The impact of adult neurogenesis on affective functions: of mice and men.

In most mammals, new neurons are not only produced during embryogenesis but also after birth. Soon after adult neurogenesis was discovered, the influence of recruiting new neurons on cognitive functions, especially on memory, was documented. Likewise, the late process of neuronal production also contributes to affective functions, but this outcome was recognized with more difficulty. This review covers hypes and hopes of discovering the influence of newly-generated neurons on brain circuits devoted to affective functions. If the possibility of integrating new neurons into the adult brain is a commonly accepted faculty in the realm of mammals, the reluctance is strong when it comes to translating this concept to humans. Compiling data suggest now that new neurons are derived not only from stem cells, but also from a population of neuroblasts displaying a protracted maturation and ready to be engaged in adult brain circuits, under specific signals. Here, we discuss the significance of recruiting new neurons in the adult brain circuits, specifically in the context of affective outcomes. We also discuss the fact that adult neurogenesis could be the ultimate cellular process that integrates elements from both the internal and external environment to adjust brain functions. While we must be critical and beware of the unreal promises that Science could generate sometimes, it is important to continue exploring the potential of neural recruitment in adult primates. Reporting adult neurogenesis in humankind contributes to a new vision of humans as mammals whose brain continues to develop throughout life. This peculiar faculty could one day become the target of treatment for mental health, cognitive disorders, and elderly-associated diseases. The vision of an adult brain which never stops integrating new neurons is a real game changer for designing new therapeutic interventions to treat mental disorders associated with substantial morbidity, mortality, and social costs.

Behavior of diclofenac from contaminated fish after cooking and in vitro digestion.

BACKGROUND: Seafood consumers are widely exposed to diclofenac due to the high contamination levels often present in aquatic organisms. It is a potential risk to public health due its endocrine disruptor properties. Limited information is available about diclofenac behavior after food digestion to enable a more realistic scenario of consumer exposure. This study aimed to evaluate cooking effects on diclofenac levels, and determine diclofenac bioaccessibility by an in vitro digestion assay, using commercial fish species (seabass and white mullet) as models. The production of the main metabolite 4'-hydroxydiclofenac was also investigated. Fish hamburgers were spiked at two levels (150 and 1000 ng g-1 ) and submitted to three culinary treatments (roasting, steaming and grilling). RESULTS: The loss of water seems to increase the diclofenac levels after cooking, except in seabass with higher levels. The high bioaccessibility of diclofenac (59.1-98.3%) observed in both fish species indicates that consumers' intestines are more susceptible to absorption, which can be worrisome depending on the level of contamination. Contamination levels did not affect the diclofenac bioaccessibility in both species. Seabass, the fattest species, exhibited a higher bioaccessibility of diclofenac compared to white mullet. Overall, cooking decreased diclofenac bioaccessibility by up to 40% in seabass and 25% in white mullet. The main metabolite 4'-hydroxydiclofenac was not detected after cooking or digestion. CONCLUSION: Thus, consumption of cooked fish, preferentially grilled seabass and steamed or baked white mullet are more advisable. This study highlights the importance to consider bioaccessibility and cooking in hazard characterization studies. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Evaluation of the Stability of a 1,8-Cineole Nanoemulsion and Its Fumigant Toxicity Effect against the Pests Tetranychus urticae, Rhopalosiphum maidis and Bemisia tabaci.

Pest control is a main concern in agriculture. Indiscriminate application of synthetic pesticides has caused negative impacts leading to the rapid development of resistance in arthropod pests. Plant secondary metabolites have been proposed as a safer alternative to conventional pesticides. Monoterpenoids have reported bioactivities against important pests; however, due to their high volatility, low water solubility and chemical instability, the application of these compounds has been limited. Nanosystems represent a potential vehicle for the broad application of monoterpenoids. In this study, an 1,8-cineole nanoemulsion was prepared by the low energy method of phase inversion, characterization of droplet size distribution and polydispersity index (PDI) was carried out by dynamic light scattering and stability was evaluated by centrifugation and Turbiscan analysis. Fumigant bioactivity was evaluated against Tetranychus urticae, Rhopalosiphum maidis and Bemisia tabaci. A nanoemulsion with oil:surfactant:water ratio of 0.5:1:8.5 had a droplet size of 14.7 nm and PDI of 0.178. Formulation was stable after centrifugation and the Turbiscan analysis showed no particle migration and a delta backscattering of ±1%. Nanoemulsion exhibited around 50% more bioactivity as a fumigant on arthropods when compared to free monoterpenoid. These results suggest that nanoformulations can provide volatile compounds of protection against volatilization, improving their bioactivity.

