[Research Progress in Niacinamide in the Prevention and Treatment of Mouth and Systemic Diseases].

Nicotinamide (NAM) is the amide form of niacin and one of the precursors of nicotinamide adenine dinucleotide (NAD +). NAM can be used as a dietary supplement or clinical therapeutic drug to replenish NAD + levels in the human body and participate in key bodily functions such as cellular metabolism and DNA repair. NAM has the advantage of low cost, wide availability, and sound biosafety. It also has multiple biological functions, including antibacterial effect, anti-inflammatory effect, and modulation of cellular immunity, producing significant ameliorative effects on skin and neurodegenerative diseases. However, most studies on NAM are still at the laboratory stage. Herein we reviewed the role and mechanism of NAM in the prevention and treatment of oral and systemic diseases, explored its potential as clinical therapeutic medication, provided some basis and references for the clinical application of nicotinamide in the prevention and treatment of various diseases, and discussed its prospects for future research and application.

[Effects of Artemisinin and Its Derivatives on Oral Microbes].

The oral environment provides suitable conditions for the colonization of various microorganisms. However, the oral microbials could be the initial factors of some kinds of oral infectious diseases, therefore the treatment against oral microbial pathogens has become an effective strategy. Artemisinin, a kind of sesquiterpene lactone extracted from Traditional Chinese Medicine Artemisia annua L., is the first-line therapy to treat tertian malaria, subtertian malaria and anti-chloroquine malaria for its high efficiency and low toxicity. In recent years, artemisinin and its derivatives have also been proven to be effective against bacteria, fungi, viruses, parasites, and tumors, some of which are closely related to oral diseases. In this review, we summarize the potential effects of artemisinin and its derivatives on oral microorganism by analyzing previous research and latest progress to provide the evidence for further improvement, and look forward to the new research directions. Further studies are needed to improve existing technologies and standards to clarify the effects of artemisinin and its derivatives on microorganisms with controversial effects, to expand the detection of microorganisms associated with oral infectious diseases, and to clarify the interaction with existing antifungal agents in the field of antifungal diseases. In addition, in the study of anti-oral infectious diseases, artemisinin and its derivatives' administration scheme, potential drug interactions, toxic and side effects and other aspects are necessary conditions for further research, which is also a new direction of research. With the maturity of the production process, the improvement of relevant research and the potential demand for the treatment of oral infectious diseases, artemisinin and its derivatives have a broad prospect in the field of oral microorganisms, and provide a new opportunity for the research and development of oral drugs.

[Research progress on the regulation of phenolic compounds of traditional Chinese herbs on oral microbes].

Phenolic compounds are widely found in natural Chinese medicinal plants and have excellent pharmacological properties, such as antioxidation and anti-inflammation. They are the main pharmacological components of many medicinal Chinese herbs. Oral microbiota, especially its composition and metabolism, is highly related to the balance of oral microecology and plays a key role in the occurrence and development of oral diseases. Recent studies have shown that phenolic compounds of traditional Chinese herbs can prevent and treat oral diseases, such as caries, periodontal disease, and oral mucosal infection, by regulating the composition, metabolites, and virulence of oral microorganisms. This review will summarize and discuss the regulation of phenolic compounds on oral microbes.

[Berberine regulates type 2 diabetes mellitus related with insulin resistance].

Insulin resistance (IR) is defined as a series of clinical manifestations for diminished effectiveness of insulin in lowering blood sugar levels caused by decreased sensitivity to insulin of liver, muscle and adipose tissue. IR is the major contributor to the etiology and pathogenesis of type 2 diabetes mellitus (T2DM). Berberine, a traditional Chinese herb extract, has been shown to be safe and effective in lowering blood sugar, alleviating insulin resistance and moderating type 2 diabetes mellitus and its complications. The bioavailability of berberine is extremely low, suggesting that it may play a role in lowering blood sugar and lipid by regulating intestinal flora. Intestinal microbiota may serve as a new potential target for berberine treatment of type 2 diabetes mellitus.

Galla chinensis Compounds Remineralize Enamel Caries Lesions in a Rat Model.

