Anticariogenic Agent Research Articles

Calotropis gigantea extract as a potential anticariogenic agents against Streptococcus mutans: An in vivo comparative evaluation.

Objective:The current study was intended to evaluate and compare the in vivo efficacy of Calotropis gigantea mouth rinse as anticariogenic agents with 0.2% chlorhexidine and Listerine mouth rinse.Materials and Methods:An experimental crossover study was conducted on sixty school children aged 14–15 years. Participants were divided into three Groups A, B, and C. In all children, baseline unstimulated saliva samples were collected and assessed for Streptococcus mutans counts. The study was conducted in three phases; each phase lasted for 8 days separated by a washout period of 15 days in between them. Groups A, B, and C were treated with 0.2% chlorhexidine, Listerine and C. gigantea extract mouth rinses, respectively, in the Phase I and assessed for salivary S. mutans counts. Subsequently, mouth rinses were crossed over as dictated by the Latin square design in Phase II and III.Results and Conclusion:All the three mouth rinses have individually shown a statistically significant reduction in the salivary S. mutans counts.

Sequence of ultrastructural changes of enamel crystals and Streptococcus mutans biofilm in early enamel caries in vitro.

Undecalcified mature enamel sections were used to observe the sequence of ultrastructural changes of enamel crystals and Streptococcus mutans biofilm in the early stages of caries. Human enamel blocks were incubated from 1 to 7 days with S. mutans suspension, and the pH of biofilm was measured. They were processed for light microscopic and transmission electron microscopy observations, and the number of bacteria located in the area adjacent to enamel surface counted. It was observed that the pH of the biofilm dropped to 4, after 1-day of incubation and the S. mutans number increased until 4-day. Round shaped enamel crystals were observed in the 2-day specimens and from the 4-day, images of crystals showing defects and perforations were visualized, becoming more defective along the incubation days. The length of time that the enamel was exposed to biofilm was the main factor for enamel crystals demineralization. Current in vitro caries induction system could standardize time-related changes of the property of Streptococcus mutans biofilm and its relation to enamel crystals demineralization at the ultrastructural level, and thus provide a useful model for the evaluation of the effects of various anti-cariogenic agents.

Evaluation of Remineralization Effects on Enamel Demineralization by Anti-cariogenic Agents using Quantitative Light-induced Fluorescence-digital (QLF-D) in vitro

Evaluation of Remineralization Effects on Enamel Demineralization by Anti-cariogenic Agents using Quantitative Light-induced Fluorescence-digital (QLF-D) in vitro

Effect of LongZhang Gargle on Biofilm Formation and Acidogenicity of Streptococcus mutans In Vitro.

Streptococcus mutans, with the ability of high-rate acid production and strong biofilm formation, is considered the predominant bacterial species in the pathogenesis of human dental caries. Natural products which may be bioactive against S. mutans have become a hot spot to researches to control dental caries. LongZhang Gargle, completely made from Chinese herbs, was investigated for its effects on acid production and biofilm formation by S. mutans in this study. The results showed an antimicrobial activity of LongZhang Gargle against S. mutans planktonic growth at the minimum inhibitory concentration (MIC) of 16% and minimum bactericidal concentration (MBC) of 32%. Acid production was significantly inhibited at sub-MIC concentrations. Biofilm formation was also significantly disrupted, and 8% was the minimum concentration that resulted in at least 50% inhibition of biofilm formation (MBIC50). A scanning electron microscopy (SEM) showed an effective disruption of LongZhang Gargle on S. mutans biofilm integrity. In addition, a confocal laser scanning microscopy (CLSM) suggested that the extracellular polysaccharides (EPS) synthesis could be inhibited by LongZhang Gargle at a relatively low concentration. These findings suggest that LongZhang Gargle may be a promising natural anticariogenic agent in that it suppresses planktonic growth, acid production, and biofilm formation against S. mutans.

Production of arabitol by yeasts: current status and future prospects.

