Effect of Magnolia Officinalis Extract on Cariogenic Activity of Mutans Streptococci

目的：从中药厚朴中提取抗变链活性成分,并研究其对变形链球菌致龋特性的影响。方法：本研究应用薄层层析,萃取分离,硅胶色谱柱层析等现代中药化学实验方法,从生药厚朴中提取出有效成分MO2,用微量液体稀释法检测不同血清型变形链球菌对MO2的敏感性。以S.mutans MT703和S.sobrinus B13为实验菌株,分析MO2对其细胞表面疏水能力和合成水不溶性葡聚糖能力的影响。结果：MO2能降低细胞表面疏水率,抑制葡糖基转移酶催化合成水不溶性葡聚糖。随着MO2浓度的升高,细胞表面疏水率下降;80μg/ml的MO2对S.mutansMT703合成水不溶性葡聚糖的抑制率为45.4%,对S.sobrinusB13合成水不溶性葡聚糖的抑制率达43.5%。结论：厚朴提取物MO2对变形链球菌致龋能力有较强抑制作用。     

Cariostatic activity of cacao mass extract

Chocolate is suspected to contain some caries-inhibitory substances. The cariostatic activity of cacao mass extract (CM), the main component of chocolate, was examined in vitro and in experimental animals. CM showed no detectable effects on the cellular growth and acid production of mutans streptococci. On the other hand, the cell-surface hydrophobicity of mutans streptococci was significantly reduced by the presence of CM. Furthermore, insoluble glucan synthesis by the glucosyltransferases from either Streptococcus mutans MT8148R or Strep. sobrinus 6715 was inhibited by CM, but not significantly. Hence, the sucrose-dependent cell adherence of mutans streptococci was also depressed by CM. Finally, CM in both a 40% sucrose diet and drinking water resulted in reductions of caries development and plaque accumulation in rats infected with Strep. sobrinus 6715, but not significantly. These results indicate that cacao mass extract possesses some anticariogenic potential, but its anticaries activity is not strong enough to suppress significantly the cariogenic activity of sucrose.     

Anticaries effect of a component from shiitake (an edible mushroom)

The caries-inhibiting effect of the extract from shiitake (Lentinus edodes), the most popular edible mushroom in Japan, was studied both in vitro and in vivo. Shiitake extract showed an inhibitory effect on water-insoluble glucan formation from sucrose by crude glucosyltransferases of Streptococcus mutans JC-2 and Streptococcus sobrinus OMZ-176. The firmly adherent plaque in the artificial plaque formation test was strongly inhibited by shiitake extract. The reduction of firmly adherent plaque caused an increase in the incidence of non- and loosely adherent plaque and a decrease in total plaque formation. A significantly lower caries score was observed in specific pathogen-free rats infected with S. mutans JC-2 and fed with a cariogenic diet containing 0.25% shiitake extract as compared with controls fed the cariogenic diet without shiitake extract.     

柠檬提取物对口腔致龋菌生长影响的研究

目的:检测柠檬提取物的生物安全性,研究柠檬提取物对主要致龋菌生长的影响,为进一步机制研究提供依据。方法:柠檬提取物ICR小鼠急性毒性试验(LD50试验):实验分两组,实验组柠檬水提浓缩液按0.05ml/10g.bw灌胃,空白对照组室温、阳光等饲养条件与实验组相同。饲养14d观察动物反应,第15天处死,解剖检查脏器情况;采用琼脂稀释法研究柠檬提取物对5种主要致龋菌(变异链球菌、血链球菌、内氏放线菌、远缘链球菌、嗜酸乳杆菌)生长的抑制作用,并采用菌落计数法检测柠檬提取物对5种细菌生长的影响。结果:ICR小鼠在14d观察期中未发现死亡现象,处死后检查各脏器无异常现象。柠檬提取物对变异链球菌、血链球菌、远缘链球菌的最小抑菌浓度MIC(minimum inhibitory concentration)为4.5g/L,对嗜酸乳杆菌和内氏放线菌的MIC为2.25g/L。5种致龋菌在柠檬提取物作用下,其生长曲线均在第6小时左右出现明显的转折点,实验组与阴性组的细菌菌量均有显著性差异(P<0.05)。结论:柠檬提取物样品LD50大于5000mg/kg.bw,属于实际无毒物质;柠檬提取物对口腔致龋菌的生长有抑制作用。     

