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Abstract Background Candida albicans is the most common fungus that causes vaginal candidiasis in immunocompetent women and catastrophic infections in immunocompromised patients. The treatment of such infections is hindered due to the increasing emergence of resistance to azoles in C. albicans. New treatment approaches are needed to combat candidiasis especially in the dwindled supply of new effective and safe antifungals. The resistance to azoles is mainly attributed to export of azoles outside the cells by means of the efflux pump that confers cross resistance to all azoles including fluconazole (FLC). Objectives This study aimed to investigate the possible efflux pump inhibiting activity of fusidic acid (FA) in C. albicans resistant isolates and the potential use of Fusidic acid in combination with fluconazole to potentiate the antifungal activity of fluconazole to restore its activity in the resistant C. albicans isolates. Methods The resistance of C. albicans isolates was assessed by determination of minimum inhibitory concentration. The effect of Fusidic acid at sub-inhibitory concentration on efflux activity was assayed by rhodamine 6G efflux assay and intracellular accumulation. Mice model studies were conducted to evaluate the anti-efflux activity of Fusidic acid and its synergistic effects in combination with fluconazole. Impact of Fusidic acid on ergosterol biosynthesis was quantified. The synergy of fluconazole when combined with Fusidic acid was investigated by determination of minimum inhibitory concentration. The cytotoxicity of Fusidic acid was tested against erythrocytes. The effect of Fusidic acid on efflux pumps was tested at the molecular level by real-time PCR and in silico study. In vivo vulvovaginitis mice model was used to confirm the activity of the combination in treating vulvovaginal candidiasis. Results Fusidic acid showed efflux inhibiting activity as it increased the accumulation of rhodamine 6G, a substrate for ABC-efflux transporter, and decreased its efflux in C. albicans cells. The antifungal activity of fluconazole was synergized when combined with Fusidic acid. Fusidic acid exerted only minimal cytotoxicity on human erythrocytes indicating its safety. The FA efflux inhibitory activity could be owed to its ability to interfere with efflux protein transporters as revealed by docking studies and downregulation of the efflux-encoding genes of both ABC transporters and MFS superfamily. Moreover, in vivo mice model showed that using fluconazole-fusidic acid combination by vaginal route enhanced fluconazole antifungal activity as shown by lowered fungal burden and a negligible histopathological change in vaginal tissue. Conclusion The current findings highlight FA’s potential as a potential adjuvant to FLC in the treatment of vulvovaginal candidiasis.

BackgroundP. aeruginosa, a significant bacterium, can cause severe illness and resistance to antibiotics. Quorum sensing (QS) systems regulate virulence factors production. Targeting QS could reduce bacteria pathogenicity and prevent antibiotic resistance. Cruciferous vegetables contain sulforaphane, known for its anti-inflammatory, antioxidant, anticancer, and antimicrobial properties.AimWe aimed to examine the inhibitory influences of sulforaphane, at a sub-inhibitory concentration (¼ minimum inhibitory concentration, MIC), on virulence and QS in P. aeruginosa.Materials and methodsThe sulforaphane’s anti-virulence actions at sub-inhibitory concentrations were explored in vitro and in vivo. A sub-MIC concentration of sulforaphane was combined with anti-pseudomonal drugs, and the results of this combination were assessed. The virtual affinity of sulforaphane for the receptors of QS was studied, and its effect on the expression of QS genes was quantified.ResultsSulforaphane significantly decreased the biofilm formation, motility, ability to withstand oxidative stress, and the synthesis of virulence extracellular enzymes such as proteases, hemolysins, and elastase, as well as other virulence factors like pyocyanin. In addition, sulforaphane lessened the severity of P. aeruginosa infection in mice. Sulforaphane reduced the antipseudomonal antibiotics’ MICs when used together, resulting in synergistic effects. The observed anti-virulence impacts were attributed to the ability of sulforaphane to inhibit QS via suppressing the QS genes’ expression.ConclusionSulforaphane shows promise as a potent anti-virulence and anti-QS agent that can be used alongside conventional antimicrobials to manage severe infections effectively. Furthermore, this study paves the way for further investigation of sulforaphane and similar structures as pharmacophores for anti-QS candidates.

