Search

In this work, we synthesized a new composite material comprised of previously formulated resveratrol nanobelt-like particles (ResNPs) and selenium nanoparticles (SeNPs), namely ResSeNPs. Characterization was provided by FESEM and optical microscopy, as well as by UV-Vis and FTIR spectroscopy, the last showing hydrogen bonds between ResNPs and SeNPs. DPPH, TBA, and FRAP assays showed excellent antioxidative abilities with ResNPs and SeNPs contributing mainly to lipid peroxidation inhibition and reducing/scavenging activity, respectively. The antibacterial effect against common medicinal implant colonizers pointed to notably higher activity against Staphylococcus isolates (minimal inhibitory concentrations 0.75–1.5%) compared to tested gram-negative species (Escherichia coli and Pseudomonas aeruginosa). Antibiofilm activity against S. aureus, S. epidermidis, and P. aeruginosa determined in a crystal violet assay was promising (up to 69%), but monitoring of selected biofilm-related gene expression (pelA and algD) indicated the necessity of the involvement of a larger number of genes in the analysis in order to further establish the underlying mechanism. Although biocompatibility screening showed some cytotoxicity and genotoxicity in MTT and alkaline comet assays, respectively, it is important to note that active antioxidative and antibacterial/antibiofilm concentrations were non-cytotoxic and non-genotoxic in normal MRC-5 cells. These results encourage further composite improvements and investigation in order to adapt it for specific biomedical purposes.

Inflammation and oxidative stress are common problems in biomaterial science. Therefore, antioxidative components, especially those of natural origin, can be of great value in improving biomaterial formulations for medical devices. It is already well known that the most notable exogenous antioxidants are ascorbic acid, polyphenolic compounds, and minerals such as selenium and zinc. In our research, we prepared a composite based on polyphenolic resveratrol nanobelts and selenium nanoparticles and explored its’ antioxidative potential.

Hepatocelularni i kolorektalni karcinom se sve ćešće javlja i ima visoku stopu smrtnosti. Postojanje aktivnih mehanizama hemorezistencije otežava korisnost hemoterapije. Upravo je pojava hemorezistencije podstakla opsežna istraživanja za razvoj novih terapeutskih agenasa i strategija za lečenje ovih vrsta karcinoma. Prirodni proizvodi biljnog porekla (sekundarni metaboliti) su bogat izvor potencijalnih lekova. Zbog toga smo u istraživanju usmerili pažnju na etil-acetatni ekstrakt biljke Frangula alnus (FA) i njegovu dominantnu komponentu emodin (E) i ispitali njihovo antikancerski potencijal na ćelijama hepatocelularnog (HepG2) i kolorektalnog (HCT116) karcinoma i citotoksičnost na normalnim MRC -5 ćelijama. Pokazan je snažan antioksidativni potencijal ekstrakta (DPPH i TBA test). Citotoksičnost ispitana MTT testom pokazala je jaku toksičnost obe supstance na ćelije HepG2 i HCT116, ali bez uticaja na MRC-5 ćelije. Dalje je analiza ćelijskog ciklusa pokazala da su i FA i E izazvali zaustavljanje u G1 fazi i blago nakupljanje ćelija u G2/M fazi. Pored toga, obe supstance su uvele ćelije u apoptozu i nekrozu i uticale su na mitohondrijalni membranski potencijal. Dalje, izazvali su značajan genotoksični efekat u kometnom testu na svim ćelijskim linijama. Može se zaključiti da su FA i E dobri kandidati za nove antikancerogene agense prirodnog porekla. Međutim, neophodna su dodatna istraživanja, posebno kada je u pitanju citotoksična aktivnost i bezbednost primene ovih supstanci., Hepatocellular and colorectal carcinoma is swiftly increasing alongside a high mortality rate. The existence of active mechanisms of chemoresistance hampers the usefulness of chemotherapy. The emergence of chemoresistance encouraged extensive research to develop new therapeutic agents and strategies for the treatment of these types of cancer. Natural products of plant origin (secondary metabolites) have been the most successful source of potential drug leads. Therefore, we turned our attention to the Frangula alnus ethyl-acetate extract (FA) and its dominant constituent emodin (E) and explored them for their anticancer potential on hepatocellular (HepG2) and colorectal (HCT116) carcinoma cells, and cytotoxicity on normal MRC-5 cells. Strong antioxidant potential of the extract was demonstrated (DPPH and TBA test). Cytotoxicity investigated by the MTT assay showed strong cell toxicity of both substances on HepG2 and HCT116 cells, but without affecting MRC-5 cells. Next, the analysis of cell cycles exhibited that both FA and E induced arrest in the G1 phase and slight accumulation of cells in the G2/M phase. In addition, both substances introduced cells into apoptosis and necrosis and modulated mitochondrial membrane potential. Further on, they caused significant genotoxic effect in comet assay applied in all cell lines. It can be concluded that FA and E are good candidates for new anticancer agents of natural origin. However, additional studies are necessary, especially when it comes to the cytotoxic activity and safety of the application of these substances.