对氨基苯甲酸对变形链球菌表面疏水性的影响

目的　研究血链球菌合成的生态调节因子---对氨基苯甲酸(PABA)对变形链球菌细胞表面疏水性的影响,从而进一步了解PABA影响细菌粘附的机制。方法　在不同PABA浓度(10-9g/L、10-7g/L、10-4g/L)的改良Carls- son液体培养基中厌氧培养变形链球菌,并采用微生物粘着碳氢化合物法测试细胞表面疏水性。结果　低浓度的 PABA可增强变形链球菌细胞表面疏水性,当浓度增加到一定范围则可降低其细胞表面疏水性。结论　PABA可能通过降低细菌非特异性疏水作用而抑制变形链球菌的粘附。     

抗变形链球菌鸡卵黄抗体对变形链球菌合成葡聚糖影响的实验研究

目的 研究抗变形链球菌鸡卵黄抗体（IgY）对变形链球菌合成葡聚糖的影响。方法 用蒽酮法测定各浓度组IgY使用后，定量菌在单位时间内合成葡聚糖的量。结果 IgY抗体对血清c型及血清g型变形链球菌合成胞外多糖均有影响，各浓度组IgY对合成胞外多糖的影响力有随着浓度升主而增强的趋势。1：16浓度组起有效，1：2浓度组的抑制作用最强（P＜0.05）。结论 IgY可以减少变链菌合成葡聚糖。     

In vitro effects of crude khat extracts on the growth, colonization, and glucosyltransferases of Streptococcus mutans

Millions of Yemenites, East Africans, and immigrants to Western countries chew khat daily for its amphetamine-like effects. There is little information in the literature concerning the possible effects of the habit on oral microbiota. Our objective was to study in vitro crude khat extract effects on Streptococcus mutans growth and sucrose-dependent colonization, and on its glucosyltransferase (GTF) activity and production. Three khat cultivars were used. Lyophilized crude aqueous khat extracts were applied to the different assays at concentrations of 0-1% (w/v). Sucrose-dependent colonization was assessed as the ability of Streptococcus mutans UA159 to form adherent biofilms in glass culture tubes. Colony forming units (CFUs) in the planktonic phase served as a measure of bacterial growth, while CFUs in the biofilm phase were used to quantify viability in the biofilms. GTFs activity was tested by incubating a crude GTFs preparation with sucrose and determining the amount of water-soluble and water-insoluble glucans formed. GTFs production was assayed by comparing intensities of GTF bands in Western blots of extracts from control and khat-containing cultures. The khat extracts effectively inhibited biofilm formation. The minimum biofilm inhibitory concentration (MBIC) varied among the cultivars (0.25-1%). The extracts also inhibited synthesis of both glucan types, particularly insoluble glucans (average 85% inhibition at 1%), with significant differences among the cultivars. However, khat increased bacterial growth and at sub-MBIC also viability within biofilms; there were no inter-cultivar differences. It is shown that khat leaves contain water-soluble constituents that inhibit some cariogenic properties of S. mutans in vitro.     