Temporal trends of persistent organic pollutant contamination in Franciscana dolphins from the Southwestern Atlantic.

Persistent organic pollutants (POPs) were analyzed in 136 blubber samples of Franciscana dolphins from Brazil (Pontoporia blainvillei), which is the most threatened dolphin in the Southwestern Atlantic. The dolphins were caught by the fishery fleet and collected from 2000 to 2018 in three regions of São Paulo state: northern São Paulo (SPN), central São Paulo (SPC), and southern São Paulo (SPS). The POPs analyzed in this study were polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDTs), Mirex, hexachlorobenzene (HCB), chlordane compounds (CHLs), hexachlorocyclohexane isomers (HCHs), and polybrominated diphenyl ethers (PBDEs). The concentrations ranged from 36 to 7200 ng g-1 lipid weight (lw) and 113-42200 ng g-1 lw for predominant compounds DDTs and PCBs, respectively. Similar profiles of PCB congeners were observed with a predominance of hexachlorinated compounds, representing approximately 50% of the total PCB amount; the highest PCB concentrations were observed from Baixada Santista (SPC) proximate to a highly urbanized and industrial coastal area. Significant differences were observed between the sexes and maturity of dolphins, mainly for PCBs, DDTs, and Mirex. In general, POPs other than HCB in Franciscana dolphins showed downward temporal trends, matching the regulatory periods for restricting and/or banning these compounds. Although POP concentrations are declining, PCB levels remain high in small dolphins, suggesting adverse health effects on Franciscanas. As organic contaminants are one of the numerous threats Franciscanas have been vulnerable to along the Brazilian coast, we recommend monitoring POPs levels every five years to check for declining (or stabilizing) trends.

Agrochemical Residues in Fish and Bivalves from Sepetiba Bay and Parnaiba River Delta, Brazil.

Accumulation of pesticides has a harmful impact on the environment and human health. The main goal of this work was to develop a method to determine and quantify the residues of thirteen pesticides in edible fish and bivalves such as parati (Mugil curema), seabass (Centropomus ssp.), mullet (Mugil brasiliensis), clams (Anomalocardia brasiliana) and mussel (Mytilus galloprovincialis) collected from Sepetiba Bay and Parnaiba River Delta (Brazil) between 2019 and 2020. Matrix solid-phase dispersion (MSPD) was used for extraction and quantification through gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). The method was validated (linearity, accuracy and precision) for fatty fish (Salmo salar), lean fish (Mugil curema) and bivalves (Mytilus edulis). The survey found linear correlation coefficients (r) equal to or greater than 0.9 for almost all analytes. The relative standard deviations (RSD) of five replicates were less than 20% for almost all analytes at different concentrations in lean fish, fatty fish and bivalves. Most analytes showed satisfactory accuracy. Alachlor herbicide was found in samples of seabass, mussels, clams and parati with levels ranging between 0.55 to 420.39 µg kg-1 dw. Ethion was found in parati (maximum 211.22 µg kg-1 dw), mussels (15.1 µg kg-1 dw) and clams (maximum 44.50 µg kg-1 dw). Alachlor was found in clams (maximum 93.1 µg kg-1 dw), and bifenthrin was found in parati (maximum 43.4 µg kg-1 dw) and clams (maximum 42.21 µg kg-1 dw). The validated method was satisfactory for the determination of eleven pesticides in the fatty fish matrix, and thirteen pesticides in the samples of lean fish and bivalves. The presence of alachlor, ethion and bifenthrin stands out.

Obtention of biodiesel through an enzymatic two-step process. Study of its performance and characteristic emissions.

We describe the enzymatic synthesis of biodiesel from waste cooking oil (WCO) in a two-step production process: hydrolysis of WCO, followed by acid-catalyzed esterification of free fatty acids (FFAs). Among the three commercial enzymes evaluated, the inexpensive lipase Lipex® 100L supported on Lewatit® VP OC 1600 produced the best overall biodiesel yield (96.3%). Finally, we assessed the combustion efficiency of the obtained biodiesel and its blends. All blends tested presented lower emissions of CO and HC compared to diesel. The NOx emissions were higher due to biodiesel's high volatility and viscosity. The cost of biodiesel production was calculated using the process described.

