How mitochondrial dysfunction affects zebrafish development and cardiovascular function: an in vivo model for testing mitochondria-targeted drugs

Background and Purpose Mitochondria are a drug target in mitochondrial dysfunction diseases and in antiparasitic chemotherapy. While zebrafish is increasingly used as a biomedical model, its potential for mitochondrial research remains relatively unexplored. Here, we perform the first systematic analysis of how mitochondrial respiratory chain inhibitors affect zebrafish development and cardiovascular function, and assess multiple quinones, including ubiquinone mimetics idebenone and decylubiquinone, and the antimalarial atovaquone. Experimental Approach Zebrafish (Danio rerio) embryos were chronically and acutely exposed to mitochondrial inhibitors and quinone analogues. Concentration-response curves, developmental and cardiovascular phenotyping were performed together with sequence analysis of inhibitor-binding mitochondrial subunits in zebrafish versus mouse, human and parasites. Phenotype rescuing was assessed in co-exposure assays. Key Results Complex I and II inhibitors induced developmental abnormalities, but their submaximal toxicity was not additive, suggesting active alternative pathways for complex III feeding. Complex III inhibitors evoked a direct normal-to-dead transition. ATP synthase inhibition arrested gastrulation. Menadione induced hypochromic anaemia when transiently present following primitive erythropoiesis. Atovaquone was over 1000-fold less lethal in zebrafish than reported for Plasmodium falciparum, and its toxicity partly rescued by the ubiquinone precursor 4-hydroxybenzoate. Idebenone and decylubiquinone delayed rotenone- but not myxothiazol- or antimycin-evoked cardiac dysfunction. Conclusion and Implications This study characterizes pharmacologically induced mitochondrial dysfunction phenotypes in zebrafish, laying the foundation for comparison with future studies addressing mitochondrial dysfunction in this model organism. It has relevant implications for interpreting zebrafish disease models linked to complex I/II inhibition. Further, it evidences zebrafish's potential for in vivo efficacy or toxicity screening of ubiquinone analogues or antiparasitic mitochondria-targeted drugs

Anti-Proliferative Activity of Meroditerpenoids Isolated from the Brown Alga Stypopodium flabelliforme against Several Cancer Cell Lines

The sea constitutes one of the most promising sources of novel compounds with potential application in human therapeutics. In particular, algae have proved to be an interesting source of new bioactive compounds. In this work, six meroditerpenoids (epitaondiol, epitaondiol diacetate, epitaondiol monoacetate, stypotriol triacetate, 14-ketostypodiol diacetate and stypodiol) isolated from the brown alga Stypopodium flabelliforme were tested for their cell proliferation inhibitory activity in five cell lines. Cell lines tested included human colon adenocarcinoma (Caco-2), human neuroblastoma (SH-SY5Y), rat basophilic leukemia (RBL-2H3), murine macrophages (RAW.267) and Chinese hamster fibroblasts (V79). Antimicrobial activity of the compounds was also evaluated against Staphylococcus aureus, Salmonella typhimurium, Proteus mirabilis, Bacillus cereus, Enterococcus faecalis and Micrococcus luteus. Overall, the compounds showed good activity against all cell lines, with SH-SY5Y and RAW.267 being the most susceptible. Antimicrobial capacity was observed for epitaondiol monoacetate, stypotriol triacetate and stypodiol, with the first being the most active. The results suggest that these molecules deserve further studies in order to evaluate their potential as therapeutic agents

Fatty acids in marine organisms: in the pursuit of bioactive agents

Natural matrices comprise a continuous resource of immeasurable biological activities and chemical entities. The diversity of marine ecosystems has provided a unique source of chemical compounds with potential bioactivities that could lead to new drug candidates. In fact, as many marine-living organisms are soft bodied and/or sessile, over evolutionary time marine eukaryotes have developed an array of metabolites and strategies by which they protect themselves against external aggressions. Research involving marine natural products revealed a broad spectrum of pharmacological activities, as anti-inflammatory, antimicrobial, antitumor and cytotoxic, and the capacity to affect the cardiovascular, immune and nervous system, among others. Fatty acids (FA) are metabolites universally present in all organisms, where they play a number of biological roles, such as building blocks in biological membranes and signalling molecules. In addition to the known set of FA, marine organisms usually display molecules with a very rich chemistry and have been the source of many novel structures that frequently display marked pharmacological properties. As pharmacological research with marine chemicals continues to be extremely active, this review will focus the biological role and potential applications of fatty acids from marine organisms, such as sponges, echinoderms and molluscs, with particular emphasis on their application in cancer, inflammation, tuberculosis and malaria

A gas chromatography-mass spectrometry multi-target method for the simultaneous analysis of three classes of metabolites in marine organisms

In this work a fast and simple multi-target gas chromatography–mass spectrometry (GC–MS) method for the simultaneous detection and absolute quantification of amino acids, fatty acids and sterols in marine organisms is proposed. The methodology was applied to the characterization of the echinoderm Marthasterias glacialis Linnaeus spiny sea star extracts. The main factors influencing the extraction of target compounds were evaluated by using different extraction procedures, solvent systems and temperature conditions and a comparison with a reference technique was performed. The most suitable procedure, capable of successfully extract the three classes of target compounds, was ethanol as solvent at 40 1C under magnetic stirring. Good analytical parameters were obtained since calibrations curves for the 40 compounds under analysis (15 amino acids, 16 fatty acids and 9 sterols) showed regression coefficients (r 2 ) ranging from 0.9844 to 0.9978, with low RSD (from 0.00 to 9.45%), and detection limits varying from 0.03 to 15.40 mg/L. The RSD values for intra- and interday variations studies were also good (RSDo13.5%, for both) and recoveries were higher than 92%. Variation in samples from different harvests and origins and their chemical composition during the year is reported. The fact that no previous treatment of samples is required can make this a useful technique for metabolite profiling in marine organisms, among others, both in biomedical and nutritional studies. Moreover, due to the fast and robust character of the proposed method it seems to be suitable for the implementation as routine analysis.info:eu-repo/semantics/publishedVersio

Chemical composition and biological screening of <em>Capsella bursa-pastoris</em>

Capsella bursa-pastoris (L.) Medik. (Brassicaceae) is a wild herb with high nutritional value that can be eaten raw or cooked. A metabolomic study was performed with different extracts of its aerial parts that were tested concerning their antiradical, acetylcholinesterase inhibitory and antibacterial activities. Phenolic compounds were identified and quantified by HPLC-DAD, organic acids and amino acids were determined by HPLC-UV, while free fatty acids and sterols were analysed by GC-ITMS. The vegetal material was rich in kaempferol-3-O-rutinoside (mean value 2247.09 mg/kg of dry plant), quinic acid (95628.00 mg/kg of dry plant), arginine (mean value of 1.18 mg/kg of dry plant), palmitic acid (284.48 mg/kg) and &#946;-sitosterol (28%). The extracts presented a concentration-dependent antiradical activity (against DPPH•, O2•- and LOO•), being most effective against •NO (EC25 0.20 µg/mL). In addition, the extracts were also acetylcholinesterase inhibitors and antibacterial active, revealing that, besides the plant's good nutritional value, it presents important biological properties as well