OBJECTIVES: To investigate the effect of Galla chinensis chemical compounds on enamel caries remineralization in rats. METHODS: A total of 40 rats were inoculated with Streptococcus sobrinus 6715 and fed a cariogenic diet (Keyes 2000). The rats were randomly divided into 4 groups and treated topically twice a day with each of the following extracts (or control) for 5 weeks: distilled and deionized water (DDW, negative control); 1,000 ppm NaF (positive control); 4,000 ppm G. chinensis crude aqueous extract (GCE), or 4,000 ppm gallic acid (GA). After the experimental period, Keyes' caries diagnosis and scoring technique was applied as a preliminary evaluation on the molar teeth. For more accurate remineralization data, the residual enamel volume of the first molar and the mineral density (MD) of the enamel were further analyzed by micro-CT. RESULTS: The severity of molar enamel caries decreased in the following order of treatment groups: DDW > GA > GCE > NaF (p < 0.05). In addition, the residual first molar enamel volume and MD values increased in the order of DDW, GA, GCE and NaF treatment groups (p < 0.05). In most molars, remineralization layers were observed on the surface of lesions. CONCLUSION: G. chinensis compounds remineralize enamel caries lesions in a rat model.

Effects of 45S5 bioglass on surface properties of dental enamel subjected to 35% hydrogen peroxide.

Tooth bleaching agents may weaken the tooth structure. Therefore, it is important to minimize any risks of tooth hard tissue damage caused by bleaching agents. The aim of this study was to evaluate the effects of applying 45S5 bioglass (BG) before, after, and during 35% hydrogen peroxide (HP) bleaching on whitening efficacy, physicochemical properties and microstructures of bovine enamel. Seventy-two bovine enamel blocks were prepared and randomly divided into six groups: distilled deionized water (DDW), BG, HP, BG before HP, BG after HP and BG during HP. Colorimetric and microhardness tests were performed before and after the treatment procedure. Representative specimens from each group were selected for morphology investigation after the final tests. A significant color change was observed in group HP, BG before HP, BG after HP and BG during HP. The microhardness loss was in the following order: group HP>BG before HP, BG after HP>BG during HP>DDW, BG. The most obvious morphological alteration of was observed on enamel surfaces in group HP, and a slight morphological alteration was also detected in group BG before HP and BG after HP. Our findings suggest that the combination use of BG and HP could not impede the tooth whitening efficacy. Using BG during HP brought better protective effect than pre/post-bleaching use of BG, as it could more effectively reduce the mineral loss as well as retain the surface integrity of enamel. BG may serve as a promising biomimetic adjunct for bleaching therapy to prevent/restore the enamel damage induced by bleaching agents.

Chemical composition of Galla chinensis extract and the effect of its main component(s) on the prevention of enamel demineralization in vitro.

To determine the chemical composition of Galla chinensis extract (GCE) by several analysis techniques and to compare the efficacy of GCE and its main component(s) in inhibition of enamel demineralization, for the development of future anticaries agents, main organic composition of GCE was qualitatively determined by liquid chromatography-time of flight-mass spectrometry (LC-TOF-MS) and quantified by high-performance liquid chromatography-diode array detector (HPLC-DAD). Inorganic ions were tested by inductively coupled plasma-atomic emission spectroscopy and F was especially measured by ion chromatography. Then, bovine enamel blocks were randomly divided into four treatment groups and were subjected to a pH-cycling regime for 12 times. Each cycle included 5-min applications with one of four treatments: 4 g⋅L(-1) GCE solution, 4 g⋅L(-1) gallic acid (GA) solution, 1 g⋅L(-1) NaF solution (positive control), deionized water (DDW, negative control), and then 60-min application in pH 5.0 acidic buffer and 5-min application in neutral buffer. Acidic buffers were retained for calcium analysis. The main organic composition of GCE were GA and its isomer, and, to a lesser extent, small molecule gallotannins. The content of GA in GCE was 71.3%±0.2% (w/w). Inorganic ions were present in various amounts, of which Ca was (136±2.82) µg⋅g(-1), and Zn was (6.8±0.1) µg⋅g(-1). No F was detected in GCE. In pH cycling, GA showed an effect similar to GCE in inhibiting enamel demineralization (P>0.05). GA was found to be the main effective, demineralization inhibiting component of GCE and could be a promising agent for the development of anticaries agents.

[Comparison of the enhanced remineralization of initial enamel carious lesions treated with original and neutral Galla chinensis in vitro].