The antibacterial activity of plant extracts containing polyphenols against Streptococcus mutans

The minimum inhibitory concentrations (MIC) of commercially available and 70% aqueous propanone (P70) extracts from plants chosen for polyphenol content on Streptococcus mutans and other bacteria were determined using a standard susceptibility agar dilution technique to investigate their potential use as anticariogenic agents. The effects on adhesion of S. mutans to glass were also studied. The lowest MICs were for the P70 extracts of red grape skin (0.5 mg ml(-1)) and green tea and sloe berry skin (2 mg ml(-1)). The commercial extracts generally had a lower activity with a minimum MIC of 2 mg ml(-1) for tea extracts, grape seed extracts and Pynogenol (extract of maritime pine). All other extracts had MICs of > or = 4 mg ml(-1). Unfermented cocoa had greater antimicrobial activity than fermented cocoa and the activity of the fractionated extract increased with the extent of epicatechin polymerization. Epicatechin polymer had an MIC of 1 mg ml(-1) and an MBC of 64 mg ml(-1). Selected extracts were tested against other oral bacteria and showed activity against gram-positive organisms. P70 extracts of unfermented cocoa, epicatechin polymer fraction, green tea and red grape seed were bacteriostatic and prevented acid production when added at the MIC to cultures of S. mutans grown in a chemically defined medium supplemented with either glucose or sucrose. There was a reduction in viability which was greater when added to washed cells, but there were some viable cells after 24 h. The extracts also reduced adherence of S. mutans to glass.     

蜂胶抑制变形链球菌生长和粘附的体外研究

目的:研究蜂胶对变形链球菌生长和粘附的影响.方法:①抑菌实验;分别将水溶性蜂胶和醇溶性蜂胶提取物等比稀释,采用钢管琼脂扩散法对变形链球菌和远缘链球菌做抑菌实验,测定最小抑菌浓度.②粘附抑制实验:在含不同浓度水溶性和醇溶性蜂胶,洗必泰,乙醇的轻唾液体培养基中培养变形链球菌,8天后测定粘附于毛细管表面变形链球菌量,并进行比较.结果:对变形链球菌和远缘链球菌最小抑菌浓度分别是:水溶性蜂胶为0.031625%和0.25%;醇溶性蜂胶均为0.078%.蜂胶各组及洗必泰组均可显著抑制变形链球菌的粘附(P＜0.05),0.5%水溶性蜂胶组,醇溶性蜂胶组及洗必泰组抑制粘附作用更强,三组之间无显著性差异(P＞0.05).结论:水溶性蜂胶和醇溶性蜂胶对变形链球菌生长和粘附都有显著的抑制作用.     

Anti-caries effects of polyphenol compound from Camellia sinensis

Polyphenol compound (designated Sunphenon) from leaf of Camellia sinensis have been partially purified by extraction of the boiling water with ethyl acetate. The effect of Sunphenon on cariogenic Streptococcus mutans groups (serotype c and g) was studied in both in vitro and in vivo. The summary of results were described as follows; 1) Addition of Sunphenon to S. mutans JC-2 (c) caused a decrease in cell viability. The activity of Sunphenon showed that multiple application are required for killing and maximum effect was seen between 60 and 90 min treatment. However, treatment of S. mutans with Sunphenon did not induce complete cell death after 90 min incubation. 2) When S. mutans JC-2 (c) was pretreated with Sunphenon, the cellular attachment on saliva-treated hydroxyapatite surface was significantly reduced. 3) When saliva-treated hydroxyapatite surface was pretreated with Sunphenon, the cellular attachment of S. mutans JC-2 (c) was also markedly inhibited. 4) Sunphenon had no inhibitory effect on lactic acid production by S. mutans JC-2 (c). 5) Sunphenon showed a strong inhibitory effect against water-insoluble glucan synthesis by glucosyltransferase from S. mutans JC-2 (c) or S. sobrinus 6715 (g). 6) specific pathogen-free rats infected with S. mutans JC-2 (c) and fed a cariogenic diet containing 0.5%. Sunphenon developed significantly fewer carious lesions than controls infected with S. mutans and fed the same diet without Sunphenon. Furthermore, feeding of the drinking water containing 0.1% Sunphenon reduced caries incident in S. mutans in infected animals.     