Characterization of Affective Behaviors and Motor Functions in Mice With a Striatal-Specific Deletion of Bmal1 and Per2.

The expression of circadian clock genes, either centrally or in the periphery, has been shown to play an integral role in the control of behavior. Brain region-specific downregulation of clock genes revealed behavioral phenotypes associated with neuropsychiatric disorders and neurodegenerative disease. The specific function of the clock genes as well as the underlying mechanisms that contribute to the observed phenotypes, however, are not yet fully understood. We assessed anxiety- and depressive-like behavior and motor functions in male and female mice with a conditional ablation of Bmal1 or Per2 from medium spiny neurons (MSNs) of the striatum as well as mice lacking one copy of Gpr88. Whereas the conditional knockout of Bmal1 and Per2 had mild effects on affective behaviors, a pronounced effect on motor functions was found in Bmal1 knockout mice. Subsequent investigation revealed an attenuated response of Bmal1 knockout mice to dopamine receptor type 1 agonist treatment, independently of the expression of targets of the dopamine signaling pathway or mitochondrial respiration in MSNs. The study thus suggests a potential interaction of Bmal1 within the direct dopamine signaling pathway, which may provide the link to a shared, MSN-dependent mechanism regulating affective behavior and motor function in mice.

Assessing positive and negative valence systems to refine animal models of bipolar disorders: the example of GBR 12909-induced manic phenotype.

Bipolar disorders are defined by recurrences of depressive and manic episodes. The pathophysiology is still unknown, and translating clinical symptoms into behaviors explorable in animal models is challenging. Animal models of bipolar disorder do not exist because cyclicity of the disease is impossible to mimic, and it is therefore necessary to study mania and depression models separately. Beyond mood, emotional biases differentiate bipolar states in humans. Mania is associated with positive biases, e.g. emotional stimuli become more rewarding and less aversive, and the opposite for depression. We propose to assess behavioral hedonic responses to innately appetitive and aversive olfactory and gustatory cues in mice as proxies for the assigned emotional valence. A mania model is therefore supposed to exhibit positive hedonic bias. Using the GBR 12909 mania model, we observed the classical hyperactivity phenotype, along with low depressive-like but high anxiety-like behaviors. Unexpectedly, GBR 12909-treated mice exhibited strong negative hedonic biases. Consequently, the GBR 12909 model of mania might not be appropriate for studying emotional disturbances associated with mania states. We propose olfactory and gustatory preference tests as crucial assessment for positive and negative valence biases, necessary for precisely characterizing animal models of bipolar disorders.

Survey on endocrine-disrupting chemicals in seafood: Occurrence and distribution.

Currently, the presence of endocrine disrupting chemicals (EDCs) in the marine environment pose а potential risk to both wildlife and human health. The occurrence of EDCs in seafood depends of several factors such as source and amounts of EDCs that reach the aquatic environment, physicochemical features of EDCs, and its accumulation in trophic chain. This review highlights the occurrence and distribution of EDCs along the seafood in the last 6 years. The following EDCs were included in this review: brominated flame retardants (PBDEs, PBBs, HBCDDs, TBBPA, and novel flame retardants); pharmaceuticals (paracetamol, ibuprofen, diclofenac, carbamazepine), bisphenols, hormones, personal care products (Musk and UV Filters), and pesticides (organochlorides, organophosphates, and pyrethroids). Some of them were found above the threshold that may cause negative effects on human, animal, and environmental health. More control in some countries, as well as new legislation and inspection over the purchase, sale, use, and production of these compounds, are urgently needed. This review provides data to support risk assessment and raises critical gaps to stimulate and improve future research.

Occurrence of pharmaceuticals in seafood from two Brazilian coastal areas: Implication for human risk assessment.

