.6%), α-phellandrene (6.3-11.7%) and cis-ocimene (5.28-7.85%). D. tortuosa EOs exhibited remarkable antioxidant activity, as well as interesting variable antifungal activities depending on the dose and fungi strain. The herbicidal activity of EOs showed significant efficacy on the inhibition of germination and seedling growth of all tested herbs. These results suggest that the EOs of Deverra tortuosa represent a valuable source of antioxidant, antifungal and phytotoxic metabolites and could be potential candidates for pest management, contributing to the promotion of sustainable agriculture.

3,3'-Diindolylmethane (DIM): A Potential Therapeutic Agent against Cariogenic Streptococcus mutans Biofilm

Indole, a metabolite of the amino acid tryptophan, has been proven to act as a signal molecule in bacteria, acting in different aspects of biofilm formation. The oral biofilm is a type of biofilm that has consequences for human health. It is a complex, three-dimensional structure that develops on the surface of teeth via the attachment of primary microbial colonizers. Many oral infections are caused by an imbalance occurring in the microorganisms naturally found in oral biofilms and are considered major public health concerns. In this study, we test the effect of a natural bis-indole, 3,3'-Diindolylmethane (DIM), in mitigating the pathogenicity of the oral biofilm inhabiting bacterium Streptococcus mutans, a bacterium that is considered to be a principal etiological agent in dental caries. Our study found that DIM was able to attenuate S. mutans biofilm formation by 92%. Additionally, treatment with DIM lowered extracellular polymeric substance (EPS) production and decreased its durability significantly under acidic conditions. Therefore, the anti-biofilm and anti-virulence properties of DIM against S. mutans bacteria in an "oral setting" provides evidence for its usefulness in reducing biofilm formation and potentially for caries attenuation.

Six Spain Thymus essential oils composition analysis and their in vitro and in silico study against Streptococcus mutans

BACKGROUND

Streptococcus mutans is a well-known oral pathogen that plays a critical role in the development of dental caries. Many studies have been directed to discover the chemical compounds present in natural products to inhibit the growth and biofilm formation activity of S. mutans. Thymus essential oils exhibit good inhibition on the growth and pathogenesis of S. mutans. However, details about the active compounds in Thymus essential oil and the inhibition mechanism still remain unclear. The aim of this study was to investigate the antimicrobial activity of 6 Thymus species (Three samples of Thymus vulgaris, two samples of Thymus zygis, and one sample of Thymus satureioides essential oils) on S. mutans, to identify the potential active components, and to reveal the underlying mechanism.

METHODS

The composition of Thymus essential oils was analyzed by gas chromatography-mass spectrometry. And its antibacterial effect was evaluated based on the bacterial growth, acid production, biofilm formation and genetic expression of virulence factors by S. mutans. Potential active components of the Thymus essential oil were identified using molecular docking and correlation analysis.

RESULTS

GC-MS analysis showed that the major components in the 6 Spain Thymus essential oils were linalool, α-terpineol, p-cymene, thymol and carvacrol. MIC and MBC analysis showed that 3 Thymus essential oils showed very sensitive antimicrobial activity, and were chosen for further analysis. The 3 Thymus essential oil exhibited a significant inhibitory effect on acid production, adherence and biofilm formation of S. mutans and the expression of virulence genes, such as brpA, gbpB, gtfB, gtfC, gtfD, vicR, spaP and relA. Correlation analysis showed that phenolic components, such as carvacrol and thymol, were positively related to DIZ value, which suggests that they are the potential antimicrobial components. Molecular docking between the Thymus essential oil components and virulence proteins also found that carvacrol and thymol exhibited strong binding affinity with functional domains of virulence genes.

CONCLUSIONS

Thymus essential oil showed significant inhibition against the growth and pathogenesis of S. mutans depending on their composition and concentration. And phenolic compounds, such as carvacrol and thymol, are the major active components. Thymus essential oil could be used in oral healthcare products as a potential anti-caries ingredient.