IntroductionThe current experiment investigated the multifaceted effects induced by microplastics and the statin Lipitor on marine benthic nematodes.MethodsThe nematodes were exposed to a single polystyrene and polyvinyl chlorides (both at 1 mg.kg-1 Dry Weight) and two Lipitor concentrations (0.1 and 1 mg.l-1), as well as to a mixture of both types of pollutants, for 30 days.ResultsThe results highlighted a significant decrease in the abundance, individual biomass, and diversity of nematodes directly with the addition of polyvinyl chlorides and/or Lipitor. These treatments induced a greater mortality rate among microvores and diatom feeders compared to other feeding types of nematodes.DiscussionThe nematofauna underwent a strong restructuring phase following exposure to microplastics and Lipitor when added alone, leading to the disappearance of sensitive species and their replacement by more tolerant taxa. The toxicity of Lipitor is attenuated by the physical bonding with polystyrene when added to a mixture and has no negative effect on marine nematode species.

Fenugreek (Trigonella foenum-graecum) has a great beneficial health effect; it has been used in traditional medicine by many cultures. Likewise, the α-amylase inhibitors are potential compounds in the development of drugs for the treatment of diabetes. The beneficial health effects of fenugreek lead us to explore the chemical composition of the seeds and their antioxidant and α-amylase inhibition activities. The flavonoid extraction from fenugreek seeds was achieved with methanol through a Soxhlet apparatus. Then, the flavonoid glycosides were characterized using HPLC-DAD-ESI-MS analysis. The antioxidant capacity of fenugreek seed was measured using DPPH, FRAP, ABTS, and CUPRAC assays. Finally, the α-amylase inhibition activity was carried out using in vitro and in silico methods. The methanolic extract was found to contain high amounts of total phenolics (154.68 ± 1.50 μg GAE/mg E), flavonoids (37.69 ± 0.73 μg QE/mg E). The highest radical-scavenging ability was recorded for the methanolic extract against DPPH (IC50 = 556.6 ± 9.87 μg/mL), ABTS (IC50 = 593.62 ± 9.35 μg/mL). The ME had the best reducing power according to the CUPRAC (A 0.5 = 451.90 ± 9.07 μg/mL). The results indicate that the methanolic extracts of fenugreek seed best α-amylase inhibition activities IC50 = 653.52 ± 3.24 μg/mL. Twenty-seven flavonoids were detected, and all studied flavonoids selected have good affinity and stabilize very well in the pocket of α-amylase. The interactions between the studied flavonoids with α-amylase were investigated. The flavonoids from fenugreek seed present a good inhibitory effect against α-amylase, which is beneficial for the prevention of diabetes and its complications.

Context: Salvia balansae de Noé (S. balansae) (Lamiaceae) is known to be an important plant used in folk medicine as an herbal remedy in Algeria. Objective: The purpose of the present study was to demonstrate the phytochemical composition, antioxidant activities, enzyme inhibitory activities, and antimicrobial activities of S. balansae extracts. Materials and methods: A methanolic extract and a petroleum ether extract from the aerial parts of the plant were assessed for their chemical composition. HPLC-MS and HPLC-DAD assessed the content of phenols, GC-MS the fatty acid composition, and ICP-MS the mineral profiles of the plant. Additionally, we evaluated the bioactivities of S. balansae extracts by the DPPH, ABTS, and CUPRAC assays, including the antioxidant potential against AChE, BChE, α-amylase, and α-glucosidase for enzyme inhibition. The antibacterial and antifungal activities of the methanolic extract were determined by the disc diffusion test against several strains of bacteria and yeasts. Results: Our findings revealed that the aerial parts of S. balansae were rich in phytochemical components and contained large amounts of minerals. Quantitative analysis of phenolic compounds by HPLC-DAD revealed the presence of 12 compounds in three major classes, flavonoids, hydroxycinnamic acid, and phenolic acid derivatives, with 0.61, 0.45, and 0.29 mg/g of extract, respectively. Nine phenolic constituents were quantified by HPLC-MS analysis; catechin (72.5%) was the main compound, followed by myricetin (21.7%). The fatty acid composition of the S. balansae petroleum ether extract by GC-MS analysis was quantified. Seventeen compounds, including palmitic acid, were identified as the major fatty acids. The antioxidant activity of the S. balansae extracts was measured by three different methods: the methanol extract provided better results than the petroleum ether extract, and interesting values were noted for the DPPH, ABTS, and CUPRAC assays of 242.7 ± 7.44, 124.1 ± 9.70, and 222.9 ± 6.05 µg/mL, respectively. The enzyme inhibition activity of the plant could not be determined. The antimicrobial results of the methanolic extract obtained from the disc diffusion method, followed by measurements of MIC, MBC, and MFC against several bacteria and yeasts, indicated that S. balansae exhibited noticeable antimicrobial and antifungal activities. Conclusions: These results provided new data about the main phenolic compounds and biological activities of extracts of the aerial parts of S. balansae, which might be an alternative source for synthetic bioactive compounds.

