Antibacterial activity of isoflavonoids isolated from Erythrina variegata against methicillin-resistant Staphylococcus aureus

AIMS: To screen 16 isoflavonoids isolated from Erythrina variegata (Leguminosae) for their antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). METHODS AND RESULTS: The roots of E. variegata were macerated with acetone. The chloroform-soluble fraction of the residue was subjected to repeated silica gel column chromatography followed by elution with various solvents. Structures of the isolated compounds were determined by extensive spectroscopic studies. Each compound was dissolved in dimethyl sulphoxide and added to agar plates (final concentration 1.56-100 microg ml(-1) and suspensions of MRSA spotted onto the agar plates to determine the minimum inhibitory concentration (MIC). Repeated silica gel chromatography yielded 16 compounds and spectroscopic studies revealed that all were isoflavonoids. Whilst 14 compounds showed antibacterial activity in this concentration range, the MIC values varied significantly among them. Of the active compounds, 3,9-dihydroxy-2,10-di(gamma,gamma-dimethylallyl)-6a,11a-dehydropterocarpan (erycristagallin) and 9-hydroxy-3-methoxy-2-gamma,gamma-dimethylallylpterocarpan (orientanol B) exhibited the highest activity with MIC values of 3.13-6.25 microg ml(-1). CONCLUSIONS: Erycristagallin and orientanol B showed the highest anti-MRSA activity (3.13-6.25 microg ml(-1). SIGNIFICANCE AND IMPACT OF THE STUDY: Erycristagallin and orientanol B could be leading compounds for phytotherapeutic agents against MRSA infections.     

Anticariogenic activity of macelignan isolated from Myristica fragrans (nutmeg) against Streptococcus mutans

The occurrence of dental caries is mainly associated with oral pathogens, especially cariogenic Streptococcus mutans. Preliminary antibacterial screening revealed that the extract of Myristica fragrans, widely cultivated for the spice and flavor of foods, possessed strong inhibitory activity against S. mutans. The anticariogenic compound was successfully isolated from the methanol extract of M. fragrans by repeated silica gel chromatography, and its structure was identified as macelignan by instrumental analysis using 1D-NMR, 2D-NMR and EI-MS. The minimum inhibitory concentration (MIC) of macelignan against S. mutans was 3.9 microg/ml, which was much lower than those of other natural anticariogenic agents such as 15.6 microg/ml of sanguinarine, 250 microg/ml of eucalyptol, 500 microg/ml of menthol and thymol, and 1000 microg/ml of methyl salicylate. Macelignan also possessed preferential activity against other oral microorganisms such as Streptococcus sobrinus, Streptococcus salivarius, Streptococcus sanguis, Lactobacillus acidophilus and Lactobacillus casei in the MIC range of 2-31.3 microg/ml. In particular, the bactericidal test showed that macelignan, at a concentration of 20 microg/ml, completely inactivated S. mutans in 1 min. The specific activity and fast-effectiveness of macelignan against oral bacteria strongly suggest that it could be employed as a natural antibacterial agent in functional foods or oral care products.     

The minimum inhibitory concentration of oral antibacterial agents against cariogenic organisms

The minimum inhibitory concentrations (MIC) of eight common dental antibacterial agents against three genera of bacteria which have been implicated in dentine caries, namely streptococci, lactobacilli and actinomycetes were investigated. The ultimate aim was to determine the most appropriate antibacterial agent which could be added to dental restorative materials for filling cavities where there was residual dentine caries. The antibacterial agents tested were chlorhexidine diacetate, chlorhexidine dihydrochloride, chlorhexidine gluconate, benzalkonium chloride, cetrimide, cetylpyridinium chloride, thymol and sodium hypochlorite. Thymol and sodium hypochlorite did not inhibit microbial growth at any of the concentrations tested. For the active antibacterial agents tested the MIC values against lactobacilli and streptococci were 0.25 microg/ml to 8.0 microg/ml and for actinomycetes 0.125 to 8.0 microg/ml. These results illustrate the wide spectrum of sensitivity of caries associated bacteria against dental antibacterial agents. From the MIC values alone, it is difficult to recommend which of the active antibacterial agents would be most effective in eliminating cariogenic organisms.     