壳寡聚糖对变形链球菌表面疏水性的影响

目的:研究壳寡聚糖对变形链球菌细胞表面疏水性的影响,从而进一步了解壳寡聚糖影响细菌黏附的机制。方法:使用不同浓度(10-2、10-1、1g/L)的壳寡聚糖溶液处理变形链球菌,并采用微生物黏着碳氢化合物法测试细胞表面疏水性。结果:随壳寡聚糖浓度增加,变形链球菌ATCC25175细胞表面疏水性有显著性降低。结论:壳寡聚糖可能通过降低细菌表面疏水作用而抑制变形链球菌的黏附。     

Effects of antibodies against a fusion protein consisting of parts of cell surface protein antigen and glucosyltransferase of Streptococcus sobrinus on cell adhesion of mutans streptococci

BACKGROUND/AIMS: The cell surface protein antigen (PAg) and glucosyltransferases (GTFs) produced by Streptococcus sobrinus are considered to be major colonization factors of the organism. METHODS: We constructed a fusion gene encoding a protein composed of the alanine-rich region of PAg (PAgA) and the glucan-binding domain (GB) of GTF-I, which catalyzes the synthesis of water-insoluble glucan in S. sobrinus. The fusion protein PAgA-GB was purified from cell extracts of Escherichia coli harboring the fusion gene, and antibodies against the fusion protein were prepared in rabbits. RESULTS: In the presence of sucrose, the antibody against PAgA-GB significantly inhibited the adhesion of both S. sobrinus MT8145 and Streptococcus mutans Xc to saliva-coated hydroxyapatite beads, and the inhibitory effect on S. sobrinus was stronger than that on S. mutans. In the absence of sucrose, the antibody against PAgA-GB significantly inhibited the adhesion of both S. sobrinus and S. mutans, however the inhibitory effect on S. sobrinus was unexpectedly weaker than that on S. mutans. A similar result was observed with the antibody against the intact recombinant PAg protein (rPAg), while the same antibody reacted more strongly against S. sobrinus than against S. mutans cells. CONCLUSION: Taken together, these results show that the antibody against S. sobrinus GTF-I may be useful for effective inhibition of the sucrose-dependent adhesion of S. sobrinus. However, PAg of S. sobrinus may not function primarily as a receptor for acquired pellicles, and other cell surface proteins may be involved in the sucrose-independent adhesion of S. sobrinus.     

Anticaries effects of polyphenolic compounds from Japanese green tea.

The dental caries inhibiting effect of the extract from Japanese green tea, one of the most popular drinks in Japan, was studied both in vitro and in vivo. The crude tea polyphenolic compounds (designated Sunphenon) from the leaf of Camellia sinensis were found to effectively inhibit the attachment of Streptococcus mutans strain JC-2 (serotype c) to saliva-coated hydroxyapatide discs. Sunphenon was also inhibitory to water-insoluble glucan formation from sucrose by crude glucosyltransferase of S. mutans JC-2 (c). Among the tea catechins tested, (-)-epigallocatechin gallate and (-)-epicatechin gallate showed the most potent inhibition of the glucosyltransferase activity. Finally, significantly lower caries scores were observed in specific pathogen free rats infected with S. mutans JC-2 (c) and fed a cariogenic diet and/or drinking water containing 0.05% Sunphenon as compared with control rats not receiving polyphenolic compounds.     

The effect of Piper betle and Psidium guajava extracts on the cell-surface hydrophobicity of selected early settlers of dental plaque

The adhesion of early settlers of dental plaque to the tooth surface has a role in the initiation of the development of dental plaque. The hydrophobic surface properties of the bacteria cell wall are indirectly responsible for the adhesion of the bacteria cell to the acquired pellicle on the tooth surfaces. In this study, the effect of aqueous extract of two plants (Psidium guajava and Piper betle) on the cell-surface hydro-phobicity of early settlers of dental plaque was determined in vitro. Hexadecane, a hydrocarbon was used to represent the hydrophobic surface of the teeth in the oral cavity. It was found that treatment of the early plaque settlers with 1 mg/ml extract of Psidium guajava reduced the cell-surface hydrophobicity of Strep. sanguinis, Strep. mitis and Actinomyces sp. by 54.1%, 49.9% and 40.6%, respectively. Treatment of these bacteria with the same concentration of Piper betle however, showed a comparatively lesser effect (< 10%). It was also observed that the anti-adhesive effect of the two extracts on the binding of the early plaque settlers to hexadecane is concentration dependent.     

