scholarly journals Systematically Studying the Optimal Amino Acid Distribution Patterns of the Amphiphilic Structure by Using the Ultrashort Amphiphiles

2020 ◽  
Vol 11 ◽  
Author(s):  
Shiqi He ◽  
Zhanyi Yang ◽  
Weikang Yu ◽  
Jiawei Li ◽  
Zhongyu Li ◽  
...  

Amphipathicity has traditionally been considered to be essential for the de novo design or systematic optimization of antimicrobial peptides (AMPs). However, the current research methods to study the relationship between amphiphilicity and antimicrobial activity are inappropriate, because the key parameters (hydrophobicity, positive charge, etc.) and secondary structure of AMPs are changed. To systematically and accurately study the effects of amphiphilicity on antimicrobial properties of AMPs, we designed parallel series of AMPs with a different order of amino acids in a sequence composed only of Arg and either Trp (WR series) or Leu (LR series), under conditions in which other vital parameters were fixed. Furthermore, based on the WR and LR peptides that can form stable amphiphilic β-sheet structures in the anionic membrane-mimetic environment, we found that high β-sheet amphipathic was accompanied by strong antimicrobial activity. Of such peptides, W5 ([RW]4W) and L5 ([RL]4L) with a nicely amphipathic β-sheet structure possessed the optimal therapeutic index. W5 and L5 also exhibited high stability in vitro and a potent membrane-disruptive mechanism. These results suggest that the alternate arrangement of hydrophobic and hydrophilic residues to form a stable amphipathic β-sheet structure is an essential factor that significantly affects the antimicrobial properties.

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4383
Author(s):  
Barbara Lapinska ◽  
Aleksandra Szram ◽  
Beata Zarzycka ◽  
Janina Grzegorczyk ◽  
Louis Hardan ◽  
...  

Modifying the composition of dental restorative materials with antimicrobial agents might induce their antibacterial potential against cariogenic bacteria, e.g., S.mutans and L.acidophilus, as well as antifungal effect on C.albicans that are major oral pathogens. Essential oils (EOs) are widely known for antimicrobial activity and are successfully used in dental industry. The study aimed at evaluating antibacterial and antifungal activity of EOs and composite resin material (CR) modified with EO against oral pathogens. Ten EOs (i.e., anise, cinnamon, citronella, clove, geranium, lavender, limette, mint, rosemary thyme) were tested using agar diffusion method. Cinnamon and thyme EOs showed significantly highest antibacterial activity against S.mutans and L.acidophilus among all tested EOs. Anise and limette EOs showed no antibacterial activity against S.mutans. All tested EOs exhibited antifungal activity against C.albicans, whereas cinnamon EO showed significantly highest and limette EO significantly lowest activity. Next, 1, 2 or 5 µL of cinnamon EO was introduced into 2 g of CR and microbiologically tested. The modified CR showed higher antimicrobial activity in comparison to unmodified one. CR containing 2 µL of EO showed the best antimicrobial properties against S.mutans and C.albicans, while CR modified with 1 µL of EO showed the best antimicrobial properties against L.acidophilus.


2004 ◽  
Vol 15 (1) ◽  
pp. 30-35 ◽  
Author(s):  
Brenda Paula Figueiredo de Almeida Gomes ◽  
José Assis Pedroso ◽  
Rogério Castilho Jacinto ◽  
Morgana Eli Vianna ◽  
Caio Cezar Randi Ferraz ◽  
...  

The aim of the present study was to analyze the antimicrobial properties of five endodontic sealers: Endo Fill, Endomethasone, Endomethasone N, Sealer 26 and AH-Plus, against the following microorganisms: Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Streptococcus sanguis and Actinomyces naeslundii. The sealers were tested immediately, 24 h, 48 h and 7 days after manipulation.The direct contact method through the observation of the microbial growth in liquid medium and the agar diffusion test were used to evaluate the antimicrobial properties of the sealers. The results, in both methodologies used, showed that immediately after manipulation, Endo-Fill and Endomethasone demonstrated the highest antimicrobial activity, with no statistically significant difference between them. Sealer 26 demonstrated the lowest antimicrobial activity. At all other times after manipulation, there were no statistically significant differences among all the sealers tested. In conclusion, none of the sealers totally inhibited the growth of the microorganisms. Furthermore, the antimicrobial activity of each sealer decreased with time and was dependent upon the microbial susceptibility to them.