The removal of heavy metals from wastewater has become the subject of considerable interest at present. Thus, the use of novel adsorbents that are highly efficient is of critical importance for the removal of Cr (VI) ions from aqueous media. The adsorption of Cr (VI) ions from aqueous solutions by a new adsorbent, cedar wood sawdust, and the optimization of its adsorption parameters, were investigated in this study. Cedar wood sawdust was used in its native and HNO3/NaOH chemically modified forms as new low-cost sorbents to remove Cr (VI) ions from aqueous solutions in a batch system. The adsorption conditions were analyzed via response surface methodology. The RSM results showed that the optimal adsorption conditions yielding the best response were an adsorbent mass of 2 g for native Cedar and 1.125 g for its activated form, a metal concentration of 150 mg/L for native Cedar and 250 mg/L for activated, a temperature of 50 °C, a pH of 1, and a contact time of 67.5 min. At optimum adsorption conditions, the maximum adsorption capacities and the adsorption yields were 23.64 mg/g and 84% for native Cedar and 48.31 mg/g and 99% for activated Cedar, respectively.

The problem of antibiotic resistance is a global critical public health concern. In light of the threat of returning to the pre-antibiotic era, new alternative approaches are required such as quorum-sensing (QS) disruption and virulence inhibition, both of which apply no discernible selective pressure on bacteria, therefore mitigating the potential for the development of resistant strains. Bearing in mind the significant role of QS in orchestrating bacterial virulence, disrupting QS becomes essential for effectively diminishing bacterial virulence. This study aimed to assess the potential use of sub-inhibitory concentration (0.25 mg/mL) of glyceryl trinitrate (GTN) to inhibit virulence in Serratia marcescens and Pseudomonas aeruginosa. GTN could decrease the expression of virulence genes in both tested bacteria in a significant manner. Histopathological study revealed the ability of GTN to alleviate the congestion in hepatic and renal tissues of infected mice and to reduce bacterial and leukocyte infiltration. This study recommends the use of topical GTN to treat topical infection caused by P. aeruginosa and S. marcescens in combination with antibiotics.

The effects of silver nanoparticles and arsenic at community levels have rarely been assessed in laboratory experiments, despite their obvious advantage in reflecting better the natural conditions compared to traditionally single species-focused toxicological experiments. In the current study, the multifaceted effects of these xenobiotics, acting alone or combined, on meiobenthic nematodes were tested in a laboratory experiment carried out in microcosms. The nematofauna was exposed to two concentrations (0.1 and 1 mg·L−1) of silver nanoparticles (Ag1/Ag2) and arsenic (As1/As2), as well as to a mixture of both compounds, for 30 days. The results particularly highlighted a significant decrease in the abundance and taxonomic diversity of nematodes directly with increasing dosages of these compounds when added alone at the highest concentration. The addition of these levels of xenobiotics seems to make the sediment matrix gluey, hence inducing greater mortality among microvores and diatoms feeders. Moreover, the nematofauna went through a strong restructuring phase following the exposure to both compounds when added alone, leading to the disappearance of sensitive taxa and their replacement with more tolerant ones. However, the similarity in nematofauna composition between control and mixtures of silver nanoparticles and arsenic (except for Ag1As2) suggests that the toxicity of the latter pollutant could be attenuated by its physical bonding to the former.