Pharmaceuticals (PhACs) are considered emerging contaminants with potential accumulation in aquatic organisms. Thus, seafood consumption may cause long-term effects and health risk for consumers. In the present study, the occurrence of PhACs in seafood from two Brazilian coastal areas, Sepetiba Bay (n = 43) and Parnaiba Delta River (n = 48), was determined for the first time, and their potential risk for human health was assessed. An eco-friendly multi-analytes method was used, after being validated for the different types of matrices (mussels, fatty and lean fish). All compounds under study were detected at least in four seafood species, including chloramphenicol, an antibiotic prohibited in animal foods. Most PhACs had mean concentrations below limit of quantification. Ibuprofen and other nonsteroidal anti-inflammatory drugs (NSAIDs), as well as simvastatin and carbamazepine were the main PhACs bioaccumulated in edible parts of seafood species from Brazil. The high trophic level carnivorous species, snook, was the most contaminated by NSAIDs, while bivalves were the seafood more contaminated by lipid regulators. The profile of contamination did not vary among different types of matrix, except in relation to carbamazepine and ketoprofen. These PhACs were more abundant in species from Sepetiba Bay, an area highly impacted by human influence. The estimated daily exposure for Brazilian population that consumes the studied species was up to 20.3 ng/kg bw/day via carib pointed-venus and 25.7 ng/kg bw/day via snooks, lower than acceptable daily intake. Thus, consumption of seafood species from Sepetiba Bay and Parnaiba Delta River seems to be safe to the population in what concerns the PhACs studied.

In Vitro Culture of Rosmarinus officinalis L. in a Temporary Immersion System: Influence of Two Phytohormones on Plant Growth and Carnosol Production.

Emerging infectious diseases have become a major global problem with public health and economic consequences. It is an urgent need to develop new anti-infective therapies. The natural diterpene carnosol exhibit a wide variety of interesting antibacterial and antiviral properties, and it is considered a theoretical inhibitor of COVID-19 Mpro. However, this compound is present in the family Lamiaceae in low quantities. To obtain carnosol in concentrations high enough to develop pharmacological studies, we evaluated the efficiency of a micropropagation protocol of Rosmarinus officinalis using a solid medium and a temporary immersion system (TIS), as well as the effect of 6-benzylaminopurine (6-BAP) and α-naphthaleneacetic acid (NAA) on the growth of shoots. Moreover, we developed and validated an analytical method to quantify carnosol using the H-point standard additions method in the high-performance liquid chromatography diode array detector (HPLC-DAD). After 30 days of culture, TIS produced the maximum number of shoots per explant (24.33 ± 1.15) on a liquid medium supplemented with 6-BAP at 5.0 mg L-1. Next, we also evaluated the effect of immersion time and frequency for TIS. After 72 days of culture, the best results were obtained with an immersion cycle of 1 min every 12 h, yielding 170.33 ± 29.40 shoots. The quantification of carnosol on the samples was performed at a flow rate of 1.2 mL min-1 using binary isocratic mobile phase system 60:40 (v/v) 10 mM formic acid (pH 3.0) (A) and acetonitrile (B) on a reverse-phase column. The content of carnosol in the in vitro cultures was around 8-fold higher than in the wild plant. The present study represents an efficient alternative method to obtain carnosol for its pre-clinical and clinical development.

Neonatal susceptibility to meningitis results from the immaturity of epithelial barriers and gut microbiota.

Neonates are highly susceptible to bacterial meningitis as compared to children and adults. Group B streptococcus (GBS) is a major cause of neonatal meningitis. Neonatal meningitis can result from GBS intestinal colonization and translocation across the intestinal barrier (IB). Here, we show that the immaturity of the neonatal intestinal microbiota leads to low resistance to GBS intestinal colonization and permissiveness of the gut-vascular barrier. Moreover, the age-dependent but microbiota-independent Wnt activity in intestinal and choroid plexus (CP) epithelia results in a lower degree of cell-cell junctions' polarization, which favors bacterial translocation. This study thus reveals that neonatal susceptibility to GBS meningitis results from the age-dependent immaturity of the intestinal microbiota and developmental pathways associated with neonatal tissue growth, which both concur to GBS gut colonization, systemic dissemination, and neuroinvasion. Whereas the activation of developmental pathways is intrinsic to neonates, interventions aimed at maturing the microbiota may help prevent neonatal meningitis.

Polybrominated diphenyl ethers and their methoxylated congeners in Douro river estuary biota: Seasonal occurrence and risk assessment.

