Effects of Shrimp Shell-Derived Chitosan on Growth, Immunity, Intestinal Morphology, and Gene Expression of Nile Tilapia (Oreochromis niloticus) Reared in a Biofloc System.

Chitosan (CH) shows great potential as an immunostimulatory feed additive in aquaculture. This study evaluates the effects of varying dietary CH levels on the growth, immunity, intestinal morphology, and antioxidant status of Nile tilapia (Oreochromis niloticus) reared in a biofloc system. Tilapia fingerlings (mean weight 13.54 ± 0.05 g) were fed diets supplemented with 0 (CH0), 5 (CH5), 10 (CH10), 20 (CH20), and 40 (CH40) mL·kg-1 of CH for 8 weeks. Parameters were assessed after 4 and 8 weeks. Their final weight was not affected by CH supplementation, but CH at 10 mL·kg-1 significantly improved weight gain (WG) and specific growth rate (SGR) compared to the control (p < 0.05) at 8 weeks. Skin mucus lysozyme and peroxidase activities were lower in the chitosan-treated groups at weeks 4 and 8. Intestinal villi length and width were enhanced by 10 and 20 mL·kg-1 CH compared to the control. However, 40 mL·kg-1 CH caused detrimental impacts on the villi and muscular layer. CH supplementation, especially 5-10 mL·kg-1, increased liver and intestinal expressions of interleukin 1 (IL-1), interleukin 8 (IL-8), LPS-binding protein (LBP), glutathione reductase (GSR), glutathione peroxidase (GPX), and glutathione S-transferase (GST-α) compared to the control group. Overall, dietary CH at 10 mL·kg-1 can effectively promote growth, intestinal morphology, innate immunity, and antioxidant capacity in Nile tilapia fingerlings reared in biofloc systems.

Vine-Winery Byproducts as Precious Resource of Natural Antimicrobials: In Vitro Antibacterial and Antibiofilm Activity of Grape Pomace Extracts against Foodborne Pathogens.

Grape pomace is the main by-product of vine-winery chains. It requires adequate treatment and disposal but is also an economically underused source of bioactive plant secondary metabolites. This study aimed to investigate the antibacterial effects of polyphenolic extracts from Aglianico (Vitis vinifera L.) grape pomace. In particular, hydroethanolic extracts obtained via an ultrasonic-assisted extraction technique were selected for antimicrobial tests. The extracts were screened for their antibacterial effects against foodborne pathogens that were both Gram-positive, in the case of Staphylococcus aureus and Bacillus cereus, and Gram-negative, in the case of Escherichia coli and Salmonella enterica subsp. enterica serovar Typhimurium, showing variable bacteriostatic and bactericidal effects. In addition, our results demonstrated that the tested grape pomace extracts can reduce the inhibitory concentration of standard antibiotics. Interestingly, selected extracts inhibited biofilm development by S. aureus and B. cereus. Overall, these new insights into the antibacterial properties of grape pomace extracts may represent a relevant step in the design of novel therapeutic tools to tackle foodborne diseases, and in the management of resistant biofilm-related infections.

Antibacterial and Antibiofilm Efficacy of Thyme (Thymus vulgaris L.) Essential Oil against Foodborne Illness Pathogens, Salmonella enterica subsp. enterica Serovar Typhimurium and Bacillus cereus.

Nowadays, the wide spread of foodborne illness and the growing concerns about the use of synthetic food additives have shifted the focus of researchers towards essential oils (EOs) as possible antimicrobials and preservatives of natural origin. Thanks to their antimicrobial properties against pathogenic and food spoilage microorganisms, EOs have shown good potential for use as alternative food additives, also to counteract biofilm-forming bacterial strains, the spread of which is considered to be among the main causes of the increase in foodborne illness outbreaks. In this context, the aim of this study has been to define the antibacterial and antibiofilm profile of thyme (Thymus vulgaris L.) essential oil (TEO) against widespread foodborne pathogens, Salmonella enterica subsp. enterica serovar Typhimurium and Bacillus cereus. TEO chemical composition was analyzed through gas chromatography-mass spectrometry (GC-MS). Preliminary in vitro antibacterial tests allowed to qualitatively verify TEO efficacy against the tested foodborne pathogens. The subsequent determination of minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values allowed to quantitatively define the bacteriostatic and bactericidal effects of TEO. To evaluate the ability of essential oils to inhibit biofilm formation, a microplate assay was performed for the bacterial biofilm biomass measurement. Results suggest that TEO, rich in bioactive compounds, is able to inhibit the growth of tested foodborne bacteria. In addition, the highlighted in vitro anti-biofilm properties of TEO suggest the use of this natural agent as a promising food preservative to counteract biofilm-related infections in the food industry.

