In vitro effects of Origanum vulgare leaf extracts on gilthead seabream (Sparus aurata L.) leucocytes, cytotoxic, bactericidal and antioxidant activities

©2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Accepted, version of a Published Work that appeared in final form in Fish and Shellfish Immunology. To access the final edited and published work see https://doi.org/10.1016/j.fsi.2018.05.005Origanum vulgare is a well-known medicinal plant that has been used since ancient times as an additive in foods and cosmetic preparations. The possible application of O. vulgare extracts in fish was assessed by using gilthead seabream (Sparus aurata) as a marine fish model due to its importance in aquaculture. The in vitro effects of aqueous and ethanolic leaf extracts of O. vulgare were tested in order to observe any immunostimulant, cytotoxic, bactericidal or antioxidant properties. The results showed that medium or high concentration of aqueous extracts and low concentrations of ethanolic extract, increased head kidney leucocyte activities as well as the number of SAF-1 cells. However, moderate to high concentrations of ethanolic extracts decreased both leucocyte activities and the number of viable SAF-1 cells, suggesting some possible toxic effect towards them. Only the highest concentration of the aqueous extract and medium to high concentrations of the ethanolic extracts showed cytotoxic activity against the tumor PLHC-1 cell line. Bactericidal activity was only detected against Vibrio harveyi, V. anguillarum and Photobacterium damselae when using the highest concentration of aqueous extract and moderate to high concentrations of ethanolic extract. Finally, both plant extracts presented antioxidant activity particularly the aqueous extract. Overall, the results suggest that both extracts (when used at the appropriate concentration) have immunostimulant, cytotoxic, bactericidal and antioxidant properties, making O. vulgare an interesting candidate for incorporation as additive in functional diets for farmed fish

Root canal microbiota as an augmented reservoir of antimicrobial resistance genes in type 2 diabetes mellitus patients

Antimicrobial resistance is a global public health problem. Root canal microbiota associated with apical periodontitis represents a well-known reservoir of antimicrobial resistance genes (ARGs). However, the effect of type 2 diabetes mellitus (T2DM) in this reservoir is unknown. This study aimed to establish if root canal microbiota associated with apical periodontitis in T2DM patients is an augmented reservoir by identifying the prevalence of nine common ARGs and comparing it with the prevalence in nondiabetic patients. Methodology: This cross-sectional study included two groups: A T2DM group conformed of 20 patients with at least ten years of living with T2DM and a control group of 30 nondiabetic participants. Premolar or molar teeth with pulp necrosis and apical periodontitis were included. A sample was collected from each root canal before endodontic treatment. DNA was extracted, and ARGs were identified by polymerase chain reaction. Results: tetW and tetM genes were the most frequent (93.3 and 91.6%, respectively), while ermA was the least frequent (8.3%) in the total population. The distribution of the ARGs was similar in both groups, but a significant difference (p<0.005) was present in ermB, ermC, cfxA, and tetQ genes, being more frequent in the T2DM group. A total of eighty percent of the T2DM patients presented a minimum of four ARGs, while 76.6% of the control group presented a maximum of three. Conclusions: Root canal microbiota associated with apical periodontitis in T2DM patients carries more ARGs. Therefore, this pathological niche could be considered an augmented reservoir

A Bioactive Extract Rich in Triterpenic Acid and Polyphenols from Olea europaea Promotes Systemic Immunity and Protects Atlantic Salmon Smolts Against Furunculosis

In the present study, the modulation of the transcriptional immune response (microarray analysis) in the head kidney (HK) of the anadromous fish Atlantic salmon (Salmo salar) fed a diet supplemented with an olive fruit extract (AQUOLIVE®) was evaluated. At the end of the trial (133 days), in order to investigate the immunomodulatory properties of the phytogenic tested against a bacterial infection, an in vivo challenge with Aeromonas salmonicida was performed. A total number of 1,027 differentially expressed genes (DEGs) (805 up- and 222 downregulated) were found when comparing the transcriptomic profiling of the HK from fish fed the control and AQUOLIVE® diets. The HK transcripteractome revealed an expression profile that mainly favored biological processes related to immunity. Particularly, the signaling of i-kappa B kinase/NF-kappa and the activation of leukocytes, such as granulocytes and neutrophils degranulation, were suggested to be the primary actors of the innate immune response promoted by the tested functional feed additive in the HK. Moreover, the bacterial challenge with A. salmonicida that lasted 12 days showed that the cumulative survival was higher in fish fed the AQUOLIVE® diet (96.9 ± 6.4%) than the control group (60.7 ± 13.5%). These results indicate that the dietary supplementation of AQUOLIVE® at the level of 0.15% enhanced the systemic immune response and reduced the A. salmonicida cumulative mortality in Atlantic salmon smolts.info:eu-repo/semantics/publishedVersio