In this study, we investigated in vitro the potential of Trichoderma harzianum to produce bioactive secondary metabolites that can be used as alternatives to synthetic compounds. The study focused on analyzing two extracts of T. harzianum using ethyl acetate and n-butanol solvents with different polarities. The extracts were examined using phytochemical analysis to determine the content of polyphenols, flavonoids, tannins, and alkaloids. Thin-layer chromatography (TLC) and Gas chromatography-mass spectroscopy (GC-MS) analysis were used to profile volatile organic metabolites (VOCs) present in the extracts. Furthermore, the extracts were tested for their antifungal ability using the poison food technique. For measuring antioxidant activity, the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) test was used. Trichoderma harzianum was shown to have a significantly high content of tannins and alkaloids, with a noticeable difference between the two extracts. GC-MS analysis identified 33 potential compounds with numerous benefits that could be used in agriculture and the medicinal industry. Moreover, strong antifungal activity was identified against Sclerotinia sclerotiorum by 94.44%, Alternaria sp. by 77.04%, and Fusarium solani by 51.48; similarly, the IC50 of antioxidant activity was estimated for ethyl acetate extract by 71.47% and n-butanol extract by 56.01%. This leads to the conclusion that Trichoderma harzianum VOCs play a significant role as an antifungal and antioxidant agent when taking into account the advantageous bioactive chemicals noted in the extracts. However, to our knowledge, this is the first study in Algeria presenting detailed phytochemical analysis and GC-MS profiling of Trichoderma harzianum for two extracts, ethyl acetate and n-butanol.

This study aims to evaluate the toxicity of ZnS nanoparticles (ZnS NP50 = 50 µg/L and ZnS NP100 = 100 µg/L) and diethyl (3-cyano-1-hydroxy-2-methyl-1-phenylpropyl)phosphonate or P (P50 = 50 µg/L and P100 = 100 µg/L) in the clams Ruditapes decussatus using chemical and biochemical approaches. The results demonstrated that clams accumulate ZnS NPs and other metallic elements following exposure. Moreover, ZnS NPs and P separately lead to ROS overproduction, while a mixture of both contaminants has no effect. In addition, data showed that exposure to P100 resulted in increased levels of oxidative stress enzyme activities catalase (CAT) in the gills and digestive glands. A similar trend was also observed in the digestive glands of clams treated with ZnS100. In contrast, CAT activity was decreased in the gills at the same concentration. Exposure to ZnS100 and P100 separately leads to a decrease in acetylcholinesterase (AChE) levels in both gills and digestive glands. Thus, AChE and CAT after co-exposure to an environmental mixture of nanoparticles (ZnS100) and phosphonate (P100) did not show any differences between treated and non-treated clams. The outcome of this work certifies the use of biomarkers and chemical assay when estimating the effects of phosphonate and nanoparticles as part of an ecotoxicological assessment program. An exceptional focus was given to the interaction between ZnS NPs and P. The antioxidant activity of P has been demonstrated to have an additive effect on metal accumulation and antagonistic agents against oxidative stress in clams treated with ZnS NPs.

Dibetou wood sawdust, SEM and IRTF characterized, collected from a local sawmill, was used in its raw and chemically activated forms using nitric acid and sodium hydroxide to retain Pb2+ ions, according to several parameters (pH, contact time, initial metal concentration, mass of adsorbent and temperature of the medium). The results obtained reveal that the removal rate of Pb2+ ions on raw and activated Dibetou sawdust reached a percentage of about 84% and 93% successively. The experimental design methodology using the full factorial design has enabled us to study and to check the influence of the various parameters on Pb2+ ions adsorption onto raw and activated Dibetou sawdust; it allowed us, also, to define the interactions between these latters. A response surface methodology (RSM) based on the central composite design (CCD) was used to optimize this process. The results obtained showed that initial concentration, pH, contact time and mass of adsorbent affected the lead (II) removal by adsorption. The optimum conditions were found as pH = 6, mass of adsorbent = 0.875 g per 100 mL of solution and contact time = 90 min for raw Dibetou and 47.5 min for activated Dibetou using a concentration of 275 mg.L−1 of metallic ion. In these conditions, removal rates of Pb2+ ions reach 94% onto raw sawdust and 99% using its activated form. The adsorption data are well fitted with Langmuir isotherm. The maximum adsorption capacities are 33.33 mg·g−1 for the raw sawdust and 61.73 mg·g−1 for its activated form. Kinetic modeling is well described by the pseudo-second order model (0.99

