scholarly journals Antimicrobial Effects against Oral Pathogens and Cytotoxicity of Glycyrrhiza uralensis Extract

Plants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 838 ◽  
Author(s):  
Song-Yi Yang ◽  
Yu-Ri Choi ◽  
Myung-Jin Lee ◽  
Min-Kyung Kang

We aimed to evaluate the antimicrobial effects of Glycyrrhiza uralensis extract on Streptococcus mutans and Candida albicans and its biocompatibility for dental applications. The antimicrobial activity of the G. uralensis extracts at concentrations of 50, 100, 150, and 200 µg/mL was assessed using agar disk diffusion tests, counting the total number of colony-forming units (CFUs), spectrophotometric growth inhibitory assays, and microbial morphology observations using scanning electron microscopy (SEM; Merin, Carl Zeiss, Oberkochen, Germany). We measured the polyphenol and flavonoid contents of G. uralensis extracts using ultraviolet–visible spectrometry and the cytotoxicity of these extracts using an MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. We identified that G. uralensis extracts had significant antimicrobial effects against S. mutans and C. albicans. The optical density of the experimental groups significantly decreased compared with that of the control group. SEM images revealed that the G. uralensis extract affected the morphology and density of S. mutans and C. albicans. The extract concentration of flavonoids, but not polyphenols, increased with increasing concentrations of the G. uralensis extract. Furthermore, cell viabilities were more than 70% for G. uralensis extracts with concentrations of 50 and 100 μg/mL. Naturally derived G. uralensis is biocompatible and exhibits an excellent antimicrobial effect against oral pathogens such as S. mutans and C. albicans. Thus, G. uralensis extracts can be used for the development of oral products that treat and prevent oral diseases.

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Francis Ocheng ◽  
Freddie Bwanga ◽  
Moses Joloba ◽  
Abier Softrata ◽  
Muhammad Azeem ◽  
...  

The study assessed the growth inhibitory effects of essential oils extracted from ten Ugandan medicinal plants (Bidens pilosa, Helichrysum odoratissimum, Vernonia amygdalina, Hoslundia opposita, Ocimum gratissimum, Cymbopogon citratus, Cymbopogon nardus, Teclea nobilis, Zanthoxylum chalybeum,andLantana trifolia) used traditionally in the management of oral diseases against oral pathogens. Chemical compositions of the oils were explored by GC-MS. Inhibitory effects of the oils were assessed on periodontopathicPorphyromonas gingivalisandAggregatibacter actinomycetemcomitansand cariogenicStreptococcus mutansandLactobacillus acidophilususing broth dilution methods at concentrations of 1%, 0.1%, and 0.01%. The most sensitive organism wasA. actinomycetemcomitans. Its growth was markedly inhibited by six of the oils at all the concentrations tested. Essential oil fromC. nardusexhibited the highest activity with complete growth inhibition ofA. actinomycetemcomitansandP. gingivalisat all the three concentrations tested, the major constituents in the oil being mainly oxygenated sesquiterpenes. Most of the oils exhibited limited effects onL. acidophilus. We conclude that essential oils from the studied plants show marked growth inhibitory effects on periodontopathicA. actinomycetemcomitansandP. gingivalis, moderate effects on cariogenicS. mutans, and the least effect onL. acidophilus. The present study constitutes a basis for further investigations and development of certain oils into alternative antiplaque agents.


Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 670
Author(s):  
Song-Yi Yang ◽  
Min-Kyung Kang

This study was conducted to determine whether nature-derived Reynoutria elliptica extracts exhibit biocompatibility and antimicrobial effects against oral pathogens such as Streptococcus mutans and Candida albicans. Fine particles of Reynoutria elliptica extract were used to probe for biocompatibility and antimicrobial activity toward these pathogens, and results were evaluated with an MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay, spectrophotometric growth inhibitory assay, the total number of colony-forming units (CFU), an agar disk diffusion test, and scanning electron microscopy (SEM). In addition, UV/VIS spectroscopy was used to determine the levels of flavonoid and polyphenol in experimental solutions. Several experimental groups showed cell viability higher than 70%, and the antimicrobial activity toward both S. mutans and C. albicans was significantly higher than was that seen for the control group. In CFU and agar disk diffusion tests with C. albicans, increases in the concentration of Reynoutria elliptica extract led to significantly increased antimicrobial effects. Additionally, SEM results showed that Reynoutria elliptica extract changed the morphology and density of S. mutans and C. albicans. The results of this research can be applied to the use of Reynoutria elliptica extracts for the development of oral products that are biologically friendly and can control oral diseases such as dental caries and candida-associated denture stomatitis.