Arabitol belongs to the pentitol family and is used in the food industry as a sweetener and in the production of human therapeutics as an anticariogenic agent and an adipose tissue reducer. It can also be utilized as a substrate for chemical products such as arabinoic and xylonic acids, propylene, ethylene glycol, xylitol and others. It is included on the list of 12 building block C3-C6 compounds, designated for further biotechnological research. This polyol can be produced by yeasts in the processes of bioconversion or biotransformation of waste materials from agriculture, the forest industry (l-arabinose, glucose) and the biodiesel industry (glycerol). The present review discusses research on native yeasts from the genera Candida, Pichia, Debaryomyces and Zygosaccharomyces as well as genetically modified strains of Saccharomyces cerevisiae which are able to utilize biomass hydrolysates to effectively produce L- or D-arabitol. The metabolic pathways of these yeasts leading from sugars and glycerol to arabitol are presented. Although the number of reports concerning microbial production of arabitol is rather limited, the research on this topic has been growing for the last several years, with researchers looking for new micro-organisms, substrates and technologies.

Antimicrobial Efficacy of Few Commercially Available Herbal and Non Herbal Tooth Pastes Against Clinically Isolated Human Cariogenic Pathogens

Objective: The aim of this study was to compare the antimicrobial efficacy of ten commercially available herbal and non herbal toothpastes. Methods: Ten toothpaste brands (A-J) were collected. A, C, D, E contained Herbal components only, toothpastes B, F, G contained herbal components and fluoride as main anticariogenic agent, toothpastes H and I contained fluoride and triclosan combination and toothpaste J contained fluoride only as main anticariogenic component. Dental caries samples were collected from 6-14 years old children having occlusal caries in permanent fully erupted molar teeth involving enamel and dentin but caries not involving dental pulp and Streptococcus mutans bacteria isolated by laboratory method. The antimicrobial activity was assessed by measuring the inhibition zones by agar well diffusion method. Results: Fluoridated toothpaste with triclosan had maximum antimicrobial activity at all concentrations when compared to Herbal toothpaste. Conclusion: Toothpastes containing fluoride and triclosan are most effective but herbal tooth pastes have the prospect of becoming safer and effective altenative and provide an ideal home care anticariogenic regimen. DOI: http://dx.doi.org/10.3329/bjdre.v5i1.22454 Bangladesh Journal of Dental Research and Education Vol.5(1) 2015: 14-18

Halloysite nanotube incorporation into adhesive systems—effect on bond strength to human dentin.

This study aimed to evaluate the effect of Halloysite® aluminosilicate clay nanotube (HNT) incorporation into a two-step etch-and-rinse (ER) and a one-step self-etch (SE) adhesive on human dentin shear bond strength (SBS). Ten groups (n = 12) were prepared according to the adhesive system (i.e., ER or SE) and amount of HNT incorporated (5-20%, w/v), as follows: commercial control (i.e., the adhesive was used as purchased, 0% HNT); experimental control (i.e., the adhesive was processed through mixing/stirring and sonication similarly to the HNT-incorporated experimental groups, but without HNT); and 5, 10, and 20% HNT. SBS testing was performed after 24 h of storage in deionized water at 37 °C. Failure modes were examined using a stereomicroscope (×40). Scanning electron microscopy (SEM) of the resin-dentin interface of selected specimens was carried out. Two-way ANOVA revealed that incorporation of HNT up to 20% (w/v) in ER and up to 10% (w/v) in SE demonstrated an increased SBS compared to their experimental controls. Compared to the commercial control, SBS of HNT-modified dentin adhesives was not significantly different for ER adhesives (p > 0.05) but was significantly higher with 5% HNT in the SE adhesive (p < 0.05). Failure modes were predominantly adhesive and mixed failures. SEM micrographs of resin-dentin interfaces for ER-commercial control and ER-10% showed a similar morphology. A thicker adhesive layer and the presence of agglomerated HNT on the resin tags were seen in ER-10%. An increased number of short resin tags in SE-5% compared with SE-commercial control were observed. HNT addition up to 20% in ER and up to 10 % in SE showed increased SBS to dentin compared with the experimental control. HNT can be used not only to reinforce adhesive resins but also hold potential for the development of bioactive adhesives by the encapsulation of matrix metalloproteinase (MMP) inhibitors or anticariogenic agents.

