The pH-Responsive Property of Antimicrobial Peptide GH12 Enhances Its Anticaries Effects at Acidic pH

2020 ◽  
pp. 1-11
Author(s):  
Wentao Jiang ◽  
Junyuan Luo ◽  
Yufei Wang ◽  
Xiangshu Chen ◽  
Xuelian Jiang ◽  
...  

Dental caries is closely related to the acidification of the biofilms on the tooth surface, in which cariogenic bacteria bring about a dramatic pH decrease and disrupt remineralisation equilibrium upon the fermentation of dietary sugars. Thus, approaches targeting the acidified niches with enhanced anticaries activities at acidic pH are highly desirable. In our previous study, a cationic amphipathic α-helical antimicrobial peptide GH12 (Gly-Leu-Leu-Trp-His-Leu-Leu-His-His-Leu-Leu-His-NH<sub>2</sub>) was designed with good stability, low cytotoxicity, and excellent antibacterial effects. Considering its potent antibacterial activity against the acidogenic bacteria and its histidine-rich sequence, it was speculated that GH12 might show enhanced antimicrobial effects at an acidic pH. In this study, the pH-responsive property of GH12 was determined to evaluate its potential as a smart acid-activated anticaries agent. GH12 possessed much lower minimal inhibitory concentrations and minimal bactericidal concentrations against various kinds of bacteria at pH 5.5 than at pH 7.2. Employing <i>Streptococcus mutans</i>, the principal caries pathogen, as the model system, it was found that GH12 showed much stronger bactericidal effects on both planktonic <i>S. mutans</i> and <i>S. mutans</i> embedded in the biofilm at pH 5.5. In addition, short-term treatment with GH12 showed much more effective inhibitory effects on water-insoluble exopolysaccharides synthesis and lactic acid production of the preformed <i>S. mutans</i> biofilm at pH 5.5. As for the mechanism exploration, it was found that the net positive charge of GH12 increased and the tryptophan fluorescence intensity heightened with the peak shifting towards the short wavelength at pH 5.5, which demonstrated that GH12 could be more easily attracted to the anionic microbial cell membranes and that GH12 showed stronger interactions with the lipid membranes. In conclusion, acidic pH enhanced the antibacterial and antibiofilm activities of GH12, and GH12 is a potential smart anticaries agent targeting the cariogenic acidic microenvironment.

Author(s):  
سعيد مزعل موازي ◽  
يحيى فائق حسين ◽  
عبد المنعم دولاني ◽  
سيف يوسف عبدالله السويدي

Recently, many studies have been conducted to discover or improve cancers treatment. The current study aims to investigate the anticancer effect of thymoquinone, cordyceps, spirulina, ganoderma lucidium, poria cocos, and lion’s mane in four different concentrations 4, 8, 16, and 32 ug (equivalent to 1 mg/mL) in two different time treatments (48 and 96 hours) on human nasal epithelial cell line RPMI 2650. By using cell culture cytotoxicity techniques and assay, the highest anticancer effect on RPMI 2650 was obtained by thymoquinone. The lowest anticancer effect was demonstrated by poria cocos and cordyceps. However, these two medications showed higher anticancer effect when given in short-term treatment (48 hours) compared to long-term treatment (96 hours). Ganoderma lucidium and spirulina showed better impact than poria cocos, cordyceps, and lion’s mane in term of cells cytotoxicity. Mild to moderate antineoplastic effect was seen by utilizing lion’s mane treatment compared other drugs. Therefore, adopting a long-term treatment of high concentrations and doses of thymoquinone, cordyceps, spirulina, ganoderma lucidium, poria cocos, and lion’s mane can be more effective in the treatment of nasal cancer. In conclusion, these drugs were found to be a promising cancer remedy; therefore, they can be utilized as alternative treatment for nasal cancer or any other type of cancer therapy.


Author(s):  
Shien Ren ◽  
Chao Fan ◽  
Liangzhi Zhang ◽  
Xianjiang Tang ◽  
Haibo Fu ◽  
...  

