Biological Mechanisms of Polyphenols against Clostridium Difficile: A Systematic Review

BACKGROUND

Clostridium difficile is an opportunistic infection that can lead to antibiotic- associated diarrhea and toxic megacolon.

OBJECTIVE

This systematic review study aimed to investigate polyphenols' antibacterial and antitoxin properties and their effects on reducing complications related to C. difficile Infections (CDI).

METHODS

This systematic review was conducted following the PRISMA guideline 2020. Multiple databases, including Web of Science, PubMed, Cochrane Library, EMBASE, and Scopus, were searched thoroughly for existing literature. After considering the inclusion and exclusion criteria for the review, 18 articles were included. Data were collected and registered into an Excel file for further investigations and conclusions.

RESULTS

Polyphenols by reducing Reactive Oxygen Species (ROS) levels, increasing inflammatory factor Interleukin 10 (IL-10), reducing Nuclear Factor kappa B (NF-κB) and Tumour Necrosis Factor- α (TNF-α), IL-6, IL-1α, IL-1β, Granulocyte Colony-stimulating Factor (G-CSF), and Monocyte Chemoattractant Protein-1 (MCP-1) and Macrophage Inflammatory Protein-1 alpha (MIP-1α) levels, and regulating the expression of Bcl-2 and Bax, make the growth and replication conditions of C. difficile more difficult and prevent it from producing toxins. Furthermore, polyphenols can exhibit prebiotic properties, promoting the growth of beneficial Bifidobacterium and Lactobacillus species and consequently regulating gut microbiota, exerting antimicrobial activities against C. difficile. They also induce their beneficial effects by inhibiting the production of C. difficile TcdA and TcdB.

CONCLUSION

Polyphenols have been reported to inhibit C. difficile growth and toxin production by several mechanisms in preclinical studies. However, more clinical studies are needed to investigate their safety in humans.

Applications of Fruit Polyphenols and Their Functionalized Nanoparticles Against Foodborne Bacteria: A Mini Review

The ingestion of contaminated water and food is known to cause food illness. Moreover, on assessing the patients suffering from foodborne disease has revealed the role of microbes in such diseases. Concerning which different methods have been developed for protecting food from microbes, the treatment of food with chemicals has been reported to exhibit an unwanted organoleptic effect while also affecting the nutritional value of food. Owing to these challenges, the demand for natural food preservatives has substantially increased. Therefore, the interest of researchers and food industries has shifted towards fruit polyphenols as potent inhibitors of foodborne bacteria. Recently, numerous fruit polyphenols have been acclaimed for their ability to avert toxin production and biofilm formation. Furthermore, various studies have recommended using fruit polyphenols solely or in combination with chemical disinfectants and food preservatives. Currently, different nanoparticles have been synthesized using fruit polyphenols to curb the growth of pathogenic microbes. Hence, this review intends to summarize the current knowledge about fruit polyphenols as antibacterial agents against foodborne pathogens. Additionally, the application of different fruit extracts in synthesizing functionalized nanoparticles has also been discussed.

The Interactions between Polyphenols and Microorganisms, Especially Gut Microbiota

This review presents the comprehensive knowledge about the bidirectional relationship between polyphenols and the gut microbiome. The first part is related to polyphenols' impacts on various microorganisms, especially bacteria, and their influence on intestinal pathogens. The research data on the mechanisms of polyphenol action were collected together and organized. The impact of various polyphenols groups on intestinal bacteria both on the whole "microbiota" and on particular species, including probiotics, are presented. Moreover, the impact of polyphenols present in food (bound to the matrix) was compared with the purified polyphenols (such as in dietary supplements) as well as polyphenols in the form of derivatives (such as glycosides) with those in the form of aglycones. The second part of the paper discusses in detail the mechanisms (pathways) and the role of bacterial biotransformation of the most important groups of polyphenols, including the production of bioactive metabolites with a significant impact on the human organism (both positive and negative).

Characterization of Phytochemicals in Berry Fruit Wines Analyzed by Liquid Chromatography Coupled to Photodiode-Array Detection and Electrospray Ionization/Ion Trap Mass Spectrometry (LC-DAD-ESI-MSn) and Their Antioxidant and Antimicrobial Activity

Fruits are a valuable source of phytochemicals. However, there is little detailed information about the compounds contained in fruit wines. In this study, wines from six different berries were analyzed using HPLC-DAD-ESI-MSⁿ. About 150 compounds were identified, including anthocyanins (34), hydroxycinnamic acids (12) and flavonols (36). Some of the compounds were identified for the first time in berry wines. The blackberry wines were found to contain the largest number of bioactive compounds (59). Elderberry wines where the richest source of polyphenols (over 1000 mg/L) and contained the largest amounts of all of the analyzed groups of compounds (hydroxycinnamic acids, anthocyanins and flavonols). The lowest concentration of polyphenols was observed in the wines made from cranberries and bilberries (less than 500 mg/L). The antioxidant activity was determined in relation to ABTS⁺, DPPH, and FRAP. The highest values were observed in the blackberry wines, and the lowest for the cranberry wines. The wines were analyzed to test their antimicrobial activity. Five of the six wines (with the exception of elderberry wine) inhibited Bacillus cereus growth and two (blackberry and cranberry wines) were active against Listeria monocytogenes.