Changes in composition and enamel demineralization inhibition activities of gallic acid at different pH values

Background. Gallic acid (GA) has been shown to inhibit demineralization and enhance remineralization of enamel; however, GA solution is highly acidic. This study was to investigate the stability of GA solutions at various pH and to examine the resultant effects on enamel demineralization. Methods. The stability of GA in H2O or in phosphate buffer at pH 5.5, pH 7.0 and pH 10.0 was evaluated qualitatively by ultraviolet absorption spectra and quantified by high performance liquid chromatography with diode array detection (HPLC-DAD). Then, bovine enamel blocks were subjected to a pH-cycling regime of 12 cycles. Each cycle included 5 min applications with one of the following treatments: 1 g/L NaF (positive control), 4 g/L GA in H2O or buffered at pH 5.5, pH 7.0 and pH 10.0 and buffers without GA at the same pH (negative control), followed by a 60 min application with pH 5.0 acidic buffers and a 5 min application with neutral buffers. The acidic buffers were analysed for dissolved calcium. Results. GA was stable in pure water and acidic condition, but was unstable in neutral and alkaline conditions, in which ultraviolet spectra changed and HPLC-DAD analysis revealed that most of the GA was degraded. All the GA groups significantly inhibited demineralization (p < 0.05) and there was no significant difference of the inhibition efficacy among different GA groups (p > 0.05). Conclusions. GA could inhibit enamel demineralization and the inhibition effect is not influenced by pH. GA could be a useful source as an anti-cariogenic agent for broad practical application.

Use of an Extract of Indian Sacred Plant Ocimum sanctum as an Anticariogenic Agent: An in vitro Study.

ABSTRACTAim: To analyze the efficacy of three different concentrations of Ocimum sanctum extract against various microorganisms, Streptococcus mutans, Streptococcus mitis, Streptococcus sanguis, Lactobacillus acidophilus.Materials and methods: Ethanolic extract of Ocimum sanctum was prepared by the hot extraction method. The extract was diluted with an inert solvent, dimethyl sulfoxide to obtain 3 different concentrations (2.5, 5 and 10%) of the extract. 0.2% chlorhexidine was used as a positive control and dimethyl sul-foxide was used as a negative control. The extract, along with the controls, was then subjected to microbiological investigation to determine which concentration among the 3 different concentrations of extract gave a wider inhibition zone against S. mutans, S. mitis, S. sanguis, L. acidophilus. The zones of inhibition were measured in millimeters.Results: Ocimum sanctum leaf extract demonstrated maximum antimicrobial activity against microorganisms responsible for dental caries at the 10% concentration level although 5 and 2.5% were also effective. Maximum activity was seen against S. mutans and S. sanguis with 10% extract.Conclusion: Ocimum sanctum leaf extract was effective against all the microorganisms.How to cite this article: Pai RK, Bhat SS, Salman A, Chandra J. Use of an Extract of Indian Sacred Plant Ocimum Sanctum as an Anticariogenic Agent: An in vitro Study. Int J Clin Pediatr Dent 2015;8(2):99-101.

Cariostatic effect of green tea in comparison with common anticariogenic agents: an in vitro study.