Abstract Plants produce various plant secondary compounds (PSCs) to deter the foraging of herbivorous mammals. However, little is known about whether PSCs can reshape gut microbiota and promote gut homeostasis of hosts. Using 16S rDNA sequencing to investigate the effects of PSCs on the gut microbiota of small herbivorous mammals, we studied plateau pikas (Ochotona curzoniae) fed diets containing swainsonine (SW) extracted from Oxytropis ochrocephala. Our results showed that both long- and short-term treatment of a single artificial diet in the laboratory significantly reduced alpha diversity and significantly affected beta diversity, core bacteria abundance, and bacterial functions in pikas. After SW was added to the artificial diet, the alpha diversity significantly increased in the long-term treatment, and core bacteria (e.g., Akkermansiaceae) with altered relative abundances in the two treatments showed no significant difference compared with pikas in the wild. The complexity of the co-occurrence network structure was reduced in the artificial diet, but it increased after SW was added in both treatments. Further, the abundances of bacteria related to altered alanine, aspartate, and glutamate metabolism in the artificial diet were restored in response to SW. SW further decreased the concentration of short-chain fatty acids (SCFAs) in both treatments. Our results suggest that PSCs play a key role in regulating gut microbiota community and intestinal homeostasis, thereby maintaining host health. Key points • Swainsonine improves the intestinal bacterial diversity of plateau pikas. • Swainsonine promotes the recovery of core bacterial abundances in the gut of plateau pikas. • Swainsonine promotes the restoration of intestinal bacterial functions of plateau pikas.


Author(s):  
Cristina M. Muntean ◽  
Nicoleta E. Dina ◽  
Ioan Bratu ◽  
Carmen Tripon ◽  
Sorina Niţu (Năstase) ◽  
...  

Author(s):  
TRISNI UNTARI DEWI ◽  
INSTIATY . ◽  
RUDIANTO SEDONO ◽  
GESTINA ALISKA ◽  
MUHAMMAD KHIFZHON AZWAR ◽  
...  

Objective: This study sought to determine the correlation between trough plasma amikacin concentrations and urinary normalized kidney injurymolecule-1 (KIM-1) concentrations as an early biomarker of nephrotoxicity in patients with sepsis who are hospitalized in an intensive care unit.Methods: In this pilot study, 12 patients with sepsis were treated with amikacin 1000 mg/day between May 2015 and September 2015. The correlationbetween trough plasma amikacin concentrations measured after the third dose and the elevation of urinary normalized KIM-1 concentrations afterthe third amikacin dose relative to the first/second dose was evaluated.Results: In total, three patients had trough plasma amikacin concentrations exceeding the safe level (>10 μg/ml). Furthermore, eight patientsdisplayed higher normalized KIM-1 concentrations after third dose than after the first/second dose; however, there was no correlation betweentrough amikacin concentrations and the elevation of urinary normalized KIM-1 concentrations (r=0.3, p=0.3).Conclusion: The study results illustrated that short-term treatment with an amikacin dose of 1000 mg/day was generally safe in patients with sepsis.


1997 ◽  
Vol 6 (4) ◽  
pp. 9-16 ◽  
Author(s):  
Alison Behrman ◽  
Robert F. Orlikoff

Sophisticated, computer-based instrumentation has become increasingly available to the voice clinician. Yet substantial questions remain regarding its clinical necessity and usefulness. A theoretical model based on the scientific method is developed as a framework that can be used to guide the clinician in the selection and application of instrumental measures. Using the process of hypothesis testing, instrumentation is presented as an integral component of clinical practice. The uses of instrumental measures, and their relevance to long- and short-term treatment goals, are addressed. Clinical examples are presented to illustrate the incorporation of instrumentation and the scientific method into assessment and treatment.


2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Quentin Binet ◽  
Catherine Lambert ◽  
Laurine Sacré ◽  
Stéphane Eeckhoudt ◽  
Cedric Hermans

Background. Acquired hemophilia A (AHA) is a rare condition, due to the spontaneous formation of neutralizing antibodies against endogenous factor VIII. About half the cases are associated with pregnancy, postpartum, autoimmune diseases, malignancies, or adverse drug reactions. Symptoms include severe and unexpected bleeding that may prove life-threatening.Case Study. We report a case of AHA associated with bullous pemphigoid (BP), a chronic, autoimmune, subepidermal, blistering skin disease. To our knowledge, this is the 25th documented case of such an association. Following treatment for less than 3 months consisting of methylprednisolone at decreasing dose levels along with four courses of rituximab (monoclonal antibody directed against the CD20 protein), AHA was completely cured and BP well-controlled.Conclusions. This report illustrates a rare association of AHA and BP, supporting the possibility of eradicating the inhibitor with a well-conducted short-term treatment.


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