Antibacterial activity of oregano essential oils against Streptococcus mutans in vitro and analysis of active components

BACKGROUND

Streptococcus mutans (S. mutans) is considered the most relevant bacteria during the transition of the non-pathogenic commensal oral microbial community to plaque biofilms that promote the development of dental caries. Oregano (Origanum vulgare L.), is a universally natural flavoring and its essential oil has been demonstrated to have good antibacterial effects. However, the specific antibacterial mechanism of oregano essential oil (OEO) against S. mutans is still not completely understood.

METHODS

In this work, the composition of two different OEOs was determined by GC‒MS. Disk-diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined to assess their antimicrobial effect on S. mutans. The inhibition of acid production, hydrophobicity, biofilm formation and real-time PCR for gtfB/C/D, spaP, gbpB, vicR, relA and brpA mRNA expression by S. mutans were assessed to preliminarily investigate the mechanisms of action. Molecular docking was performed to simulate the interactions with the virulence proteins and active constituents. MTT test using immortalized human keratinocytes cells was also performed to investigate cytotoxicity.

RESULTS

Compared with the positive drug Penicillin /streptomycin 100X (DIZ: 34.13 ± 0.85 mm, MIC: 0.78125 μL/mL, MBC: 6.25 μL/mL), the essential oils of Origanum vulgare L. (DIZ: 80 mm, MIC: 0.625μL/mL, MBC:2.5μL/mL) and Origanum heracleoticum L. (DIZ: 39.67 ± 0.81 mm, MIC: 0.625μL/mL, MBC: 1.25μL/mL) could also exhibit similar effects to inhibit the acid production and reduce the hydrophobicity and biofilm formation of S. mutans at 1/2-1MIC concentration. And gene expression of gtfB/C/D, spaP, gbpB, vicR and relA were found to be downregulated. Due to the composition of essential oils from different sources being highly variable, through effective network pharmacology analysis, we found that OEOs contained many effective compounds, like carvacrol and its biosynthetic precursors γ-terpinene and p-cymene, which may directly target several virulence proteins of S. mutans. Besides, no toxic effect was instigated by OEOs at 0.1 μL/mL in the immortalized human keratinocytes cells.

CONCLUSION

The integrated analysis in the present study suggested that OEO might be a potential antibacterial agent for the prevention of dental caries.

Anti-Streptococcus mutans, anti-adherence and anti-acidogenic activity of Uvaria chamae P. Beauv

ETHNOPHARMACOLOGICAL RELEVANCE

Streptococcus mutans a key pathogen, produces biofilm, acids and extracellular polysaccharides in the oral cavity; which leads to the development of dental caries. Control of these pathogenic markers can prevent dental caries. Uvaria chamae P. Beauv. is a medicinal plant traditionally used for many ailments including oral infections. Root, leaves and bark extracts has proven antibacterial activity including activity against caries causing S. mutans. However, its effect on the virulence properties of S. mutans, responsible for the development of dental caries, has not been studied.

AIM OF THE STUDY

This study investigated the phytochemical constituents, anti-S. mutans, anti-adherence and anti-acidogenic activity of U. chamae root extract.

MATERIALS AND METHODS

Extracts were prepared and phytochemical analysis was performed. Minimum inhibitory concentrations (MIC) were determined, and MIC and sub-MIC concentrations of the best solvent were selected for their effect on the virulence factors of S. mutans. The results were analysed using one-way ANOVA and Wilcoxon Rank Sum Tests.

RESULTS

The dichloromethane extract, with proanthocyanidin as a major chemical constituent, produced an MIC of 0.02 mg/ml. At 6 h, exposure to 0.005, 0.01, and 0.02 mg/ml extract significantly reduced S. mutans adherence by 39, 59, and 77% respectively (p < 0.05). Uvaria chamae also significantly inhibited acid production in S. mutans at 10, 12, 14 and 16 h (p < 0.05). At ½ MIC, the plant extract caused remarkable downregulation of the virulence genes responsible for the adherence, biofilm formation, extracellular polysaccharide synthesis and acid production.

CONCLUSIONS

This suggests that U. chamae extract may potentially be used to inhibit the proliferation of S. mutans and silencing the expression of pathology-related genes, which will prevent the development of dental caries.