Microplastics pollution in freshwater fishes in the South of Italy: Characterization, distribution, and correlation with environmental pollutants.

In this study, we investigated the presence, abundance, and chemical nature of microplastics (MPs) in the freshwater fish gastrointestinal tract in the South of Italy, and evaluated the possible correlation between MPs and environmental pollutants. Fifty specimens belonging to five species (Scardinius erythrophthalmus, Barbus barbus, Rutilus rubilio, Leuciscus cephalus, Salmo trutta), from twenty sites were collected. MPs chemical feature was identified by means of Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) and Raman microscopy. MPs were represented by 34.86 % fragments, film, and foam (all together MPs) and 65.14 % by fibers (MFs). The mean number of MPs/MFs per fish ranged from 6.25 ± 4.35 in R. rubilio and 2.26 ± 1.94 in B. barbus. The highest number of MPs/MFs per g of GIT was found in R. rubilio (9.07 ± 9.66), and the lowest in S. erythrophthalmus (0.75 ± 0.53). The highest number of MPs/MFs per fish species was found in L. cephalus (16), and the lowest in S. erythrophthalmus (4). Black predominated in every type of plastic debris identified, followed by blue and white, respectively for MFs and MPs. Polyethylene (PE), polyethylene terephthalate (PET), polystyrene (PS), and polypropylene (PP), were the main plastic polymers found. At fish sampling sites, comparing concentrations in soils of potentially toxic elements and persistent organic pollutants with the number of MPs/MFs in fish, a significant correlation was noted with polychlorinated biphenyls (PCBs) and, in particular, with PCB 105, PCB 118, PCB 156, PCB 157, and PCB 167. A strong correlation was also observed with all types of polycyclic aromatic hydrocarbon (PAHs) particularly with benzo(ghi)perylene, dibenz(a,h)anthracene, benzo(b)fluoranthene, benz(a)anthracene, benzo(a)pyrene, and pyrene. The results of this study would be useful to draft management and action plans, promote intervention plans aiming at removing threats to species and habitats, and address ways of renaturalization.

Towards Green Strategies of Food Security: Antibacterial Synergy of Essential Oils from Thymus vulgaris and Syzygium aromaticum to Inhibit Escherichia coli and Staphylococcus aureus Pathogenic Food Isolates.

Foodborne diseases continue to represent an important public health issue. The control of food spoilage and pathogenic microorganisms is achieved mainly by synthetic chemicals, unfortunately associated to several undesirable aspects. The growing requirement for new and safe alternative strategies has resulted in the research of agents from natural sources with antimicrobial properties, such as essential oils (EOs). This study's purpose was to define the antibacterial profile of thyme (Thymus vulgaris) and cloves (Syzygium aromaticum) essential oils against both Gram-positive and Gram-negative important foodborne pathogenic bacteria. Gas chromatography mass spectrometry analysis was performed for EOs' chemical composition. Qualitative in vitro antimicrobial assays (i.e., agar well diffusion method and disk-volatilization method) allowed for verification of the efficacy of EOs, used individually and in binary combination and both in liquid and vapor phase, against Staphylococcus aureus and Escherichia coli food isolates. Minimal inhibitory concentrations and minimal bactericidal concentration values have been used to quantitatively measure the antibacterial activity of EOs, while the fractional inhibitory concentration index has been considered as a predictor of in vitro antibacterial synergistic effects. The microbiological tests suggest that thyme and cloves EOs, rich in bioactive compounds, are able to inhibit the growth of tested foodborne bacteria, especially in vapor phase, also with synergistic effects. Results provide evidence to consider the tested essential oils as promising sources for development of new, broad-spectrum, green food preservatives.

Dietary Supplementation with a Blend of Hydrolyzable and Condensed Tannins Ameliorates Diet-Induced Intestinal Inflammation in Zebrafish (Danio rerio).

