Stonefish venom antiserum 2000unit solution for injection vials

Marine organisms possess a diverse array of unique substances, many with wide ranging potential for applications in medicine, industry, and other sectors. Stonefish (Synanceia spp.), a bottom-dwelling fish that inhabit shallow and intertidal waters throughout the Indo-Pacific, harbour two distinct substances, a venom, and an ichthyocrinotoxin. Stonefish are well-known for the potent venom associated with their dorsal spines as it poses a significant risk to public health. Consequently, much of the research on stonefish focusses on the venom, with the aim of improving outcomes in cases of envenomation. However, there has been a notable lack of research on stonefish ichthyocrinotoxins, a class of toxin that is synthesised within specialised epithelial cells (i.e., tubercles) and exuded onto the skin. This has resulted in a substantial knowledge gap in our understanding of these animals. This review aims to bridge this gap by consolidating literature on the ecological functions and biochemical attributes of ichthyocrinotoxins present in various fish species and juxtaposing it with the current state of knowledge of stonefish ecology. We highlight the roles of ichthyocrinotoxins in predator defence, bolstering innate immunity, and mitigating integumentary interactions with parasites and detrimental fouling organisms. The objective of this review is to identify promising research avenues that could shed light on the ecological functions of stonefish ichthyocrinotoxins and their potential practical applications as therapeutics and/or industrial products.

Abstract licence: CC BY-NC-ND

Stonefish are regarded as one of the most venomous fish in the world. Research on stonefish venom has chiefly focused on the in vitro and in vivo neurological, cardiovascular, cytotoxic and nociceptive effects of the venom. The last literature review on stonefish venom was published over a decade ago, and much has changed in the field since. In this review, we have generated a global map of the current distribution of all stonefish (Synanceia) species, presented a table of clinical case reports and provided up-to-date information about the development of polyspecific stonefish antivenom. We have also presented an overview of recent advancements in the biomolecular composition of stonefish venom, including the analysis of transcriptomic and proteomic data from Synanceia horrida venom gland. Moreover, this review highlights the need for further research on the composition and properties of stonefish venom, which may reveal novel molecules for drug discovery, development or other novel physiological uses.

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Reef stonefish (Synanceia verrucosa) is one of the most venomous fishes, but its biomedical study has been restricted to molecular cloning and purification of its toxins, instead of high-throughput genetic research on related toxin genes. In this study, we constructed a chromosome-level haplotypic genome assembly for the reef stonefish. The genome was assembled into 24 pseudo-chromosomes, and the length totaled 689.74 Mb, reaching a contig N50 of 11.97 Mb and containing 97.8% of complete BUSCOs. A total of 24,050 protein-coding genes were annotated, of which metalloproteinases, C-type lectins, and stonustoxins (sntx) were the most abundant putative toxin genes. Multitissue transcriptomic and venom proteomic data showed that sntx genes, especially those clustered within a 50-kb region on the chromosome 2, had higher transcription levels than other types of toxins as well as those sntx genes scatteringly distributed on other chromosomes. Further comparative genomic analysis predicted an expansion of sntx-like genes in the Percomorpha lineage including nonvenomous fishes, but Scorpaenoidei species experienced extra independent sntx duplication events, marking the clear-cut origin of authentic toxic stonustoxins. In summary, this high-quality genome assembly and related comparative analysis of toxin genes highlight valuable genetic differences for potential involvement in the evolution of venoms among Scorpaeniformes fishes.

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BACKGROUND: Animal venom systems are considered as valuable model for investigating the molecular mechanisms underlying phenotypic evolution. Stonefish are the most venomous and dangerous fish because of severe human envenomation and occasionally fatalities, whereas the genomic background of their venom has not been fully explored compared with that in other venomous animals. RESULTS: In this study, we followed modern venomic pipelines to decode the Synanceia verrucosa venom components. A catalog of 478 toxin genes was annotated based on our assembled chromosome-level genome. Integrative analysis of the high-quality genome, the transcriptome of the venom gland, and the proteome of crude venom revealed mechanisms underlying the venom complexity in S. verrucosa. Six tandem-duplicated neoVTX subunit genes were identified as the major source for the neoVTX protein production. Further isoform sequencing revealed massive alternative splicing events with a total of 411 isoforms demonstrated by the six genes, which further contributed to the venom diversity. We then characterized 12 dominantly expressed toxin genes in the venom gland, and 11 of which were evidenced to produce the venom protein components, with the neoVTX proteins as the most abundant. Other major venom proteins included a presumed CRVP, Kuntiz-type serine protease inhibitor, calglandulin protein, and hyaluronidase. Besides, a few of highly abundant non-toxin proteins were also characterized and they were hypothesized to function in housekeeping or hemostasis maintaining roles in the venom gland. Notably, gastrotropin like non-toxin proteins were the second highest abundant proteins in the venom, which have not been reported in other venomous animals and contribute to the unique venom properties of S. verrucosa. CONCLUSIONS: The results identified the major venom composition of S. verrucosa, and highlighted the contribution of neoVTX genes to the diversity of venom composition through tandem-duplication and alternative splicing. The diverse neoVTX proteins in the venom as lethal particles are important for understanding the adaptive evolution of S. verrucosa. Further functional studies are encouraged to exploit the venom components of S. verrucosa for pharmaceutical innovation.

