From the Titanic and other shipwrecks to biofilm prevention: The interesting role of polyphenol-protein complexes in biofilm inhibition

Obovatol inhibits proliferation, invasion and immune escape of hepatocellular carcinoma cells through modulating the JAK/STST3/PD-L1 pathway

BACKGROUND

Hepatocellular carcinoma (HCC) is a common cancer that is fatal and has a dismal prognosis. Obovatol (Ob), a novel lignan derived from the leaf and stem bark of Magnolia obovata Thunb, has exhibited anti-tumor effect on diverse tumors. However, its effect and mechanisms on HCC remain to be further explored.

METHODS

Huh7 and Hep3B cells, as well as BALB/c nude mice were used to determine the function and mechanisms of Ob on growth, invasion and immune escape by cell counting kit-8, transwell, enzyme-linked immunosorbent assay (ELISA) and western blot experiments.

RESULTS

Ob reduced the cell viability of Huh7 and Hep3B cells, with a IC50 value of 57.41 µM and 62.86 µM, respectively. Ob declined the invasion ability, the protein expression of N-cadherin and the concentrations of IL-10 and TGF-β, whereas increased the E-cadherin expression and the contents of IFN-γ and IL-2 in Hep3B and Huh7 cells. Mechanically, Ob decreased the protein level of p-JAK/JAK, p-STAT3/STAT3 and PD-L1, which was partly restored with the treatment of RO8191, an activator of JAK/STAT3 axis. The effect of Ob on the cell viability, the invasion ability, the protein level of N-cadherin and E-cadherin, and the concentrations of IL-10, TGF-β, IFN-γ and IL-2 in both Hep3B and Huh7 cells was reversed with the management of RO8191. In vivo, Ob reduced tumor volume and weight, the level of N-cadherin, PD-L1, p-JAK/JAK, and p-STAT3/STAT3, with an elevated expression of E-cadherin and IFN-γ.

CONCLUSION

Ob downregulated the JAK/STST3/PD-L1 pathway to attenuate the growth, invasion and immune escape of HCC.

Protective effects and regulatory mechanisms of Platycodin D against LPS-Induced inflammatory injury in BEAS-2B cells

Platycodin D (PLD), a major bioactive component of triterpene saponins found in Platycodon grandiflora, is renowned for its anti-inflammatory and antioxidant properties. This study aims to explore the protective effects and regulatory mechanisms of PLD in an LPS-induced inflammation injury model of BEAS-2B cells. Initially, PLD was identified from Platycodon grandiflora extracts utilizing UPLC-Q-TOF-MS/MS technology. The effects of PLD on the viability, morphology, ROS levels, and inflammatory factors of LPS-induced BEAS-2B cells were then investigated. The results showed that PLD significantly alleviated LPS-induced oxidative stress and inflammatory injury. Further analysis revealed that PLD positively influenced apoptosis levels, mitochondrial morphology, and related gene expression, indicating its potential to mitigate LPS-induced apoptosis and alleviate mitochondrial dysfunction. Using molecular docking technology, we predicted the binding sites of PLD with mitochondrial autophagy protein. Gene expression levels of autophagy-related proteins were measured to determine the impact of PLD on mitochondrial autophagy. Additionally, the study examined whether the mitochondrial autophagy agonists rapamycin (RAPA) could modulate the upregulation of inflammasome-related factors NLRP3 and Caspase-1 in LPS-induced BEAS-2B cells. This was done to evaluate the regulator mechanisms of PLD in pulmonary inflammatory injury. Our findings suggest that PLD's mechanism of action involves the regulation of mitochondrial autophagy, which in turn modulates inflammatory responses.