OBJECTIVE: To compare the effect of original and neutral Galla chinensis in promoting the remineralization of initial enamel carious lesions in vitro and to investigate the influence of Galla chinensis with different pH on the promoting effect. METHODS: Bovine sound enamel slabs were demineralized to produce initial carious lesion in vitro. Then the lesions were exposed to a pH-cycling regime for 12 days. Each daily cycle included 4 × 1 min application of one of four treatments: distilled and deionized water (DDW), aqueous solutions of NaF, acidic or neutral aqueous solutions of Galla chinensis extract (GCE). Before and after pH-cycling, the surface topography of the enamel slabs was observed by atomic force microscopy (AFM), and the integrated mineral loss and lesion depth of all the specimens were analysed by transverse microradiography. RESULTS: AFM images revealed the surface topographical changes of GCE-treated enamel. The percentage change of integrated mineral loss (ΔIML%) of the samples of NaF group, DDW group, pH 3.8 GCE group and pH 7.0 GCE group was (-38 ± 14)%, (+43 ± 7)%, (-10 ± 4)% and (-11 ± 4)% respectively. The percentage of lesion depth (ΔLD%) of the samples of NaF group, DDW group, pH 3.8 GCE group and pH 7.0 GCE group was (-27.79 ± 3.51)%, (+21.13 ± 2.83)%, (-8.43 ± 3.32)% and (-9.20 ± 3.89)% respectively. There was no significant difference in ΔIML% and ΔLD% between pH 3.8 and pH 7.0 GCE-treated enamel. CONCLUSIONS: There is no significant difference in enhancement of remineralization of initial enamel carious lesions between the original and neutral Galla chinensis. Different pH Galla chinensis does not have obvious influence on remineralization. It is unnecessary to regulate the pH value of queous solution of Galla chinensis extract which acts as a anti-caries agent.

[Role of enamel organic matrix in the remineralization of initial demineralized enamel and artificial hydroxylapatite treated with Galla chinensis].

OBJECTIVE: To observe the remineralization of initial demineralized enamel and artificial hydroxylapatite treated with Galla chinensis in vitro, and to assess the effect of enamel organic matrix on the potential of Galla chinensis to promote the remineralization of initial enamel carious lesions, further to elucidate the mechanism of Galla chinensis in promoting the remineralization of initial enamel carious lesion. METHODS: Bovine sound enamel blocks, non-organic enamel blocks and artificial hydroxylapatite blocks were demineralized and exposed to a pH-cycling. During the pH-cycling, the specimens were randomly treated with 1 g/L NaF, 4 g/L Galla chinensis extract (GCE) or double deionized water (DDW). Surface microhardness of all the samples was measured before and after the pH-cycling, and percentage surface microhardness recovery (% SMHR) was calculated. The surface morphology was observed by scanning electron microscopy. RESULTS: A significant increase in microhardness (P < 0.05) with many irregular deposits and prominences on GCE treated regular enamel blocks were observed. No significant increase in that of the regular enamel treated with DDW, enamel disposed of its organic matrix or artificial hydroxylapatite treated with GCE were observed (P > 0.05). No obvious changes in the SEM images of regular enamel treated with DDW, enamel disposed of its organic matrix or artificial hydroxylapatite treated with GCE compared to those of them before pH-cycling. CONCLUSION: Galla chinensis enhances the remineralization of initial enamel carious lesions in vitro. The organic matrix of enamel was shown to play a substantial role in the observed mechanism.

Effect of Galla chinensis on enhancing remineralization of enamel crystals.

The aim of this scanning electron microscopy (SEM) study was to investigate the effect of chemical compounds of Galla chinensis (GCE, gallic acid) on the remineralization of enamel crystals in vitro. Bovine enamel blocks with an in vitro produced initial lesion were used. The lesions were subjected to a pH-cycling regime for 12 days. Each daily cycle included 4 x 1 min applications with one of six treatments: group A: 1000 ppm F aq. (as NaF, positive control); group B: deionized water (DDW, negative control); group C: 4000 ppm crude aqueous extract of GCE; group D: 4000 ppm gallic acid; group E: 4000 ppm GCE with 1000 ppm F; group F: 4000 ppm gallic acid with 1000 ppm F. The surface and vertical section of the enamel lesions were analyzed by SEM. The results indicated that the chemical compounds of G. chinensis could regulate the de-/remineralization balance through influencing the morphology and structure of enamel crystals, and the mechanisms seem to be different for GCE and gallic acid.