Fermented foods containing psychobiotics are of growing interest among food scientists. Human-derived Limosilactobacillus reuteri DSM 17938, a gut symbiont and potential psychobiotic strain, has been shown to exhibit the following health benefits: anti-inflammation and GABA-production capacity, as well as modulation of pathogen and cancer cell growth. The aim of this research was to develop an acid-coagulated fresh soft quark-type cheese, fermented with L. reuteri DSM 17938, with enhanced bioactivity, sensory acceptability, and overall likeability. Psychobiotic-containing cheeses represent the food of a new generation, so it is of great importance to gain the trust of the consumers. To develop a familiar taste, cheese samples were enriched with mushroom powders of Agaricus bisporus and Pleurotus ostreatus. A high abundance of lactic acid bacteria was maintained in all cheese samples (>log 7.64 CFU/mL), while cheese extracts exhibited cytotoxicity to colon cancer cell line HCT116 (up to 30.96%) in vitro. Additionally, cheese samples provided a favorable medium for the growth of the probiotic Escherichia coli Nissle 1917 (>log 7.11 CFU/mL). Sensory evaluation revealed high scores for all samples (up to 97.21% of maximum overall quality). The survey conducted in this study offered insights into consumer willingness to try products containing psychobiotics. This study demonstrates the potential for the successful development of fermented food products with L. reuteri DSM 17938, which exhibits all the desired traits that consumers may receive well. Further research is required to explore the potential health benefits of these innovative food products.

The aim of the study was to investigate the potency of Cinnamomum camphora cineoliferum and Melaleuca ericifolia essential oils (EOs) against facultative and obligate anaerobes isolated from teeth’ infected root canals. Biocompatibility of the EOs was also in the study focus. Chemical composition of the EOs was determined by GC/MS analysis. Their antibacterial potential and cytotoxicity were evaluated by microdilution and MTT assays, respectively. Statistical analysis was performed by Student’s t-test and one way ANOVA. Two the most abundant constituents of C. camphora cineoliferum EO were 1,8-cineole and sabinene, while in M. ericifolia EO the dominant were linalool and 1,8-cineole. MICs achieved against all tested strains were in the ranges 0.95±0.50 - 22.50±0.00 mg/mL and 0.65±0.00 - 23.35±7.80 mg/mL for the C. camphora cioneoliferum and M. ericifolia EOs, respectively. Statistical analysis showed that response to both oils has not differed between facultative and obligate anaerobes. Sensitivity pattern of the tested strains was different for the EOs and the positive control triple antibiotic paste (TAP): while E. faecalis and certain strains of S. salivarius were among the most sensitive to the oils, they were the least susceptible to the conventional antimicrobial TAP. Although the observed cytotoxicity of the EOs after 30 min of cell exposition was high (50.78-66.35% and up to 70% for C. camphora cioneoliferum and M. ericifolia EOs, respectively) it was lower than that of positive control (1.5% NaOCl, p<0.05). To conclude, both EOs showed promising antibacterial potential and achieved at least the same or even better biocompatibility than the conventional intracanal antimicrobials. Obtained results strongly encourage future research with an aim to formulate C. camphora cioneoliferum and M. ericifolia EO- based irrigants and medicaments, that could be used in endodontic practice.