In vitro effects of astaxanthin on bacterial and cell viability, cell migration and mitochondrial activities in four fish cell lines

Astaxanthin (AX) is a pigment commonly used in aquaculture. It is added to salmonid, shrimp, and crayfish feeds to produce the appropriate pink coloration to the flesh of these animals. Different in vitro effects of AX were studied to understand its mode of action in fish. The antioxidant activity and the potential bactericidal effects of AX on three fish pathogenic bacteria (Vibrio harveyi, V anguillarum and Photobacterium damselae) were determined. After 24 h of incubation with AX, no significant effects on the viability of V. harveyi were observed, while the viability of V. anguillarum and P. damselae was increased and decreased, respectively. These results are discussed according to the presence or absence of bacterial carotenoid cleavage oxygenases. Fish cell lines (SAF-1, DLB-1, FuB-1 and PLHC-1) were cultured and incubated for 24 h with different concentrations of AX (0, control, 0.1, 1 and 10 µM) and then cell viability was assessed. No significant effects or increased viability were observed in cells incubated with AX. To determine the effects of AX on cell migration, the scratch assay was performed. While no significant differences were detected when using SAF-1 or PLHC-1 cells, the inclusion of AX, at any of the concentrations tested, significantly (p < 0.05) increased the forward velocity in DLB-1 and FuB-1 cells. In addition, several parameters of mitochondrial metabolism were evaluated using the Agilent Seahorse XF mitochondrial stress assay kit. Different results were obtained depending on the cell line used and the mitochondrial parameter assayed but, in general, no significant effects or increases were detected after incubation of cells with AX. In conclusion, the results revealed that the effects of AX depend on the bacterium and cell line used in the assays and these findings improve our understanding of the mode of action of AX in fish and its potential applications in aquaculture

Preparation of Silver-Doped Alumina Spherical Beads with Antimicrobial Properties

The synthesis of composites with antibacterial properties is of great interest for the development of new biomedical applications. The antimicrobial properties of silver have been verified against microorganisms such as bacteria, viruses, and fungi; interest in silver has been renewed, so several technologies are currently in development, especially in dental materials. The purpose of this work was to improve the parameters for producing silver-doped alumina spherical beads using sodium alginate as a sacrificial template. Alumina is a biocompatible and thermally stable ceramic, while silver was used for its bactericidal properties. The obtained spheres presented a mean diameter of 2 mm, with an irregular surface and intertwined particles after a sintering process. After electrodeposition, white spheres turned to a dark gray color, demonstrating the presence of silver nanoparticles and fractal silver dendrites on the surface. Spheres were characterized by SEM, FTIR, and XRD. Antimicrobial activity of the alumina-AgP spheres against E. coli, S. aureus, K. pneumoniae, and S. mutans was analyzed by turbidimetry. The specific antimicrobial activity of all the composites showed specific antibacterial effects, independently of the amount of silver deposited, probably due to the differences in the microbial cell wall structures. Therefore, antibacterial activity depends on microbiological and structural characteristics of each bacterium

Polymer-Based Hydroxyapatite–Silver Composite Resin with Enhanced Antibacterial Activity for Dental Applications

The primary objective of this investigation was to synthesize a resin incorporating nanoparticles of hydroxyapatite and silver (HA-NpsAg) to enhance biocompatibility and antimicrobial efficacy, thereby facilitating potential implementation within the dental industry. These enhancements aim to ensure reliable, durable, functional, and aesthetically pleasing restorations while concurrently reducing susceptibility to bacterial colonization within the oral cavity. Hydroxyapatite powders were prepared using the sol–gel method and doped with silver nanoparticles obtained by chemical reduction. The crystalline amorphous calcium phosphate powder had a particle size of 279 nm, and the silver nanoparticles had an average diameter of 26.5 nm. Resin spheres containing HA-NpsAg (RHN) were then synthesized at two concentrations (0.5% and 1%) by dissolving the initial monomer mixture in tetrahydrofuran. Subsequent antimicrobial evaluations were conducted via agar diffusion and turbidimetry, employing three strains of Gram-negative bacteria (E. coli, K. oxytoca, and P. aeruginosa) and three strains of Gram-positive bacteria (S. mutans, S. aureus, and B. subtilis). The findings revealed that P. aeruginosa exhibited maximum susceptibility to RHN powder at a concentration of 0.5%, while RHN powder at 1% concentration demonstrated maximal inhibition against S. aureus and S. mutans. Overall, our study highlights the successful synthesis of a dental resin with hydroxyapatite and silver nanoparticles, exhibiting bactericidal properties at low silver concentrations. These findings hold promise for enhancing dental materials with improved antimicrobial efficacy and clinical performance