Author(s):  
Uzochukwu Gospel Ukachukwu ◽  
Daniel Okwaje ◽  
Damian Chukwu Odimegwu

Abstract Typhoid fever, a systemic infection caused by Salmonella typhi has maintained a high morbidity and mortality profile around the globe especially in developing countries. Though currently licensed vaccines are efficacious in prevention of the infection, their potency is ephemeral; hence, they require a boost by employing adjuvants that are safe and instrumental in achieving a better prolonged protective immune defense outfit. In this work, Moringa oleifera ethyl acetate leaf extract was evaluated for its possible adjuvant property to a heat-killed ST vaccine. Mice were vaccinated with typhoid vaccine and subsequently, daily weight of mice was measured. Also, post-vaccination microbial colony counts were enumerated after challenging the mice with Salmonella typhi cells. From the blood culture results, MO extract demonstrated an excellent synergistic antimicrobial effect as the mice group administered our formulated vaccine-MO extract combination had the lowest microbial load (12.25 ± 4.86) colony forming units following microbial challenge, when compared to the mice groups administered the vaccine alone (37.25 ± 4.5) and the MO extract alone (31.25 ± 9.43). Furthermore, assessment of the mice body weight of treated groups showed a growth pattern that did not deviate significantly from those of the control group. In conclusion, MO extract demonstrated a promising synergistic antimicrobial effect on coadministration with the typhoid fever vaccine against S. typhi and did not lead to adverse side effects in mice.


2018 ◽  
Vol 69 (8) ◽  
pp. 2081-2088 ◽  
Author(s):  
Alin Alexandru Odor ◽  
Edwin Sever Bechir ◽  
Deborah Violant ◽  
Victoria Badea

Moderate and severe periodontitis represents a challenge in the non-surgical periodontal therapy. Due to the lack of evidence regarding the antimicrobial effectiveness of 940 nm diode laser in periodontal treatment, this study aimed to evaluate the antimicrobial effect of hydrogen peroxide (H2O2) photolysis performed with 940 nm diode laser in the treatment of moderate and severe periodontitis. Twenty-five patients with 100 teeth were selected for this pilot study. The test teeth were randomly assigned to one of the four treatment groups: Group 1: scaling and root planning (SRP) (control group); and the following experimental groups: Group 2: H2O2; Group 3: 940 nm diode laser therapy; Group 4: 940 nm diode laser therapy and H2O2. Clinical examinations, like probing depth (PD), clinical attachment level (CAL) and bleeding on probing (BOP) were performed before and after the treatment. The microbiological evaluation, effectuated before and after the treatment, included nine periodontal bacteria species and investigated by means of real-time PCR assay. The clinical and bacterial differences in the tested groups, was assessed between control group and the other three experimental groups, as well as between the experimental groups. The total bacteria load was reduced for all four studied groups. Group 4 (diode laser + H2O2) showed significant bacterial reduction of the major periodontal bacteria like Pg., Tf., Td., Pi., Pm., Fn (p[0.001) than the other 3 groups (p]0.001). Also the periodontal clinical parameters, like PD, CAL and BOP showed a significant reduction after the photolysis of H2O2 with the 940 nm diode laser (p[0.001). Differences between tested groups showed a significant beneficial results in regard to Group 4.It is suggested that the photoactivation of H2O2 with the 940 nm diode laser can be used successfully in adjunctive to the non-surgical periodontal treatment as a bactericidal tool.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1176
Author(s):  
Vanesa Pérez-Laguna ◽  
Yolanda Barrena-López ◽  
Yolanda Gilaberte ◽  
Antonio Rezusta

