Trypanocidal activity of organic extracts from the Brazilian and Spanish marine sponges

Abstract Chagas' disease is a parasitic infection caused by protozoan Trypanosoma cruzi that affect millions of people worldwide. The available drugs for treatment of this infection cause serious side effects and have variable efficacy, especially in the chronic phase of the disease. In this context, natural compounds have shown great potential for the discovery of new chemotherapies for the treatment of this infection and various other diseases. In present study, we evaluated the in vitro antiprotozoal activity of five species of Brazilian and Spanish marine sponges (Condrosia reniformes, Tethya rubra, Tethya ignis, Mycale angulosa and Dysidea avara) against T. cruzi. By GC–MS data, we observed that in these extracts were present the major classes of the following compounds: hydrocarbons, terpenes, steroids and alcohols. The extracts showed activity against the three forms of this parasite and did not induce toxicity in mammalian cells. Better activities were observed with the extracts of marine sponges, C. reniformes (EC50 = 0.6 μg/ml), D. avara (EC50 = 1.1 μg/ml) and M. angulosa (EC50 = 3.8 μg/ml), against trypomastigote forms. In intracellular amastigote forms, the extract of T. ignis showed IC50 of 7.2 μg/ml and SI of 24.65. On this basis, our results indicate that these extracts can be promising chemotherapeutic agents against T. cruzi.

Antimicrobial (including antimollicutes), antioxidant and anticholinesterase activities of Brazilian and Spanish marine organisms – evaluation of extracts and pure compounds

Abstract This work describes the antimicrobial, antioxidant and anticholinesterase activities in vitro of organic extracts from fourteen seaweeds, eleven sponges, two ascidians, one bryozoan, and one sea anemone species collected along the Brazilian and Spanish coast, as well as the isolation of the diterpene (4R, 9S, 14S)-4α-acetoxy-9β,14α-dihydroxydolast-1(15),7-diene (1) and halogenated sesquiterpene elatol (2). The most promising antimicrobial results for cell wall bacteria were obtained by extracts from seaweeds Laurencia dendroidea and Sargassum vulgare var. nanun (MIC 250 μg/ml), and by the bryozoan Bugula neritina (MIC 62.5 μg/ml), both against Staphylococcus aureus. As for antimollicutes, extracts from seaweeds showed results better than the extracts from invertebrates. Almost all seaweeds assayed (92%) exhibited some antimicrobial activity against mollicutes strains (Mycoplasma hominis,Mycoplasma genitalium,Mycoplasma capricolum and Mycoplasma pneumoniae strain FH). From these seaweeds, A1 (Canistrocarpus cervicornis), A11 (Gracilaria sp.) and A4 (Lobophora variegata) showed the best results for M. pneumoniae strain FH (MIC 250 μg/ml). Furthermore, compounds 1 and 2 were also assayed against mollicutes strains M. hominis,M. genitalium,M. capricolum,M. pneumoniae strain 129 and M. pneumoniae strain FH, which showed MIC > 100 μg/ml. Antioxidant activities of extracts from these marine organisms were inactive, except for E7 (from sponge Ircinia sp.), which exhibited moderated antioxidant activities for two methods assayed (IC50 83.0 ± 0.1 μg/ml, and 52.0 ± 0.8 mg AA/g, respectively). Finally, for the anticholinesterase activity, all the 29 samples evaluated (100%) exhibited some level of activity, with IC50 < 1000 μg/ml. From these, seaweeds extracts were considered more promising than marine invertebrate extracts [A10 (IC50 14.4 ± 0.1 μg/ml), A16 (IC50 16.4 ± 0.4 μg/ml) and A8 (IC50 14.9 ± 0.5 μg/ml)]. The findings of this work are useful for further research aiming at isolation and characterization of active compounds.

Evaluation of Marine Brown Algae and Sponges from Brazil as Anticoagulant and Antiplatelet Products.

The ischemic disorders, in which platelet aggregation and blood coagulation are involved, represent a major cause of disability and death worldwide. The antithrombotic therapy has unsatisfactory performance and may produce side effects. So, there is a need to seek molecules with antithrombotic properties. Marine organisms produce substances with different well defined ecological functions. Moreover, some of these molecules also exhibit pharmacological properties such as antiviral, anticancer, antiophidic and anticoagulant properties. The aim of this study was to evaluate, through in vitro tests, the effect of two extracts of brown algae and ten marine sponges from Brazil on platelet aggregation and blood coagulation. Our results revealed that most of the extracts were capable of inhibiting platelet aggregation and clotting measured by plasma recalcification tests, prothrombin time, activated partial thromboplastin time, and fibrinogenolytic activity. On the other hand, five of ten species of sponges induced platelet aggregation. Thus, the marine organisms studied here may have molecules with antithrombotic properties, presenting biotechnological potential to antithrombotic therapy. Further chemical investigation should be conducted on the active species to discover useful molecules for the development of new drugs to treat clotting disorders.