1,721,111 research outputs found
Histone Deacetylase Inhibitors from Marine Invertebrates
Full text linkHistone deacetylases (HDACs) are key components of the epigenetic machinery controlling gene expression. They are involved in chromatin remodeling events via post-translational histone modifications but may also act on nonhistone proteins, influencing many fundamental cellular processes. Due to the key involvement of HDACs in serious human pathologies, including cancer, HDAC inhibitors (HDACis) have received increased attention in recent years. It is known that marine invertebrates produce significant amounts of secondary metabolites showing active pharmacological properties and an extensive spectrum of biomedical applications. The aim of this review is to gather selected studies that report the extraction and identification of marine invertebrate-derived compounds that possess HDACi properties, grouping the producing species according to their taxonomic hierarchy. The molecular, biochemical, and/or physiological aspects, where available, and modes of action of these naturally occurring HDACis will be recapitulated, taking into consideration their possible utilization for the future design of analogs with increased bioavailability and efficacy, less toxicity, and, also, higher isoform selectivity
Does Bacillus thuringiensis Affect the Stress and Immune Responses of Rhynchophorus ferrugineus Larvae, Females, and Males in the Same Way?
Full text linkSIMPLE SUMMARY: Rhynchophorus ferrugineus is a destructive quarantine pest of palm trees, now widely distributed. Although broad-spectrum insecticides are often used to protect palm against R. ferrugineus, there is increasing concern about their effects on the environment and human health, especially where palm trees are located in urban areas. As an environmentally friendly entomopathogen, Bacillus thuringiensis (Bt) has been widely used to prevent other pest infestations. Although Bt products are the most sold bio-insecticides, there are still many interesting features to be investigated in the relationship of Bt and its hosts. We investigated the effect of Bt on larvae, females, and males. This research yielded experimental evidence of significant mortality and significant effects on immune system and stress answer. Within a few hours, stress due to Bt infection was detected in the hemocytes and in the brain providing better insights into the insect-pathogen interaction and highlighting the potential use of Bt in R. ferrugineus management. ABSTRACT: Bacillus thuringiensis (Bt) is considered a potentially useful entomopathogen against red palm weevil (RPW) Rhynchophorus ferrugineus. We compared the effects of Bt on mature larvae, females, and males. The pathogenicity of Bt was evaluated, estimating: Median Lethal Dose (LD(50)), Median Lethal Time (LT(50)), Total Hemocyte Count (THC), and Differential Hemocyte Counts (DHC), and the expression of the stress protein Heat Shock Protein 70 (Hsp 70) in hemocytes and the brain. Mortality exhibited a positive trend with the dosage and duration of exposure to Bt. Larvae were more susceptible than adults, and the LD(50) of females was almost double the value of that of the larvae. LT(50) value was higher for females than for males and larvae. Treatment with sub-lethal doses of Bt induced a decrease in THC in larvae, females, and males. In treated larvae, plasmatocytes decreased, while oenocytes and spherulocytes increased. In treated females, all types of hemocytes decreased, while in males the number of plasmatocytes decreased and granulocytes increased. We also registered the stress response directly on hemocytes showing that, already at 3 h after eating Bt, the expression of the stress protein Hsp 70 was modulated. This effect was also observed in brain tissue at 6 h after treatment. The results confirm that Bt treatment induces a pathogenic state in larvae and adults of both sexes, with effects after only a few hours from ingestion; however, the effects are different in magnitude and in type of target
Motility and acoustic signals of the decapod Cherax destructor
No full textThe present study examined for the first time the sound production and motility of the freshwater decapod crustacean Cherax destructor. An acoustic and video system was used to monitor the behavior of 10 individual (5 males and 5 females) in an experimental tank. Video data were used to analyze three motility variables (velocity, distance moved, and angular velocity). Acoustic data were analyzed to obtain abundance and these acoustic parameters: duration, 1st and 2nd peak frequency, sound pressure level (SPL) and the bandwidth. Both males and females produced short-duration pulses that could be grouped into three categories, high, medium, and low frequency. Males showed a higher rate of emission of mid-frequency sounds than females. The sounds emitted by females had significantly higher 1st and 2nd peak frequencies (Mean± DS: F1= 23±32 kHz; F2= 17±20 kHz) than males (F1= 10±15 kHz Mean± DS; F2= 11±16 kHz), sound duration was also higher in females (10±7 ms) than in males (8±4 ms), otherwise, SPL was higher in males (133±5 dB re 1μParms) than in females (132±7 dBre 1 μParms). Concerning the motility, there is no particular differences in velocity and distance moved, on the contrary, angular velocity was greater in males (21±39 deg/s) than in females (18±41 deg/s). This study is part of a wider one on the behaviour associated with the production of sounds by these animals observed both individually and in groups and on the behavioural and biochemical responses to potential sources of anthropogenic noise disturbance
THE TOXIC EFFECT OF AN OXYLIPINS-CONTAINING MACROALGAE EXTRACT ON SEA URCHIN REPRODUCTION
No full textThe classical view of food webs, with plants and algae considered as passive participants, has been revaluated in recent years, since it is now clear that plants and algae possess complex and highly evolved chemical defenses against their grazers, including the production of bioactive molecules. Among these, oxylipins play a pivotal role in the systemic defense mechanisms of macroalgae, accumulating in response to pathogens, metals and against mechanical tissue disruption by grazers. Diatoms are known to be able to compromise the hatching success of their grazers, such as copepods and sea urchins, by releasing toxic oxylipins in the environment after cell damage and during grazing.