2013 ◽  
Vol 14 (5) ◽  
pp. 924-929 ◽  
Author(s):  
Reena Kulshrestha ◽  
J Kranthi ◽  
P Krishna Rao ◽  
Feroz Jenner ◽  
V Abdul Jaleel ◽  
...  

ABSTRACT Aim The present study was conducted to evaluate the efficacy of commercially available herbal toothpastes against the different periodontopathogens. Materials and methods Six herbal toothpastes that were commonly commercially available were included in the study. Colgate herbal, Babool, Meswak, Neem active, Dabur red toothpastes were tested for the study whereas sterile normal saline was used as control. Antimicrobial efficacies of dentifrices were evaluated against Streptococcus mutans and Actinobacillus actinomycetemcomitans. The antimicrobial properties of dentifrices were tested by measuring the maximum zone of inhibition at 24 hours on the Mueller Hinton Agar media inoculated with microbial strain using disk diffusion method. Each dentifrice was tested at 100% concentration (full strength). Results The study showed that all dentifrices selected for the study were effective against the entire test organism but to varying degree. Neem active tooth paste gave a reading of 25.4 mm as the zone of inhibition which was highest amongst all of the test dentifrices. Colgate Herbal and Meswak dentifrices recorded a larger maximum zone of inhibition, measuring 23 and 22.6 mm respectively, compared to other toothpastes. All other dentifrices showed the zone of inhibition to be between 17 and 19 mm respectively. Conclusion The antibacterial properties of six dentifrices were studied in vitro and concluded that almost all of the dentifrices available commercially had antibacterial properties to some extent to benefit dental health or antiplaque action. How to cite this article Jenner F, Jaleel VA, Kulshrestha R, Maheswar G, Rao PK, Kranthi J. Evaluating the Antimicrobial Activity of Commercially Available Herbal Toothpastes on Microorganisms Associated with Diabetes Mellitus. J Contemp Dent Pract 2013;14(5):924-929.


2012 ◽  
Vol 7 (7) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Samah Djeddi ◽  
Khadidja Djebile ◽  
Ghania Hadjbourega ◽  
Zoubida Achour ◽  
Catherine Argyropoulou ◽  
...  

The chemical composition of the essential oil obtained from the aerial parts of Santolina chamaecyparissus L., growing in Algeria, was investigated by GC-MS analyses. A total of 36 compounds were identified, accounting for 91.7% of the essential oil obtained. Camphor (31.1%) and cubenol (17.0%) were the predominant compounds. The potential of the antimicrobial activity was also investigated and the tested sample proved to be very active against Klebsiella pneumonia and Candida albicans (34.1 ± 0.02 mm and 35.0 ± 0.01 mm, respectively). Transverse sections of the leaf and stem of the plant suggest that the essential oil is localized in endogenous and exogenous sites.


2017 ◽  
Vol 13 ◽  
pp. 239-247 ◽  
Author(s):  
Georgy A. Frolov ◽  
Yakov N. Karasenkov ◽  
Alexander A. Gusev ◽  
Olga V. Zakharova ◽  
Anna Yu. Godymchuk ◽  
...  

Preparation of nontoxic antimicrobial solutions is a priority in the development of new antibiotics. The in vitro effect of the chemical composition of the dispersed phase and dissolved solids in the dispersion medium on the antimicrobial properties of aqueous colloidal solutions of nanoparticles of a number of metals and metal oxides against microorganisms of different species - bacterial dental plaque, Bacillus cereus, and spores of vaccine strain Bacillus anthracis STI - 1 were studied in this work.


2021 ◽  
Vol 7 (1) ◽  
pp. 01-05
Author(s):  
Jikia Maia

The antimicrobial activity of filling materials was studied to improve the quality of treatment of complicated caries in vitro. Resorcin-formalin cement Resodont (“Latus”, Ukraine) - № 1; Endocort zinc oxide-eugenol cement (“Latus”, Ukraine) - No. 2; materials based on zinc oxide eugenol cement with dexamethasone: Endomethasone ivory (Septodont, France) - No. 3 and Endofil ("Produit Dentaires SA", Switzerland) - No. 4. To assess the antimicrobial activity of the studied materials, test microorganism strains were used: Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 6783, Candida albicans ATCC 885-653. As a result of the study, it was established that filling materials have different antimicrobial activity. Resodont has the greatest antimicrobial activity on the test culture. Endomethason is active in relation to the test cultures studied, inferior to Resodont in its antimicrobial properties. Endocort and Endofil have less antimicrobial activity than Resodont and Endomethason, but have approximately equal growth retardation rates. It should be noted that with respect to Staphylococcus aureus, Endocort was found to be almost 1.5 times more active than Endofil. The conducted studies confirm that the materials for filling of root canals by Resodont and Endocort (Latus, Ukraine) have a pronounced antibacterial effect. They are competitive with foreign sealers and are the materials of choice, having a significantly lower cost.


