scholarly journals The Multifunctional Sactipeptide Ruminococcin C1 Displays Potent Antibacterial Activity In Vivo as Well as Other Beneficial Properties for Human Health

2021 ◽  
Vol 22 (6) ◽  
pp. 3253
Author(s):  
Clarisse Roblin ◽  
Steve Chiumento ◽  
Cédric Jacqueline ◽  
Eric Pinloche ◽  
Cendrine Nicoletti ◽  
...  

The world is on the verge of a major antibiotic crisis as the emergence of resistant bacteria is increasing, and very few novel molecules have been discovered since the 1960s. In this context, scientists have been exploring alternatives to conventional antibiotics, such as ribosomally synthesized and post-translationally modified peptides (RiPPs). Interestingly, the highly potent in vitro antibacterial activity and safety of ruminococcin C1, a recently discovered RiPP belonging to the sactipeptide subclass, has been demonstrated. The present results show that ruminococcin C1 is efficient at curing infection and at protecting challenged mice from Clostridium perfringens with a lower dose than the conventional antibiotic vancomycin. Moreover, antimicrobial peptide (AMP) is also effective against this pathogen in the complex microbial community of the gut environment, with a selective impact on a few bacterial genera, while maintaining a global homeostasis of the microbiome. In addition, ruminococcin C1 exhibits other biological activities that could be beneficial for human health, as well as other fields of applications. Overall, this study, by using an in vivo infection approach, confirms the antimicrobial clinical potential and highlights the multiple functional properties of ruminococcin C1, thus extending its therapeutic interest.

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3303 ◽  
Author(s):  
Wanda Mączka ◽  
Katarzyna Wińska ◽  
Małgorzata Grabarczyk

Geraniol is a monoterpenic alcohol with a pleasant rose-like aroma, known as an important ingredient in many essential oils, and is used commercially as a fragrance compound in cosmetic and household products. However, geraniol has a number of biological activities, such as antioxidant and anti-inflammatory properties. In addition, numerous in vitro and in vivo studies have shown the activity of geraniol against prostate, bowel, liver, kidney and skin cancer. It can induce apoptosis and increase the expression of proapoptotic proteins. The synergy of this with other drugs may further increase the range of chemotherapeutic agents. The antibacterial activity of this compound was also observed on respiratory pathogens, skin and food-derived strains. This review discusses some of the most important uses of geraniol.


2021 ◽  
Vol 9 (2) ◽  
pp. 189-199
Author(s):  
Md. Zia Uddin ◽  
◽  
Md. Sohel Rana ◽  
Subrata Chowdhury ◽  
Arkajyoti Paul ◽  
...  

The present research intended to explore the biological activities, namely acute toxicity test and hypoglycemic as well as in vitro anti-arthritic along with the antibacterial activity of crude methanol extracts with its different soluble fractions like petroleum ether (PESF), carbon tetrachloride (CTCSF), chloroform (CSF) and aqueous soluble fraction (AQSF) of Holigarna longifolia and Elatostema papillosum. Phytochemical screening was performed by established protocols. Acute toxicity and hypoglycemic effects were performed in experimental and alloxan-induced diabetic rats. In vitro anti-arthritic and antibacterial activity were conducted by protein denaturation inhibitory and disc diffusion methods. It was observed that no rats exhibit any lethality types, which reveal the safety of plant fractionates. It was also seen that both plants' fractionates showed significant (p < 0.01) activity on hyperglycemia compared to standard. Upon investigation, it was observed that crude methanol and its CS fraction of E. papillosum and only CS fraction of H. longifolia significantly (p < 0.05) inhibited denaturation of bovine serum albumin protein compared to standard diclofenac sodium. Moreover, it was observed that crude methanol extract and its CS fraction of E. papillosum showed significant inhibitory action on all Gram-positive bacteria's growth. In contrast, the PES fraction highlighted an inhibitory zone of 26.7 and 24.7 mm, respectively, towards B. subtilis and S. aureus. This study provides some support to explain the traditional uses of H. longifolia and E. papillosum.