Ericaria brachycarpa, a canopy-forming brown algae belonging to the Sargassaceae family, contribute to form the habitat in the Mediterranean Sea for the sea urchin species Arbacia lixula, whose grazing activity exerts a primary control on the abundance of canopy-forming algae, including E. brachycarpa, and the formation of barren grounds. The aim of this work was to evaluate the effects of an oxylipins-containing extract from E. brachycarpa on the development of A. lixula embryos, evaluating the fertilization success and the embryotoxic activity from fertilization (0 h) to the pluteus stage (72 h). The range of concentrations tested was chosen to cover a full 0-100 % abnormality curve, with doses ranging from 0 to 40 μg/mL. The extract was added at three developmental endpoints: zygote (0 hpf), gastrula (24 hpf) and pluteus (48 hpf) and showed a dose-dependent and developmental stage-specific effect. Gastrulae were the most sensitive to the extract with the lowest EC50 (5.366 μg/mL). At low concentrations we measured the changes of two morphological parameters to compare the ability to correctly grow and calcify in the four-armed pre-feeding echinopluteus stage: the length of the post-oral arm and larval body width. We found a great decrease of these two parameters in exposed embryos compared to controls, that may eventually lead to an impaired ability to feed and thus ultimately reduce the possibility to correctly metamorphose. The highest concentration tested (40 μg/ml) caused 100% mortality of the embryos at all stages. Western Blot experiments showed the modulation of different molecular markers (HSP60, LC3, p62, CHOP and cleaved caspase-7), showing enhanced autophagy at low concentrations and apoptosis at high concentrations. The TUNEL assay confirmed high levels of fragmented DNA in 48 h exposed embryos.
These data support the hypothesis that macroalgae may exert a sort of population control against their grazers, releasing in the marine environment toxic compounds, such as oxylipins, following their tissue disruption by sea urchins and other grazers. Sea urchins intense grazing can greatly decrease the abundance of seaweeds, leading to the “sea-urchin barren ground”. Since A. lixula will potentially benefit from warmer temperatures and the population control implemented by E. brachycarpa on its reproductive success may not be sufficient in a climate change scenario, a deeper understanding of the A. lixula-E. brachycarpa interaction will have a key importance for next decades, to avoid the risk of a greater amount of barrens in the sublittoral rocky surfaces of the Mediterranean Sea
Antitumoral compounds from vertebrate sister group: A review of Mediterranean ascidians
No full textAmong the diseases that afflict the human population, cancer is one for which many drug treatments are not yet
known or effective. Moreover, the pharmacological treatments used often create serious side effects in sick
patients and for this reason, it is essential to find effective and less harmful treatments. To date, marine biodiversity is a real source of metabolites with antitumoral activity and among invertebrates’ ascidians have been the main source to obtain them. Mediterranean area is the richest in biodiversity and contains several ascidian species used in drugs development during the years. However, many more Mediterranean ascidian species have not been studied and could be a source of useful bioactive compounds. This review aims to summarize the scientific studies that analyzed the antitumor compounds obtained from different Mediterranean ascidians species, encouraging them to search further compounds in other new species to improve pharmacological treatments and human population life
Biological activities of the extracts from macroalgae Carpodesmia crinita, Carpodesmia brachycarpa, Asparagopsis taxiformis
No full textMarine species represent a rich source of biologically active products that can be used in various fields. Among them, marine algae produce numerous secondary metabolites responsible for different biological activities such as: immunomodulatory [1], antioxidant [2], and antimicrobial [3]. The aim of
this study was chemically characterizing the extracts of three macroalgae species: Carpodesmia crinite (Duby) Orellana & Sansón, 2019, Carpodesmia brachycarpa (J. Agardh) Orellana & Sansón 2019, Asparagopsis taxiformis (Delile) Trevisan 1845 and evaluate their biological activities. The characterization of the secondary metabolites was performed by HPLC-MS and the results obtained showed higher meroterpenoids levels. Moreover, the extracts tested against the Arbacia lixula sea