The current study evaluated the effects of hydrolyzable and condensed tannins from chestnut and quebracho wood, respectively (TSP, Silvafeed®), on zebrafish with intestinal inflammation induced by a plant-based diet (basal diet). Four experimental diets were prepared as follows: the basal diet + 0 TSP, the basal diet + TSP at 0.9 g/kg of feed, the basal diet + TSP at 1.7 g/kg of feed, and the basal diet + TSP at 3.4 g/kg of feed. Eighty-four zebrafish (Danio rerio) were fed for 12 days with the experimental diets. In zebrafish fed the basal diet, intestine integrity appeared to be altered, with damaged intestinal villi, high immunoexpression of tumor necrosis factor-α (TNFα) and cyclooxygenase 2 (COX2), and high expression of the cox2, interleukin 1 (il-1b), interleukin 8 (cxcl8-l1), and tnfα genes. The tannin treatment partially restored intestinal morphology and downregulated the expression of cytokines. The best activity was detected with 1.7 and 3.4 g/kg of feed. In the guts of all groups, Proteobacteria, Fusobacteria, Firmicutes, and Bacteroidetes were the most represented phyla. The most represented genera were Plesiomonas and Sphingomonas, belonging to the Proteobacteria phylum; Cetobacterium, belonging to the Fusobacteria phylum; and Lactobacillus, belonging to the Firmicutes phylum. No significant differences were detected among groups, except for a slight decrease in the Fusobacteria phylum and slight increases in the Shewanella and Bacteroides genera with TSP. In conclusion, these results suggest that tannins can improve the zebrafish intestinal inflammation caused by a terrestrial-plant-based diet in a dose-dependent manner.

Histopathological damage and stress- and immune-related genes' expression in the intestine of common carp, Cyprinus carpio exposed to copper and polyvinyl chloride microparticle.

The present study aimed at assessing the singular and combined effects of water copper and polyvinyl chloride microplastic (MPVC) on intestinal copper accumulation, histopathological damage, and stress-/immune-related genes' expression in common carp, Cyprinus carpio. Four groups of fish were maintained in triplicate: control (kept in clean water), Cu (exposed to 0.25 mg/L of copper), MPVC (exposed to 0.5 mg/L of MPVC), and Cu-MPVC (exposed to 0.25 mg/L of copper + 0.5 mg/L of MPVC). After 14-day exposure, the fish of Cu and Cu-MPVC treatments exhibited significantly higher intestinal copper contents, compared to the fish of control and MPVC treatments. In this regard, the Cu-MPVC fish had significantly higher copper content than the Cu fish. Exposure to copper and/or MPVC significantly upregulated the intestinal heat shock protein 70 (hsp70), cytochrome P450 family 1 subfamily A member 1 (cyp1a1), lysozyme (lys), defensin (def), mucin 2 (muc2), and mucin 5 (muc5) expression. The highest expression of hsp70, cyp1a1, lys, and def was related to Cu-MPVC treatment; whereas, the highest expression of muc2 and muc5 was observed in Cu and MPVC treatments. Exposure to copper and/or MPVC induced intestinal damage, which Cu-MPVC fish exhibited the highest severity. The present study revealed that exposure to copper and/or MPVC causes intestinal histopathological damage and upregulation in stress- and immune-related genes' expression. The most serious effects were observed in Cu-MPVC treatment that might be due to additive effects of copper and MPVC and/or higher copper accumulation in this treatment.

Combined and Singular Effects of Ethanolic Extract of Persian Shallot (Allium hirtifolium Boiss) and Synbiotic Biomin®IMBO on Growth Performance, Serum- and Mucus-Immune Parameters and Antioxidant Defense in Zebrafish (Danio rerio).