Background and aims. Anticariogenic effects of different mouthrinses have been shown previously. In this in vitro study the anticariogenic effects of polyphenol extract of green tea with 0.05% fluoride, 0.2% chlorhexidine and fluoride-chlorhexidine were compared.Materials and methods. This in vitro study was performed on 50 maxillary premolars in 5 groups: 1) normal saline; 2) a 10% solution of green tea polyphenol extract; 3) 0.05% fluoride; 4) 0.2% chlorhexidine; and 5) fluoride-chlorhexidine. Each tooth was placed in a tube which contained a cariogenic solution. Every day the teeth were washed (depending on the experimental groups) with 5 mL of mouthrinse solution. The depth of the caries was measured under a polarized light microscope. Data were analyzed using SPSS 13.0 with Kolmogorov-Smirnov, one-way ANOVA and Tukey tests.Results. The mean and standard deviation (in µm) of caries depth were 194±16.43, 175±17.94, 142±9.34, 155±13.27, and 144±8.57 in groups 1 to 5, respectively, with significant differences between the groups (P<0.001). Tukey test showed that although there was no significant difference in the depth of caries in groups 1 and 2 (P>0.001), they were significantlyless than those in groups 3 to 5 (P<0.001). There was no significant difference between decay depth of groups 3, 4 and 5 (P>0.001).Conclusion. The anticariogenic effect of fluoride-chlorhexidine was the highest among the groups. Although green tea showed higher cariostatic effects than normal saline, in comparison with other mouthrinses, it is less effective. More re-search is strongly recommended for clinical use of green tea as an anticariogenic agent.

Plant species used in dental diseases: Ethnopharmacology aspects and antimicrobial activity evaluation

Ethnopharmacological relevance: Ethnopharmacological surveys show that several plant species are used empirically by the population, in oral diseases. However, it is necessary to check the properties of these plant species.Aim of the study: To evaluate in vitro antimicrobial activity against Streptococcus mutans from plant species selected in a previous ethnopharmacology study.Materials and methods: An ethnopharmacological survey was conducted with users of a dental clinic school services, located in Sao Luis, Maranhão, Brazil, aiming to identify plant species used in oral diseases treatment. From the ethnopharmacological survey, species were selected for in vitro antimicrobial activity evaluation against Streptococcus mutans, by agar diffusion method and determination of Minimum Inhibitory Concentration (MIC).Results: Two hundred and seventy one people participated in the research: 55.7% reported the use of plants for medicinal purposes, 29.5% of which have knowledge and/or use plants for some type of oral disease. Thirty four species belonging to 24 (twenty four) botanical families were reported, being Aloe vera L., Anacardium occidentale L., Schinus terebinthifolius Raddi, Chenopodium ambrosioides L. and Punica granatum L. the most cited. The most commonly reported indications were healing after tooth extraction, followed by toothache, inflammation and bleeding gums., The determination of Minimum Inhibitory Concentration (MIC) demonstrated that Punica granatum L., Psidium guajava L. and Schinus terebinthifolius Raddi showed similar activity to 0.12% chlorhexidine, used as positive control.Conclusion: That result is important to follow up the study of these species in the search for new anticariogenic agents originated by plants.

Inhibitory efficacy of cyclo(l-leucyl-l-prolyl) from mangrove rhizosphere bacterium–Bacillus amyloliquefaciens (MMS-50) toward cariogenic properties of Streptococcus mutans

Since Streptococcus mutans is the principal etiologic agent causing dental caries, by encompassing an array of unique virulence traits, emerging treatment strategies that specifically target the virulence of this pathogen may be promising as alternative approaches compared to conventional antibiotic therapy. In this perspective, we investigated chloroform extract of cell-free culture supernatant from mangrove rhizosphere bacterium Bacillus amyloliquefaciens (MMS-50) in terms of anticariogenic properties of S. mutans, without suppressing its viability. Crude chloroform extract of MMS-50 was subjected to column and high performance liquid chromatographic techniques to obtain the active fraction (AF), and MMS-50 AF was used for all further assays. GC–MS and FT-IR were carried out to identify the major components present in MMS-50 AF. Comparative gene expression analysis of some biofilm-forming and virulence genes (vicR, comDE, gtfC, and gbpB) was done by real-time PCR. Cyclo(l-leucyl-l-prolyl) was found to be the chief compound in MMS-50 AF responsible for bioactivity. The minimum and maximum inhibitory concentrations of MMS-50 AF against S. mutans were found to be 100 and 250 μg/mL, respectively. Anti-virulence assays performed using below-sub-MIC levels of MMS-50 AF (30 μg/mL) resulted in significant reduction in adherence (68%), acid production, acid tolerance, glucan synthesis (32%), biofilm formation (53.5%) and cell surface hydrophobicity, all devoid of affecting its viability. The micrographs of CLSM and SEM further confirmed the antibiofilm and anti-virulence efficacies of MMS-50 AF. Expression data showed significant reduction in expression of all studied virulence genes. Thus, the current study unveils the anticariogenic potential of cyclo(l-leucyl-l-prolyl) from B. amyloliquefaciens, as well as its suitability as a novel and alternative anticariogenic agent against dental caries.