urchin modulate the total and differential cellular count demonstrating their involvement in immunity responses. Furthermore, important antimicrobial activities were observed by testing these extracts against the bacterial strains Listeria monocytogenes and Staphylococcus aureus. For the first time our study shows the effects of macroalgae extracts on the immunomodulatory activity in Arbacia
lixula sea urchin and important antimicrobial activity. The results obtained, although preliminary, are certainly encouraging and our purpose is also improved this information performing biochemical and molecular assays of extracts obtained to understand better the potential that these metabolites have towards the sea urchin Arbacia lixula that graze on these macroalga
Natural Anticancer Peptides from Marine Animal Species: Evidence from In Vitro Cell Model Systems
Full text linkAnticancer peptides are short and structurally heterogeneous aminoacidic chains, which display selective cytotoxicity mostly against tumor cells, but not healthy cells, based on their different cell surface properties. Their anti-tumoral activity is carried out through interference with intracellular homeostasis, such as plasmalemma integrity, cell cycle control, enzymatic activities and mitochondrial functions, ultimately acting as angiogenesis-, drug resistance- and metastasis-inhibiting agents, immune stimulators, differentiation inducers and necrosis or extrinsic/intrinsic apoptosis promoters. The marine environment features an ever-growing level of biodiversity, and seas and oceans are poorly exploited mines in terms of natural products of biomedical interest. Adaptation processes to extreme and competitive environmental conditions led marine species to produce unique metabolites as a chemical strategy to allow inter-individual signalization and ensure survival against predators, infectious agents or UV radiation. These natural metabolites have found broad use in various applications in healthcare management, due to their anticancer, anti-angiogenic, anti-inflammatory and regeneration abilities. The aim of this review is to pick selected studies that report on the isolation of marine animal-derived peptides and the identification of their anticancer activity in in vitro cultures of cancer cells, and list them with respect to the taxonomical hierarchy of the source organism
Heatwave conditions increase the toxicity of phthalates in marine organisms
No full textClimate change- driven marine heatwaves are major risk for marine organisms already facing other anthropogenic hazards, such as chemical contamination in coastal areas. In this study we analyzed the impacts of marine heatwaves and phthalic acid esters (PAEs) pollution as single and combined stressors on development of the sea urchin Arbacia lixula. We tested whether the temperature suggested as optimal for development (24 °C) of this thermophilus species would enhance tolerance to PAEs pollution compared to that showed under ambient temperature (18 °C). Embryo-larval bioassays were conducted in exposures to two temperatures (control: 18 °C, heatwave condition: 24 °C) and ten PAEs concentrations (control: 0 mg L-1; treated: range 0.1-50 mg L-1) in all combinations. Ecotoxicological responses were investigated at three functional levels: i) exposure-response relationships, finding that heatwave exposure increased PAEs- induced toxicity and mortality rates with an EC50 lower by 76 %; ii) morphological, finding combined temperature and PAEs increased abnormality and stunted skeleton growth; iii) biochemical, showing that temperature was the main driver for the modulation of activity of stress response enzymes (alkaline phosphatase, esterase and peroxidase). We show that heatwave conditions negatively impacted sea urchin embryos facing pollution and decreased their tolerance to PAEs. Our results indicate that 24 °C is not the optimal temperature for development of A. lixula from the southwestern Mediterranean and highlight that assays based on just one biological level or single stressor can be misleading to deduce health risks to marine organisms and their thermal optimum, indicating the need for more integrative approaches
Separated hemocyte populations from the ascidian Ciona intestinalis contain and release in vitro opsonizingCa++-independent and β-galactoside specific lectins
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