This study was carried out to evaluate combined and singular effects of ethanolic extract of Persian shallot (Allium hirtifolium Boiss) and synbiotic Biomin®IMBO on growth performance, innate immune responses, and antioxidant defense in zebrafish (Danio rerio). Fish with initial weight of 151.90 ± 0.31 mg were allocated in 21 10-L glass aquariums. The experimental groups were as follows: T1, control (without any supplementation); T2, 1% synbiotic; T3, 3% synbiotic; T4, 1% Persian shallot (as a medical plant); T5, 3% Persian shallot; T6, 1% Persian shallot and 1% synbiotic; T7, 3% Persian shallot and 3% synbiotic. At the end of the experiment (60 days), all treatments significantly showed higher final weight (FW), weight gain (WG), WG (%), and specific growth rate (SGR) compared with the fish fed on control diet. Furthermore, both synbiotic Biomin®IMBO and Persian shallot significantly improved intestine immune parameters including lysozyme, alternative complement hemolytic activity (ACH50), total immunoglobulin (total Ig), and myeloperoxidase (MPO) of zebrafish compared to fish fed on control diet (p < 0.05). Also, in all experimental groups, hepatic catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GR) activities significantly increased compared to the control group. Whereas, the highest MDA level was observed in the control group compared to the treatments (p < 0.05). Moreover, skin mucus immune parameters of zebrafish have been noticeably improved with synbiotic Biomin®IMBO and Persian shallot compared to fish fed on the control diet (p < 0.05). The results indicate that synbiotic or Persian shallot supplemented diet could enhance the general health status of the zebrafish.

The Gene Regulatory Roles of Herbal Extracts on the Growth, Immune System, and Reproduction of Fish.

The crucial need for safe and healthy aquatic animals obligates researchers in aquaculture to investigate alternative and beneficial additives. Medicinal herbals and their extracts are compromised with diverse effects on the performances of aquatic animals. These compounds can affect growth performance and stimulate the immune system when used in fish diet. In addition, the use of medicinal herbs and their extracts can reduce oxidative stress induced by several stressors during fish culture. Correspondingly, aquatic animals could gain increased resistance against infectious pathogens and environmental stressors. Nevertheless, the exact mode of action where these additives can affect aquatic animals' performances is still not well documented. Understanding the mechanistic role of herbal supplements and their derivatives is a vital tool to develop further the strategies and application of these additives for feasible and sustainable aquaculture. Gene-related studies have clarified the detailed information on the herbal supplements' mode of action when administered orally in aquafeed. Several review articles have presented the potential roles of medicinal herbs on the performances of aquatic animals. However, this review article discusses the outputs of studies conducted on aquatic animals fed dietary, medicinal herbs, focusing on the gene expression related to growth and immune performances. Furthermore, a particular focus is directed to the expected influence of herbal supplements on the reproduction of aquatic animals.

Effects of Apple (Malus pomila) Pomace-Derived Pectin on the Innate Immune Responses, Expressions of Key Immune-Related Genes, Growth Performance, and Digestive Enzyme Activity of Rainbow Trout (Oncorhynchus mykiss).

Pectins are a group of carbohydrates found in structural parts of terrestrial plants with wide industrial and biomedical applications. This study was designed to investigate the dietary effects of apple pomace-derived pectin (APDP) in rainbow trout (Oncorhynchus mykiss). Four formulated diets were provided with different inclusion levels of APDP for 30 days: 0, 5, 10, and 20 g kg-1; referred to as control, P1, P2, and P3, respectively. In this study, 300 fish (3.56 ± 0.007 g) were randomly distributed into twelve fiberglass tanks and fed 3% of their respective body weight four times a day. At the end of the experiment, growth parameters, including weight gain, specific growth rate, and food conversion ratio (FCR) were significantly improved in P1 and P2 treatments compared to those of the other treatments. Results from proximate composition analysis showed that protein content increased, and lipid decreased in the P2 and P3 groups. Serum lysozyme, complement activity, total immunoglobulin levels, and total protein were significantly enhanced in all treatments compared to those of the control group. Gene expression results showed no significant difference in regulation of interleukin-1ß (IL-1ß); however, up-regulation of lysozyme, interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) was observed in both P1 and P2. Unlike lipase, the activity of protease and amylase significantly increased in fish receiving different levels of APDP compared to the control (p < 0.05). In conclusion, the present findings suggest APDA as a promising feed additive for rainbow trout.

Dietary inclusion of watermelon rind powder and Lactobacillus plantarum: Effects on Nile tilapia's growth, skin mucus and serum immunities, and disease resistance.