Isoflavonoids from roots of Erythrina zeyheri

Five isoflavonoids, (+/-)-7,2',4'-trihydroxy-8,3'-di(gamma,gamma-dimethylallyl)isoflavanone, (3R)-7,4'-dihydroxy-2'-methoxy-6,8-di(gamma,gamma-dimethylallyl)isoflavanone, (3R)-7,2',4'-trihydroxy-6,8-di(gamma,gamma-dimethylallyl)isoflavan, 2',4'-dihydroxy-8-gamma,gamma-dimethylallyl-2",2"-dimethylpyrano-[5,6:6,7]isoflavan and (6aS, 11aS)-3,6a-dihydroxy-9-methoxy-4,10-di(gamma,gamma-dimethylallyl)pterocarpan, along with five known compounds, were isolated from the roots of Erythrina zeyheri. Their structures were established on the basis of spectroscopic evidence, and their antibacterial activities against methicillin-resistant Staphylococcus aureus (MRSA) were estimated by determining minimum inhibitory concentrations.     

Modifications of hydrophobicity, in vitro adherence and cellular aggregation of Streptococcus mutans by Helichrysum italicum extract

AIMS: The purpose of the present study was to examine whether sublethal concentrations of Helichrysum italicum extract could affect some of the cariogenic properties of Streptococcus mutans. METHODS AND RESULTS: We studied the antibacterial activity of H. italicum (ethanolic extract) against oral streptococci (Strep. mutans ATCC 35668, Strep. salivarius ATCC 13419 and Strep. sanguis ATCC 10556) and its influence on cell-surface hydrophobicity, in vitro sucrose-dependent adherence to glass surface and cellular aggregation of Strep. mutans. The results indicate that all streptococci were susceptible to ethanolic extract with minimum inhibitory concentration (MIC) values of 31.25-62.50 microg x ml(-1). Sub-MIC concentrations of H. italicum (7.81-31.25 microg x ml(-1)) reduced the hydrophobicity and the adherence (almost 90%) to glass surface of Strep. mutans. The aggregation in the presence of dextran T2000 was also affected. CONCLUSION: The inhibitory activity of H. italicum extract on Strep. mutans is worthy of further study. SIGNIFICANCE AND IMPACT OF THE STUDY: There is considerable interest in the use of natural compounds as alternative methods to control undesirable micro-organisms.     

Different antibacterial actions of isoflavones isolated from Erythrina poeppigiana against methicillin-resistant Staphylococcus aureus

AIMS: To screen six isoflavones isolated from Erythrina poeppigiana (Leguminosae) for their antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). METHODS AND RESULTS: Stem bark of E. poeppigiana was macerated with acetone and the methylene chloride-soluble fraction of the residue was applied to repeated silica gel column chromatography and eluted. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by a broth dilution method. Inactive compounds that failed inhibiting bacterial growth at 25 microg ml(-1) were further investigated for their combination effects with methicillin and oxacillin. Of the isolated isoflavones, 5,7,4'-trihydroxy-8,3'-di(gamma,gamma-dimethylallyl)isoflavone (isolupalbigenin) exhibited the highest anti-MRSA activity (MICs: 1.56-3.13 microg ml(-1); MBCs: 6.25-12.5 microg ml(-1)), followed by 5,7,4'-trihydroxy-6-gamma,gamma-dimethylallylisoflavone (erythrinin B). Inactive compounds were combined with methicillin or oxacillin, 5,4'-dihydroxy-(3',4'-dihydro-3'-hydroxy)-2',2'-dimethylpyrano[5',6':6,7]isoflavone (M-Wi-2) intensifying the susceptibility of MRSA strains to these antibiotics. In all but one strain, the MIC values of methicillin were reduced from > or =100 to 6.25-12.5 microg ml(-1) in the presence of M-Wi-2 (25 microg ml(-1)). CONCLUSIONS: Isoflavones from E. poeppigiana showed two different antibacterial activities against MRSA: direct growth inhibition and intensification of methicillin sensitivity. SIGNIFICANCE AND IMPACT OF THE STUDY: Isolupalbigenin and M-Wi-2 could lead to the development of compounds for new approaches against MRSA infection.     