A laboratory bioassay was performed to assess the ecotoxicity of ciprofloxacin on a meiobenthic nematodes community from Bizerte lagoon (NE Tunisia). Four ciprofloxacin doses [D1 (50 µg/g), D2 (100 µg/g), D3 (200 µg/g), and D4 (500 µg/g)] were applied to the substrate, and responses were studied after one month. Discernible differences were observed between control assemblages and those populating ciprofloxacin treated substrates. All univariate indices were affected significantly compared to those in the control microcosm with increasing antibiotic concentration. The non-parametric Multi-Dimensional Scaling based on species abundances (MDS) showed significant separation of the control microcosm from the antibiotic-treated populations. The nematode species responses to the fluoroquinolone treatments varied: Odontophora villoti was reduced at all concentrations of ciprofloxacin and was considered “sensitive,” whereas Metoncholaimus pristiurus was affected by moderate concentrations; its abundance increased with the highest dose D4 and was described as “opportunistic.” Paramonohystera pilosa, whose abundance increased with antibiotic doses appeared “resistant.” Keywords: Meiobenthic nematodes, Susbstrate, Antibiotic, Ciprofloxacin, Exposure, Bioassay

An experiment was conducted using microcosms with connected sedimentary compartments to assess the effects of three polycyclic aromatic hydrocarbons (PAHs) on free-living marine nematodes from Bizerte Bay (northeastern Tunisia). Over 30 days, the nematofauna were exposed to four treatment sediments, including one with chrysene (150 ppb), chrysene (150 ppb) plus fluoranthene (75 ppb), chrysene (150 ppb) and phenanthrene (15 ppb), and an uncontaminated reference. Numerical and qualitative community simplifications occurred in contaminated sediments relative to the reference. The diversity of nematodes differed based on hydrocarbon combinations. Multivariate analyses revealed communities in contaminated compartments differed from those in the initial natural sediment and reference. Differences in sensitivities of nematodes to hydrocarbons and in migratory abilities occurred. Rhabditis sp., Calamicrolaimus honestus, and Oncholaimus campylocercoides were in all compartments and classified as tolerant to PAHs. Nematodes observed only in control compartments, including Parasphaerolaimus paradoxus, Encheliidae (sp.), Trichotheristus mirabilis, and Theristus pertenuis were considered sensitive. Keywords: Microcosm, Free-living marine nematodes, Polycyclic aromatic hydrocarbons, Migration, Abundance, Species diversity

Heavy metals cause deleterious effects on human health and drastically alter the biogeochemical cycles within freshwater habitats. The main human activities leading to heavy metal contamination of various aquatic ecosystems comprise the industry, agriculture, urbanization, transport and mining. Lake Nasser is the main freshwater source in Egypt, usually polluted from upstream human activities from the hydrographic basin of the River Nile. The current study surveyed the impact of heavy metals contamination (i.e., Cd, Zn, Pb and Cu) in water, sediment and two Nile Tilapia (Oreochromis niloticus) fish organs (liver and muscles) at six sampling sites along Lake Nasser. Additionally, the effects of heavy metals bioaccumulation in the aquatic ecosystem, via water, sediments and fish organs were investigated. The conclusion is that the water of Lake Nasser is safe for use in terms of human consumption, agricultural utilization and public sanitation.

