Effect of selenium and acidification in freshwater environment was assessed solitary but no reports are available on the impacts of both factors act together. In the present study, effects of ...combined simultaneous exposure to selenium (Se) and low pH were assessed in Mozambique tilapia, Oreochromis mossambicus. Responses were measured based on antioxidant defenses (enzymatic SOD, CAT, GPx and non-enzymatic GSH), biotransformation enzyme (GST), metallothionein levels (MT), oxidative damage (LPO, CP), Na+/K+-ATPase (NKA) activity in gills and liver tissues and neurotoxicity (acetylcholinesterase, AChE) response in brain tissue. Fish were exposed to combined treatment at different pH levels (7.5, control (optimum pH for tilapia growth); 5.5, low pH) and Se concentrations (0, 10, and 100 μg L−1). Toxicity levels of Se were not significantly different under control and low pH indicating that pH did not affect Se toxicity. Levels of GSH and MT were enhanced in Se-exposed fish at both pH. Combined effects of high Se concentration and low pH decreased SOD and CAT activities and increased those of GPx and GST. However, organisms were not able to prevent cellular damage (LPO and CP), indicating a condition of oxidative stress. Furthermore, inhibition of Na+/K+-ATPase activity was showed. Additionally, neurotoxicity effect was observed by inhibition of cholinesterase activity in organisms exposed to Se at both pH conditions. As a result, the combined stress of selenium and freshwater acidification has a slight impact on antioxidant defense mechanisms while significantly inhibiting cholinesterase and Na+/K + -ATPase activity in fish. The mechanisms of freshwater acidification mediating the toxic effects of trace non-metal element on freshwater fish need to investigate further.
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•Oreochromis mossambicus were exposed to Se under low and appropriate pH levels (5.5 and 7.5).•O. mossambicus activated defense mechanisms of GPx, GST, GSH and MT when exposed under different concentrations of Se under different pH levels.•Exposure of different concentrations of Se under different pH levels, O. mossambicus showed failure of SOD and CAT led to oxidative stress effect on LPO and CP.•Combined effect of different pH levels and high concentration of Se for inhibit the activity of AChE and Na+/K+-ATPase of O. mossambicus.
This study aimed to assess whether the addition of calcium carbonate (CaCO3) to increase Calcium levels reduces the long-term nitrite (NO2−) toxicity in pacu Piaractus mesopotamicus juveniles. The ...fish were exposed for 60 days to six treatments comprised by the interaction of three NO2− concentrations (0, 15 and 30 NO2−-N mg L−1) and two Calcium levels (60 and 150 CaCO3 mg L−1), all in triplicate. The zootechnical indices, as well as blood and oxidative stress parameters were evaluated at the end of experimental period. The results showed that at lower hardness, NO2− exposure led to enhanced lipid peroxidation (LPO) levels of muscle and gills and compromised the food conversion rate. Otherwise, the LPO levels were kept at basal condition and no changes were found in zootechnical parameters at higher hardness treatments. Thus, the increase in Calcium levels up to 150 CaCO3 mg L−1 using CaCO3 may reduce the NO2− toxic levels in pacu juveniles, and may be an interesting strategy of water quality management, especially in intensive production systems.
•The prolonged exposure to nitrite (NO2-) levels result in tertiary stress responses in pacu Piaractus mesopotamicus.•The addition of calcium carbonate (CaCO3) to increase water hardness reduces the long- term NO2- toxicity in juvenile pacu.•At lower hardness, NO2- exposure led to enhanced levels of lipid peroxidation (LPO) of muscle and gills in juvenile pacu.•The increase in hardness is an interesting strategy of water quality management, especially in intensive production systems.