Aims Because the Staphylococcus aureus is one of the most well‐known pathogens associated with medical devices and nosocomial infections, the aim of the study was to examine antibiofilm potential of emodin against it. Methods and Results Antibacterial activity was examined through microdilution assay. Antibiofilm testing included crystal violet staining of biofilm biomass and morphology analysis by Atomic force microscopy (AFM). Furthermore, aerobic respiration was monitored using the Micro‐Oxymax respirometer. For investigation of gene expression qRT‐PCR was performed. Emodin demonstrated strong antibacterial activity and ability to inhibit biofilm formation of all tested strains. The effect on preformed biofilms was spotted in few strains. AFM revealed that emodin affects biofilm structure and roughness. Monitoring of respiration under emodin treatment in planktonic and biofilm form revealed that emodin influenced aerobic respiration. Moreover, qRT‐PCR showed that emodin modulates expression of icaA, icaD, srrA and srrB genes, as well as RNAIII, and that this activity was strain‐specific. Conclusion The results obtained in this study indicate the novel antibiofilm activity of emodin and its multiple pathways of action. Significance and Impact of Study This is the first study that examined pathways through which emodin expressed its antibiofilm activity

Selenium is an especially important element for the functioning of antioxidative enzymes, making it one of the essential micronutrients. Although selenium is required in extremely small amounts, often it is lacking from the organism. However, inorganic and organic sources of selenium are known to possess considerable toxicity. Recently, the nanoparticle form of selenium has been shown to exhibit lesser toxicity, and also better antimicrobial and other biological effects, than selenium-containing compounds. Nanotechnology has already found application in many fields, for improving material properties for various purposes, among them, in the process of improving food characteristics. It is possible that selenium nanoparticles can be applied as antimicrobial agents in food, and there has been growing interest in this area of research. We have synthesized selenium nanoparticles (SeNPs) by chemical reduction method, using sodium selenite, ascorbic acid, and bovine serum albumin. The antimicrobial activity of these particles has been assessed by minimum inhibitory concentration assay and colony-forming units count, on Listeria monocytogenes and Salmonella enterica, which are common bacterial food contaminants. As intestinal microbiota, especially probiotic bacteria, have been shown to play important role in organism functioning, we also tested how SeNPs influence Lactobacillus rhamosus and Lactobacillus plantarum. To evaluate cytotoxicity, we used MTT assay on the human intestinal cell line (HT-29). Antioxidative properties were assessed by DPPH assay. SeNPs showed higher antibacterial activity on pathogenic bacteria than on probiotic strains. Cytotoxic effect was present only in the highest tested concentrations. The antioxidative activity was considerable, resulting in above 80% reduction of DPPH free radical, at 1 g/ml of SeNPs. Based on these results, SeNPs are a promising subject for further research in developing materials for food packaging or as antimicrobial sel

Acinetobacter baumannii is an emerging nosocomial pathogen resistant to a wide spectrum of antibiotics, with great potential to form a biofilm, which further aggravates treatment of infections caused by it. Therefore, searching for new potent agents that are efficient against A. baumannii seems to be a necessity. One of them, which has already been proven to possess a wide spectrum of biological activities, including antimicrobial effect, is cinnamon essential oil. Still, further increase of antibacterial efficacy and improvement of bioavailability of cinnamon oil is possible by emulsification process. The aim of this study was comparative analysis of cinnamon essential oil and its emulsion against biofilm forming A. baumannii clinical isolates. Furthermore, the investigation of toxicological aspects of possible applications of essential oil and emulsion was done as well. Gas chromatography–mass spectrometry of essential oil indicated trans-cinnamaldehyde as the most abundant component. The cinnamon emulsion was synthesized from cinnamon essential oil by combining modified low- and high- energy methods. Synthesized emulsion was characterized with Fourier-transform infrared spectroscopy and photon correlation spectroscopy. Both substances exhibited significant antibacterial (minimal inhibitory concentrations in the range 0.125–0.5 mg/ml) and antibiofilm effects (inhibitions of formation and reduction of pre-formed biofilm were 47–81 and 30–62%, respectively). Compared to essential oil, the efficacy of emulsion was even stronger considering the small share of pure oil (20%) in the emulsion. The result of biofilm eradication assay was confirmed by scanning electron microscopy. Even though the cytotoxicity was high especially for the emulsion, genotoxicity was not determined. In conclusion, strong antibacterial/antibiofilm effect against A. baumannii of the cinnamon essential oil and the fact that emulsification even potentiated the activity, seems to be of great signif