Centaurea parviflora (C. parviflora), belonging to the family Asteraceae, is an Algerian medicinal plant used in folk medicine to treat different diseases related to hyperglycemic and inflammatory disorders, as well as in food. The present study aimed to assess the total phenolic content, in vitro antioxidant and antimicrobial activity and phytochemical profile of the extracts of C. parviflora. The extraction of phenolic compounds from aerial parts was conducted using solvents of increasing polarity starting from methanol, resulting in crude extract (CE), to chloroform extract (CHE), ethyl acetate extract (EAE) and butanol extract (BUE). The total phenolic, flavonoid and flavonol contents of the extracts were determined using the Folin–Ciocalteu and AlCl3 methods, respectively. The antioxidant activity was measured with seven methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, galvinoxyl free-radical-scavenging test, 2,2′-Azino-Bis(3-Ethylbenzothiazoline-6-Sulfonic Acid) (ABTS) assay, cupric reducing antioxidant capacity (CUPRAC), reducing power, Fe+2-phenanthroline reduction assay and superoxide-scavenging test. The disc-diffusion method aimed at testing the sensitivity of bacterial strains toward our extracts. A qualitative analysis with thin-layer chromatography of the methanolic extract was performed. Moreover, HPLC-DAD-MS was used to establish the phytochemical profile of the BUE. The BUE was found to contain high amounts of total phenolics (175.27 ± 2.79 µg GAE/mg E), flavonoids (59.89 ± 0.91 µg QE/mg E) and flavonols (47.30 ± 0.51 µg RE/mg E). Using TLC, different components such as flavonoids and polyphenols were noted. The highest radical-scavenging ability was recorded for the BUE against DPPH (IC50 = 59.38 ± 0.72 µg/mL), galvinoxyl (IC50 = 36.25 ± 0.42 µg/mL), ABTS (IC50 = 49.52 ± 1.54 µg/mL) and superoxide (IC50 = 13.61 ± 0.38 µg/mL). The BUE had the best reducing power according to the CUPRAC (A0.5 = 71.80 ± 1.22 μg/mL), phenanthroline test (A0.5 = 20.29 ± 1.16 μg/mL) and FRAP (A0.5 = 119.17 ± 0.29 μg/mL). The LC-MS analysis of BUE allowed us to identify eight compounds including six phenolic acids and two flavonoids: quinic acid, five chlorogenic acid derivatives, rutin and quercetin 3-o-glucoside. This preliminary investigation revealed that the extracts of C. parviflora have a good biopharmaceutical activity. The BUE possesses an interesting potential for pharmaceutical/nutraceutical applications.

The Pipper nigram (P. nigram) leaf extract was used for the biosynthesis of copper oxide nanoparticles (CuO NPs) and the successful formation of the resultant product was confirmed through several physicochemical techniques. The chemical structure and the elemental composition were analysed through Fourier transform infrared (FTIR) and energy dispersive X-ray (EDX) spectroscopies, respectively. The crystalline structure and crystallite size were investigated through an X-ray diffractometer (XRD) and a monoclinic crystallite with a size of 40.68 nm was reported. Even-distributed particles with an average particle size of 49.75 nm were seen in the scanning electron micrograph (SEM), whereas the thermal stability was checked during the thermogravimetric analysis (TGA). The ultra-violet and visible (UV-Visible) spectroscopy was operated to study the light absorbance phenomena and to determine the band gap energy from the absorption edge, which was found to be 1.47 eV. The CuO NPs were used as antibacterial agents against gram-negative bacteria (GNB) and gram-positive bacteria (GPB), and greater inhibition zones were seen against the former one. The antioxidant test was also carried out against 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals and the antioxidant potential of CuO NPs was found to be higher than ascorbic acid.

The effects of pharmaceutical under aquatic biota are still not well established. In this investigation, we assessed the results of a common pharmaceutical’s, triclosan (TCS), treatment on physiological and biochemical status of the Mediterranean mussels. Filtration and respiration rates were statistically reduced after treatment with highest considered concentration TCS2 = 100 µg·L−1. However, no modification (p > 0.05) was detected after treatment with TCS1 = 50 µg·L−1. For biochemical responses, oxidative stress parameters including H2O2 level and antioxidant enzymes were enhanced following concentration in considered organs. In parallel, Malondialdheyde content was measured in mussels after TCS treatment and lipid peroxidation occurred at high TCS concentration. Neurotoxicity evaluated by acetylcholinesterase (AChE) activity was induced in gills and digestive glands after exposure to TCS2. Overall, physiological impairment, oxidative stress, lipid peroxidation and neurotoxicity could be induced by triclosan in mussels. The association of physiological and biochemical biomarkers constitute a useful tool to measure the impact of pharmaceuticals in marine organism.

