scholarly journals Chamaecyparis obtusaSuppresses Virulence Genes inStreptococcus mutans

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Eun-Hee Kim ◽  
Sun-Young Kang ◽  
Bog-Im Park ◽  
Young-Hoi Kim ◽  
Young-Rae Lee ◽  
...  

Chamaecyparis obtusa (C. obtusa)is known to have antimicrobial effects and has been used as a medicinal plant and in forest bathing. This study aimed to evaluate the anticariogenic activity of essential oil ofC. obtusaonStreptococcus mutans, which is one of the most important bacterial causes of dental caries and dental biofilm formation. Essential oil fromC. obtusawas extracted, and its effect on bacterial growth, acid production, and biofilm formation was evaluated.C. obtusaessential oil exhibited concentration-dependent inhibition of bacterial growth over 0.025 mg/mL, with 99% inhibition at a concentration of 0.2 mg/mL. The bacterial biofilm formation and acid production were also significantly inhibited at the concentration greater than 0.025 mg/mL. The result of LIVE/DEAD® BacLight™Bacterial Viability Kit showed a concentration-dependent bactericidal effect onS. mutansand almost all bacteria were dead over 0.8 mg/mL. Real-time PCR analysis showed that gene expression of some virulence factors such asbrpA, gbpB, gtfC,andgtfDwas also inhibited. In GC and GC-MS analysis, the major components were found to beα-terpinene (40.60%), bornyl acetate (12.45%),α-pinene (11.38%),β-pinene (7.22%),β-phellandrene (3.45%), andα-terpinolene (3.40%). These results show thatC. obtusaessential oil has anticariogenic effect onS. mutans.

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Beom-Su Kim ◽  
Sun-Ju Park ◽  
Myung-Kon Kim ◽  
Young-Hoi Kim ◽  
Sang-Bong Lee ◽  
...  

The aim of the study was to evaluate the antibacterial activity of essential oil extracted fromChrysanthemum boreale(C. boreale) onStreptococcus mutans(S. mutans). To investigate anticariogenic properties, and bacterial growth, acid production, biofilm formation, bacterial adherence ofS. mutanswere evaluated. Then gene expression of several virulence factors was also evaluated.C. borealeessential oil exhibited significant inhibition of bacterial growth, adherence capacity, and acid production ofS. mutansat concentrations 0.1–0.5 mg/mL and 0.25–0.5 mg/mL, respectively. The safranin staining and scanning electron microscopy results showed that the biofilm formation was also inhibited. The result of live/dead staining showed the bactericidal effect. Furthermore, real-time PCR analysis showed that the gene expression of some virulence factors such asgtfB,gtfC,gtfD,gbpB,spaP,brpA,relA, andvicR ofS. mutanswas significantly decreased in a dose dependent manner. In GC and GC-MS analysis, seventy-two compounds were identified in the oil, representing 85.42% of the total oil. The major components were camphor (20.89%),β-caryophyllene (5.71%),α-thujone (5.46%), piperitone (5.27%),epi-sesquiphellandrene (5.16%),α-pinene (4.97%), 1,8-cineole (4.52%),β-pinene (4.45%), and camphene (4.19%). These results suggest thatC. borealeessential oil may inhibit growth, adhesion, acid tolerance, and biofilm formation ofS. mutansthrough the partial inhibition of several of these virulence factors.


2021 ◽  
Author(s):  
Roudaina Abdel Samad ◽  
Karim Raafat ◽  
Alissar Al Khatib ◽  
Hadi Abou Chacra ◽  
nada EL DARRA

Abstract Background: A huge amount of citrus by-products are being wasted every year; these by-products can be used in the extraction of essential oils which can be used in different fields. Many methods have been used in the extraction of orange essential oil (E.O). This study focuses on the extraction of essential oil from orange by-product, using a newly developed extraction technique. This technique is a prototype combining a conventional method, namely, the hydrodistillation with the ultrasound-assisted extraction. Indeed, the traditional extraction methods of essential oils are time-consuming and expensive, moreover many organic compounds may decompose at high retained temperatures.Methods: a combination of traditional method with sonication improves efficiency and quality of the extraction, since ultrasonic extraction with precise and controlled operating parameters leads to higher extraction yields with minimum energy consumption. Therefore, the orange essential oil obtained using the prototype was compared to two commercial oils (CO1 and CO2) to create a valid comparison. Quality and safety tests have been performed, as well as bacterial load, antibacterial activities using the disc diffusion method, minimum inhibitory concentration (MIC), and prevention of bacterial biofilm formation.Results: As a result of extraction, the prototype method has shorten the extraction time, gave a higher quantity, and improved the extraction of essential oil from citrus peels without affecting oil composition when comparing it to hydrodistillation method. Conclusion: Orange E.O can be used as natural antibacterial agents to minimize bacterial growth, and inhibit biofilm formation by Staphylococcus aureus, Listeria monocytogenes and E.coli.


Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1315
Author(s):  
Anton Schestakow ◽  
Matthias Hannig

Chitosan and tannic acid are known for their antibacterial properties. In the present in-situ study, their antibacterial and anti-adherent effects on biofilm formation on enamel were investigated. Six subjects carried upper jaw splints with bovine enamel specimens, allowing in-situ biofilm formation. During the two-day trial, subjects rinsed with experimental solutions that contained either chitosan, tannic acid (pH = 2.5), tannic acid (pH = 7) or hydrochloric acid. Water served as the negative and chlorhexidine as the positive control. Rinsing occurred four or five times following two different rinsing protocols to investigate both the immediate and long-lasting effects. After 48 h of intraoral exposure, the dental plaque was stained with LIVE/DEAD® BacLight, and fluorescence micrographs were evaluated by using the software ImageJ. The results were verified by scanning electron microscopy. Rinsing with chitosan resulted in little immediate antibacterial and anti-adherent effects but failed to show any long-lasting effect, while rinsing with tannic acid resulted in strong immediate and long-lasting effects. Except for a slightly lower antibacterial effect, the neutral solution of tannic acid was as good as the acidic solution. Hydrochloric acid showed neither an antibacterial nor an anti-adherent effect on dental biofilm formation. Experimental solutions containing tannic acid are promising anti-biofilm agents, irrespective of the pH values of the solutions. Chitosan, on the other hand, was not able to prevent biofilm formation.


2021 ◽  
Vol 15 (4) ◽  
pp. 324-329
Author(s):  
Pengxiang Lai ◽  
Xin-Chen Zhang ◽  
Lin Zhu ◽  
Xin-Yu Li ◽  
Li-Chuan Liu

The essential oil (EO) of aerial parts of Mallotus repandus (Willd.) Muell. Arg. was extracted by hydrodistillation and characterized by GC/FID and GC/MS. Fifty-one compounds comprising 97.1% of the EO were identified, of which α-humulene (18.7%), β-selinene (12.8%), aciphyllene (10.7%), (E)-caryophyllene (8.4%), α-copaene (5.5%), humulene epoxide II (4.9%) and caryophyllene oxide (4.3%) were the major compounds. The EO was evaluated for antibacterial properties using broth microdilution method and crystal-violet static biofilm formation assay. The M. repandus EO possessed a bactericidal effect against tested gram-positive bacteria strains (MIC = MBC: 0.05-0.10 mg/mL). Further, the EO showed the ability to inhibit the biofilm formation of Staphylococcus aureus. In addition, the potential synergistic effect was assessed by checkerboard method. Combination of the M. repandus EO with Streptomycin showed synergistic effects against the tested bacterial strains. This study demonstrates that M. repandus EO could be further explored as good alternative for potential pharmaceuticals.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Seung-Il Jeong ◽  
Beom-Su Kim ◽  
Ki-Suk Keum ◽  
Kwang-Hee Lee ◽  
Sun-Young Kang ◽  
...  

We isolated a single chemical compound fromA. continentalisand identified it to be kaurenoic acid (KA) and investigated the influence of anticariogenic properties. Inhibitory effects of KA on cariogenic properties such as growth, acid production, biofilm formation, and the adherence ofS. mutanswere evaluated. Furthermore, real-time PCR analysis was performed to evaluate the influence of KA on the genetic expression of virulence factors. KA significantly inhibited the growth and acid production ofS. mutansat 2–4 μg/mL and 4 μg/mL of KA, respectively. Furthermore, the adherence onto S-HAs was inhibited at 3-4 μg/mL of KA and biofilm formation was significantly inhibited when treated with 3 μg/mL KA and completely inhibited at 4 μg/mL. Also, the inhibitory effect of KA on biofilm formation was confirmed by SEM. In confocal laser scanning microscopy, bacterial viability gradually decreased by KA in a dose dependent manner. Real-time PCR analysis showed that the expressions ofgtfB, gtfC, gbpB, spaP, brpA, relA, andvicRwere significantly decreased inS. mutanswhen it was treated with KA. These results suggest that KA fromA. continentalismay be a useful agent for inhibiting the cariogenic properties ofS. mutans.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1783
Author(s):  
Alessandra Cataldo Cataldo Russomando ◽  
Ronit Vogt Vogt Sionov ◽  
Michael Friedman ◽  
Irith Gati ◽  
Ron Eliashar ◽  
...  