Inhibition of major virulence pathways of Streptococcus mutans by quercitrin and deoxynojirimycin: a synergistic approach of infection control.

ObjectivesTo evaluate the synergistic effect of Quercitrin and Deoxynojirimycin (DNJ) together with their individual inhibitory effect against virulence pathways of Streptococcus mutans.MethodologyMICs of both the compounds were determined by the microdilution method, followed by their in vitrosynergy using checkerboard and time kill assay. The nature of interaction was classified as synergistic on the basis of fractional inhibitory concentration index (FICI) value of ≤0.5. Furthermore, the activity of Quercitrin and DNJ was evaluated individually and in combination against various cariogenic properties of S. mutans UA159 such as acidogenesis, aciduracity, glucan production, hydrophobicity, biofilm and adherence. Moreover, expression of virulent genes in S. mutans was analysed by quantitative RT- PCR (qRT-PCR) and inhibition of F1F0-ATPase, lactate dehydrogenase and enolase was also evaluated. Finally, scanning electron microscopy (SEM) was used to investigate structural obliteration of biofilm.ResultsThe in vitro synergism between Quercitrin and DNJ was observed, with a FICI of 0.313. Their MIC values were found to be 64 μg/ml and 16 μg/ml respectively. The synergistic combination consistently showed best activity against all the virulence factors as compared to Quercitrin and DNJ individually. A reduction in glucan synthesis and biofilm formation was observed at different phases of growth. The qRT-PCR revealed significant downregulation of various virulent genes. Electron micrographs depicted the obliteration of biofilm as compared to control and the activity of cariogenic enzymes was also inhibited.ConclusionsThe whole study reflects a prospective role of Quercitrin and DNJ in combination as a potent anticariogenic agent against S. mutans.

The effect of Propolis and Xylitol chewing gums on salivary Streptococcus mutans count: a clinical trial.

Streptococcus mutans is one of the most common cariogenic microorganisms. Use of natural anticariogenic agents, such as Xylitol has been well-established in the literature. On the other hand, there is a scarcity of studies that have reported the antimicrobial potential of Propolis as an anticariogenic chewing agent; hence, the present study was designed. To evaluate and compare the anticariogenic action of two commercial chewing gums Propolis and Xylitol on the salivary S. mutans count in a group of children from Bengaluru city. Clinical setting and experimental design. Thirty healthy children aged 8-11 years with decayed, missing, and filled teeth (dmft)/DMFT index score≥3 were included in the study. Before the test, unstimulated saliva was collected. Children divided into Group I and II were given Propolis and Xylitol chewing gums respectively; to chew for 15 min. Saliva samples were then collected at 15 min (just after spitting) and after 1 h. The amount of S. mutans in saliva was evaluated using a selective media (MSAB). In addition, compliance of the two chewing gums among the children was tested with a questionnaire. Student's t-test. Six samples out of 30 were excluded due to no growth. The total number of bacterial colonies was significantly reduced when compared to baseline in both the groups. Propolis gum showed statistically significant reduction in the number of colonies as compared to Xylitol. Xylitol gum was more preferred than Propolis gum by the children. Propolis chewing gum can be used as an anticariogenic agent in children.