An eight-week investigation was conducted to access the potential impact of dietary watermelon rind powder (WMRP) and L. plantarum CR1T5 (LP) administered individually or in combination on immunity, disease resistance, and growth rate of Nile tilapia fingerlings cultured in a biofloc system. Three hundred twenty fish (average weight 16.57 ± 0.14 g) were distributed into 16 tanks at a rate of 20 fish per tank. The fish were fed different diets: Diet 1 (0 g kg-1 WMRP and 0 CFU g-1 L. plantarum) (control), Diet 2 (40 g kg-1 WMRP), Diet 3 (108 CFU g-1 LP), and Diet 4 (40 g kg-1 WMRP + 108 CFU g-1 LP) for eight weeks. A completely randomized design (CRD) with four replications was applied. Skin mucus, serum immunity, and growth parameters were analyzed every 4 weeks, and a challenge study against S. agalactiae was conducted at the end of the experiment. The findings showed that the inclusion of WMRP + LP, administrated individually or in a mixture, significantly (P<0.05) stimulated growth, skin mucus, and serum immune parameters of Nile tilapia fingerlings compared with the control. The highest values were detected in fish fed the combination of WMRP and LP, as opposed to individual administration of either WMRP or LP, in which no significant differences were detected. Within the challenge study, the relative percent survival (RPS) in Diet 2, Diet 3, and Diet 4 was 48.0%, 52.0%, and 68.0%, respectively. Fish fed 40 g kg-1 WMRP + LP produced significantly higher RPS and protection against S. agalactiae than the other treated groups. Current results suggest that the dual administration of WMRP and LP maybe an effective feed additive for Nile tilapia grown in an indoor biofloc system, capable of improving growth parameters and increasing resistance to S. agalactiae infection.

Chestnut Shell Tannins: Effects on Intestinal Inflammation and Dysbiosis in Zebrafish.

The aim of the present study was to test the possible ameliorative efficacy of phytochemicals such as tannins on intestinal inflammation and dysbiosis. The effect of a chestnut shell (Castanea sativa) extract (CSE) rich in polyphenols, mainly represented by tannins, on k-carrageenan-induced intestinal inflammation in adult zebrafish (Danio rerio) was tested in a feeding trial. Intestinal inflammation was induced by 0.1% k-carrageenan added to the diet for 10 days. CSE was administered for 10 days after k-carrageenan induced inflammation. The intestinal morphology and histopathology, cytokine expression, and microbiota were analyzed. The k-carrageenan treatment led to gut lumen expansion, reduction of intestinal folds, and increase of the goblet cells number, accompanied by the upregulation of pro-inflammatory factors (TNFα, COX2) and alteration in the number and ratio of taxonomic groups of bacteria. CSE counteracted the inflammatory status enhancing the growth of health helpful bacteria (Enterobacteriaceae and Pseudomonas), decreasing the pro-inflammatory factors, and activating the anti-inflammatory cytokine IL-10. In conclusion, CSE acted as a prebiotic on zebrafish gut microbiota, sustaining the use of tannins as food additives to ameliorate the intestinal inflammation. Our results may be relevant for both aquaculture and medical clinic fields.

The Effect of Novel Packaging Technology on Food Safety and Quality.

This Special Issue of Foods, The Effect of Novel Packaging Technology on Food Safety and Quality, contains seven papers that were refereed and selected in accordance with the usual editorial standards of the journal [...].

Replacement of Fish Meal by Black Soldier Fly (Hermetia illucens) Larvae Meal: Effects on Growth, Haematology, and Skin Mucus Immunity of Nile Tilapia, Oreochromis niloticus.

Fish meal (FM) is no longer a sustainable source for the increasing aquaculture industry. Animal proteins from insects may be used as a FM alternative source as long as they do not create adverse effects in fish. Black soldier fly larvae meal (BSFLM) was tested in a 12-week experiment on Nile tilapia (Oreochromis niloticus). Four hundred and twenty (14.77 ± 2.09 g) fish were divided into seven groups and were fed seven diets: control (0% BSFLM-100% FM), and FM replaced by BSFLM at rates of 10%, 20%, 40%, 60%, 80% and 100%. Growth indexes, feed utilization efficiency indices, feed intake, and survival rate were not significantly different (p > 0.05) between FM and BSFLM fed fish. Values of red blood cell, white blood cells, hemoglobin, hematocrit, mean corpuscular volume and hemoglobin, mean corpuscular hemoglobin concentration, red blood cell distribution width, and platelet values were not affected by BSFLM. Skin, mucus lysozyme, and peroxidase activities were improved in BSFLM fed fish. BSFLM can be used as a substitution for FM in the Nile tilapia (O. niloticus) diet at up to a 100% rate with no adverse effects.

Short-term exposure to the simple polyphenolic compound gallic acid induces neuronal hyperactivity in zebrafish larvae.

