Mar. Drugs, Volume 5, Issue 4 (December 2007) – 8 articles , Pages 136-241

The genus Pseudoalteromonas is a marine group of bacteria belonging to theclass Gammaproteobacteria that has come to attention in the natural product andmicrobial ecology science fields in the last decade. Pigmented species of the genus havebeen shown to produce an array of low and high molecular weight compounds withantimicrobial, anti-fouling, algicidal and various pharmaceutically-relevant activities.Compounds formed include toxic proteins, polyanionic exopolymers, substitutedphenolic and pyrolle-containing alkaloids, cyclic peptides and a range of bromine-substituted compounds. Ecologically, Pseudoalteromonas appears significant and to datehas been shown to influence biofilm formation in various marine econiches; involved inpredator-like interactions within the microbial loop; influence settlement, germinationand metamorphosis of various invertebrate and algal species; and may also be adopted bymarine flora and fauna as defensive agents. Studies have been so far limited to arelatively small subset of strains compared to the known diversity of the genussuggesting that many more discoveries of novel natural products as well as ecologicalconnections these may have in the marine ecosystem remain to be made. Full article

With an apparent increase of harmful algal blooms (HABs) worldwide,healthcare providers, public health personnel and coastal managers are struggling toprovide scientifically-based appropriately-targeted HAB outreach and education. Since1998, the Florida Poison Information Center-Miami, with its 24 hour/365 day/year freeAquatic Toxins Hotline (1-888-232-8635) available in several languages, has received over 25,000 HAB-related calls. As part of HAB surveillance, all possible cases of HAB-relatedillness among callers are reported to the Florida Health Department. This pilot studyevaluated an automated call processing menu system that allows callers to access bilingualHAB information, and to speak directly with a trained Poison Information Specialist. Themajority (68%) of callers reported satisfaction with the information, and many provided specific suggestions for improvement. This pilot study, the first known evaluation of use and satisfaction with HAB educational outreach materials, demonstrated that the automated system provided useful HAB-related information for the majority of callers, and decreased the routine informational call workload for the Poison Information Specialists, allowing them to focus on callers needing immediate assistance and their healthcare providers. These results will lead to improvement of this valuable HAB outreach, education and surveillance tool. Formal evaluation is recommended for future HAB outreach and educational materials. Full article

Sarcotriol (ST) has been shown to be chemopreventive on 7,12-dimethylbenz( a)anthracene (DMBA) initiated and 12-O-tetradecanoylphorbol-13-acetate (TPA)- promoted skin tumor development in CD-1 mice in recent studies from our laboratory. The objective of this study was to determine the chemopreventive effects of ST on ultraviolet B (UVB)-induced skin tumor development in female SKH-1 hairless mice, an experimental model relevant to human skin cancer development, and its possible mechanisms of action. Female SKH-1 mice were divided into two groups: Control and ST treated. Control was topically treated with 100 μL acetone and ST treated group administered with 30 μg ST in 100 μL acetone one hour before UVB exposure. For UVB-induced tumorigenesis, carcinogenesis was initiated and promoted by UVB (180 mJ/cm2). Group weights and tumor counts were taken once every week. After 30 weeks, mice were sacrificed and dorsal skin samples were collected. The proteins from the skin sample were further used for SDSPAGE and Western blotting using specific antibodies against caspase-3, caspase-8, caspase-9 and p53. Tumor multiplicity was found 19.6, 5.2 in the control and ST treated groups respectively. Caspase-3, -8, -9 and p53 were significantly (P < 0.05) upregulated in ST treated group compared to Control group. Together, this study for the first time identifies the chemopreventive effects of ST in UVB-induced carcinogenesis possibly by inducing apoptosis and upregulating p53. Full article

Diverse species of cyanobacteria have recently been discovered to produce theneurotoxic non-protein amino acid β-methylamino-L-alanine (BMAA). In Guam, BMAAhas been studied as a possible environmental toxin in the diets of indigenous Chamorropeople known to have high levels of Amyotrophic Lateral Sclerosis/ ParkinsonismDementia Complex (ALS/PDC). BMAA has been found to accumulate in brain tissues ofpatients with progressive neurodegenerative illness in North America. In Guam, BMAAwas found to be produced by endosymbiotic cyanobacteria of the genus Nostoc which livein specialized cycad roots. We here report detection of BMAA in laboratory cultures of afree-living marine species of Nostoc. We successfully detected BMAA in this marinespecies of Nostoc with five different methods: HPLC-FD, UPLC-UV, Amino AcidAnalyzer, LC/MS, and Triple Quadrupole LC/MS/MS. This consensus of five differentanalytical methods unequivocally demonstrates the presence of BMAA in this marinecyanobacterium. Since protein-associated BMAA can accumulate in increasing levelswithin food chains, it is possible that biomagnification of BMAA could occur in marineecosystems similar to the biomagnification of BMAA in terrestrial ecosystems. Productionof BMAA by marine cyanobacteria may represent another route of human exposure toBMAA. Since BMAA at low concentrations causes the death of motor neurons, low levelsof BMAA exposure may trigger motor neuron disease in genetically vulnerableindividuals. Full article