Inhibition of Streptococcus mutans adhesion to buccal epithelial cells by an aqueous extract of Thymus vulgaris

OBJECTIVES: The aim of this study was to investigate the effect of an extract of Thymus vulgaris (thyme) on the growth of Streptococcus mutans (S. mutans) and the adhesion of this bacterium to human buccal epithelial cells. METHODS: Different concentrations of an aqueous extract of thyme were prepared and the effects investigated on growth of S. mutans. Furthermore, the effect of these extracts on adhesion of S. mutans to buccal epithelial cells was also investigated and compared with the effects of chlorhexidine digluconate. RESULTS: The data revealed that exposure of S. mutans to thyme extract showed a time and concentration-dependent decrease in bacterial viability. The greatest effect was observed when S. mutans had been exposed to 20% thyme extract for a period of 48 h which resulted in 96% inhibition of bacterial growth. Furthermore, the adhesion of S. mutans to buccal epithelial cells was also reduced when either buccal epithelial cells or S. mutans had been pre-incubated with different concentrations of aqueous thyme extracts (83-98% and 75-89% inhibition respectively). There was also greater reduction in the adherence of bacterial cells to buccal epithelial cells after mouth rinsing with 20% aqueous thyme extract compared to rinsing with chlorhexidine digluconate (45% and 89% inhibition of bacterial adhesion respectively). CONCLUSION: The diminished adherence of S. mutans to buccal epithelial cells after exposure to various concentrations of aqueous thyme extract as well as the antimicrobial properties of this plant may have clinical relevance.     

紫地榆防龋活性筛选及其防龋机制初步研究

目的:研究紫地榆各提取物防龋活性和活性成分对口腔致龋菌的增殖抑制以及产酸、产多糖功能的影响.方法:以洗必泰和五倍子作为阳性对照,采用试管二倍稀释法研究紫地榆提取物对2种主要致龋菌生长和代谢的影响,先测定紫地榆5种提取物对变形链球菌(S.mutans)、黏性放线菌(A.viscosus)的最低抑菌浓度(MIC)及最低杀菌浓度(MBC),从中筛选出防龋活性部位;再测定低于MIC的4个浓度的紫地榆防龋活性部位对2种致龋菌产酸、产多糖的影响.结果:紫地榆正丁醇萃取部位对2种致龋菌抑制效果最好,对细菌产酸、产多糖均有一定的抑制作用,但作用弱于洗必泰和五倍子.结论:紫地榆正丁醇萃取部位可抑制致龋菌生长代谢,可能是一种天然防龋药物.     

Caries inhibitory activity of cacao bean husk extract in in-vitro and animal experiments

Cacao bean husk extract (CBH) was examined for inhibitory effects on the caries-inducing properties of mutans streptococci in vitro and on caries development in specific pathogen-free Sprague-Dawley rats infected with mutans streptococci. CBH reduced the growth rate of almost all oral streptococci examined, which resulted in the reduction of acid production. Furthermore, insoluble glucan synthesis by the glucosyltransferases from Streptococcus mutans MT8148R and Streptococcus sobrinus 6715 was significantly inhibited by CBH. Hence, the sucrose-dependent cell adherence of mutans streptococci was also depressed by CBH. The administration of CBH in drinking water resulted in significant reductions of caries development and dental plaque accumulation in rats infected with either Strep. sobrinus 6715 or Strep. mutans MT8148R, and the minimum cariostatic concentration was 1.0 mg/ml. These results indicate that CBH possesses powerful anticariogenic potential.     