Growth Biocontrol of Foodborne Pathogens and Spoilage Microorganisms of Food by Polish Propolis Extracts

Propolis is a natural mixture produced by bees from plant resin substances. This study focuses on the general characteristics of five samples of Polish extract propolis originating from agricultural areas. Chemical composition with high performance liquid chromatography‒diode array detector method, total content of flavonoids and polyphenols, and antioxidative activity were determined in the ethanol extracts of propolis (EEP) samples. Minimum inhibitory concentration (MIC), minimum bactericidal/fungicidal concentration (MBC/MFC) and time-kill curves were studied for foodborne pathogens and food spoilage microorganisms. In EEPs the predominant flavonoid compounds were pinocembrin, chrysin, pinobanksin, apigenin, and kaempferol and the predominant phenolic acids were p-coumaric acid, ferulic acid, and caffeic acid. A strong antioxidative action of propolis in vitro was observed (IC50 for DPPH radical was at the level of 0.9-2.1 µg/mL). EEPs had MIC values for bacteria in the range of 1-16 mg/mL, whereas MIC for fungi ranged from 2 to 32 mg/mL. Extract of propolis originating from southern Poland was distinguished by higher content of bioactive components, and stronger antioxidative and antimicrobial activity than EPPs from the remaining areas of Poland. The results indicate the possibility of applying ethanol extracts from Polish propolis to protect food against microbiological spoilage.

Nutrients, Bioactive Compounds and Bioactivity: The Health Benefits of Sweet Cherries (Prunus avium L.)

Background:

Sweet cherries are one of the most appreciated fruits worldwide as well as one of the great sources of several active substances, as phytochemical compounds (carotenoids, serotonin, melatonin and phenolic compounds) as well as in nutritive compounds (sugars and organic acids). Accumulating research demonstrate that their supplementation in our daily diet can contradict oxidative stress, mitigating or even attenuating chronic diseases, as cancerous processes, antiinflammatory- related disorders, diabetes, and neurological and cardiovascular pathologies. Therefore, the aims of this review are to present an overview on the effects of sweet cherries as health promotors, giving emphasis to the health benefits of their bioactive compounds, particularly their antimicrobial, antioxidant, antidiabetic, anticancer, anti-neurodegeneration, anti-inflammatory and cardiovascular effects.

Methods:

Research and online content about sweet cherry fruits is reviewed. The information available has been read several times to avoid inconsistencies. In addition, according what we read, original figures were done and added to facilitate understanding and to enrich the paper.

Results:

In this review, a total of 202 original reports were used. In respect to health benefits, it is possible to confirm by several studies that, in fact, the consumption of sweet cherries has positive impacts in human health, owing to their wealthy and vast constitution, particularly in phenolic compounds, vitamins and carotenoids whose health properties were already documented.

Conclusion:

The findings of this review support the evidence that sweet cherries can be applied in pharmaceutical and food formulations, since they are able to diminish free radical species and proinflammatory markers, preventing and/ or ameliorating oxidative-stress disorders.

Molecular insight into the therapeutic potential of phytoconstituents targeting protein conformation and their expression

BACKGROUND

Native protein conformation is essential for the functional activity of the proteins and enzymes. Defects in conformation or alterations in expression of the proteins have been reported in various diseases.

PURPOSE

The aim of this study is to review the molecular insight into the therapeutic potential of phytoconstituents targeting protein conformations or expressions.

METHODS

Published literatures were searched in PubMed, Scopus, Web of Science; Article published till Dec 2017 were extracted. The literature was assessed from the Central University of Rajasthan, India. Present study evaluate article based on the role of active plant constituents on the conformation and expression of the different proteins.

RESULTS

Plant components play their role either at the molecular level or cellular level and exhibit antibacterial, antiviral, anti-neurodegenerative and other activities. Plant active compounds isolated from different plants may either stabilize or destabilize the conformation of proteins or alter expression level of the protein involved in these diseases, therefore, can play a significant role in preventing diseases caused by the alteration in these proteins.

CONCLUSION

In the present article, we have reviewed the molecular mechanism of plant active compounds, their target proteins, methods of extraction and identification, and their biological significances. Therefore, a proper understanding of the effect of these herbal molecules on the concerned proteins may help to develop new herbal-based therapeutics for various diseases.

Plant Polyphenols as Antioxidant and Antibacterial Agents for Shelf-Life Extension of Meat and Meat Products: Classification, Structures, Sources, and Action Mechanisms

Oxidative processes and meat spoilage bacteria are major contributors to decreasing the shelf-life of meat and meat products. Oxidative processes occur during processing, storage, and light exposure, lowering the nutritional and sensory value and acceptability of meat and generating toxic compounds for humans. Polyphenols inhibit oxidative processes in 3 ways: as reactive species scavengers, lipoxygenase inhibitors, and reducing agents for metmyoglobin. Thus, polyphenols are candidate antioxidants for meat and meat products. The cross-contamination of meat with spoilage and pathogenic microorganisms can occur in production lines and result in economic losses. The ability of polyphenols to interact with bacterial cell wall components and the bacterial cell membrane can prevent and control biofilm formation, as well as inhibit microbial enzymes, interfere in protein regulation, and deprive bacterial cell enzymes of substrates and metal ions. Thus, polyphenols are candidate antimicrobial agents for use with meat and meat products. Commercially available polyphenols can decrease primary and secondary lipid peroxidation levels, inhibit lipoxygenase activity, improve meat color stability, minimize the degradation of salt-soluble myofibrillar protein and sulfhydryl groups, and retard bacterial growth. Further studies are now needed to clarify the synergistic/antagonistic action of various polyphenols, and to identify the best polyphenol classes, concentrations, and conditions of use.