Anti-microbial activity of Punica granatum on streptococcus in dental caries patients and healthy individuals: A comparative study

Background: Researchers today are driven toward the medicinal and therapeutic value of the natural products like Aloe vera, basil, turmeric, green tea, pomegranate (Punica granatum) to prevent dental caries. The aim of the present study was to determine the antimicrobial activity of pomegranate aril extract on streptococci in dental caries patients and healthy individuals. Materials and Methods: The study group included 40 subjects; age comprised of 18-26 years 20 dental caries patients were taken as an experimental group (after observing the decayed missing fi lled teeth index) and 20 healthy individuals without caries as a control group. Two samples were collected from each subject. The collected sample was streaked on Mitis Salivarius Agar, which was incubated at 37°C for 24 h. The colony forming units (CFU) were counted using manual colony counter, and the data were analyzed using paired t-test and unpaired t-test. Results: The results obtained after pomegranate swish in the experimental group showed a percentage reduction of 52.2% (P < 0.0001) and 33.8% (P < 0.0001) in control group for the CFU. The comparison of after sample between the experimental group and the control group was highly signifi cant. Conclusion: The result obtained in the study clearly demonstrates that the pomegranate aril extract has an antimicrobial eff ect against Streptococcus, thus acting as an anti-cariogenic agent.

Antimicrobial activity of Euclea undulata, Euclea divinorum and Diospyros lycioides extracts on multi- drug resistant Streptococcus mutans

The antimicrobial activities of three Zimbabwean chewing sticks (Euclea undulata, Euclea divinorum and Diospyros lycioides) on multi-drug resistant (MDR) Streptococcus mutans were determined. Thirty one isolates of S. mutans were obtained from 47 carious teeth and antibiotic sensitivity testing was done using the disc diffusion assay for all isolates. The resistance pattern of each isolate against eight antibiotics was noted. Eight resistance patterns were identified, and 19 isolates showed resistance to at least 4 antibiotics; these were considered MDR. Eight MDR and 2 multi-drug sensitive isolates were then assayed against methanol, acetone, diethyl ether and aqueous extracts of E. undulata, E. divinorum and D. lycioides. The broth macro-dilution assay was used to determine the minimum inhibitory concentration (MIC) of the extracts. All E. divinorum extracts showed no antimicrobial activity. Stem methanol extracts of E. undulata and root and stem methanol extracts of D. lycioides showed anti S. mutans activity. The largest inhibition zones were exhibited by methanol extracts of E. undulata (60 mm) and D. lycioides (54 mm). MICs ranged from 0.385 to 11.22 mg/ml and minimum bactericidal concentration (MBCs) from 0.485 to 20.20 mg/ml. D. lycioides and E. undulata extracts have potential use as anticariogenic agents. Key words: Streptococcus mutans, dental caries, antimicrobial activity, multi-drug resistant

In Vitro Anticariogenic Effects of Drymocallis rupestris Extracts and Their Quality Evaluation by HPLC-DAD-MS3 Analysis

In this study, for the first time, we investigated in vitro inhibitory effects of Drymocallis rupestris extracts and their subfractions obtained with solvents of different polarity (aqueous, 50% ethanolic, diethyl ether, ethyl acetate and n-butanolic) against bacterial viability and caries virulence factors of Streptococcus spp. strains. The diethyl ether subfraction (PRU2) showed bacteriostatic and bactericidal activity against mutans streptococci, with minimum inhibitory concentrations (MICs) in the range of 0.75–1.5 mg/mL and minimum bactericidal concentrations (MBCs) in the range of 1.5–3 mg/mL. Furthermore, PRU2 inhibited biofilm formation by Streptococci in a dose-dependent manner. It was also found that all five D. rupestris preparations exhibited diverse inhibitory effects on de novo synthesis of water-insoluble and water-soluble α-d-glucans by glucosyltransferases of the mutans group streptococci. The phytochemical profile of investigated samples was determined by spectrophotometric and chromatographic (HPLC-DAD-MS3) methods. The high polyphenol (total phenol, phenolic acids, tannins, proantocyanidins, and flavonoids) contents were found which correlated with anticariogenic activity of the analyzed samples. The results demonstrate that D. rupestris extracts and their subfractions could become useful supplements for pharmaceutical products as a new anticariogenic agent in a wide range of oral care products. Further studies are necessary to clarify which phytoconstituents of D. rupestris are responsible for anticaries properties.

