Kamil Jurowski

Tetrodotoxin (TTX) is one of the most potent naturally occurring neurotoxins and continues to attract considerable scientific, clinical, forensic, and regulatory attention. Historically associated with pufferfish poisoning in East and Southeast Asia, TTX has recently emerged as a global food safety concern due to its detection in an increasing number of marine and terrestrial organisms and its expanding geographical distribution, including European coastal waters. Despite decades of research, important questions regarding its biosynthesis, ecological origin, toxicokinetics, and environmental dissemination remain unresolved. This review provides a comprehensive overview of current knowledge on TTX. The chemical structure, physicochemical properties, proposed biosynthetic origin, and diversity of naturally occurring TTX analogues are discussed. Attention is devoted to the toxin’s mechanism of action, which involves high-affinity binding to voltage-gated sodium channels and subsequent inhibition of sodium ion conductance, leading to neuromuscular paralysis and potentially fatal respiratory failure. Current evidence regarding toxicokinetics, tissue distribution, elimination pathways, and the suitability of different biological matrices for laboratory confirmation of exposure is also summarized. The review further examines the analytical challenges associated with TTX determination, including its high polarity, occurrence at trace concentrations, rapid elimination from blood, and frequent co-occurrence with structurally related analogues. The evolution of analytical methodologies is presented, from early bioassays and chromatographic techniques with fluorescence or UV detection to advanced liquid chromatography–mass spectrometry platforms, high-resolution mass spectrometry, capillary electrophoresis, immunochemical assays, and emerging biosensor-based approaches. Finally, current regulatory perspectives and risk assessment strategies are discussed in the context of the increasing occurrence of TTX in seafood and the growing need for harmonized monitoring programs. Collectively, this review summarizes the current state of the art, identifies key knowledge gaps, and highlights future directions in TTX research.

The online version contains supplementary material available at 10.1007/s00204-026-04379-y.

Understanding the toxicity of serotonergic tryptamines is becoming increasingly important from both clinical and forensic perspectives, yet experimental data for these compounds remain extremely limited. Despite their growing medical relevance and widespread non-medical use, there is still no systematic evaluation of their toxicological risks. This study presents the first comprehensive in silico assessment of key toxicological endpoints for six tryptamines of clinical and forensic interest: tryptamine, psilocin, psilocybin (4-PO-DMT),N, N-dimethyltryptamine (DMT), 5-methoxy-N, N-dimethyltryptamine (5-MeO-DMT),and O-acetylpsilocin (4-AcO-DMT). A multi-model computational approach was applied using STopTox, admetSAR 3.0, ADMETlab 3.0, ACD/Labs Percepta, Toxtree, ProTox 3.0, OCHEM, TEST, and VEGA QSAR, following OECD principles for QSAR model validation. The study covered acute systemic toxicity (LD₅₀), organ-specific effects, cardiotoxicity (hERG inhibition), genotoxicity (Ames test), irritation potential, and estrogenic activity (ER-α binding). All compounds were classified as Cramer Class III (high toxicological concern). Predicted oral LD₅₀ values were in the 100-500 mg/kg range, indicating moderate to high acute toxicity. Cardiovascular and gastrointestinal systems were consistently identified as primary targets (predicted effect ≥ 90%). DMT and 5-MeO-DMT showed the highest predicted hERG inhibition (20 < IC₅₀ < 45 µM), suggesting possible cardiotoxic potential, while psilocybin demonstrated lower risk (IC₅₀ ≈ 760 µM). Most tryptamines were predicted to be non-mutagenic and non-endocrine active (LogRBA < - 3).

Lysergamide analogs such as ALD-52, 1P-LSD, 1B-LSD, 1 V-LSD, and 1cP-LSD have emerged as new psychoactive substances (NPS) with hallucinogenic potential, yet their toxicological profiles remain largely unexplored. In this study, a comprehensive in silico assessment was conducted using multiple platforms (e.g., ADMETlab 3.0, Percepta, STopTox, ProTox 3.0, VEGA, TEST 5.1.2) to predict critical toxicological parameters relevant to clinical and forensic toxicology. Acute toxicity was predicted for all compounds, with LD₅₀ values in rats ranging from 49 to 85 mg/kg (Percepta) and oral/inhalation exposure identified as the most concerning routes. Organ-specific toxicity highlighted elevated pulmonary risk for 1 V-LSD (92%) and 1cP-LSD (81%), and highest predicted hematotoxicity for 1P-LSD (76%) and 1B-LSD (75%). Genotoxicity alerts were consistently identified for ALD-52 and 1cP-LSD (up to 90% predicted probability, Percepta), while OCHEM classified all compounds as non-mutagenic. Cardiotoxicity assessment revealed the strongest hERG channel inhibition for 1 V-LSD (IC₅₀ = 1.4 µM, Percepta), suggesting elevated proarrhythmic potential. Dermal and ocular irritation risks were uniformly low across platforms. The results support that structural modifications at the N-1-acyl position influence toxicity patterns, particularly affecting cardiopulmonary and genotoxic endpoints. These findings underscore the utility of in silico methods for early risk assessment and prioritization of lysergamide-based NPS for further toxicological evaluation.

Modern toxicology is experiencing a major paradigm shift driven by the demand for efficient chemical safety assessment and the ethical and economic limits of animal testing. In silico toxicology, understood as the use of computational tools and computer-based simulations to predict and analyze toxic effects, has become a core element of this transformation. By enabling rapid, cost-effective, and mechanistically based hazard assessment, computational approaches bridge science, industry, and regulation. This development echoes the idea of “heartbroken toxicology”, where the scientific, industrial, and regulatory domains have grown apart. In silico methods offer a way to reconnect these dimensions and foster a shared framework for decision-making. This narrative review summarizes current advances, methodological foundations, and key challenges of in silico toxicology, emphasizing its expanding role in regulatory and industrial contexts and the need for harmonized validation, standardization, and education to secure its place as a cornerstone of 21st-century toxicology.