Root canal morphology of permanent maxillary teeth in the Han nationality in Chinese Guanzhong area: a new modified root canal staining technique.

INTRODUCTION: The purpose of this study was to investigate the canal morphology of 504 maxillary permanent teeth of subjects of Han nationality in Chinese Guanzhong area. METHODS: Maxillary permanent teeth were randomly collected in Guanzhong area. After regular preparation, the teeth were immersed into ink without preparing access cavities and then put into hyperbaric oxygen chamber (0.6 Mpa) for 2 hours to let the ink penetrate into root canal from apical foramen, apical deltas and foramen of lateral canals under stable positive pressure. After demineralization and clearing, the following observations were made: (1) number of root canals, (2) root canal configuration by using Vertucci's classification, (3) presence of lateral canals, and (4) frequency of apical deltas. RESULTS: All the teeth were well-stained, and the fine details were well-revealed. Apical deltas (12.2%-83.3%) and lateral canals (13.7%-68.8%) could be frequently found in all types of maxillary teeth. Most of central incisors (95.8%), lateral incisors (91.4%), and canines (75.4%) displayed type I canal configuration, whereas most of first premolars (87.3%) and second premolars (72.3%) possessed 2 canals with type II, IV, or VI canal configuration. The majority of distobuccal roots and palatal roots of first molars (88.9%, 97.8%), second molars (92.0%, 94.0%), and third molars (87.5%, 91.6%) possessed type I canal configuration. The prevalence of mesiobuccal roots with type I configuration was 66.7% in maxillary first molars, 82% in second molars, and 62.5% in third molars. CONCLUSIONS: The modified technique of canal staining can effectively reveal detailed root canal system. The canal configuration of maxillary teeth in subjects of Han nationality in Chinese Guanzhong area is consistent with previous reports in other races.

Chemical and crystallographic study of remineralized surface on initial carious enamel treated with Galla chinensis.

To investigate the morphologic, chemical and crystallographic characters of remineralized surface on initial carious enamel treated with Galla chinensis, scanning electron microscopy equipped with energy dispersive analysis spectroscopy were used, and X-ray microdiffraction (microzone XRD) was used for the first time to analyze in situ the microzone crystallite of remineralized surface on carious enamel. Bovine sound enamel slabs were demineralized to produce initial carious lesion in vitro. Then, the lesions were exposed to a pH-cycling regime for 12 days of remineralization. Each daily cycle included 4x1 min applications with one of the three treatments: distilled and deionized water (DDW); 1 g/L NaF; 4 g/L G. chinensis extract (GCE). After the treatments, some rod-like deposits and many irregular prominences were found on GCE-treated enamel surface, and the intensities of Ca and P signals showed a tendency to increase; Ca:P ratio was significantly higher than that of DDW-treated enamel. X-ray microdiffraction showed hydroxyapatite was still the main component of GCE-treated enamel, and the crystallinity was increased, the crystal lattice changed gently with decreased lattice parameter a. These results indicated the potential of GCE in promoting the remineralization of initial enamel carious lesions, and supported the previous hypothesis about GCE mechanism. Combined with the anti-bacteria and demineralization inhibition properties of GCE, the natural G. chinensis may become one more promising agent for caries prevention.

Effects of Galla chinensis on the surface topography of initial enamel carious lesion: an atomic force microscopy study.

To investigate the effect of Galla chinensis on the surface topography of initial enamel carious lesion, atomic force microscope (AFM) was used, and it was a new AFM application in enamel de-/remineralization research. Bovine sound enamel slabs were demineralized to produce initial carious lesion in vitro. Then, the lesions were exposed to a pH-cycling regime for 12 days. Each daily cycle included 4x1 min applications with one of three treatments: negative control group: deionized water; positive control group: 1 g/L aqueous solutions of NaF; experimental group: 4 g/L aqueous solutions of G. chinensis extract (GCE). The surface topography and roughness were investigated on the enamel slabs before and after pH-cycling by AFM. 3D AFM images revealed the surface topographical changes of GCE-treated enamel. Significant difference existed before and after the pH-cycling among the groups. AFM offers a powerful tool for enamel de-/remineralization research. The surface roughness results provide the evidences to remineralization of carious lesion, and indicate the potential of G. chinensis in promoting the remineralization. G. chinensis may become one more promising agent for caries prevention.