The aim of the study was to develop a sustained-release varnish (SRV) containing chlorhexidine (CHX) for sinonasal stents (SNS) to reduce bacterial growth and biofilm formation in the sinonasal cavity. Segments of SNS were coated with SRV-CHX or SRV-placebo and exposed daily to bacterial cultures of Staphylococcus aureus subsp. aureus ATCC 25923 or Pseudomonas aeruginosa ATCC HER-1018 (PAO1). Anti-bacterial effects were assessed by disc diffusion assay and planktonic-based activity assay. Biofilm formation on the coated stents was visualized by confocal laser scanning microscopy (CLSM) and high-resolution scanning electron microscopy (HR-SEM). The metabolic activity of the biofilms was determined using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) method. Disc diffusion assay showed that SRV-CHX-coated SNS segments inhibited bacterial growth of S. aureus subsp. aureus ATCC 25923 for 26 days and P. aeruginosa ATCC HER-1018 for 19 days. CHX was released from coated SNS segments in a pH 6 medium up to 30 days, resulting in growth inhibition of S. aureus subsp. aureus ATCC 25923 for 22 days and P. aeruginosa ATCC HER-1018 for 24 days. The MTT assay showed a reduction of biofilm growth on the coated SNS by 69% for S. aureus subsp. aureus ATCC 25923 and 40% for P. aeruginosa ATCC HER-1018 compared to the placebo stent after repeated exposure to planktonic growing bacteria. CLSM and HR-SEM showed a significant reduction of biofilm formation on the SRV-CHX-coated SNS segments. Coating of SNS with SRV-CHX maintains a sustained delivery of CHX, providing an inhibitory effect on the bacterial growth of S. aureus subsp. aureus ATCC 25923 and P. aeruginosa ATCC HER-1018 for approximately 3 weeks.


Nanoscale ◽  
2020 ◽  
Vol 12 (41) ◽  
pp. 21344-21358
Author(s):  
Hajo Frerichs ◽  
Eva Pütz ◽  
Felix Pfitzner ◽  
Tobias Reich ◽  
Athanasios Gazanis ◽  
...  

Ce1−xBixO2−δ is an active halogenation catalyst with maximum activity for x ≈ 0.2 due to the effects of zeta-potential and BET surface area. Ce1−xBixO2−δ/polyethersulfone nanocomposites block bacterial biofilm formation of Gram-negative bacteria.


Author(s):  
B.D. Tall ◽  
K.S. George ◽  
R. T. Gray ◽  
H.N. Williams

Studies of bacterial behavior in many environments have shown that most organisms attach to surfaces, forming communities of microcolonies called biofilms. In contaminated medical devices, biofilms may serve both as reservoirs and as inocula for the initiation of infections. Recently, there has been much concern about the potential of dental units to transmit infections. Because the mechanisms of biofilm formation are ill-defined, we investigated the behavior and formation of a biofilm associated with tubing leading to the water syringe of a dental unit over a period of 1 month.


2018 ◽  
Vol 16 (S1) ◽  
pp. S48-S54
Author(s):  
Y. Ez zoubi ◽  
S. Lairini ◽  
A. Farah ◽  
K. Taghzouti ◽  
A. El Ouali Lalami

The purpose of this study was to determine the chemical composition and to evaluate the antioxidant and antibacterial effects of the Moroccan Artemisia herba-alba Asso essential oil against foodborne pathogens. The essential oil of Artemisia herba-alba was analyzed by gas chromatography coupled with mass spectroscopy. The antibacterial activity was assessed against three bacterial strains isolated from foodstuff and three bacterial strains referenced by the ATCC (American Type Culture Collection) using the disk diffusion assay and the macrodilution method. The antioxidant activity was evaluated using the DPPH (2, 2-diphenyl-1- picrylhydrazyl) method. The fourteen compounds of the Artemisia herba-alba essential oil were identified; the main components were identified as β-thujone, chrysanthenone, α-terpineol, α-thujone, α-pinene, and bornyl acetate. The results of the antibacterial activity obtained showed a sensitivity of the different strains to Artemisia herba-alba essential oil with an inhibition diameter of 8.50 to 17.00 mm. Concerning the MICs (minimum inhibitory concentrations), the essential oil exhibited much higher antibacterial activity with MIC values of 2.5 μl/ml against Bacillus subtilis ATCC and Lactobacillus sp. The essential oil was found to be active by inhibiting free radicals with an IC50 (concentration of an inhibitor where the response is reduced by half) value of 2.9 μg/ml. These results indicate the possible use of the essential oil on food systems as an effective inhibitor of foodborne pathogens, as a natural antioxidant, and for potential pharmaceutical applications. However, further research is needed in order to determine the toxicity, antibacterial, and antioxidant effects in edible products.


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