Anti HSV-1 activity of halistanol sulfate and halistanol sulfate C isolated from Brazilian marine sponge Petromica citrina (Demospongiae).

The n-butanol fraction (BF) obtained from the crude extract of the marine sponge Petromica citrina, the halistanol-enriched fraction (TSH fraction), and the isolated compounds halistanol sulfate (1) and halistanol sulfate C (2), were evaluated for their inhibitory effects on the replication of the Herpes Simplex Virus type 1 (HSV-1, KOS strain) by the viral plaque number reduction assay. The TSH fraction was the most effective against HSV-1 replication (SI = 15.33), whereas compounds 1 (SI = 2.46) and 2 (SI = 1.95) were less active. The most active fraction and these compounds were also assayed to determine the viral multiplication step(s) upon which they act as well as their potential synergistic effects. The anti-HSV-1 activity detected was mediated by the inhibition of virus attachment and by the penetration into Vero cells, the virucidal effect on virus particles, and by the impairment in levels of ICP27 and gD proteins of HSV-1. In summary, these results suggest that the anti-HSV-1 activity of TSH fraction detected is possibly related to the synergic effects of compounds 1 and 2.

Anti-infective potential of marine invertebrates and seaweeds from the Brazilian coast.

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 (IC50). Cytotoxicity on VERO cells was evaluated by the MTT assay (CC50). The results were expressed as SI = CC50/IC50. 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.

New cytotoxic cucurbitacins from Wilbrandia ebracteata Cogn.

Chemical investigation of the roots of Wilbrandia ebracteata Cogn. (Cucurbitaceae) led to the isolation of two new (1- 2) and four known (3- 6) cucurbitacins. Their structures were elucidated by NMR and MS and compared with related compounds. The in vitro cytotoxicity of isolated compounds was evaluated against RD, KB, HCT-8, and A549 cell lines showing strong activity.

TSH fraction from Petromica citrina: A potential marine natural product for the treatment of sepsis by Methicillin-resistant Staphylococcus aureus (MRSA).

BACKGROUND AND PURPOSE: Antibiotic resistance is now a worldwide public health problem. A potential alternative source in the search for new antibiotics is the bioactive molecules obtained from marine products, as the halistanol trisulfate, obtained from Petromica citrina, and herein investigated from its antimicrobial and anti-inflammatory properties. EXPERIMENTAL APPROACH: The antimicrobial activity of the fractionation products (TSH fraction, halistanol sulfate (HS) and halistanol sulfate C (HS-C)) of the marine sponge Petromica citrina was evaluated against twenty bacteria and two fungi strains by the disk diffusion and microdilution methods. After initial in vitro tests, an in vivo assay was proposed, to evaluate survival and inflammatory parameters in an animal model of peritonitis mediated by MRSA. The animals are treated with TSH fraction (1, 2.5 and 5 mg kg-1) or Vancomycin (30 mg kg-1) twice (6 and 18 h after induction) until organ removal for evaluation of the inflammatory profile, or for 3 days, 12 h each (6 h, 18 h, 30 h, 42 h, 54 h and 66 h after induction) in animals which were followed-up for by five days, for the evaluation of survival. KEY RESULTS: The BF fraction, TSH fraction, HS and HS-Cinhibited, in vitro, the Enterococcus faecalis, Staphylococcus aureus and Candida albicans growth. Moreover, these samples were effective against S. aureus (MSSA), MRSA and Vancomycin-Resistence Enterococcus (VRE). The in vivo results demonstrated that TSH fraction reduced mortality when compared to the saline group. To evaluate the role of inflammation in outcomes of peritonitis, cytokines (IL-1ß, IL-6, TNF-α) and MPO activity were measured. In general, anti-inflammatory activity was detected in animals treated with TSH in different doses. CONCLUSION AND IMPLICATIONS: These data suggest that TSH may be an interesting alternative for the treatment infections by Gram-positive resistant bacteria, due to its antimicrobial profile associated with its anti-inflammatory properties.