Toxins

The French Society for Toxinology (SFET) held its 31st annual meeting (RT31) on 1–2 December 2025 at Hôtel Le Saint Paul in Nice, France, on the famous French Riviera. The meeting, which gathered 75 participants from around the world, was organised there for the second consecutive year, while previous editions were all held in Paris. The RT31 main theme, “Toxins: Playing with and fighting them”, explored recent, cutting-edge research in the field of animal venoms and of toxins from algal, animal, bacterial, fungal, plant and microbial origins, in emphasizing the evolution of the toxins, their modes of action and roles, and ways of counteracting intoxinations. These key topics were largely covered through 26 oral and 18 poster communications, organized into three main thematic areas covering three specific aspects of toxinology, along with a traditional fourth, more general session enabling participants to present recent data outside of these themes but nevertheless providing valuable information to the field. This report presents the abstracts of nine of the invited lectures, 14 of the selected lectures, and 16 of the posters, in accordance with the authors’ agreement to publish them. Also, we announce the winners of the “Best Oral Communication” and “Best Poster Communication” awards, which recognize the outstanding contributions of young researchers and their inventive work in toxinology.

Shoulder spasticity is a common consequence of upper motor neuron lesions and may be associated with soft tissue contractures, limiting functional recovery. While both cryoneurolysis and tendon lengthening procedures are used individually in refractory cases, their combined effect has not been clearly established. It is consequently necessary to assess the efficacy of combining cryoneurolysis and percutaneous pectoral tenotomy in reducing shoulder spasticity and improving passive range of motion in patients with refractory shoulder spasticity and contracture. This retrospective, single-centre cohort study included 15 adults (≥19 years) with chronic shoulder spasticity and clinically confirmed musculotendinous contracture, previously treated with botulinum toxin injections without sufficient functional response, and free of pharmacological effects (last injection >4 months prior). All patients underwent cryoneurolysis targeting motor branches to the pectoral muscles. Outcomes included Modified Ashworth Scale (MAS) and shoulder Passive Range Of Motion (PROM). The combined approach provided significant improvements in spasticity severity for shoulder flexion (p < 0.01) and abduction (p < 0.01), and significant improvements in maximum PROM for shoulder flexion (p < 0.0001) and abduction (p < 0.0001). Combining cryoneurolysis and pectoral tenotomy appears feasible, safe, and clinically beneficial in selected patients with both spasticity and tendon contracture. Cryoneurolysis addresses the neural component, while tenotomy may restore mechanical excursion. This sequential diagnostic and therapeutic approach may enhance personalized management of mixed spastic–contracture shoulder limitations and could be applicable to other joints.

Microcystins (MCs), a group of potent hepatotoxins from cyanobacterial blooms, threaten global water security due to the resistance to conventional treatment processes and multi-organ toxicity to human. This study innovatively proposed a novel sequential process combining UV irradiation with biodegradation by Sphingopyxis sp. m6 for efficient microcystin-LR (MC-LR) removal. Results revealed that sequential UV-C pretreatment followed by Sphingopyxis sp. m6 biodegradation achieved complete degradation of 1 mg/L of MC-LR within 1 h of the biological phase, drastically reducing the treatment time compared to biodegradation alone (5 h). Mechanistic investigation revealed that low-dose UV-C (50 mJ/cm²) pretreatment induced MC-LR photoisomerization consistently with previously reported Adda geometric isomers. These photoisomers, along with residual parent MC-LR, were subsequently mineralized by Sphingopyxis sp. m6. Enzymatic pathway analysis confirmed a dual-pathway degradation, where Mlr enzymes processed both the native toxin and its isomeric forms, leading to a series of linearized peptides and Adda-derived products. Critically, the process achieved efficient detoxification, as confirmed by the restoration of HepG2 cell proliferation and protein phosphatase 2A activity. Moreover, response surface methodology optimized the key parameters (31.49 °C, pH of 7.36, 0.23 mg/L) for the highest degradation efficiency. This work provides an energy- and cost-efficient strategy for MC-LR remediation and elucidates the molecular mechanism of UV-induced photoisomerization facilitating subsequent biodegradation.