This manuscript describes the evaluation of anti-infective potential
in vitro of organic extracts from nine sponges, one ascidian, two octocorals, one bryozoan, and 27 seaweed species collected along the Brazilian coast. Antimicrobial activity was tested against
Staphylococcus aureus (ATCC 25923),
Enterococcus faecalis (ATCC 29212),
Pseudomonas aeruginosa (ATCC 27853),
Escherichia coli (ATCC 25922) and
Candida albicans (ATCC 10231) by the disk diffusion method. Antiprotozoal activity was evaluated against
Leishmania braziliensis (MHOM/BR/96/LSC96-H3) promastigotes and
Trypanosoma cruzi (MHOM/BR/00/Y) epimastigotes by MTT assay. Activity against intracellular amastigotes of
T. cruzi and
L. brasiliensis in murine macrophages was also evaluated. Antiviral activity was tested against Herpes Simplex Virus type 1 (HSV-1, KOS strain) by the plaque number reduction assay (IC
50). Cytotoxicity on VERO cells was evaluated by the MTT assay (CC
50). The results were expressed as SI = CC
50/IC
50. The most promising antimicrobial results were obtained against
S. aureus and
C. albicans with
Dragmacidon reticulatum. Among the seaweeds, only
Osmundaria obtusiloba showed moderate activity against
P. aeruginosa. Concerning antiprotozoal activity,
Bugula neritina,
Carijoa riseii,
Dragmaxia anomala and
Haliclona (
Halichoclona)
sp. showed the most interesting results, mainly against extracellular promastigote forms of
L. braziliensis (66, 35.9, 97.2, and 43.6% inhibition, respectively). Moreover, six species of seaweeds
Anadyomene saldanhae,
Caulerpa cupressoides,
Canistrocarpus cervicornis,
Dictyota sp.,
Ochtodes secundiramea, and
Padina sp. showed promising results against
L. braziliensis (87.9, 51.7, 85.9, 93.3, 99.7, and 80.9% inhibition, respectively), and only
Dictyota sp. was effective against
T. cruzi (60.4% inhibition). Finally, the antiherpes activity was also evaluated, with
Haliclona (
Halichoclona)
sp. and
Petromica citrina showing the best results (SI = 11.9 and SI > 5, respectively). All the active extracts deserve special attention in further studies to chemically characterize the bioactive compounds, and to perform more refined biological assays.
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