2021 ◽  
Author(s):  
Jessica Bratt

<p>The spread of antibiotic resistance and the emergence of multi-drug resistant bacteria is a major threat to public health. This study investigated a unique cytosine rich DNA structure, the i-Motif to deliver soluble Ag+ as a novel antimicrobial agent (AgiMs). AgiMs were evaluated in vitro against P. aeruginosa and A. baumannii strains. AgiMs displayed significant antibacterial activity against both P. aeruginosa and A. baumannii (median MIC: 0.875 µM and 0.75 µM, respectively) by rapid, bactericidal and concentration-dependent effect. Low concentrations of AgiMs showed efficacy against PAO1 20-h biofilms, resulting in 57% reduction in biomass (5 x MIC). A single dose of AgiMs extended survival of G. Mellonella larvae, with the therapeutic benefit paralleled in the reduction of internal bacterial load. Synergistic interactions were observed with the combination of AgiMs and tobramycin, a common antibiotic used to treat P. aeruginosa infections; indicating the potential for AgiMs to reinstate the potency of current antibiotics. This silver-based agent might be an alternative to the failing antibiotic regimes for MDR resistant infections. Further in vitro and in vivo studies are warranted to confirm the therapeutic potential. </p>


Author(s):  
Maria Miklasińska-Majdanik ◽  
Małgorzata Kępa ◽  
Robert Wojtyczka ◽  
Danuta Idzik ◽  
Tomasz Wąsik

There is a growing body of evidence that flavonoids show antibacterial activity against both Gram-positive and Gram-negative bacteria. The mechanisms of action of phenolic compounds on bacterial cell have been partially attributed to damage to the bacterial membrane, inhibition of virulence factors such as enzymes and toxins, and suppression of bacterial biofilm formation. What is more, some natural polyphenols, aside from direct antibacterial activity, exert a synergistic effect when combined with common chemotherapeutics. Many studies have proved that in synergy with antibiotics plant flavonoids pose a promising alternative for therapeutic strategies against drug resistant bacteria. In this review most recent reports on antimicrobial action of polyphenols on Staphylococcus aureus strains are described, highlighting where proven, the mechanisms of action and the structure–activity relationships. Since many reports in this field are, to some extent, conflicting, a unified in vitro and in vivo susceptibility testing algorithms should be introduced to ensure the selection of effective antibacterial polyphenolic compounds with low cytotoxicity and minimal side effects.


2021 ◽  
Vol 152 (3) ◽  
pp. 345-356
Author(s):  
Shijun Su ◽  
Qing Zhou ◽  
Xuemei Tang ◽  
Feng Peng ◽  
Tingting Liu ◽  
...  

AbstractA series of myricetin derivatives containing sulfonate groups were designed and synthesized. Preliminary antibacterial activity showed that most of the target compounds exhibited significant biological activities against Xanthomonas axonopodis pv. Citri (Xac), Ralstonia solanacearum (Rs), and Xanthomonas oryzae pv. Oryzae (Xoo). In particular, the EC50 value of compound 3e was 13.76 μg/cm3 against Xac, which was better than commercial reagents bismerthiazol (50.32 µg/cm3) and thiodiazole copper. (83.27 µg/cm3), and the EC50 value of compound 3j was 11.92 μg/cm3 against Xoo in vitro, The result was better than that of bismerthiazol (72.08 µg/cm3) and thiodiazole copper (99.26 µg/cm3). Compound 3j displayed the better in vivo activity against rice bacterial leaf blight than bismerthiazol and thiodiazole copper. Meanwhile, the antibacterial mechanism of compounds 3e and 3j was studied by scanning electron microscope (SEM). These results suggested that myricetin derivatives containing sulfonate can be considered as a new antibacterial reagents. Graphic abstract


2021 ◽  
Vol 13 (1) ◽  
pp. 110-126
Author(s):  
Ruchi Sankhwar ◽  
Shilpi Yadav ◽  
Abhishek Kumar ◽  
Ravi Kr. Gupta

Gram-positive bacteria cause various diseases from the superficial skin to deep tissue infections. The capability of causing numerous diseases is due to the production of virulence factors which are tightly regulated by the virulence genes. Various Gram-positive pathogenic bacteria e.g. Staphylococcus, Mycobacterium, and Listeria are capable of causing lethal infections in humans and animals. Conventional antibiotics, targeted antibiotics, and combinatorial drugs are used as therapeutic agents against Gram-positive pathogens. Due to intricate virulence pathway bacteria readily adopt resistance to available drugs. Therefore, there is need to develop some alternative approaches to combat these infections. Various natural extracts are effective against pathogenic bacteria with or without the available drugs. Curcumin is a natural extract of Curcuma longas rhizome, known as turmeric. Curcumin shows various biological activities such as antimicrobial, antioxidant and anti-inflammatory. It also shows strong antibacterial activity against Gram-positive and few Gram-negative bacteria. Besides all these beneficial applications, major drawbacks of curcumin are poor aqueous solubility and less bioavailability. However, drug delivery approaches including nanoformulation are developed to increase its stability in vitro and in vivo settings. The present review article focused on the translation of potential applications of curcumin in various diseases specifically caused by Gram-positive pathogens. Various methods used for the formulations of curcumin nanoparticles, combinatorial strategies with curcumin nanoparticles and their application in the prevention of infections have been discussed. The present article also discusses the future aspects of curcumin-nanoparticles and its use as an alternative therapeutic approach against pathogens.