Antioxidant therapy for hepatic diseases: a double-edged sword

Liver diseases are complex conditions, significantly influenced by oxidative stress. This comprehensive review assesses the therapeutic role of antioxidants like l-ascorbic acid and α tocopherol, beta-carotene, various minerals, and plant-based ingredients in mitigating oxidative stress-induced liver diseases. The manuscript delves into the critical influence of genetic and epigenetic factors on disease susceptibility, progression, and response to antioxidant therapy. While animal studies suggest antioxidant efficacy in liver disease treatment, human trials remain inconclusive, and caution is advised due to its possible potential pro-oxidant effects. Moreover, the interactions of antioxidants with other drugs necessitate careful consideration in the management of polypharmacy in liver disease patients. The review underscores the need for further research to establish the clinical benefits of antioxidants with understanding of possible antioxidant toxicities to elucidate the intricate interplay of genetic, epigenetic, and environmental factors in liver diseases. The aim is to foster a better understanding of the knowledge on hepatic disease management with judicial antioxidant therapies.

Anticancer Potential of the Plant-Derived Saponin Gracillin: A Comprehensive Review of Mechanistic Approaches

With the increasing prevalence of cancer and the toxic side effects of synthetic drugs, natural products are being developed as promising therapeutic approaches. Gracillin is a naturally occurring triterpenoid steroidal saponin with several therapeutic activities. It is obtained as a major compound from different Dioscorea species. This review was designated to summarize the research progress on the anti-cancer activities of gracillin focusing on the underlying cellular and molecular mechanisms, as well as its pharmacokinetic features. The data were collected (up to date as of May 1, 2023) from various reliable and authentic literatures comprising PubMed, Springer Link, Scopus, Wiley Online, Web of Science, ScienceDirect, and Google Scholar. The findings demonstrated that gracillin displays promising anticancer effects through various molecular mechanisms, including anti-inflammatory effects, apoptotic cell death, induction of oxidative stress, cytotoxicity, induction of genotoxicity, cell cycle arrest, anti-proliferative effect, autophagy, inhibition of glycolysis, and blocking of cancer cell migration. Additionally, this review highlighted the pharmacokinetic features of gracillin, indicating its lower oral bioavailability. As a conclusion, it can be proposed that gracillin could serve as a hopeful chemotherapeutic agent. However, further extensive clinical research is recommended to establish its safety, efficacy, and therapeutic potential in cancer treatment.

Hydrogen bond-driven assembly of coral-like soy protein isolate-tannic acid microcomplex for encapsulation of limonene

BACKGROUND

The encapsulation of flavor and aroma compounds has great potential in foods, while effective preparation in the food industry is still a great challenge. Inspired by leather tanning, tannic acid (TA) was used for deep crosslinking through hydrogen bond-driven assembly on soy protein isolate for encapsulating limonene with a high loading ratio.

RESULTS

The added TA changed the protein structure and formed a limonene-loaded microcomplex. The morphology of these microcomplexes changed from smooth to rough, followed by the formation of smooth nanoparticle aggregates, by changing the amount of TA. The encapsulation efficiency and loading ratio were increased from 0.78% and 4.30% to 59.32% and 45.78% after increasing TA from 1.875 to 60 mg mL^-1 . The result of confocal laser scanning microscopy indicated that limonene is evenly distributed in microcomplexes. Additionally, the results of thermal stability demonstrated protection of limonene by soy protein-tannic acid microcomplex.

CONCLUSION

It is suggested that the added TA improved the encapsulation efficiency and loading ratio. Limonene is loaded in the complex in two ways. The present research provides a new and easy path for the preparation of the non-thermal soy protein aroma carrier. © 2022 Society of Chemical Industry.

Can polyphenolic surface modifications prevent fungal colonization of titanium dental implants?

Oral biofilms can be a major health problem causing infections and chronic inflammation of mucosal tissue. While much effort is put in the investigation of bacteria in biofilms, the role of fungi is often neglected, despite Candida albicans playing a key role in the formation of multispecies oral biofilms. With the rise of antibiotic resistance, new strategies to reduce microbial growth need to be found. Therefore, plant derived polyphenolic molecules have been suggested to reduce both adhesion and growth of pathogenic bacteria and fungi. In this study, we investigated the use of polyphenolic coatings to reduce adhesion and biofilm formation of C. albicans BWP17 on titanium implants. Tannic acid and pyrogallol coatings altered the hydrophobic and charge properties of titanium surfaces, and both compounds were gradually released as active molecules over time. Despite such effects, we found no significant inhibition on growth and biofilm formation of C. Albicans, indicating that the release of active molecules from the coatings did not reach relevant inhibitory concentrations. However, a potential antibiofilm effect was observed by the pH-dependent disassembly of the polyphenolic layer, which caused the biofilm to detach. Hence, further efforts are required to create tailored implant surfaces, which sustainably reduce microbial growth and adhesion.