Especially added on many industrial and domestic products as flame retardants (FRs), polybrominated diphenyl ethers (PBDEs) are among the chemicals of high environmental concern because of their potential harmfulness for environmental and human health. Seafood consumption is considered the main source of PBDEs and their methoxylated congeners (MeO-BDEs) for humans. The present study aims to investigate the seasonal occurrence of six PBDEs and eight MeO-BDEs congeners using Douro river biota (different trophic levels) as sentinels, as well as to evaluate the human exposure risk to PBDEs through seafood consumption. Biota samples (n = 273) were collected from one of the most important Portuguese estuaries in the north-western coast of Portugal at four different seasons (2019-2020). The analyses were performed by an environmental-friendly extraction procedure followed by Gas Chromatography coupled to a triple quadrupole detector (GC-MS/MS). PBDEs were detected in all seafood samples analysed, with means ranging from 0.02 ng g-1 ww (flounder in autumn) to 3.75 ng g-1 ww (mussel in winter). Levels of lower-brominated PBDE congeners were significantly higher than higher-brominated ones in all seasons (p < 0.01). MeO-BDEs ranged from 0.001 ng g-1 ww (grey mullet in summer) to 5.66 ng g-1 ww (green crab in spring). Crabs and mussels presented the highest means of PBDEs and MeO-BDEs. Regarding the health risk assessment of the studied PBDE congeners (47, 99, and 153), consumption of Douro river fish is not a case of concern for consumers.

Equatorial Atlantic pelagic predators reveal low content of PBDEs in contrast to MeO-BDEs: An analysis of brominated diphenyl ethers in blue shark and yellowfin tuna.

Polybrominated diphenyl ethers (PBDEs) and their methoxylated analogues (MeO-BDEs) are widely distributed in the environment. The main concern about the presence of PBDEs and MeO-BDEs in fish is due to their potential endocrine disruption effects in the specimens, and their potential risk to the health of human consumers. Considering these concerns, the goal of this study was to investigate the occurrence of PBDEs and MeO-BDEs in muscle tissues of blue shark (BSH), Prionace glauca, and yellowfin tuna (YFT), Thunnus albacares, caught in the Equatorial Atlantic Ocean (EAO), North-eastern Brazilian waters, and to evaluate the potential risk of human exposure by consumption. Muscle tissues of YFT and BSH were extracted using a Soxhlet apparatus and an Accelerated Solvent Extractor (ASE), respectively. PBDEs and MeO-BDEs were analysed by GC-NCI-MS. Concentrations of PBDEs ranged from not detected (nd) to 10 ng g-1 lipid weight (lw) in YFT muscle samples, while PBDE levels in BSH muscle samples ranged from

Inhibition of squalene synthase of rat liver by abietane diterpenes derivatives.

In the current study, chemical composition of cultivated Salvia canariensis L was determined. Carnosol was the main product isolated. We prepared more lipophilic derivatives from carnosol, and both isolated and semisynthetic abietane diterpenes were evaluated in vitro as inhibitors of squalene synthase. Among the compounds tested, carnosol was the most potent inhibitor (IC50 = 17.6 µM). These results highlight the great potential of this species for the production of new ingredients in nutritional supplements for the treatment of hyperlipidemia.

Tanshinones and their Derivatives: Heterocyclic Ring-Fused Diterpenes of Biological Interest.

The available scientific literature regarding tanshinones is very abundant, and after its review, it is noticeable that most of the articles focus on the properties of tanshinone I, cryptotanshinone, tanshinone IIA, sodium tanshinone IIA sulfonate and the dried root extract of Salvia miltiorrhiza (Tan- Shen). However, although these products have demonstrated important biological properties in both in vitro and in vivo models, their poor solubility and bioavailability have limited their clinical applications. For these reasons, many studies have focused on the search for new pharmaceutical formulations for tanshinones, as well as the synthesis of new derivatives that improve their biological properties. To provide new insights into the critical path ahead, we systemically reviewed the most recent advances (reported since 2015) on tanshinones in scientific databases (PubMed, Web of Science, Medline, Scopus, and Clinical Trials). With a broader perspective, we offer an update on the last five years of new research on these quinones, focusing on their synthesis, biological activity on noncommunicable diseases and drug delivery systems, to support future research on its clinical applications.

New Approach to Accelerated Image Annotation by Leveraging Virtual Reality and Cloud Computing.

Three-dimensional imaging is at the core of medical imaging and is becoming a standard in biological research. As a result, there is an increasing need to visualize, analyze and interact with data in a natural three-dimensional context. By combining stereoscopy and motion tracking, commercial virtual reality (VR) headsets provide a solution to this critical visualization challenge by allowing users to view volumetric image stacks in a highly intuitive fashion. While optimizing the visualization and interaction process in VR remains an active topic, one of the most pressing issue is how to utilize VR for annotation and analysis of data. Annotating data is often a required step for training machine learning algorithms. For example, enhancing the ability to annotate complex three-dimensional data in biological research as newly acquired data may come in limited quantities. Similarly, medical data annotation is often time-consuming and requires expert knowledge to identify structures of interest correctly. Moreover, simultaneous data analysis and visualization in VR is computationally demanding. Here, we introduce a new procedure to visualize, interact, annotate and analyze data by combining VR with cloud computing. VR is leveraged to provide natural interactions with volumetric representations of experimental imaging data. In parallel, cloud computing performs costly computations to accelerate the data annotation with minimal input required from the user. We demonstrate multiple proof-of-concept applications of our approach on volumetric fluorescent microscopy images of mouse neurons and tumor or organ annotations in medical images.