Author(s):  
Michał Zimecki ◽  
Krzysztof Kaczmarek

The consequences of manipulations in structure and amino acid composition of native cyclolinopeptide A (CLA) from linen seeds and its linear precursor on their biological activities and mechanisms of action are reviewed. The modifications included truncation of the peptide chain, replacement of amino acid residues with proteinogenic or non-proteinogenic ones, modifications of peptide bond, and others. The studies revealed changes in the immunosuppressive potency of these analogs investigated in a number of in vitro and in vivo experimental models, predominantly in rodents, as well as differences in their postulated mechanism of action. The modified peptides were compared with cyclosporine A and parent CLA. Some of the synthesized and investigated peptides show potential therapeutic usefulness.


2018 ◽  
Vol 6 ◽  
Author(s):  
Tengfei Liu ◽  
Yuqing Liu ◽  
Menglong Liu ◽  
Ying Wang ◽  
Weifeng He ◽  
...  

Abstract Background Bacterial infection is one of the most common complications in burn, trauma, and chronic refractory wounds and is an impediment to healing. The frequent occurrence of antimicrobial-resistant bacteria due to irrational application of antibiotics increases treatment cost and mortality. Graphene oxide (GO) has been generally reported to possess high antimicrobial activity against a wide range of bacteria in vitro. In this study, a graphene oxide-quaternary ammonium salt (GO-QAS) nanocomposite was synthesized and thoroughly investigated for synergistic antibacterial activity, underlying antibacterial mechanisms and biocompatibility in vitro and in vivo. Methods The GO-QAS nanocomposite was synthesized through amidation reactions of carboxylic group end-capped QAS polymers with primary amine-decorated GO to achieve high QAS loading ratios on nanosheets. Next, we investigated the antibacterial activity and biocompatibility of GO-QAS in vitro and in vivo. Results GO-QAS exhibited synergistic antibacterial activity against bacteria through not only mechanical membrane perturbation, including wrapping, bacterial membrane insertion, and bacterial membrane perforation, but also oxidative stress induction. In addition, it was found that GO-QAS could eradicate multidrug-resistant bacteria more effectively than conventional antibiotics. The in vitro and in vivo toxicity tests indicated that GO-QAS did not exhibit obvious toxicity towards mammalian cells or organs at low concentrations. Notably, GO-QAS topically applied on infected wounds maintained highly efficient antibacterial activity and promoted infected wound healing in vivo. Conclusions The GO-QAS nanocomposite exhibits excellent synergistic antibacterial activity and good biocompatibility both in vitro and in vivo. The antibacterial mechanisms involve both mechanical membrane perturbation and oxidative stress induction. In addition, GO-QAS accelerated the healing process of infected wounds by promoting re-epithelialization and granulation tissue formation. Overall, the results indicated that the GO-QAS nanocomposite could be applied as a promising antimicrobial agent for infected wound management and antibacterial wound dressing synthesis.


2020 ◽  
Vol 23 (7) ◽  
pp. 931-939
Author(s):  
Zein Sima ◽  
Hammouh Fadwa ◽  
Dababneh Basem ◽  
Gammoh Omar ◽  
Al-Smadi Ahmed

2021 ◽  
Author(s):  
Jessica Bratt

<p>The spread of antibiotic resistance and the emergence of multi-drug resistant bacteria is a major threat to public health. This study investigated a unique cytosine rich DNA structure, the i-Motif to deliver soluble Ag+ as a novel antimicrobial agent (AgiMs). AgiMs were evaluated in vitro against P. aeruginosa and A. baumannii strains. AgiMs displayed significant antibacterial activity against both P. aeruginosa and A. baumannii (median MIC: 0.875 µM and 0.75 µM, respectively) by rapid, bactericidal and concentration-dependent effect. Low concentrations of AgiMs showed efficacy against PAO1 20-h biofilms, resulting in 57% reduction in biomass (5 x MIC). A single dose of AgiMs extended survival of G. Mellonella larvae, with the therapeutic benefit paralleled in the reduction of internal bacterial load. Synergistic interactions were observed with the combination of AgiMs and tobramycin, a common antibiotic used to treat P. aeruginosa infections; indicating the potential for AgiMs to reinstate the potency of current antibiotics. This silver-based agent might be an alternative to the failing antibiotic regimes for MDR resistant infections. Further in vitro and in vivo studies are warranted to confirm the therapeutic potential. </p>


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