Behavioral interventions have shown promising neuroprotective effects, but the cascade of molecular, brain and behavioral changes involved in these benefits remains poorly understood. Projecte ...Moviment is a 12-week (5 days per week-45 min per day) multi-domain, single-blind, proof-of-concept randomized controlled trial examining the cognitive effect and underlying mechanisms of an aerobic exercise (AE), computerized cognitive training (CCT) and a combined (COMB) groups compared to a waitlist control group. Adherence was > 80% for 82/109 participants recruited (62% female; age = 58.38 ± 5.47). In this study we report intervention-related changes in plasma biomarkers (BDNF, TNF-α, HGF, ICAM-1, SDF1-α) and structural-MRI (brain volume) and how they related to changes in physical activity and individual variables (age and sex) and their potential role as mediators in the cognitive changes. Our results show that although there were no significant changes in molecular biomarker concentrations in any intervention group, changes in ICAM-1 and SDF1-α were negatively associated with changes in physical activity outcomes in AE and COMB groups. Brain volume changes were found in the CCT showing a significant increase in precuneus volume. Sex moderated the brain volume change in the AE and COMB groups, suggesting that men may benefit more than women. Changes in molecular biomarkers and brain volumes did not significantly mediate the cognitive-related benefits found previously for any group. This study shows crucial initial molecular and brain volume changes related to lifestyle interventions at early stages and highlights the value of examining activity parameters, individual difference characteristics and using a multi-level analysis approach to address these questions.
Arsenic (As) is a ubiquitous contaminant in the environment and it is known to induce oxidative stress in aquatic organisms. In an attempt to remove As from water, some studies have suggested the ...titanium dioxide nanomaterial (nTiO
) as a promising alternative. However, it has been observed that nTiO
can induce toxicity alone or in combination with metals, and this toxicity is dependent on its crystalline form of nanomaterial (mainly rutile as nTiO
R and anatase as nTiO
A, respectively). Considering that both (nTiO
and As) can occur together, the objective of this study was to evaluate if co-exposure to rutile and anatase may influence accumulation, metabolisation, and toxicity of arsenite (As
) in the golden mussel Limnoperna fortunei after 48 h of co-exposure to nTiO
(1 mg/L) and As (50 μg/L). Accumulation and chemical speciation of As in organisms were determined. Also, biochemical analyses, such as the activity of the enzymes glutathione S-transferase omega (GSTΩ), catalase (CAT) and glutathione S-transferase (GST), as well as lipid peroxidation (LPO) were investigated. Results showed that co-exposure to nTiO
A + As changed accumulation pattern of metalloid in gills and digestive gland. Both crystalline forms of nTiO
affected the metabolisation capacity favoring the accumulation of more toxic As compounds and nTiO
A alone or in combination with As showed induce oxidative stress in gills of L. fortunei. In this way, it has a high potential risk of the co-exposure of these contaminants to aquatic organisms, and it also needs to consider the nanomaterial (nTiO
) properties and their application in the environmental remediation, carefully and judiciously.
The reproducibility crisis in biomedical research has spurred much debate about the causes of the failure to validate experimental results. But the discussion may be overlooking one crucial factor ...that is inherent to research with low sample sizes: random variation.
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•Maltodextrin was used to microencapsulate stripped weakfish protein hydrolysate.•Microencapsulate protein hydrolysates were evaluated in vitro and in vivo.•Microencapsulation ...decreased the hygroscopicity of protein hydrolysates.•Microencapsulated hydrolysates showed in vitro antioxidant activity.•Protein hydrolysate or microencapsulated protect in vivo from oxidative stress.
This study aimed to microencapsulate protein hydrolysates from stripped weakfish (Cynoscion guatucupa) industrial byproducts produced by Alcalase (HA) and Protamex (HP) by spray drying, using maltodextrin as wall material. The physicochemical characteristics, and in vitro antioxidant and Angiotensin-I converting enzyme-inhibitory activities were evaluated during storage. Both microencapsulated hydrolysates showed spherical shape (~3.6 µm particle diameter), low water activity (<0.155) during storage and reduced hygroscopicity (~30%) compared to the free hydrolysate. Infrared spectroscopy evidenced the maltodextrin-hydrolysate interaction. Based on the in vitro results, nematoid C. elegans in L1 larval stage were treated with free and microencapsulated HP, which demonstrated a protective effect on nematoid exposed to oxidative stress (survival ~ 13% control, 77% free HP, and 85% microencapsulated HP) and improved their growth and reproduction rate. Thus, microencapsulation appears to be a good alternative to maintain hydrolysates stability during storage, showing bioactivity in C. elegans.