Genus Lupinus (Fabaceae): a review of ethnobotanical, phytochemical and biological studies

OBJECTIVES

Lupinus is a large and diverse genus comprising approximately 200 species, belonging to the family Fabaceae. Lupinus plants have been used for heart stimulants, nerves, urinary tract infections, skin disorders, and psoriasis in folk medicine. This review aims to recap the traditional medicinal uses, nutritional value, phytochemical profile, and biological activities of Lupinus species.

KEY FINDINGS

From the literature survey, Lupinus is considered as a factory of various phytochemicals like flavonoids, iso-flavonoids, alkaloids, triterpenoids. The presence of proteins, essential fatty acids, and amino acids, as well as alkaloids, minerals, and dietary fibers, indicated that the plants in this genus had a high nutritional value. The Lupinus extracts displayed promising antidiabetic, anticancer, antimicrobial, antidiabetic, antihypertensive, antioxidant, anti-inflammatory, and antimicrobial activities.

CONCLUSIONS

The current review provides updated information that could drive the researchers for further studies. The in vitro and in vivo experiments have demonstrated various pharmacological properties. Some pharmacokinetic and toxicological investigations are warranted to ensure its safety and validity for human use.

Exploiting the antibacterial mechanism of phenazine substances from Lysobacter antibioticus 13-6 against Xanthomonas oryzae pv. oryzicola

Bacterial leaf streak caused by Xanthomonas oryzae pv. oryzicola (Xoc) is one of the most destructive diseases affecting rice production worldwide. In this study, we extracted and purified phenazine substances from the secondary metabolites of Lysobacter antibioticus 13-6. The bacteriostatic mechanism of phenazine substances against Xoc was investigated through physiological response and transcriptomic analysis. Results showed that phenazine substances affects the cell membrane permeability of Xoc, which causes cell swelling and deformation, blockage of flagellum synthesis, and imbalance of intracellular environment. The changes in intracellular environment affect the physiological and metabolic functions of Xoc, which reduces the formation of pathogenic factors and pathogenicity. Through transcriptomic analysis, we found that among differentially expressed genes, the expression of 595 genes was induced significantly (275 up-regulated and 320 down-regulated). In addition, we observed that phenazine substances affects three main functions of Xoc, i.e., transmembrane transporter activity, DNA-mediated transposition, and structural molecular activity. Phenazine substances also inhibits the potassium ion transport system that reduces Xoc resistance and induces the phosphate ion transport system to maintain the stability of the internal environment. Finally, we conclude that phenazine substances could retard cell growth and reduce the pathogenicity of Xoc by affecting cell structure and physiological metabolism. Altogether, our study highlights latest insights into the antibacterial mechanism of phenazine substances against Xoc and provides basic guidance to manage the incidence of bacterial leaf streak of rice.

Chemical aspects of polyphenol-protein interactions and their antibacterial activity

The hunt for novel antibiotics has become a global public health imperative due to the rise in multidrug-resistant microorganisms, untreatable infection cases, overuse, and inefficacy of modern antibiotics. Polyphenols are getting much attention in research due to their multiple biological effects; their use as antimicrobial agents is attributed to their activity and that microbes have a hard time developing resistance to these natural compounds. Polyphenols are secondary metabolites produced in higher plants. They are known to possess various functional properties in the human body. Polyphenols also exhibit antibacterial activities against foodborne pathogens. Their antibacterial mechanism is based on inhibiting bacterial biofilm formation or inactivating enzymes. This review focused on polyphenol-protein interactions and the creation of this complex as a possible antibacterial agent. Also, different phenolic interactions on bacterial proteins, efflux pump, cell membrane, bacterial adhesion, toxins, and other bacterial proteins will be explored; these interactions can work in a synergic combination with antibiotics or act alone to assure bacterial inhibition. Additionally, our review will focus on polyphenol-protein interaction as a possible strategy to eradicate bacteria because polyphenols have shown a robust enzyme-inhibitory characteristic and a high tendency to complex with proteins, a response that neutralizes any bactericidal potential.