An emotional-response model of bipolar disorders integrating recent findings on amygdala circuits.

Because of our classification system limitations for defining psychiatric disorders and understanding their physiopathology, a new research area based on dimensions has emerged. It consists of exploring domains derived from fundamental behavioral components linked to neurobiological systems. Emotional processing is among the most affected dimensions in bipolar disorders (BD), but is excluded from the definition criteria. The purpose of this review is to synthesize the emotional responses disruption during the different phases of BD, using intensity and valence as the two key characteristics of emotions. We integrate those emotional disruptions into an original, emotion-based model contrasting with the current diagnostic frame built on mood. Emotional processing is underpinned by cortico-limbic circuits involving the amygdala. Recent publications showed the crucial role of the amygdala in emotional processes triggered by stimuli of negative, but also positive valence. We show how these neuroscience data can provide physiological basis for emotional disturbances observed in BD. We conclude with translational perspectives to improve the current knowledge about neural substrates underlying altered emotional responses characterizing BD.

Pyrethroid insecticides along the Southwestern Atlantic coast: Guiana dolphin (Sotalia guianensis) as a bioindicator.

The presence of pyrethroid compounds in hepatic tissue of Guiana dolphins (Sotalia guianensis) is reported for the first time. Twelve pyrethroids were determined in 50 animals from eight locations of the Brazilian coast. The highest average concentration of total pyrethroids (∑PYR) was 1166 ng.g-1 lw, with values ranging from 148 to 5918 ng.g-1 lw, in Ilha Grande Bay, Rio de Janeiro State, while the Espírito Santo State had the highest median, 568 ng.g-1 lw. Permethrin was the predominant compound in most areas, contributing for 42% to 81% of the ∑PYR, whereas cypermethrin was the most abundant compound in Guanabara and Sepetiba bays (79% and 81%, respectively), both located in Rio de Janeiro State. Biological factors were not correlated with pyrethroids concentration. Tetramethrin and es/fenvalerate compounds were negatively correlated to the age, suggesting degradation/metabolization capacity in these animals that increases throughout life. Despite being metabolized and excreted, the wide use of these pollutants is reflected in relevant concentrations found in Guiana dolphins. This is the first study evaluating pyrethroids in a representative number of hepatic samples and covering >2600 km of coast. The overall lack of information on pyrethroids in cetaceans highlights the importance of understanding the profile and distribution of these pollutants in dolphins which exclusively inhabit the Southwestern Atlantic coast.

Halogenated natural products in birds associated with the marine environment: A review.

Halogenated natural products (HNPs) are widespread compounds found at high concentrations in top predators such as seabirds. This paper reviews available data on methoxylated polybrominated diphenyl ethers (MeO-BDEs), heptachloro-1'-methyl-1,2'-bipyrrole (Q1) and 1,1'-dimethyl-2,2'-bipyrroles (HDBPs) in these animals. In all, 25 papers reported such HNPs in seabirds. White tailed sea eagle from Sweden was the seabird species with higher MeO-BDEs levels in eggs and blood, while in liver the European shag from Norway was the one. Regarding HDBPs, glaucous gull livers from North Water Polynya and Leach's storm petrel eggs from South Canada (NE Atlantic) showed the highest levels, while brown skua eggs presented the highest concentration of Q1. DBP-Br4Cl2 and DBP-Br6 were the most abundant HDBPs in seabirds, although only one study investigated DBP-Br6. Furthermore, 2'-MeO-BDE-68/6'-MeO-BDE-47 ratios were lower than one in mostly of the studies (91%). The main sources of methoxylated congeners found in seabirds might to be from sponges and/or associated organisms (bacteria). The scarcity of data in seabirds showed the gap in knowledge. Few studies were done especially in tropical areas and Southern Hemisphere and the most were conducted in the northwest part of the globe. This review arouses the need of knowledge about the distribution of these compounds in seabirds worldwide as well as it encourages toxicological studies to better understand the possible effects of HNPs on seabirds.