Inhibiting effect of Dorstenia asaroides extracts on cariogenic properties of Streptococcus mutans

The aim of this study was to examine the effects of Dorstenia asaroides extracts on cariogenic properties of the most cariogenic bacteria, Streptococcus mutans. Hexane (HFr), ethyl-acetate (EFr) and chloroform (CFr) extracts obtained from D. asaroides rhizomes were submitted to chemical analyses, Minimal Inhibitory Concentrations (MIC), glycolysis assay and S. mutans 12-h-old initial biofilms. Chemical characterization showed that all the extracts present furanocoumarins. The MIC values were 80 (HFr and CFr) and 50 μg/mL (EFr). Acid production by S. mutans cells was significantly disrupted by HFr (12.5 mg/mL), EFr (at 2.5; 6.25 and 12.5 mg/mL) and CFr (at 2.5, 6.25 and 12.5 mg/mL) (p < 0.01). Topical applications of HFr, EFr and CFr significantly reduced the colony forming units of S. mutans biofilms compared with those treated with control group in order to 20, 30 and 25% respectively (p < 0.01). The results of the present study suggest that rhizomes of D. asaroides had inhibitory effects on cariogenic properties of S. mutans.     

Erythrina poeppigiana-derived phytochemical exhibiting antimicrobial activity against Candida albicans and methicillin-resistant Staphylococcus aureus

AIMS: To screen five phytochemicals isolated from Erythrina poeppigiana (Leguminosae) for antimicrobial activity against both Candida albicans and methicillin-resistant Staphylococcus aureus (MRSA). METHODS AND RESULTS: Roots of E. poeppigiana were macerated with acetone and the chloroform-soluble fraction of the residue was subjected to repeated silica gel column chromatography using various eluting solvents. Structures of the isolated compounds were determined by extensive spectroscopic studies. Each compound was dissolved in dimethyl sulphoxide and added to agar plates (final concentration: 1.56-100 microg ml(-1)) and minimum inhibitory concentrations (MICs) against C. albicans and MRSA were determined. Spectral data indicated the presence of three different types of phytochemicals; isoflavonoids (erypoegin A, demethylmedicarpin and sandwicensin), alpha-methyldeoxybenzoin (angolensin) and cinnamylphenol (erypostyrene). While all compounds showed anti-MRSA activity in this concentration range, isoflavonoids and alpha-methyldeoxybenzoin failed to inhibit the growth of C. albicans. Erypostyrene (E-1-[2-hydroxy-4-methoxy-5-(gamma,gamma-dimethylallyl)benzyl]-2-(4-hydroxyphenyl)ethylene) exhibited not only the highest anti-MRSA activity (MIC value of 6.25 microg ml(-1)) but also anti-candidal potency (MIC value of 50 microg ml(-1)). The compound reduced viable cell numbers of C. albicans and MRSA by approximately 1 of 2000 and 1 of 1000 after 1 h incubation at each MIC, respectively. CONCLUSIONS: A new cinnamylphenol, erypostyrene, possessed anti-candidal and anti-MRSA activity. SIGNIFICANCE AND IMPACT OF THE STUDY: Erypostyrene could be a leading candidate for development of antimicrobial agents with anti-candidal and anti-MRSA activity.     

Chemical compositions and antimicrobial activities of four different Anatolian propolis samples

Propolis means a gum that is gathered by bees from various plants. It is known for its biological properties, having antibacterial, antifungal and healing properties. The aims of this study were to evaluate the antimicrobial activity of four different Anatolian propolis samples on different groups of microorganisms including some oral pathogens and comparison between their chemical compositions. Ethanol extracts of propolis (EEP) were prepared from four different Anatolian propolis samples and examined whether EEP inhibit the growth of the test microorganisms or not. For the antimicrobial activity assays, minimum inhibitory concentrations (MIC) were determined by using macrodilution method. The MIC values of the most effective propolis (TB) were 2 microg/ml for Streptococcus sobrinus and Enterococcus faecalis, 4 microg/ml for Micrococcus luteus, Candida albicans and C. krusei, 8 microg/ml for Streptococcus mutans, Staphylococcus aureus, Staphylococcus epidermidis and Enterobacter aerogenes, 16 microg/ml for Escherichia coli and C. tropicalis and 32 microg/ml for Salmonella typhimurium and Pseudomonas aeruginosa. The chemical compositions of EEP's were determined by high-temperature high-resolution gas chromatography coupled to mass spectrometry. The main compounds of four Anatolian propolis samples were flavonoids such as pinocembrin, pinostropin, isalpinin, pinobanksin, quercetin, naringenin, galangine and chrysin. Although propolis samples were collected from different regions of Anatolia all showed significant antimicrobial activity against the Gram positive bacteria and yeasts. Propolis can prevent dental caries since it demonstrated significant antimicrobial activity against the microorganisms such as Streptococcus mutans, Streptococcus sobrinus and C. albicans, which involves in oral diseases.     