Enhanced mechanical properties, anti-biofilm activity, and cytocompatibility of a methacrylate-based polymer loaded with native multiwalled carbon nanotubes

OBJECTIVES

We aimed to optimize the mechanical and biological properties of a conventional methacrylate-based dental polymer by loading it with double- and triple-walled carbon nanotubes as growth (DTWCNTG).

METHODS

A formulation of bisphenol A-glycidyl methacrylate and triethylene glycol dimethacrylate (mass ratio = 2:1) was mixed with DTWCNTG at concentrations of 0.0% (control), 0.001%, 0.005%, and 0.010%. The concentrations were physicochemical and morphologically evaluated, and antibacterial activity was assessed by seeding a Streptococcus mutans strain (ATCC 25175) on the experimental polymeric surfaces. Cellular survival and osteodifferentiation were evaluated in epithelial (HaCat) and preosteoblast cells (MC3T3-E1).

RESULTS

The 0.001% DTWCNTG concentration yielded higher compressive strength, elastic modulus, flexural strength, flexural modulus, water sorption, and solubility than the control. The degree of conversion and color did not significantly change with a low amount of DTWCNTG incorporated into the polymer. Antibacterial activity significantly improved when tested on the 0.001% DTWCNTG discs. No groups showed cytotoxicity in a short-term analysis and adding DTWCNTG favored MC3T3-E1 mineralization over the control, particularly in the 0.001% formulation.

SIGNIFICANCE

The micro-addition of 0.001% DTWCNTG confers mechanical resistance, antimicrobial properties, and bioactivity to methacrylate-based polymers without significantly compromising color. Incorporating DTWCNTG improved dental composite properties and could be a biomodified material for minimally invasive procedures.

Chemical composition and antimicrobial activity of the leaf essential oil of Ravenia spectabilis Engl. (Rutaceae)

Ravenia spectabilis Engl. belongs to the family Rutaceae is known to possess several biologically active phytomolecules. This study was planned to investigate the chemical composition and antimicrobial activity of the leaf essential oil of R. spectabilis. The hydrodistillation of fresh leaves of R. spectabilis gave 0.19 ± 0.02% essential oil. The resulting essential oil was analysed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Altogether, thirty-one constituents forming 97.6 ± 1.72% of the total oil composition were identified. Major components of the oil were sabinene (60.8 ± 0.36%), α-pinene (5.4 ± 0.30%), myrcene (4.8 ± 0.25%), δ-3-carene (4.7 ± 0.62%) and β-pinene (4.3 ± 0.17%). The in-vitro antimicrobial potential of the oil was examined against eight human pathogenic bacterial and fungal strains. The essential oil showed significant activity against Staphylococcus aureus, Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus epidermidis, Candida albicans, and Candida kefyr. This is the first report on R. spectabilis leaf essential oil composition and its antimicrobial activity. The essential oil could be a promising natural source of sabinene and antimicrobial for developing new phytotherapeutics.

Inhibitory effects of sodium new houttuyfonate on growth and biofilm formation of Streptococcus mutans

The present study aimed to assess the impact of sodium new houttuyfonate (SNH) on growth and biofilm formation of Streptococcus mutans, and the combinatorial effects of SNH with cariostatic agents. The effects of SNH on S. mutans planktonic cultures were assessed by growth curve assay. The effects of SNH on S. mutans biofilm and extracellular polysaccharides (EPS) production were observed via crystal violet (CV) assay, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, colony-forming unit (CFU) counting assay, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Quantitative real-time polymerase chain reaction (qPCR) was applied to investigate the regulatory effects of SNH on the expression of virulence genes of S. mutans. Checkerboard microdilution assay was performed to investigate the combinatorial effects of SNH with two common cariostatic agents. SNH acted as an inhibitor on planktonic cell growth, biofilm formation and EPS production of S. mutans. SNH also downregulated the expression of gtfBCD and comDE systems and exhibited synergism with chlorhexidine (CHX). In conclusion, this study indicated a possibility for SNH to become an anticaries agents by its antimicrobial activity and synergistic effects with CHX against S. mutans.