A growing body of evidence suggests that the biological effects of polyphenols are not restricted to antioxidant activity, but they exert a wide range of modulatory effects on metabolic pathways, cellular signaling and gene expression. In this study, we tested the minimum safe concentration of gallic acid (GA) in 72 hpf zebrafish larvae in order to evaluate the effects on the central nervous system and the behavioral response. We showed that a short exposure (30 min) induces the depletion of the two main excitatory and inhibitory neurotransmitters, Glu and GABA, respectively, in the larval nervous system. The acute impairment of GABAergic-glutamatergic balance was paralleled by an increase of the fosab neuronal activity marker in specific brain areas, such as the forebrain, olfactory bulbs, pallial area, ventral midbrain, tegmentum, and the medulla oblongata ventral area. The neuronal excitation was mirrored by the increased cumulative motor response. The inhibition of the olfactory epithelium with brief cadmium exposition suggests a direct involvement of olfaction in the larvae response to GA. Our results demonstrate that a brief exposure to GA induces motoneuronal hyperexcitability in zebrafish. The behavioral response was probably elicited through the activation of an odorous, or chemical, stimulus. The specificity of the activated neuronal territories suggests the involvement of additional signaling pathways. Although the underlying molecular mechanisms remain to be elucidated, our data support the hypothesis that GA acts as an excitatory molecule, capable of inducing a specific nerve response. These results offer a new vision on potential effects of GA.

In silico analysis of the antimicrobial activity of phytochemicals: towards a technological breakthrough.

BACKGROUND: The complications associated with infections from pathogens increasingly resistant to traditional drugs lead to a constant increase in the mortality rate among those affected. In such cases the fundamental purpose of the microbiology laboratory is to determine the sensitivity profile of pathogens to antimicrobial agents. This is an intense and complex work often not facilitated by the test's characteristics. Despite the evolution of the Antimicrobial Susceptibility Testing (AST) technologies, the technological breakthrough that could guide and facilitate the search for new antimicrobial agents is still missing. METHODS: In this work, we propose the experimental use of in silico instruments, particularly feedforward Multi-Layer Perceptron (MLP) Artificial Neural Network, and Genetic Programming (GP), to verify, but also to predict, the effectiveness of natural and experimental mixtures of polyphenols against several microbial strains. RESULTS: We value the results in predicting the antimicrobial sensitivity profile from the mixture data. Trained MLP shows very high correlations coefficients (0,93 and 0,97) and mean absolute errors (110,70 and 56,60) in determining the Minimum Inhibitory Concentration and Minimum Microbicidal Concentration, respectively, while GP not only evidences very high correlation coefficients (0,89 and 0,96) and low mean absolute errors (6,99 and 5,60) in the same tasks, but also gives an explicit representation of the acquired knowledge about the polyphenol mixtures. CONCLUSIONS: In silico tools can help to predict phytobiotics antimicrobial efficacy, providing an useful strategy to innovate and speed up the extant classic microbiological techniques.

Active Edible Polysaccharide-Based Coating for Preservation of Fresh Figs (Ficus carica L.).

Fresh figs are very sensitive to microbial spoilage, even in cold storage conditions. Thus, fresh figs are high perishable products during postharvest with microbiological decay that induces an unpleasant taste and smell due to rot, and suitable conservation methods must therefore be applied. The fruit usually is consumed fresh locally, dried, or preserved longer term in other transformed forms. A sustainable approach to extend the shelf-life of figs can be constituted by application of an edible coating able to maintain the quality of the fruit during storage. A comparison between fresh figs in a commercial preservation system, with the figs preserved in an edible coating, and an active edible coating to preserve their quality characteristics was carried out. The coating efficacy was enhanced with the addition of pomegranate peel extract at two different concentrations. The inclusion of a component with high antioxidant activity in an edible coating proved to be an excellent method for preserving the quality of this highly perishable fruit. The application of natural products, obtained from renewable sources, represents a simple and economic strategy, but also a tool capable of preserving the quality of the fruit during the postharvest storage, which is often consumed in production areas due to shelf-life problems.

Phytocompounds vs. Dental Plaque Bacteria: In vitro Effects of Myrtle and Pomegranate Polyphenolic Extracts Against Single-Species and Multispecies Oral Biofilms.