The in vitro effect of manuka honeys on growth and adherence of oral bacteria

Honey has been used since ancient times and more recently, for the healing of wounds and against infectious diseases. The aim of our study was to investigate the effect of two manuka honeys showing different potencies of their antibacterial activity, on potentially pathogenic oral bacteria. The antimicrobial activity was examined by determining the MIC and MBC using the macro dilution broth technique. The effect on the adherence was tested on growing cells of Streptococcus mutans on a glass surface and on a multi-species biofilm grown on saliva-coated hydroxyapatite discs. As expected, the antibacterial activity of manuka 1 (with higher potency of antibacterial activity) was the most important. The two tested honeys weakly inhibited the adherence of S.mutans cells to a glass surface at sub-MIC concentration. Manuka 1 showed a total inhibition of multi-species biofilm at the concentration of 200 μg/ml manuka 2 inhibited biofilm formation weakly at the concentration of 200 μg/ml but firmly at the concentration of 500 μg/ml. Our findings suggest that manuka honeys might be able to reduce oral pathogens within dental plaque. These two honeys appear to be able to control dental biofilm deposit.     

Effects of compounds found in Nidus Vespae on the growth and cariogenic virulence factors of Streptococcus mutans

Nidus Vespae (honeycomb) is a kind of traditional Chinese medicine that has been demonstrated to inhibit the growth and acid-production of oral cariogenic bacteria. Subsequent studies showed that the chloroform/methanol (Chl/MeOH) chemical extraction of Nidus Vespae was the most effective inhibitor of growth and acidogenicity of Streptococcus mutans. In this study, we isolated the chemical compounds of the Nidus Vespae Chl/MeOH extraction, tested their antimicrobial activity against six cariogenic bacteria and further evaluated the acid inhibition properties, anti-F-ATPase activity and anti-LDH activity against S. mutans. The isolated flavonoids, quercetin and kaempferol, inhibited the growth of bacteria (S. mutans, Streptococcus sobrinus, Streptococcus sanguis, Actinomyces viscosus, Actinomyces naeslundii and Lactobacillus rhamnosus) with minimum inhibitory concentrations (MICs) ranging from 1 to 4 mg/ml and minimum bactericidal concentrations (MBCs) from 4 to 16 mg/ml. In addition, quercetin and kaempferol at sub-MIC levels significantly inhibited acidogenicity and acidurity of S. mutans cells. Treated with the test agents, the F-ATPase activity was reduced by 47.37% with 1mg/ml quercetin and by 49.66% with 0.5mg/ml kaempferol. The results showed that quercetin and kaempferol contained in Chl/MeOH extraction presented remarkably biological activity, suggesting that Nidus Vespae might be useful as a potential preventive and therapeutic agent in dental caries.     

Antimicrobial effect of Korean propolis against the mutans streptococci isolated from Korean

The aim of this study was to determine the optimal concentration of Korean propolis against clinical isolates of mutans streptococci (MS) from Koreans. The antimicrobial activity was evaluated using the minimum inhibitory concentration (MIC) and time-kill curves against mutans streptococci. The MIC(90) values of propolis for MS were 35 μg/ml. Propolis had a bacteriostatic effect on Streptococcus mutans ATCC 25175(T) and bactericidal effects on Streptococcus sobrinus ATCC 33478(T) at > 2 × MIC (70 μg/ml). These results suggest that the propolis can be used in the development of oral hygiene products for the prevention of dental caries.     