[Effects of the active compounds of M. officinalis on cariogenic bacteria].

OBJECTIVE: To investigate the effects of the principal biologically active compounds of M. officinalis on the growth and acid generation of the main cariogenic bacteria. METHODS: Streptococcus mutans, Streptococcus sanguis, Actinomyces naeslundii, Actinomyces viscosus, Lactobacillus rhamnosus were chosen as the experimental bacteria. The active compounds (Magnolol and Honokiol) were separated from M. officinalis and then the effects of the two agents on the growth and acid generation of the bacteria were assessed. The minimal inhibitory concentration (MIC) and the minimal biofilm eradication concentration (MBEC) of the test strains were determined by MBEC-Device. RESULTS: It was found that the growth of not only plantonic bacteria but also the biofilm were efficiently inhibited by Magnolol and Honokiol. The two agents could also inhibit the acid production of the test strains. CONCLUSION: M. officinalis may be an effective anti-caries agent, and further researches will be necessary to define its usefulness in this aspect.

[Effect of Galla Chinesis on the demineralization of dental root tissue in pH cycling model].

OBJECTIVE: To evaluate the anti-demineralization efficacy of Galla Chinesis in pH cycling model for elucidating the anti-root caries mechanism. METHOD: Anti-demineralization efficacy evaluation of the natural medicine in the pH-cycling models was used . Sound human root blocks were pH-cycled through the treatment solution, acidic buffer and neutral buffer. The cycling times for demineralization study were 12 times, 2 times per day. The acidic buffers were retained for calcium analysis by atomic adsorption spectroscopy. The sections of blocks were analysed after pH-cycling by CLSM. Treatments were 4 g x L(-1). Galla Chinesis, 1 g x L(-1) NaF solution and distilled water. RESULT: Galla Chinesis was found to inhibit the demineralization in the pH cycling model. Although the effect was not as good as fluoride, there was no significant difference between the two groups. CONCLUSION: These data suggest that Galla Chinesis could modulate the mineralisation behaviour of root tissue in a defined chemical circumstance. These findings support the proposition that Galla Chinesis may be a promising anticaries natural medicine in the future.

[Effects of traditional Chinese medicine on oral bacteria biofilm].

OBJECTIVE: To investigate the effects of compounds of Galla chinensis extract (GCE) and Nidus vespae extract-1 (WVE1) on oral bacteria biofilm structure and activity and to determine the possibility of caries prevention by the compounds. METHODS: The morphology and activity of treated-oral bacterial biofilm and untreated-oral bacterial biofilm were observed by using fluorescence microscope in combination of idio-fluorochrome to label the died and living bacteria. The visible light semiquantitative method was used to measure biomass glucosyltransferase (GTF, A620) values and to determine the effects of active compounds of GCE and NVE1 on GTF of oral bacteria biofilm. RESULTS: The living bacteria in the untreated 24 h bacterial biofilm was dominant, and only a small number of died bacteria were found, the biofilm structure was regular and clear. GCE, GCE-B and NVE1 could inhibit the bacteria in the dental biofilm, which showed significant difference with the negative control. GCE and NVE1 could also inhibit GTF activity of 24 h bacterial biofilm in comparison with the negative control. CONCLUSIONS: The traditional Chinese medicine Galla chinensis and Nidus vespae could not only inhibit bacteria growth on oral bacterial biofilm, but also function by adjusting biofilm structure, composition and GTF activity of 24 h bacterial biofilm.

[Effect of chemical compounds of Galla chinensis on enamel surface rehardening in vitro].

OBJECTIVE: To evaluate the effect of chemical compounds extracted from Galla chinensis on enamel surface rehardening in vitro. METHODS: Sixty bovine enamel blocks with early carious lesions were randomly divided into six groups: group1 treated NaF (positive control); group2 with GCE; group3 with GCE-B; group4 with GCE-B1; group5 with GCE-B2 and group6 with deionized water (negative control). The lesions were subjected to a pH-cycling regime for 12 days. Surface enamel microhardness was measured on the enamel blocks before and after demineralization. After pH-cycling, and the percentage of surface microhardness recovery (SMHR) was calculated. RESULTS: Obvious increase of the surface hardness of the enamel was observed in all the treatments except GCE-B2 and deionized water (P < 0.05). CONCLUSIONS: The present study demonstrates the potential of the three GCEs (GCE, GCE-B and GCE-B1) to effect net rehardening of artificial carious lesions under dynamic pH-cyclic conditions.