In Biofloc Technology (BFT), the disposal of solid waste represents a sustainability gap within. The presence of polyphenols in biofloc extracts has been reported, and these molecules have been ...widely explored for the synthesis of silver nanoparticles (AgNPs) in green nanotechnology. Polyphenols are employed to reduce silver ions and stabilize AgNPs. Compared to conventional methods (chemical synthesis), green synthesis makes the production of AgNPs sustainable and environmentally friendly by offering lower costs and avoiding the generation of hazardous waste that could impact the environment. This study proposes the extraction of polyphenols from bioflocs and their use as reducing and capping agents in the green synthesis of silver nanoparticles as a way to add value to the waste generated in BFT. Response Surface Methodology was used to obtain better extraction conditions by investigating the influence of four reaction variables (temperature, time, ethanol concentration, and solvent/solute ratios). The obtained extract was used to synthesize silver nanoparticles (BFAgNPs), which were used to determine the minimum inhibitory activity (MIC) and bactericidal activity (MBC) against Acinetobacter baumannii and Pseudomonas aeruginosa, as well as their anti-biofilm activity (inhibition and destruction) against A. baumannii. The highest polyphenol content was 1,918 μg gallic acid equivalents/g and the antioxidant activity was 1,278 μM Trolox equivalents/g for DPPH and 12,513 μM Trolox equivalents/g for ABTS. BFAgNPs exhibited an average diameter of 25.3 nm, as observed by transmission electron microscopy. Dynamic light scattering indicated a particle diameter of 123.2 nm, and polydispersity index (PDI) of 0.15. The zeta potential was measured at −22.5 mV. Fourier-transform infrared spectroscopy revealed distinct bands at 3616, 2924, 1682, 1532, 1234, and 1042 cm-1. BFAgNPs demonstrated MIC (38.8 μg/mL and 19.4 μg/mL for A. baumannii and P.aeruginosa), and MBC (77.5 μg/mL and 38.8 μg/mL for A. baumannii and P.aeruginosa) and antibiofilm activity, (47.3% inhibition and 27.8% destruction, respectively). It was concluded that the biofloc residue constitutes a source of polyphenols useful for the synthesis of AgNP with antibacterial capacity, thus representing a potential alternative for the waste valorization of BFT effluent.
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•Biofloc residues generated in the BFT system are sources of polyphenols.•Polyphenols extracts were used to syntethize silver nanoparticles (AgNP).•AgNP exhibit inhibitory activity against Acinetobacter baumannii and Pseudomonas aeruginosa.•AgNP presented anti-biofilm activity against A. baumannii.•Biofloc residues show potential for the green synthesis of AgNP.
The present study investigated the best photoperiod for culturing pacu (
Piaractus mesopotamicus
) in recirculation aquaculture systems (RAS) based on its growth performance and hematological and ...oxidative stress responses. Juveniles (∼ 5 g) were subjected to five treatments (in triplicate): 24 L (light):0D (dark), 15 L: 09D, 12 L:12D, 9 L:15D, and 0 L:24D for 45 days. A total of 225 pacu individuals were randomly distributed among 15 tanks of 210 L (
n
= 15 per tank). Zootechnical, hematological (glucose, lactate, hematocrit, and hemoglobin), and antioxidant and oxidative stress parameters (glutathione S-transferase (GST), total antioxidant capacity against peroxyl radicals (ACAP), and lipid peroxidation (LPO) were analyzed. The zootechnical parameters (e.g., weight gain, Fulton’s condition factor, and specific growth rate) were better and worse with 9 L:15D and 24 L:0D photoperiods, respectively. The hepatosomatic index was higher and lower in the 0 L:24D and 9 L:15D photoperiods. Blood lactate levels and antioxidant and oxidative stress responses were increased in the longest photoperiods (15 L:9D and 24 L:0D). In contrast, the treatments that showed lower oxidative damage (liver, gills, brain, and muscle) were 9 L:15D and 12 L:12D. In conclusion, manipulating artificial light is one way to improve fish growth and health, where the best photoperiod for pacu farming in RAS is 9 L:15D.