Chemical Derivatization of Commercially Available Condensed and Hydrolyzable Tannins

Novel valorization routes for tannins were opened by the development of a simple, straightforward, robust, and flexible approach to the selective functionalization of condensed and hydrolyzable tannins. Irrespective of the different degrees of polymerization, different commercial tannins were efficiently functionalized by the generation of an ether linkage bound to a short linker carrying the desired functional group. Functionalizations could be realized at varying degrees of technical loadings, i.e., amounts of introduced tannin-alien functionalities per number of phenolic hydroxyl groups. The same strategy was found suitable for the synthesis of polyethylene glycol-functionalized tannin copolymers. Condensed tannins functionalized with carboxylic acid moieties could be converted into a tannin-oligopeptide hybrid.

The PentaFOLD 3.0 Algorithm for the Selection of Stable Elements of Secondary Structure to be Included in Vaccine Peptides

AIMS

The aim of this study was to create a new version of the PentaFOLD algorithm and to test its performance experimentally in several proteins and peptides.

BACKGROUND

Synthetic vaccines can cause production of neutralizing antibodies only in case if short peptides form the same secondary structure as fragments of full-length proteins. The Penta- FOLD 3.0 algorithm was designed to check stability of alpha helices, beta strands, and random coils using several propensity scales obtained during analysis of 1730 3D structures of proteins.

OBJECTIVE

The algorithm has been tested in the three peptides known to keep the secondary structure of the corresponding fragments of full-length proteins: the NY25 peptide from the Influenza H1N1 hemagglutinin, the SF23 peptide from the diphtheria toxin, the NQ21 peptide from the HIV1 gp120; as well as in the CC36 peptide from the human major prion protein.

METHODS

Affine chromatography for antibodies against peptides accompanied by circular dichroism and fluorescence spectroscopy were used to check the predictions of the algorithm.

RESULTS

Immunological experiments showed that all abovementioned peptides are more or less immunogenic in rabbits. The fact that antibodies against the NY25, the SF23, and the NQ21 form stable complexes with corresponding full-length proteins has been confirmed by affine chromatography. The surface of SARS CoV-2 spike receptor-binding domain interacting with hACE2 has been shown to be unstable according to the results of the PentaFOLD 3.0.

CONCLUSION

The PentaFOLD 3.0 algorithm (http://chemres.bsmu.by/PentaFOLD30.htm) can be used with the aim to design vaccine peptides with stable secondary structure elements.

Biomimetic surface coatings for marine antifouling: Natural antifoulants, synthetic polymers and surface microtopography

Marine biofouling is a ubiquitous problem that accompanies human marine activities and marine industries. It exerts detrimental impacts on the economy, environment, ecology, and safety. Traditionally, mainstream approaches utilize metal ions to prevent biological contamination, but this also leads to environmental pollution and damage to the ecosystem. Efficient and environmentally friendly coatings are urgently needed to prevent marine devices from biofouling. Since nature is always the best teacher for humans, it offers us delightful thoughts on the research and development of high-efficiency, broad-spectrum and eco-friendly antifouling coatings. In this work, we focus on the research frontier of marine antifouling coatings from a bionic perspective. Enlightened by three distinctive dimensions of bionics: chemical molecule bionic, physiological mechanism bionic, and physical structure bionic, the research status of three main bioinspired strategies, which are natural antifoulants, bioinspired polymeric antifouling coatings, and biomimetic surface microtopographies, respectively, are demonstrated. The antifouling mechanisms are further interpreted based on biomimetic comprehension. The main fabrication methods and antifouling performances of these coatings are presented along with their advantages and drawbacks. Finally, the challenges are summarized, and future research prospects are proposed. It is believed that biomimetic antifouling strategies will contribute to the development of nontoxic antifouling techniques with exceptional repellency and stability.