Candidiasis is very common and complicated to treat in some cases due to increased resistance to antifungals. Antimicrobial photodynamic therapy (aPDT) is a promising alternative treatment. It is based on the principle that light of a specific wavelength activates a photosensitizer molecule resulting in the generation of reactive oxygen species that are able to kill pathogens. The aim here is the in vitro photoinactivation of three strains of Candida spp., Candida albicans ATCC 10231, Candida parapsilosis ATCC 22019 and Candida krusei ATCC 6258, using aPDT with different sources of irradiation and the photosensitizer methylene blue (MB), alone or in combination with chlorhexidine (CHX). Irradiation was carried out at a fluence of 18 J/cm2 with a light-emitting diode (LED) lamp emitting in red (625 nm) or a white metal halide lamp (WMH) that emits at broad-spectrum white light (420–700 nm). After the photodynamic treatment, the antimicrobial effect is evaluated by counting colony forming units (CFU). MB-aPDT produces a 6 log10 reduction in the number of CFU/100 μL of Candida spp., and the combination with CHX enhances the effect of photoinactivation (effect achieved with lower concentration of MB). Both lamps have similar efficiencies, but the WMH lamp is slightly more efficient. This work opens the doors to a possible clinical application of the combination for resistant or persistent forms of Candida infections.


Author(s):  
Paula Virginia Michelon TOLEDO ◽  
Felipe Francisco TUON ◽  
Larissa BAIL ◽  
Francine MANENTE ◽  
Polliane ARRUDA ◽  
...  

BACKGROUND: Animal models are useful to evaluate the efficacy of antimicrobials in experimental sepsis. AIM: To elucidate the steps of producing an experimental model for the treatment of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae sepsis METHODS: Several ESBL inoculums ranging from 1.5x109 colony-forming units per milliliter (CFU/mL) to 2.0x1010 CFU/mL were administered by peritoneal injection in adults Wistar rats. Outcomes and microbiological data of quantitative peritoneal and blood cultures were observed in untreated animals. Animals which received 2.0x1010 CFU/mL inoculums were treated with single meropenem dose (30mg/kg) after one hour and those which received 1.0x1010 CFU/mL inoculums were treated immediately with three doses of meropenem 50 mg/kg. Outcomes were observed for 24 hours after inoculation. RESULTS: Solutions with 1.5 x109 and 6.0x109 CFU/mL were not lethal within 24 hours. Inoculums of 1.0x1010 CFU/mL were lethal in 80% and solutions with 2.0x1010 CFU/mL were lethal in 100% of animals. ESBL lethal sepsis (1.0x1010CFU/mL) was treated immediately with 50 mg/kg of meropenem every eight hours for 24 hours and presented 40% mortality compared with 80% mortality of the control group (p=0.033). Quantitative cultures of peritoneal fluid presented 104 CFU/mL or less for treated animals compared to more than 105 for untreated animals (p=0.001). CONCLUSION: Inoculums of 1.0x1010CFU/mL achieved the best results to study a model of lethal sepsis and this model of treatment of carbapenem-susceptible Enterobacteriaceae can serve as control to further evaluation of treatment of carbapenemase-producing Enterobacteriaceae models.


2018 ◽  
Vol 29 (5) ◽  
pp. 459-464 ◽  
Author(s):  
Larissa Tais Soligo ◽  
Ediléia Lodi ◽  
Ana Paula Farina ◽  
Matheus Albino Souza ◽  
Cristina de Mattos Pimenta Vidal ◽  
...  

Abstract The aim of this study was to compare the efficacy of grape seed extract (GSE), calcium hypochlorite [Ca(ClO)2], and sodium hypochlorite (NaOCl) irrigant solutions with rotary or reciprocating instrumentation for disinfection of root canals inoculated with Enterococcus faecalis. The mesiobuccal root canals of mandibular molars were prepared and inoculated with Enterococcus faecalis for 21 days. The roots were then randomly divided into the following eight experimental groups (n=11) according to the instrumentation technique and disinfection protocol: ProTaper Next or Reciproc R25 with sodium chloride (control group), 6% NaOCl, 6% Ca(ClO)2, or 50% GSE used for irrigation during instrumentation. The antimicrobial activity was determined on the basis of a reduction in colony-forming units (CFUs) counted on bacterial samples collected before and after root canal instrumentation and expressed as a percentage of reduction. Data were evaluated by two-way ANOVA followed by Tukey HSD post-hoc tests (p<0.05). No significant differences were observed in bacterial reduction between the ProTaper Next and Reciproc R25 systems (p>0.05), regardless of the irrigant solution used. Furthermore, all active solutions (6% NaOCl, 50% GSE, and 6% Ca(ClO)2) showed similar potential to reduce bacterial counts (p>0.05) and were significantly more effective than sodium chloride (control) (p<0.05). The results suggest that the GSE and Ca(ClO)2 have potential clinical application as irrigant solutions in endodontic therapy since they present bactericidal efficacy against Enterococcus faecalis.