Release Kinetics of Calcium and Quercetin from Chewing Gum as a Novel Antiplaque and Antimicrobial Device

There is a growing interest in the use of anticariogenic and antimicrobial agents to prevent demineralization and promote remineralization of dental enamel for the prevention of oral diseases. The purpose of this study was to develop a novel chewing-system containing as Casein-Phosphopeptides-Amorphous-Calcium-Phosphate (CPP-ACP) as Quercetin (Qt) and evaluate their release using in vitro and in vivo experiments. In vitro and in vivo experimental protocols were designed to test the percentages of Ca from CPP-ACP and Qt released with time and their delivery rate from a chewing gum. The in vitro experiments were performed using a specifically designed chewing apparatus to test the release of Ca and Qt in artificial saliva in function of chewed time, while the in vivo experiments required a chew-out method with volunteers and the residual CPP-ACP and Qt present in the chewed gums was analyzed. This study demonstrated that both CPP-ACP'Ca and Qt were released during chewing although CPP-ACP'Ca was released from the chewing gum in a slower and more controlled manner than Qt. They were also both effectively retained in the oral cavity for all the investigated chewing time and according to their monitored release concentrations they were able to serve as a novel antiplaque agent. This research concludes that both drugs were efficiently released during the mastication process to fully exploit their anti-carious activity.

Antibacterial substances from Albizia myriophylla wood against cariogenic Streptococcus mutans

Albizia myriophylla has been used for long by Thai traditional healers as an important ingredient herb in Thai herbal formulas for caries. In this study, three flavonoids lupinifolin (6), 8-methoxy-7,3',4'-trihydroxyflavone (7), and 7,8,3',4'-tetrahydroxyflavone (8), a triterpenoid lupeol (3) as well as four sterols β-sitosterone (1), stigmasta-5,22-dien-3-one (2), β-sitosterol (4), and stigmasterol (5) were isolated from A. myriophylla wood. The antibacterial activity of these compounds against Streptococcus mutans ATCC 25175 was performed using broth microdilution method. All compounds exhibited antibacterial activity against S. mutans with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) ranging from 1-256 and 2-256 μg/ml, respectively. Among the isolated compounds, lupinifolin (6) was found to be the most potent with MIC and MBC of 1 and 2 μg/ml, respectively. Lupinifolin (6) also showed a strong activity against ten clinical isolates of S. mutans with MIC and MBC ranging from 0.25-2 and 0.5-8 μg/ml, respectively. These results reported the bioactive ingredients of A. myriophylla which support its ethnomedical claims as well. Lupinifolin (6) may have a potential to be a natural anticariogenic agent.

Anticariogenic and phytochemical evaluation of Eucalyptus globules Labill.

In the present study, in vitro anticariogenic potential of ethyl acetate, hexane and methanol and aqueous extracts of plant leaves of Eucalyptus globules Labill. were evaluated by using four cariogenic bacteria, Lactobacillus acidophilus, Lactobacillus casei, Staphylococcus aureus and Streptococcus mutans. Agar well diffusion method and minimum inhibitory concentration (MIC) were used for this purpose. The ethyl acetate extracted fraction of plant leaves showed good inhibitory effects against all selected bacteria. In Eucalyptus globules, hexane and ethyl acetate extracts found highly effective against, Lactobacillus acidophilus with MIC value of 0.031 and 0.062 mg/mL, respectively. Qualitative phytochemical investigation of above extracts showed the presence of alkaloids, phenolic compounds, steroids, cardiac glycosides and terpenes. Based on the MIC value and bioautography, ethyl acetate of plant leaf was selected for further study. Further investigation on the structure elucidation of the bioactive compound using IR, GC-MS and NMR techniques revealed the presence of alpha-farnesene, a sesquiterpene. Eucalyptus globules plant leaf extracts have great potential as anticariogenic agents that may be useful in the treatment of oral disease.