The effect of herbal extracts in an experimental mouthrinse on established plaque and gingivitis

Abstract. The purpose of the present study was to establish in vitro the inhibiting effect of a herbal extract mixture on a selected number of micro-organisms and to test in vivo the effect of a mouthwash containing 6.3 mg/ml herbal extract mixture on plaque and gingivitis as compared to a minus active control mouthrinse. The herbal extract was a mixture of: Juniperus communis (juniper), Urtica dioca (nettle), Achillaea millefolium (yarrow); 1:1:1. In the study, in-vitro, the effect of pure herbal extract mixture on acid production of Streptococcus mutans was tested and the minimum inhibitory concentrations (MIC) of the following micro-organisms were tested: Streptococcus mutans, Streptococcus mitis, Actynomyces viscosus, Actynomyces naeslundii, Actinobacillus actinomycetemcomitans, Prevotella intermedia, Campylobacter rectus, Fusobacterium nucleatum, Veillonella parvula. The MIC-values for A. viscosus and P. gingivalis were 100 mg/ml. The MIC-values for A. naeslundii and A. actinomycetemcomitans were considerably lower (10 mg/ml). S. mitis was the most susceptible of the tested organisms to the extract with a MIC value of 1 mg/ml. S. mutans, C. rectus, V. parvula, and F. nucleatum were not influenced by the extracts. No inhibitory effect of the 6.3 mg/ml herbal extract mixture was observed on the acid production of S. mutans. For the study in-vivo, 45 volunteers were selected on the basis of having moderate gingival inflammation. As efficacy parameters the plaque index, modified gingival index and angulated bleeding index were assessed. The subjects were randomly divided among 3 experimental groups (2× test and 1‘minus active’control). The participants were requested to rinse with 10 ml of mouthwash twice a day for a period of three months. After 6 weeks and 3 months, the same clinical indices as at baseline were recorded. The results show no difference between the two test groups and the control group. In conclusion, the results of the present study have shown that the mixture of the 3 herbal extracts, Juniperus communis, Urtica dioca and Achillaea millefolium when used in a mouthrinse has no effect on plaque growth and gingival health.     

口腔常见致病菌的表面疏水性分析

目的：分析测试几种口腔常见致病菌的细胞表面疏水性，为研究细菌非特异性黏附机制提供科学理论参数。方法：采用碳氢化合物黏着法测试细菌表面疏水性。结果：不同种类的细菌、同种细菌的不同菌株间疏水性均存在差异。每株细菌表面具有其相对稳定的参考值范围。结论：口腔细菌具有强弱不同的疏水作用。     

Inhibitory activity of garlic (Allium sativum) extract on multidrug-resistant Streptococcus mutans

Garlic (Allium sativum) extract has been known to have inhibitory activity on various pathogenic bacteria, viruses and fungi. The objective of present investigation was to study in vitro inhibitory activity of garlic extract on multidrug-resistant (MDR) strains of Streptococcus mutans isolated from human carious teeth. Filter sterilized aqueous extract of garlic was prepared and used in the present study. For isolation of S. mutans, extracted human carious teeth were cultured in Todd-Hewit broth and Mitis-Salivarius-Bacitracin agar. S. mutans was characterized by colony morphology, biochemical tests and other conventional bacteriological procedures. Disk sensitivity tests and broth dilution methods were used to determine antibiotic sensitivity profile and inhibitory activity of garlic extract on S. mutans isolated from carious teeth. Of 105 carious teeth tested, 92 (87.6%) isolates of S. mutans were recovered, among which 28 (30.4%) were MDR since they were resistant to four or more antibiotics. The highest rate of resistance was observed for tetracycline (30.4%) and least resistance (0%) to teichoplanin and vancomycin while 22.8% and 23.9% of the isolates were resistant to penicillin and amoxicillin, respectively. Chlorhexidine minimum inhibitory concentration (MIC) for MDR and non-MDR S. mutans varied from 2 to 16 microg ml(-1) and from 0.25 to 1 microg ml(-1), respectively (P<0.05). All isolates, MDR and non-MDR of S. mutans were sensitive to garlic extract with the MIC ranging from 4 to 32 microg ml(-1). Considering in vitro data obtained in the present study, mouthwashes or toothpaste containing optimum concentration of garlic extract could be used for prevention of dental caries.