蜂胶对变形链球菌抑菌活性的研究进展

龋病是一种微生物感染性疾病,变形链球菌是引起其发生发展的主要致龋菌之一。近年来天然药物对龋病防治的研究已成为热点,而蜂胶是一种天然抗菌剂,国内外相关研究表明蜂胶对变形链球菌的生长、产酸、粘附、产胞外多糖及牙菌斑等方面有抑制的作用。本研究就蜂胶对变形链球菌的主要致龋毒力因子的作用研究作一综述。     

Antimicrobial activity of hydrophobic xanthones from Cudrania cochinchinensis against Bacillus subtilis and methicillin-resistant Staphylococcus aureus

Ten xanthones with one or two isoprenoid groups and a prenylated benzophenone isolated from roots of Cudrania cochinchinensis (Moraceae) were tested for their antimicrobial activities against Bacillus subtilis and methicillin-resistant Staphylococcus aureus (MRSA). Among these compounds, gerontoxanthone H exhibited considerable antibacterial activity against B. subtilis (MIC = 1.56 microg/ml). Four xanthones, gerontoxanthone I, toxyloxanthone C, cudraxanthone S, and 1,3,7-trihydroxy-2-prenylxanthone, showed weak antibacterial activity against the bacterium (MICs = 3.13-6.25 microg/ml). These compounds also exhibited similar MIC values against methicillin-sensitive S. aureus, MRSAs, and Micrococcus luteus.     

Effect of a novel antimicrobial peptide chrysophsin-1 on oral pathogens and Streptococcus mutans biofilms

Dental caries and pulpal diseases are common oral bacterial infectious diseases. Controlling and reducing the causative pathogens, such as Streptococcus mutans and Enterococcus faecalis, is a key step toward prevention and treatment of the two diseases. Chrysophsin-1 is a cationic antimicrobial peptide having broad-spectrum bactericidal activity against both Gram-positive and Gram-negative bacteria. In this study, we investigated the antibacterial activity of chrysophsin-1 against several oral pathogens and S. mutans biofilms and performed a preliminary study of the antimicrobial mechanism. Cytotoxic activity of chrysophsin-1 against human gingival fibroblasts (HGFs) was investigated. Minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and time-kill assay were used to evaluate the killing effect of chrysophsin-1. Scanning electron microscopy (SEM) was used to analyze morphological and membrane change in oral pathogens. Live/Dead staining, in conjunction with confocal scanning laser microscopy (CSLM), was used to observe and analyze S. mutans biofilms. MIC and MBC results demonstrated that chrysophsin-1 had different antimicrobial activities against the tested oral microbes. Lysis and pore formation of the cytomembrane were observed following treatment of the bacteria with chrysophsin-1 for 4h or 24h by SEM. Furthermore, CLSM images showed that chrysophsin-1 remarkably reduced the viability of cells within biofilms and had a significantly lethal effect against S. mutans biofilms. Toxicity studies showed that chrysophsin-1 at concentration between 8 μg/ml and 32 μg/ml had little effect on viability of HGFs in 5 min. Our findings suggest that chrysophsin-1 may have potential clinical applications in the prevention and treatment of dental caries and pulpal diseases.     

Purification and characterization of an antibacterial protein in the skin secretion of rockfish Sebastes schlegeli

An antibacterial protein in the skin secretion of rockfish (Sebastes schlegeli) was purified by lectin affinity chromatography on Con A-Sepharose and gel filtration on TSKgel G3000SW. The antibacterial protein featured the high molecular mass and selective action against Gram-negative bacteria. The molecular mass of the protein was estimated to be approximately 150 kDa in gel filtration and approximately 75 kDa by SDS-PAGE, suggesting that it is dimeric. The antibacterial principle was an acidic glycoprotein with pI 4.5, 3.4% reducing sugar and 2.8% amino sugar. Its sugar chains had N-type (high mannose-type) oligosaccharide and sialic acid components. It inhibited strongly the growth of Aeromonas salmonicida, Photobacterium damselae and Shewanella putrefaciens with a minimum inhibitory concentration (MIC) of approximately 3 microg/ml, and moderately the growth of Vibrio parahaemolyticus and A. hydrophila with a MIC of 12.5 microg/ml and 25 microg/ml, respectively. The values of the minimum bactericidal concentration were almost equivalent to those of MIC. The potent sensitivity against virulent pathogens such as A. hydrophila, A. salmonicida and P. damselae may contribute considerably to the innate host defense mechanism to combat microbes on the mucosal surfaces of the rockfish.     