In the last decades, resistant microbial infection rate has dramatically increased, especially infections due to biofilm-producing strains that require increasingly complex treatments and are responsible for the increased mortality percentages compared with other infectious diseases. Considering that biofilms represent a key factor for a wide range of chronic infections with high drug tolerance, the treatment of biofilm-causing bacterial infections represents a great challenge for the future. Among new alternative strategies to conventional antimicrobial agents, the scientific interest has shifted to the study of biologically active compounds from plant-related extracts with known antimicrobial properties, in order to also evaluate their antibiofilm activity. In this regard, the aim of this study has been to assess the antibiofilm activity of polyphenolic extracts from myrtle leaf and pomegranate peel against oral pathogens of dental plaque, an excellent polymicrobial biofilm model. In particular, the in vitro antibiofilm properties of myrtle and pomegranate extracts, also in binary combination, were highlighted. In addition to inhibiting the biofilm formation, the tested polyphenolic extracts have been proven to destroy both preformed single-species and multispecies biofilms formed by Streptococcus mutans, Streptococcus oralis, Streptococcus mitis, and Rothia dentocariosa oral isolates, suggesting that the new natural sources are rich in promising compounds able to counteract biofilm-related infections.

In vitro Synergy of Polyphenolic Extracts From Honey, Myrtle and Pomegranate Against Oral Pathogens, S. mutans and R. dentocariosa.

The increasing incidence rate of oral diseases, the wide spread of antimicrobial resistance, and the adverse effects of conventional antibiotics mean alternative prevention and treatment options are needed to counteract oral pathogens. In this regard, our study aims to evaluate the antibacterial activity of polyphenolic extracts prepared from acacia honey, myrtle leaves, and pomegranate peel against cariogenic bacteria, such as Streptococcus mutans and Rothia dentocariosa. The chemical-physical parameters of acacia honey and the RP-HPLC polyphenolic profile of pomegranate peel extract have been previously described in our studies, while the characterization of myrtle extract, performed by HPLC analysis, is reported here. All the extracts were used singly and in binary combinations to highlight any synergistic effects. Moreover, the extracts were tested in association with amoxicillin to evaluate their ability to reduce the effective dose of this drug in vitro. The values of minimal inhibitory concentrations and minimal bactericidal concentrations have been used to quantitatively measure the antibacterial activity of the single extracts, while the fractional inhibitory concentration index has been considered as predictor of in vitro anticariogenic synergistic effects. Finally, a time-kill curve method allowed for the evaluation of the bactericidal efficacy of the combined extracts. The microbiological tests suggest that acacia honey, myrtle, and pomegranate extracts are able to inhibit the cariogenic bacteria, also with synergistic effects. This study provides useful and encouraging results for the use of natural extract combinations alone or in association with antibiotics (adjuvant therapy) as a valid alternative for the prevention and treatment of oral infectious diseases.

Dietary inclusion of chestnut (Castanea sativa) polyphenols to Nile tilapia reared in biofloc technology: Impacts on growth, immunity, and disease resistance against Streptococcus agalactiae.

A feeding trial was carried out to examine the effects of adding chestnut (Castanea sativa) polyphenols (CSP) on the growth, skin mucus and serum immune parameters of Nile tilapia (Oreochromis niloticus). Five experimental diets with inclusion levels of 0, 1, 2, 4, and 8 g kg-1 of CSP were fed to Nile tilapia fingerlings (12.77 ± 0.17 g fish-1) during an eight-week trial. Fish were analyzed on the fourth and eighth week to determine the influences of CSP on growth, skin mucus, and serum immune parameters. Challenging test versus Streptococcus agalactiae was evaluated at the end of the trial. Fish fed with CSP enriched diets displayed a significant increase (P ≤ 0.05) in growth and a decline in feed conversion ratio (P ≤ 0.05). Similarly, skin mucus and serum immune parameters were significantly increased (P ≤ 0.05) in fish fed CSP with respect to the control. The effects were already evident four weeks after the CSP administration. The disease protection test displayed that the fish's survival rate was significantly higher (P < 0.05) in CSP diets over the control. The relative percentage of survival (RSP) was 62.5, 75.0, 58.3, and 37.5 in fish fed diets contained 1, 2, 4, and 8 g kg-1 CSP, respectively. The best effect on growth, immune response, and disease resistance were shown in Nile tilapia fed with a diet supplementation of 2 g kg-1 CSP.