In the context of the French Phytoplankton and Phycotoxins MonitoringNetwork (REPHY) programme, shellfish samples were harvested from different locationswhere harmful algae blooms were known to have occurred. For all shellfish samples foundpositive by the mouse bioassay for diarrhetic shellfish poisoning (DSP) toxins, liquidchromatography (LC) coupled with mass spectrometry (MS) was used to search for thefollowing lipophilic toxins: okadaic acid (OA), dinophysistoxins (DTXs), pectenotoxins(PTXs), azaspiracids (AZAs), yessotoxins (YTXs), spirolides (SPXs) and gymnodimines(GYMs). In order to investigate the presence of acyl-OAs and/or acyl-DTX-1,-2 (DTX-3),alkaline hydrolysis was performed on all samples, and LC/MS analyses were carried out onthe samples before and after hydrolysis. The results revealed different lipophilic toxinprofiles as a function of the shellfish sampling location. The primary finding was that all ofthe samples contained OA and acyl-OA. In addition, other lipophilic toxins were found inshellfish samples: DTX-2, acyl-DTX-2 and SPXs (SPX-A, SPX-desMeC) on the Atlanticcoast (Southern Brittany, Arcachon), and pectenotoxins (PTX-2, PTX-2-seco-acid and 7-epi-PTX-2-seco-acid) on the Mediterranean coast (Thau lagoon, the island of Corsica).This paper reports on the first detection of PTX-2, SPX-A and their derivatives in Frenchshellfish. Full article

Polymeric 3-alkylpyridinium salts (poly-APS) present in the marine spongeReniera sarai show a broad spectrum of biological activities. They are lytic to erythrocytesand various other mammalian cells, enabling the transfection of the latter with alien DNA.Furthermore, they show inhibitory effects to marine bacteria and can inhibit fouling ofmicro- and macroorganisms to submerged surfaces. Finally, poly-APS act as potentcholinesterase inhibitors. The kinetics of acetylcholinesterase inhibition by poly-APS invitro is complex and comprises several successive phases ending in irreversible inhibitionof the enzyme. The latter is accounted for by aggregation and precipitation of the enzyme-inhibitor complexes. Poly-APS are lethal to rats in concentrations above 2.7 mg/kg.Monitoring of the basic vital functions and histopathological analysis showed that theeffects directly ascribable to acetylcholinesterase inhibition are only observed afterapplication of lower concentrations of poly-APS. At higher concentrations, such effectswere masked by other, more pronounced and faster developing lethal effects of the toxin,such as haemolysis and platelet aggregation. Full article

Eight sesquiterpene quinones: ilimaquinone (1), smenospongidine (3),smenospongiarine (5), smenospongine (7), and their corresponding 5-epimers 2, 4, 6, and 8,isolated from the Palauan marine sponge Hippospongia sp., were examined regarding theireffects on TNF-α production in LPS-stimulated RAW 264.7 cells. 5-Epi-smenospongine(8) promoted the production of TNF-α to a level three times greater than the control at10 μM, but compounds 1-7 did not show apparent activity. The results suggest that thecis-decaline ring and a primary amine in the benzoquinone ring are necessary for activity.This is the first study to report the modulation of TNF-α production by a sesquiterpenequinone. Full article

Toxic blooms of cyanobacteria are ubiquitous in both freshwater and brackishwater sources throughout the world. One class of cyanobacterial toxins, calledmicrocystins, is cyclic peptides. In addition to ingestion and dermal, inhalation is a likelyroute of human exposure. A significant increase in reporting of minor symptoms,particularly respiratory symptoms was associated with exposure to higher levels ofcyanobacteria during recreational activities. Algae cells, bacteria, and waterborne toxinscan be aerosolized by a bubble-bursting process with a wind-driven white-capped wavemechanism. The purposes of this study were to: evaluate sampling and analysis techniquesfor microcystin aerosol, produce aerosol droplets containing microcystin in the laboratory,and deploy the sampling instruments in field studies. A high-volume impactor and an IOMfilter sampler were tried first in the laboratory to collect droplets containing microcystins.Samples were extracted and analyzed for microcystin using an ELISA method. Thelaboratory study showed that cyanotoxins in water could be transferred to air via a bubble-bursting process. The droplets containing microcystins showed a bimodal size distributionwith the mass median aerodynamic diameter (MMAD) of 1.4 and 27.8 μm. The samplingand analysis methods were successfully used in a pilot field study to measure microcystinaerosol in situ. Full article