Investigação das atividades tripanocida e leishmanicida de macroalgas marinhas

Abstract

The Chagas disease and leishmaniasis are neglected tropical d iseases (NTDs) with a significant impact on public health. The d rugs used to treat these diseases have severe side effects and low efficacy, leading t o the search for new drugs that are more effective and safer for their treatments. Alt hough seaweeds have been recognized as a source of several biologically active compoun ds, few studies have focused on the activity against the parasites that cause t hese diseases, mainly in Brazil. In the present study, a screening was carried out usi ng 48 seaweed collected in the Região dos Lagos, in the State of Rio de Janei ro, in order to identify activity against Trypanosoma cruzi epimastigotes and Leishmania amazonensis promastigotes. The extracts were prepared with a dichloromethan e: methanol (2: 1) mixture. At initial screening, the viability of the trea ted parasites was evaluated by the MTT assay. The IC 50 was determined by flow cytometry a nd the CC50 of the extracts in LLC MK2 cells was evaluated by the MTT assay. To det ermine the effect of the extracts on the integrity of the plasma membrane of the pa rasites, the propidium iodide marker was used. The work tested, for the first time, the t rypanocidal and leishmanicidal effect of twenty species of seaweed, which were never evaluated before. Fifteen seaweed extracts were able to impair the proliferation of T. cruzi , while only four extracts were effective in reducing the growth of L. amazonensis . Laurencia dendroidea and Canistrocarpus cervicoris were the species that presented higher trypanocidal and leishmanicidal activity among the seawee d tested. However, the extracts from these two were high cytotoxicity against LLCMK 2. Five species of seaweed exhibited an unprecedented effect against T. cruzi : Acanthophora spicifera , Codium intertextum , Codium taylori , Dasya ocellata and Plocamium brasiliense . However, Plocamium brasiliense was more promising because it had one of the greatest inhibitory effects among trypanosomatids tested an d low cytotoxicity in LLCMK2 cells. Thus, we highlight the potential of Plocamium brasiliense extract, which should be a priority for chemical characterization and perfo rmance of new biological assays using other developmental forms of T. cruzi and L. amazonenis , are fundamental in the search for new drugs for neglected dise ases.