Antibacterial activity of triterpene acids and semi-synthetic derivatives against oral pathogens

Triterpene acids (ursolic, oleanoic, gypsogenic, and sumaresinolic acids) isolated from Miconia species, along with a mixture of ursolic and oleanolic acids and a mixture of maslinic and 2-a-hydroxyursolic acids, as well as ursolic acid derivatives were evaluated against the following microorganisms: Streptococcus mutans, Streptococcus mitis, Streptococcus sanguinis, Streptococcus salivarius, Streptococcus sobrinus, and Enterococcus faecalis, which are potentially responsible for the formation of dental caries in humans. The microdilution method was used for the determination of the minimum inhibitory concentration (MIC) during the evaluation of the antibacterial activity. All the isolated compounds, mixtures, and semi-synthetic derivatives displayed activity against all the tested bacteria, showing that they are promising antiplaque and anticaries agents. Ursolic and oleanolic acids displayed the most intense antibacterial effect, with MIC values ranging from 30 microg/mL to 80 microg/mL. The MIC values of ursolic acid derivatives, as well as those obtained for the mixture of ursolic and oleanolic acids showed that these compounds do not have higher antibacterial activity when compared with the activity observed with either ursolic acid or oleanolic acid alone. With regard to the structure-activity relationship of triterpene acids and derivatives, it is suggested that both hydroxy and carboxy groups present in the triterpenes are important for their antibacterial activity against oral pathogens.     

Antimicrobial actions of α-mangostin against oral streptococci

The increasing prevalence of dental caries is making it more of a major world health problem. Caries is the direct result of acid production by cariogenic oral bacteria, especially Streptococcus mutans. New and better antimicrobial agents active against cariogenic bacteria are badly needed, especially natural agents derived directly from plants. We have evaluated the inhibitory actions of α-mangostin, a xanthone purified from ethanolic extracts of the tropical plant Garcinia mangostana L., by repeated silica gel chromatography. α-Mangostin was found to be a potent inhibitor of acid production by S. mutans UA159, active against membrane enzymes, including the F(H+)-ATPase and the phosphoenolpyruvate - sugar phosphotransferase system. α-Mangostin also inhibited the glycolytic enzymes aldolase, glyceraldehyde-3-phosphate dehydrogenase, and lactic dehydrogenase. Glycolysis by intact cells in suspensions or biofilms was inhibited by α-mangostin at concentrations of 12 and 120 μmol·L?1, respectively, in a pH-dependent manner, with greater potency at lower pH values. Other targets for inhibition by α-mangostin included (i) malolactic fermentation, involved in alkali production from malate, and (ii) NADH oxidase, the major respiratory enzyme for S. mutans. The overall conclusion is that α-mangostin is a multitarget inhibitor of mutans streptococci and may be useful as an anticaries agent.     

The effect of statherin and its shortened analogues on anaerobic bacteria isolated from the oral cavity

The susceptibility (MIC) of 44 strains of anaerobic bacteria isolated from the oral cavity and 3 standard strains to statherin and its C-terminal fragments with sequences QYQQYTF, YQQYTF, QQYTF, QYTF and YTF was determined by means of plate dilution technique in Brucella agar with 5% content of defibrinated sheep's blood, menadione and hemin. The culture was anaerobic. As shown, at concentrations from 12.5 to 100 microg/ml statherin and its C-terminal fragments inhibited the growth of anaerobic bacteria isolated from the oral cavity. Peptostreptococcus strains were the most susceptible to statherin and YTF (MIC < or = 12.5 mg/ml), whereas the most susceptible to the peptides investigated were Fusobacterium necrogenes and Fusobacterium necrophorum strains: QYQQYTF, YQQYTF, QQYTF, QYTF (MIC < or = 12.5 microg/ml). Prevotella oralis, Bacteroides forsythus and Bacteroides ureolyticus strains exhibited the lowest susceptibility (MIC > 100 microg/ml). When analysing the bacteriostatic activity of statherin it should be pointed out that the concentrations of this peptide used in microbiological investigations are within the range of physiological concentrations determined for whole saliva when at rest and stimulated in healthy donors of 19-25 years of age. Since the anaerobes investigated may be involved in the diseases of periodontum, the results presented seem to have also a practical aspect, i.e. a possibility to apply the C-terminal fragments of statherin as a novel therapeutic agent, affecting favourably the oral cavity.