Natural chemicals and earth elements are increasingly used in research as basis for novel materials intended for use in medicine. Among phytopharmaceuticals, more specifically polyphenols, resveratrol is known for its’ antioxidative, anticancer, antimicrobial, and other beneficial effects. Selenium, an essential trace element, is lately being recognized in nanoparticle form as less toxic and equally or more efficient than commercially available forms. The synergy of these two agents have not been shown until lately, when their synergistic antioxidative and gene expression effects were investigated for the purpose of treating Alcheimer disease. During our previous research, we have successfully synthesized pure resveratrol particles, as well as selenium nanoparticles (SeNPs). Both of them were separately investigated regarding their biological activities. The first step in evaluation of their possible synergistic antioxidative effect was obtaining the stable composite of these two materials. Synthesis parameters and processing methods were varied, and obtained suspensions assessed by their macroscopic and microscopic characteristics. The sample with both components homogeneously distributed in the particle form, was chosen for further experiments. Ultraviolet-visible (UV-Vis) spectrophotometry and Fourier transform infrared spectroscopy (FTIR) were used to characterize sample, and antioxidative activity (by DPPH reduction assay), and cytocompatibility (using MTT cytotoxicity assay) were additionally determined. Results showed improved cytocompatibility as compared to pure resveratrol particles, and preserved, significantly high antioxidative potential.

Objective: Acinetobacter baumannii is a pathogenic species which presents a danger to healthcare facilities due to the rapid spread of antibiotic resistance. Plants are currently being explored as a potential source of bioactive compounds that could be used to combat infectious diseases. Cinnamon is used as a food spice, but essential oil has been proven for antimicrobial activity. Due to reduced stability and solubility of essential oil, nanoemulsion (NE) synthesis could provide stronger antimicrobial effects. Investigation and comparison of antimicrobial activity of cinnamon (Cinnamomum zeylanicum L.) bark essential oil (EO) and NE on the A. baumannii ATCC19606 and clinical isolates. Effect of EO and NE on biofilm formation and biofilm eradication. Methods: GC/MS was performed in order to determine chemical composition of commercially purchased EO (P0125285, Frey + Lau, GmbH, Henstedt-Ulzburg, Germany). Droplet/particle size and polydispersity index of NE was determined by photon correlation spectroscopy (PCS). Minimal inhibitory concentration of EO and NE were defined using MIC assay. Effects of EO and NE were also examined on biofilm formation and eradication. Crystal violet staining was used for biofilm biomass quantification. Results: GC/MS analysis determined that the most common compound was trans-Cinnamaldehyde (61.9%). NE droplet/particles had multimodal distribution, shown by PCS. MIC values for EO were in range 0.25mg/mL — 0.5mg/mL, and for NE 0.125mg/mL — 0.25mg/mL. Both tested substances showed good effect on biofilm eradication, and destroyed biofilm biomass up to 64%, whilst the inhibition of biofilm formation was up to 70%. Conclusion: Taking all the results into account, it is a good start for further investigations of both EO and NE as a potential antimicrobial agent. Deeper knowledge about the mechanisms of actions of both of these tested substances could help us to understand the best and the most effective way to use them, in order to combat ag