Roles of the Polyphenol-Gut Microbiota Interaction in Alleviating Colitis and Preventing Colitis-Associated Colorectal Cancer

Accumulating evidence indicates that the gut microbiota can promote or inhibit colonic inflammation and carcinogenesis. Promotion of beneficial gut bacteria is considered a promising strategy to alleviate colonic diseases including colitis and colorectal cancer. Interestingly, dietary polyphenols, which have been shown to attenuate colitis and inhibit colorectal cancer in animal models and some human studies, appear to reach relatively high concentrations in the large intestine and to interact with the gut microbial community. This review summarizes the modulatory effects of polyphenols on the gut microbiota in humans and animals under healthy and diseased conditions including colitis and colitis-associated colorectal cancer (CAC). Existing human and animal studies indicate that polyphenols and polyphenol-rich whole foods are capable of elevating butyrate producers and probiotics that alleviate colitis and inhibit CAC, such as Lactobacillus and Bifidobacterium. Studies in colitis and CAC models indicate that polyphenols decrease opportunistic pathogenic or proinflammatory microbes and counteract disease-induced dysbiosis. Consistently, polyphenols also change microbial functions, including increasing butyrate formation. Moreover, polyphenol metabolites produced by the gut microbiota appear to have anticancer and anti-inflammatory activities, protect gut barrier integrity, and mitigate inflammatory conditions in cells and animal models. Based on these results, we conclude that polyphenol-mediated alteration of microbial composition and functions, together with polyphenol metabolites produced by the gut microbiota, likely contribute to the protective effects of polyphenols on colitis and CAC. Future research is needed to validate the causal role of the polyphenol-gut microbiota interaction in polyphenols' anti-colitis and anti-CAC effects, and to further elucidate mechanisms underlying such interaction.

Environmentally Friendly Water-Based Self-Crosslinking Acrylate Dispersion Containing Magnesium Nanoparticles and Their Films Exhibiting Antimicrobial Properties

A water-based polymeric acrylate dispersion (latex) containing MgO nanoparticles, which had been added at a concentration of 1.5% (with respect to the monomers) during the preparation procedure, was investigated as an environmentally friendly binder for sanitary interior paints. The properties of this new latex were compared to those of a reference system free of the magnesium nanoparticles, synthesized by the same route, i.e., by semi-continuous emulsion polymerization. Tests were made in order to ascertain the mechanical and chemical properties, flash corrosion resistance and antimicrobial effect of the latex films. The results revealed that the new latex containing magnesium nanoparticles provided solvent-resistant coating films having pronounced antimicrobial activity against all the tested bacterial and fungal strains. The desirable antimicrobial properties can be ascribed to the sharp-edged character of magnesium nanoparticles, the peroxidation of lipids and the formation of reactive oxygen species. Moreover, no flash corrosion was formed beneath coating films containing magnesium nanoparticles, which can be attributed to the alkaline action due to the dissolution of a fraction of MgO in latex medium. The results of all of the tests provided evidence of the superiority of the polymeric dispersion with the magnesium nanoparticles to the reference system containing no nanoparticles.

Research trends in food chemistry: A bibliometric review of its 40 years anniversary (1976-2016)

This study presents a general bibliometric overview of the major scientific developments that have been published in Food Chemistry, since its first issue (1976). The bibliometric data were retrieved from the scopus database. The review identifies the most cited, productive authors, and the leading institutions and countries of the journal, based on bibliometric indicators. The research hot spots in the period from 1976 to 2016 were identified by using the visualization of similarities software (Vosviewer), and the graphical mapping of the authors was developed to visualize networks between authors. A total of 20,050 publications was analysed and the most influential subjects covered by the journal were identified. Topics related to the antioxidant components of foods and the analytical quantification of contaminants or components of food were identified as being most relevant.The bibliometric analyses indicate a significant evolution of the journal in terms of publications, scientometric performance and themes covered.