https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

(2002). The Effects of Harmful Algal Blooms on Aquatic Organisms. Reviews in Fisheries Science: Vol. 10, No. 2, pp. 113-390.

The Effects of Harmful Algal Blooms on Aquatic Organisms

Global demand for macroalgal and microalgal foods is growing, and algae are increasingly being consumed for functional benefits beyond the traditional considerations of nutrition and health. There is substantial evidence for the health benefits of algal-derived food products, but there remain considerable challenges in quantifying these benefits, as well as possible adverse effects. First, there is a limited understanding of nutritional composition across algal species, geographical regions, and seasons, all of which can substantially affect their dietary value. The second issue is quantifying which fractions of algal foods are bioavailable to humans, and which factors influence how food constituents are released, ranging from food preparation through genetic differentiation in the gut microbiome. Third is understanding how algal nutritional and functional constituents interact in human metabolism. Superimposed considerations are the effects of harvesting, storage, and food processing techniques that can dramatically influence the potential nutritive value of algal-derived foods. We highlight this rapidly advancing area of algal science with a particular focus on the key research required to assess better the health benefits of an alga or algal product. There are rich opportunities for phycologists in this emerging field, requiring exciting new experimental and collaborative approaches.

https://link.springer.com/content/pdf/10.1007%2Fs10811-016-0974-5.pdf

Algae as nutritional and functional food sources: revisiting our understanding

In the last three decades the discovery of metabolites with biological activities from macroalgae has increased significantly. However, despite the intense research effort by academic and corporate institutions, very few products with real potential have been identified or developed. Based on Silverplatter MEDLINE and Aquatic Biology, Aquaculture & Fisheries Resources databases, the literature was searched for natural products from marine macroalgae in the Rhodophyta, Phaeophyta and Chlorophyta with biological and pharmacological activity. Substances that currently receive most attention from pharmaceutical companies for use in drug development, or from researchers in the field of medicine-related research include: sulphated polysaccharides as antiviral substances, halogenated furanones from Delisea pulchra as antifouling compounds, and kahalalide F from a species of Bryopsis as a possible treatment of lung cancer, tumours and AIDS. Other substances such as macroalgal lectins, fucoidans, kainoids and aplysiatoxins are routinely used in biomedical research and a multitude of other substances have known biological activities. The potential pharmaceutical, medicinal and research applications of these compounds are discussed.

Medicinal and pharmaceutical uses of seaweed natural products: A review

Venomous animals have evolved a vast array of peptide toxins for prey capture and defence. These peptides are directed against a wide variety of pharmacological targets, making them an invaluable source of ligands for studying the properties of these targets in different experimental paradigms. A number of these peptides have been used in vivo for proof-of-concept studies, with several having undergone preclinical or clinical development for the treatment of pain, diabetes, multiple sclerosis and cardiovascular diseases. Here we survey the pharmacology of venom peptides and assess their therapeutic prospects.

/pdf/therapeutic-potential-of-venom-peptides-49q2vx6v60.pdf

Therapeutic potential of venom peptides

Vibrio sp. isolated from a xanthid crab, Atergatis floridus, was cultured, and tetrodotoxin (TTX) and anhydroTTX were indicated to be present in several fractions of the cell extract and the culture medium by reverse phase HPLC. The presence of the C9-base in alkaline hydrolyzates of these fractions was confirmed by GC-MS and UV spectrometry. These results showed the production of TTX and anhydroTTX in the Vibrio sp., thus indicating one of the origins of TTX in nature.

Occurrence of tetrodotoxin and anhydrotetrodotoxin in Vibrio sp. isolated from the intestines of a xanthid crab, Atergatis floridus.

Among the marine toxins relevant for human intoxication, tetrodotoxin (TTX) has been known as one of the most prejudicial. Puffer fish were originally thought to be the only animal from which TTX could be isolated. Subsequent works determined that TTX also existed in a range of marine organisms of different phylogenic classes and a very few amphibians. The production of TTX is generally accepted to be associated with bacteria. This paper presents the current evidences for the distribution of TTX and its analogs in several vertebrates and invertebrates, along with the probable origin of TTX.

Distribution and origin of tetrodotoxin

A number of type strains of marine bacteria, including members of the family Vibrionaceae, were cultured and examined for tetrodotoxin productivity by high-performance liquid chromatography and gas chromatography-mass spectrometry. Most of the Vibrionaceae strains produced tetrodotoxin, anhydrotetrodotoxin, or both.

Marine bacteria which produce tetrodotoxin.

Ostreopsis sp., a possible origin of palytoxin (PTX) in parrotfish Scarus ovifrons.

To clarify the mechanism of toxification in animals contaminated with tetrodotoxin, the intestinal contents of the puffer Fugu vermicularis vermicularis were examined for bacterial flora in 1985. Twenty-six out of 33 strains belonged to the genus Vibrio. These bacteria were classified into Groups I to VII, based on biological and biochemical characters. High performance liquid chromatography and gas chromatography-mass spectrometry, together with mouse bioassay for toxicity, clearly demonstrated that Group I produced tetrodotoxin and anhydrotetrodotoxin under cultivation with a medium composed of Phytone peptone (BBL) and NaCl. Some other groups also produced this toxin and/or related substances to some extent. Strains of Group I were all identified as Vibrio alginolyticus. Two strains among four produced a detectable amount of tetrodotoxin and/or anhydrotetrodotoxin, as measured by all instrumental analyses applied. Our findings suggest that some strains of V. alginolyticus are closely related to the toxification of the puffer, and probably of other species.

Tamao Noguchi

Papers

Occurrence of tetrodotoxin and anhydrotetrodotoxin in Vibrio sp. isolated from the intestines of a xanthid crab, Atergatis floridus.

Distribution and origin of tetrodotoxin

Marine bacteria which produce tetrodotoxin.

Ostreopsis sp., a possible origin of palytoxin (PTX) in parrotfish Scarus ovifrons.

Vibrio alginolyticus, a tetrodotoxin-producing bacterium, in the intestines of the fish Fugu vermicularis vermicularis