The aim of this work was to study the ecotoxicological effects of an endocrine disruptor triclosan on the clam Ruditapes decussatus. The bivalves were exposed to three concentrations of this biocide (C1 = 100 ng/L, C2 = 200 ng/L and C3 = 500 ng/L) for three and seven days. The impact was assessed at the gills and digestive glands, through activities of an antioxidant defense biomarker (Gluthatione S-Transferase, GST), a damage biomarker (Malondialdehyde, MDA), and a neurotoxicity biomarker (Acetylcholinesterase, AChE). Furthermore, histological traits were approached in different organs to evaluate any possible alteration induced by triclosan. It appears from this study that both gills and digestive glands responded discernibly to triclosan and effects were concentration-dependent. The stressed clams showed a significant increase in their GST and MDA activities in gills and digestive glands compared to controls for both time slots considered. In turn, the AChE activity was clearly inhibited in both organs in a time dependent way. The histological study made it possible to observe several structural pathologies caused by triclosan in the gills and the digestive gland. These alterations consisted mainly of inflammatory reactions, malformations of the lamellae and fusion of the gill filaments, degeneration of the connective tissue, and the erosion of the gill cilia with the appearance of certain severe alterations (cell necrosis and apoptosis), which can thus cause a malfunction of the gills and eventually lead to a reduction in oxygen consumption and a disruption of the osmoregulation for bivalves. Alterations in the digestive gland have also been detected, mainly by epithelial alterations, thinning of the tubules, and alteration of the basal cell membrane which can impair the ability of clams to absorb food. At germinal cells, several damages were observed in the oocytes which probably disturbed the reproductive function and the fertility of the clams. The damages observed in female gonads were caused by the cytolysis of a large number of oocytes through autophagy and necrosis at 200 ng triclosan/L. Moreover, at 500 ng triclosan/L, hemocytic infiltration was observed in acini and apoptotic bodies reflected in the fragmentation of more than 90% of oocytes.

The main interest in the valorization of vegetable wastes is due to the peculiarity of their chemical composition in substances that present important properties. Among these substances, antioxidants could replace those industrially manufactured. In the present study, three solvents of different polarities (hexane, ethanol, and water) were applied for the extraction of phenolic compounds from Cynara cardunculus L. waste using two extraction methods: Soxhlet Extraction (SE) and Ultrasonic-Assisted Extraction (UAE). The obtained extracts were then characterized by Fourier-Transform Infrared (FTIR) spectroscopy and spectrophotometric determination of Total Phenolics (TPC), Total Flavonoids (TFC), and Condensed Tannins (CT). Total Antioxidant Capacity (TAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity of ethanol and water extracts of leaves and stems were also evaluated. High extraction yields were obtained by UAE. Water extracts had high yield regardless of the technique used for leaves and stems, and these extracts showed high TAC of 534.72 ± 3.83 mg AAE/g FM for leaves and 215.70 ± 8.87 mg AAE/g FM (mg of ascorbic acid equivalent per g of FM) for stems, and IC50 of 2077.491 μg/mL for leaves and 1248.185 μg/mL for stems. We explain the latter by the high total phenolic contents (TPCs), which reach 579.375 ± 3.662 mg GAE/g FM (mg of gallic acid equivalents per g of fresh matter) for leaves and 264.906 ± 3.500 mg GAE/g FM for stems. These results confirmed that the leaves and stems of the studied cardoon waste were, indeed, interesting sources of natural antioxidants.

The aim of the current study was to assess the multifaceted effects of the polycylic aromatic hydrocarbon phenanthrene, mainly used in the colouring, explosive, and pharmaceutical industries, on the physiology of two bivalve species with economic value as seafood, namely, the Mediterranean mussel Mytilus galloprovincyalis and the European clam Ruditapes decussatus. The current study assessed how the phenanthrene affected several biomarkers and biometric endpoints in both bivalves, based on an in vivo experiment in silico approach. The bivalves were exposed during four time slots (i.e., 7, 15, 21, and 28 days) to two concentrations of phenanthrene in water (50 µg/L and 100 µg/L). For the clam R. decussatus, an additional contamination of sediment was applied due their typical benthic lifestyle (50 µg/kg and 100 µg/kg). The phenanthrene significantly reduced the ability of bivalves to tolerate desiccation and their Median Lethal Time, and also inhibited the activity of the enzyme acetylcholinesterase in a time-dependent manner. The activity of catalase indicated that bivalves also experienced oxidative stress during the first 21 days of the experiment. The significant decline in catalase activity observed during the last week of the experiment for the mussel M. galloprovincyalis supported a depletion of enzymes caused by the phenanthrene. The phenanthrene has also toxicokinetic and toxicodynamic properties, as assessed by the in silico approach. Overall, the results obtained suggest that the bivalves Ruditapes decussatus and M. galloprovincyalis can be used as a sentinel species in monitoring studies to assess the environmental impact of phenanthene in marine ecosystems. The significance of our findings is based on the fact that in ecotoxicology, little is known about the chronic effects, the simultaneous use of multiple species as bioindicators, and the interactions molecular modelling.