2018 ◽  
Vol 43 (3) ◽  
pp. 315-325 ◽  
Author(s):  
AMO Dal Piva ◽  
LPC Contreras ◽  
FC Ribeiro ◽  
LC Anami ◽  
SEA Camargo ◽  
...  

SUMMARY Introduction: This study evaluated the morphology, biofilm formation, and viability of human gingival fibroblasts in contact with two monolithic ceramics after two different finishing techniques: polishing or glazing. For this, 92 blocks (4.5 × 4.5 × 1.5 mm) of each ceramic were made using high translucency zirconia partially stabilized by yttrium (YZHT) and lithium silicate reinforced by zirconium (ZLS). Methods and Materials: Blocks were sintered and then divided into glazing (g) or polishing (p) surface finish. Surface roughness (Ra and RSm) was evaluated through a contact rugosimeter and profilometry. Specimens were contaminated for heterotypic biofilm formation with Streptococcus mutans, Streptococcus sanguinis and Candida albicans for 16 hours. Biofilm was quantified by counting the colony forming units (CFU/mL) and analyzed by scanning electron microscopy (SEM). Fibroblast viability was evaluated by MTT assay. Surface free energy (SFE) was also determined. Roughness data were evaluated using nonparametric tests, while SFE, MTT and CFU results were evaluated by analysis of variance and Tukey test, and MTT data were also submitted to t-test (all, α=0.05). Results: Results showed that polished samples presented a lower high profile mean (p&lt;0.001); however, YZHTg presented less space between defects (p=0.0002). SFE showed that YZHT presented higher SFE than ZLS. Profilometry evidenced more homogeneity on polished surfaces. The interaction of finishing technique and microorganisms influenced the CFU (p=0.00). MTT assay demonstrated initial severe cytotoxic behavior for polished surfaces. SEM images showed homogeneous surfaces, except for glazed YZHT. Conclusion: Glazed surfaces have a greater roughness and tend to accumulate more biofilm. Polished surfaces have higher SFE; however, they are temporarily cytotoxic.


2003 ◽  
Vol 14 (1) ◽  
pp. 58-62 ◽  
Author(s):  
Carlos Estrela ◽  
Rosane Galhardo Ribeiro ◽  
Cyntia R.A. Estrela ◽  
Jesus Djalma Pécora ◽  
Manoel Damião Sousa-Neto

The objective of this study was to analyze the antimicrobial effect of 2% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX) by agar diffusion test and by direct exposure test. Five microorganisms: Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Bacillus subtilis, Candida albicans, and one mixture of these were used. These strains were inoculated in brain heart infusion (BHI) and incubated at 37ºC for 24 h. For the agar diffusion test (ADT), 18 Petri plates with 20 ml of BHI agar were inoculated with 0.1 ml of the microbial suspensions, using sterile swabs that were spread on the medium, obtaining growth in junction. Fifty-four paper disks (9 mm in diameter) were immersed in the experimental solutions for 1 min. Subsequently, three papers disks containing one of the substances were placed on the BHI agar surface in each agar plate. The plates were maintained for 1 h at room temperature, and then incubated at 37ºC for 48 h. The diameter of microbial inhibition was measured around the papers disks containing the substances. For the direct exposure test, 162 #50 sterile absorbent paper points were immersed in the experimental suspensions for 5 min, and were then placed on Petri plates and covered with one of the irrigant solutions, or with sterile distilled water (control group). After intervals of 5, 10 and 30 min, the paper points were removed from contact with the solutions and individually immersed in 7 ml of Letheen Broth, followed by incubation at 37ºC for 48 h. Microbial growth was evaluated by turbidity of the culture medium. A 0.1 ml inoculum obtained from the Letheen Broth was transferred to 7 ml of BHI, and incubated at 37ºC for 48 h. Bacterial growth was again evaluated by turbidity of the culture medium. Gram stain of BHI cultures was used for verification of contamination and growth was determined by macroscopic and microscopic examination. The best performance of antimicrobial effectiveness of NaOCl was observed in the direct exposure test, and of CHX was observed in the agar diffusion test. The magnitude of antimicrobial effect was influenced by the experimental methods, biological indicators and exposure time.


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