Author(s):  
Haïfa Debbabi ◽  
Ridha El Mokni ◽  
Ibrahim Jlassi ◽  
Rajesh K Joshi ◽  
Saoussen Hammami

Abstract Chemical composition and antimicrobial activity of Teucrium capitatum L. subsp. lusitanicum essential oil was investigated for the first time in the present study. Qualitative and quantitative analyses of the chemical composition by gas chromatography and mass spectrometry (GC–FID and GC–MS) revealed the presence of 60 compounds representing 97.6% of the whole constituents. The main compounds were germacrene D (47.1%), spathulenol (5.8%), α-selinene (5.3%), germacrene A (2.9%), δ-cadinene (2.8%) and cubenol (2.7%). In vitro, the antimicrobial activity was investigated against five bacterial strains along with the yeast Candida albicans using broth microdilution assay. T. capitatum subsp. lusitanicum essential oil showed significant activity against the gram-positive bacteria Staphylococcus aureus (MIC = MBC = 78 μg mL−1), Bacillus subtilis (MIC = MBC = 156 μg mL−1) and the yeast C. albicans (MIC = MFC = 156 μg mL−1). The great potential of antimicrobial effects is most likely due to the very high percentage of sesquiterpene hydrocarbons particularly to germacrene D, for which the antimicrobial properties have been previously reported.


Author(s):  
Jaishree Sharma ◽  
Padma Kumar

Objective: The present study was carried out to evaluate the in vitro antimicrobial activity of water, methanolic and pet ether extracts from leaves and fruit of A. marmelos and C. papaya. Methods: Crude extract of leaves and fruit of Aegle marmelos and Carica papaya were prepared for series of polar solvents by hot extraction method in soxhlet then the extracts were first screened for its antimicrobial activity by “Disc Diffusion Assay” against medically important bacteria, plant pathogen and fungi. Fractions showing activities were then used to determine MIC (minimum inhibitory concentration) and MBC/MFC (minimum bactericidal and fungicidal concentration) by broth dilution and total activity were also calculated.Result: Aegle marmelos shows comparatively significant antimicrobial activity than Carica papaya. However antimicrobial activity was found both solvent and organism dependent. Almost all the extracts of Aegle marmelos show an inhibitory effect against most of the test organism whereas the test extracts Carica papaya show an inhibitory effect against the very few test organisms. Lowest MIC values 0.0195 mg/ml were recorded against Roultella planticola and Klebsiella pneumonae indicate the significant antimicrobial potential of the test extracts. The high value of TA was recorded against Roultella planticola in both the plants. Data were analyzed by one way ANNOVA and values were considered significant at P<0.05Conclusion: The MIC and MBC/MFC values of Aegle marmelos showed its broad antimicrobial potential and is promising in the development of phytomedicine for antimicrobial properties then Carica papaya.


2015 ◽  
Vol 61 (3) ◽  
pp. 93-104
Author(s):  
Basel Saleh ◽  
Lila Al-Halab ◽  
Ayman Al-Mariri

Summary The current study aimed to investigate antimicrobial activity of methanol, ethanol, acetone, ethyl acetate and hot water (leaves and twigs fractions) Psidium guajava L. crude extracts against three bacteria and two fungi pathogens. Antimicrobial activity expressed by disc-diffusion assay (zone of inhibitions - ZIs), activity index (AI) and minimum inhibitory concentration (MICs) that were measured as reported in many investigations. Based upon the estimated ZIs, AI and MICs values, hot water twigs <1 cm diameter extract was the most potent against all tested microorganisms. The MICs value ranged between 4 and 7.2 mg/ml for bacteria, while, it was between 14.5 and 37.3 mg/ml for fungi. Moreover, ethyl acetate had the lowest antimicrobial activity compared to the other tested solvents. From the results obtained herein, it could be concluded that P. guajava serve as antibacterial and antifungal agent.


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