Effects of Nidus Vespae extract and chemical fractions on the growth and acidogenicity of oral microorganisms.

Nidus Vespae is the honeycomb of Polistes Olivaceous (De Geer), P. Japonicus Saussure, and Parapolybiavaria Fabricius. It is known to have a number of pharmacological effects, including antimicrobial, anti-inflammatory, anti-virus, anti-tumor and anesthetic properties. The present study evaluated the antimicrobial activity and acid inhibition properties of extracts and chemical fractions of Nidus Vespae. The raw material was first extracted using 95% ethanol/water. Subsequent fractions were prepared from this extract using cyclohexane/ethyl acetate, petroleum ether/ethyl acetate, and chloroform/methanol. For the antimicrobial activity assays, minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined using the microdilution method. The chloroform/methanol (Chl/MeOH) fraction showed the highest antibacterial activities with a MIC of 8-16mg/ml and an MBC of 16-32mg/ml. In addition, the extract and chemical fractions of Nidus Vespae showed a remarkable capacity for inhibiting the acid production of common oral bacteria at sub-MIC concentrations. Sub-MIC levels of the petroleum ether/ethyl acetate fraction significantly inhibited acid production by Streptococcus mutans ATCC 25175. The significant antiacidogenic activity demonstrated by Nidus Vespae shows it to be a promising source of novel anticariogenic agents.

[Study of susceptibility of oral bacteria biofilm to traditional Chinese drug preventing caries].

OBJECTIVE: Using MBEC-Assay to assay minimal biofilm eradication concentration (MBEC) of Galla Chinensis and Nidus Vespae to oral bacterial biofilm. To set up traditional Chinese medicine susceptibility pharmacodynamic empirical study methods of oral bacterial biofilm. METHODS: Cariogenic bacteria strains were selected (Streptococcus mutans ATCC 25175, Streptococcus sanguis ATCC 10556, Lactobacillus rhamnosus AC 413, Actinomyces naeslundii WVU 627) in this study. Extraction components of Galla Chinensis were GCE (aqueous extract), GCE-B (30% alcohol extract) and extraction components of Nidus Vespae were NVE1 (95% alcohol extract). (1) To observe oral bacterial biofilm formatiom in MBEC-Device at different time. (2) MBEC-HTP-Assay: The minimal inhibitory concentration (MIC) and minimal biofilm eradication concentration (MBEC) of GCE, GCE-B and NVE1 to oral bacteria strains were determined. RESULTS: Oral bacterial biofilm were readily formed on the lid of MBEC-Device under selected condition (observed by SEM). Oral cariogenic bacteria growing as plankton populations were sensitive to GCE, GCE-B and NVE1. To GCE, GCE-B and NVE1, oral cariogenic bacterial biofilm were 2-16 times less susceptible than growing plankton bacteria. GCE and GCE-B were the most effective medicine against oral cariogenic bacterial biofilm. NVE1 were effective in killing oral-bacterial biofilm at relatively high concentration. CONCLUSION: GCE and GCE-B were effective medicine against oral cariogenic bacterial biofilm. MBEC (minimal biofilm eradication concentration) can provide a relative accurate medicine concentration for clinical test.

[An in vitro study on effect of Nidus vespae extract on the acid production of three strains of oral bacteria].

OBJECTIVE: To inquire into the effect of different of Nidus Vespae extract (NVE) on growth and acid production of Streptococcus mutans, Streptococcus sanguis and Actinomyces viscosus. METHODS: Streptococcus mutans ATCC 25175, Streptococcus sanguis ATCC 10556 and Actinomyces viscosus ATCC 19246 were chosen as the experimental bacteria. Four extracts of Nidus Vespae were prepared and then the effects of these Nidus Vespae extracts on the acid production were determined. RESULTS: All of Nidus Vespae extracts could inhibit the growth the of the three strains, and NVE1, NVE3, NVE4 could inhibit the acid production of the three strains, NVE2 could inhibit the acid production of Actinomyces viscosus. CONCLUSION: Four extracts of Nidus Vespae could inhibit the acid production of three bacteria strains.