Abstract High‐throughput sequencing has the potential to describe biological communities with high efficiency yet comprehensive assessment of diversity with species‐level resolution remains one of the most challenging aspects of metabarcoding studies. We investigated the utility of curated ribosomal and mitochondrial nematode reference sequence databases for determining phylum‐specific species‐level clustering thresholds. We compiled 438 ribosomal and 290 mitochondrial sequences which identified 99% and 94% as the species delineation clustering threshold, respectively. These thresholds were evaluated in HTS data from mock communities containing 39 nematode species as well as environmental samples from Vietnam. We compared the taxonomic description of the mocks generated by two read‐merging and two clustering algorithms and the cluster‐free Dada2 pipeline. Taxonomic assignment with the RDP classifier was assessed under different training sets. Our results showed that 36/39 mock nematode species were identified across the molecular markers (18S: 32, JB2: 19, JB3: 21) in UClust_ref OTUs at their respective clustering thresholds, outperforming UParse_denovo and the commonly used 97% similarity. Dada2 generated the most realistic number of ASVs (18S: 83, JB2: 75, JB3: 82), collectively identifying 30/39 mock species. The ribosomal marker outperformed the mitochondrial markers in terms of species and genus‐level detections for both OTUs and ASVs. The number of taxonomic assignments of OTUs/ASVs was highest when the smallest reference database containing only nematode sequences was used and when sequences were truncated to the respective amplicon length. Overall, OTUs generated more species‐level detections, which were, however, associated with higher error rates compared to ASVs. Genus‐level assignments using ASVs exhibited higher accuracy and lower error rates compared to species‐level assignments, suggesting that this is the most reliable pipeline for rapid assessment of alpha diversity from environmental samples.

The current work investigated the ecotoxicological effects induced by Titanium Dioxide (TiO2) nanoparticles (NPs), used at three different concentrations (C1 = 10 μg·L−1, C2 = 100 μg·L−1 and C3 = 1000 μg·L−1) in a laboratory experiment, on the freshwater mussel Unio ravoisieri. Biochemical analyses of gills and digestive glands revealed a stress-related disruption of the antioxidant system. The catalase activity and the rates of malonedialdehyde and hydrogen peroxide production were significantly higher in both organs following the exposure to TiO2 NPs and was concentration-dependent. In addition, based on the observed changes in acetylcholinesterase activity, it can be concluded that the disturbance threshold for the cholinergic system was less than 1 mg·L−1 of TiO2. Overall, the results suggest that the mussel Unio ravoisieri could be used as a sentinel species in monitoring surveys assessing the environmental impact of metallic nanoparticles in freshwater systems.

The exposure of habitats to the herbicide diuron, one of the most effective and highly used antifouling agents worldwide, leads to serious environmental toxicity, mainly for marine invertebrates. Moreover, nanoparticles (NPs) act as carriers of organic pollutants in marine ecosystems, thereby influencing their bioaccumulation and toxicity in exposed organisms. This study aimed to investigate the individual and combined toxicity of diuron and two NPs (ZnO NPs and TiO _2 NPs) at sub-lethal doses on the marine mussel Mytilus galloprovincialis .

The current bioassay aims the evaluation of the ecotoxicity of the silver nanoparticles (NPs) (100 and 200 μ g l ^−1 ) on Ruditapes decussatus after 48 h and 7 days of its exposure. The biochemical analyses performed at gills and digestive glands showed a disturbance of the antioxidant system following the exposure of clams to Ag NPs. The catalase activity was induced and varied significantly depending on the concentration of Ag NPs and the exposure time, as well as the organ analysed. Simultaneousely, a decrease in Gluthation S -Transferase activity was observed at all concentrations tested and organs considered. The acetylcholinesterase activity results confirmed that the threshold of Ag NPs able to disrupt the the cholinergic system was less than 100 μ g l ^−1 . In overall, silver nanoparticles had a significant caused antagonistic effect on clams in both oxidative- and cholinergic states. Furthermore the findings obtained in this study demonstrated that Ruditapes decussatus can employed as a potential bioindicative species in the assessment of the toxicity of such an emerging material as Ag NPs.