Deep-Sea Anemones Are Prospective Source of New Antimicrobial and Cytotoxic Compounds.

Aleksandra Kvetkina,Marina Isaeva,Roman Popov,Mikhail Pivkin,Emma Kozlovskaya,Irina Gladkikh,Ekaterina Yurchenko,Margarita Monastyrnaya,Pavel Dmitrenok,Elena Kostina,Elena Leychenko,Irina Bakunina,Stanislav Anastyuk,Victoria Chausova

doi:10.3390/md19120654

Abstract

The peculiarities of the survival and adaptation of deep-sea organisms raise interest in the study of their metabolites as promising drugs. In this work, the hemolytic, cytotoxic, antimicrobial, and enzyme-inhibitory activities of tentacle extracts from five species of sea anemones (Cnidaria, orders Actiniaria and Corallimorpharia) collected near the Kuril and Commander Islands of the Far East of Russia were evaluated for the first time. The extracts of Liponema brevicorne and Actinostola callosa demonstrated maximal hemolytic activity, while high cytotoxic activity against murine splenocytes and Ehrlich carcinoma cells was found in the extract of Actinostola faeculenta. The extracts of Corallimorphus cf. pilatus demonstrated the greatest activity against Ehrlich carcinoma cells but were not toxic to mouse spleen cells. Sea anemones C. cf. pilatus and Stomphia coccinea are promising sources of antimicrobial and antifungal compounds, being active against Gram-positive bacteria Bacillus subtilis, Staphylococcus aureus, and yeast Candida albicans. Moreover, all sea anemones contain α-galactosidase inhibitors. Peptide mass fingerprinting of L. brevicorne and C. cf. pilatus extracts provided a wide range of peptides, predominantly with molecular masses of 4000–5900 Da, which may belong to a known or new structural class of toxins. The obtained data allow concluding that deep-sea anemones are a promising source of compounds for drug discovery.

Highlights

Deep-sea organisms, including sea anemones, are a rich source of biologically active compounds
Four sea anemones were identified as Actinostola callosa (Verrill, 1882) (Figure 1f), Actinostola faeculenta (McMurrich, 1893) (Figure 1e), Stomphia coccinea (Müller, 1776) (Figure 1d) from the Actinostolidae family, and L. brevicorne (McMurrich, 1893) (Figure 1b) from Liponematidae family belonging to order Actiniaria, and one as C
Sea anemone S. coccinea prefers bouldery–gravelly substrata, shell debris, and sometimes, it occurs in silted seabed, but it can detach from the substratum and swim

Summary

Introduction

Deep-sea organisms, including sea anemones, are a rich source of biologically active compounds. They survive under extreme conditions in the absence of light, low levels of oxygen, and intensely high pressure that necessitate a diverse array of biochemical and physiological adaptations that may affect their gene regulation, primary metabolic pathways, and, their secondary metabolites [1,2]. According to the ToxProt database [4], 252 peptide and protein toxins from 47 species of sea anemones are currently known, which covers less than 4% of all known species (≈1100). This makes it possible to consider unexplored and little-studied species to be sources of new biologically active protein compounds, many of which undoubtedly have pharmacological potential. Sea anemone venoms are a complex mixture of peptide and protein components, such as actinoporins [5–9], phospholipases A2 [10,11], neurotoxins [12], and enzymes and their inhibitors [13,14]

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