Biochemical biomarkers were evaluated in the barnacle Balanus improvisus (Crustacea: Cirripedia) sampled from both polluted and reference sites in the Patos Lagoon Estuary, Southern Brazil. During ...winter, higher glutathione S-transferase (GST) activity was recorded in the barnacles from the polluted sites, indicating environmental exposure to contaminants. Relatively low lipid peroxide levels (LPO) were also observed in barnacles from polluted sites, indicating that oxidative stress by lipid peroxidation was not a major threat in barnacles from those sites. Seasonal differences in the GST and total oxyradical scavenging capacity (TOSC) could have contributed to the low LPO levels in the summer relative to the levels in the winter. Catalase activity and metallothionein levels were not affected by contamination or seasonality. The seasonal changes observed in biomarker responses were paralleled by the differences in temperature, which could have affected physiological responses, including the balance between pro-oxidants and antioxidants.
•Glutathione S-transferase activity was increased in barnacles from polluted sites.•GST, TOSC and LPO seasonal responses were associated to water temperature.•Lipid peroxide levels were decreased in barnacles from polluted sites.•Biochemical biomarkers were evaluated in the cosmopolitan barnacle Balanus improvisus
Lifestyle interventions are promising strategies to promote cognitive health in aging. Projecte Moviment examines if aerobic exercise (AE), computerized cognitive training (CCT), and their ...combination (COMB) improves cognition, psychological health, and physical status compared to a control group. We assessed the moderating role of age and sex and the mediating effects of cardiorespiratory fitness (CRF), physical activity (PA), and psychological health on intervention-related cognitive benefits.
This was a 12-week multi-domain, single-blind, proof-of-concept randomized controlled trial (RCT). 96 healthy adults aged 50-70 years were assigned to AE, CCT, COMB, and a wait-list control group. The per protocol sample, which completed the intervention with a level of adherence > 80%, consisted of 82 participants (62% female; age = 58.38 ± 5.47). We assessed cognition, psychological health, CRF, and energy expenditure in PA at baseline and after the intervention. We regressed change in each outcome on the treatment variables, baseline score, sex, age, and education. We used PROCESS Macro to perform the mediation and moderation analyses.
AE benefited Working Memory (SMD = 0.29,
= 0.037) and Attention (SMD = 0.33,
= 0.028) including the Attention-Speed (SMD = 0.31,
= 0.042) domain, compared to Control. COMB improved Attention (SMD = 0.30,
= 0.043), Speed (SMD = 0.30,
= 0.044), and the Attention-Speed (SMD = 0.30,
= 0.041) domain. CTT group did not show any cognitive change compared to Control. Sportive PA (S-PA) and CRF increased in AE and COMB. Age and sex did not moderate intervention-related cognitive benefits. Change in S-PA, but not in CRF, significantly mediated improvements on Attention-Speed in AE.
A 12-week AE program improved Executive Function and Attention-Speed in healthy late-middle-aged adults. Combining it with CCT did not provide further benefits. Our results add support to the clinical relevance of even short-term AE as an intervention to enhance cognition and highlight the mediating role of change in S-PA in these benefits.
www.ClinicalTrials.gov, identifier NCT03123900.
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