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Background: Fish venoms have been poorly characterized and the available information about their composition suggests they are uncomplicated secretions that, combined with epidermal mucus, could induce an inflammatory reaction, excruciating pain, and, in some cases, local tissue injuries. Methods: effects with the presence of some potentially toxic venom components. Results: We observed a strong lesion on the skin and evident necrosis in the skeletal muscle. None of the tissue-damaging effects were induced by the fraction containing cytolysins, membrane pore-forming toxins ubiquitously present in species of scorpionfish, stonefish, and lionfish, among others. On the contrary, injuries were associated with the presence of other components, which have remained practically ignored so far. This is the case of an abundant protein, present in venom, with homology to a Golgi-associated plant pathogenic protein 1-like (GAPR1), which belongs to the same protein superfamily as venom CRISPs and insect allergens. Conclusion: This GAPR1-like protein and the hyaluronidase are probably responsible for the hemostasis impairment and hemorrhagic lesions observed in mouse skin, whereas muscle injuries can be indirectly caused by a combination of inflammatory and hemorrhagic events. More information is required to establish the components accountable for the myonecrotic effect.

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The stonefish Synanceia verrucosa and Synanceia horrida are arguably the most venomous fish species on earth and the culprits of severe stings in humans globally. Investigation into the venoms of these two species has mainly focused on protein composition, in an attempt to identify the most medically relevant proteins, such as the lethal verrucotoxin and stonustoxin components. This study, however, focused on medically relevant small molecules, and through nuclear magnetic resonance, mass spectroscopy, and fractionation techniques, we discovered and identified the presence of three molecules new to stonefish venom, namely γ‐aminobutyric acid (GABA), choline and 0 ‐acetylcholine, and provide the first report of GABA identified in a fish venom. Analysis of the crude venoms on human nicotinic acetylcholine receptors (nAChRs) and a GABA A receptor (GABA A R) showed S. horrida venom could activate neuronal (α7) and adult muscle‐type (α1β1δε) nAChRs, while both crude S. horrida and S. verrucosa venoms activated the GABA A R (α1β2γ2). Cytotoxicity studies in immunologically relevant cells (human PBMCs) indicated the venoms possess cell‐specific cytotoxicity and analysis of the venom fractions on Na + channel subtypes involved in pain showed no activity. This work highlights the need to further investigate the small molecules found in venoms to help understand the mechanistic pathways of clinical symptoms for improved treatment of sting victims, in addition to the discovery of potential drug leads.

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Hyaluronidases are ubiquitous enzymes in animal venoms, where they act as auxiliary toxins that facilitate the diffusion of other components by hydrolyzing hyaluronic acid (HA) in the extracellular matrix. In this study, we purified and biochemically characterized a hyaluronidase from the venom of the scorpionfish Scorpaena plumieri, a venomous fish from the Brazilian coast. The enzyme, designated Sp-H, was isolated with high purity through ammonium sulfate fractionation, size-exclusion chromatography, and anion-exchange chromatography. SDS-PAGE and MALDI-TOF MS revealed a monomeric glycoprotein with a molecular mass of ∼78 kDa. Sp-H exhibited maximal activity in pH range 5.8-6.5, was not significantly affected by NaCl concentrations up to 0.45 M, and retained activity for at least 30 days at 4 °C, -25 °C, or -80 °C. Peptide fragments identified by LC-MS/MS showed partial similarity (80-94 %) with hyaluronidases from stonefish and lionfish. Functionally, Sp-H enhanced the hemorrhagic activity of a snake venom metalloproteinase, indicating a diffusion-enhancing role consistent with that of hyaluronidases from other venomous animals. Moreover, anti-Sp-H IgG specifically recognized the enzyme and completely neutralized its activity in vitro. These findings identify Sp-H as a stable, immunogenic enzyme with biochemical properties comparable to other Scorpaenoid hyaluronidases. Although further studies are required to confirm its role in vivo, Sp-H represents a relevant component for understanding S. plumieri envenomation and a useful model for future studies on fish venom enzymes.

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Venoms are known to modulate immunological processes. In this study, we investigated the immunomodulatory properties of venoms from two stonefish species, Synanceia verrucosa (SvV) and Synanceia horrida (ShV), using immunological assays including reverse-transcription quantitative polymerase chain reaction (RT-qPCR), cytometric bead array (CBA), and enzyme-linked immunosorbent assay (ELISA). Both venoms exhibited significant immunosuppressive activity, particularly in lipopolysaccharide (LPS)-stimulated human peripheral blood mononuclear cells (PBMCs), with less pronounced effects on phorbol 12-myristate 13-acetate with ionomycin (P/I)-stimulated cells. The venoms primarily suppressed Th1-associated cytokines (TNF, IFN-γ, IL-6, and IL-12), as well as IL-10 (Th2) and MCP-1, indicating a stronger inhibition of the Th1 subset. SvV demonstrated greater activity compared to ShV, suppressing cytokines on which ShV had no effect, and having activity at concentrations as low as 1.25 μg/mL. Stability studies showed that both frozen and lyophilized venoms retained immunosuppressive activity comparable to fresh venom, while reversed-phase high-performance liquid chromatography (RP-HPLC) abolished this activity entirely. Size-exclusion chromatography (SEC) revealed the immunosuppressive activity was strongest in the early and late fractions of each venom. Our results highlight the selective immunosuppressive effects of S. verrucosa and S. horrida venoms on human PBMCs, particularly via modulation of Th1 cytokines in response to LPS. The stability and bioactivity of specific venom fractions underscore their potential as sources for novel immunotherapeutic agents.

Abstract licence: CC BY