One of the main bioactive compounds of interest from the Ulva species is the sulfated polysaccharide ulvan, which has recently attracted attention for its anticancer properties. This study investigated the cytotoxic activity of ulvan polysaccharides obtained from Ulva rigida in the following scenarios: (i) in vitro against healthy and carcinogenic cell lines (1064sk (human fibroblasts), HACAT (immortalized human keratinocytes), U-937 (a human leukemia cell line), G-361 (a human malignant melanoma), and HCT-116 (a colon cancer cell line)) and (ii) in vivo against zebrafish embryos. Ulvan exhibited cytotoxic effects on the three human cancer cell lines tested. However, only HCT-116 demonstrated sufficient sensitivity to this ulvan to make it relevant as a potential anticancer treatment, presenting an LC₅₀ of 0.1 mg mL⁻¹. The in vivo assay on the zebrafish embryos showed a linear relationship between the polysaccharide concentration and growth retardation at 7.8 hpf mL mg⁻¹, with an LC₅₀ of about 5.2 mg mL⁻¹ at 48 hpf. At concentrations near the LC₅₀, toxic effects, such as pericardial edema or chorion lysis, could be found in the experimental larvae. Our in vitro study supports the potential use of polysaccharides extracted from U. rigida as candidates for treating human colon cancer. However, the in vivo assay on zebrafish indicated that the potential use of ulvan as a promising, safe compound should be limited to specific concentrations below 0.001 mg mL⁻¹ since it revealed side effects on the embryonic growth rate and osmolar balance.

Bovistella utriformis (Bull.) Demoulin & Rebriev is a cosmopolitan puffball mushroom traditionally recognized for its anti-inflammatory and wound-healing properties. This study aimed to evaluate the cytotoxic profile, regenerative potential, and molecular effects of polysaccharides extracted from B. utriformis (PsBU) using complementary in vitro and in vivo approaches. Thermogravimetric analysis revealed good thermal stability up to 300 °C with 26.91% residual mass at 800 °C. Human HaCaT keratinocytes were used to assess cell viability, proliferation, and cell-cycle distribution through MTT assays and flow cytometry, while wound-healing activity was examined using in vitro scratch assays. PsBU exhibited no cytotoxic effects across concentrations from 19.53 to 10,000 µg mL⁻¹, with cell viability remaining above 68%. At 5000 and 10,000 µg mL⁻¹, viability increased to 130% and 126%, respectively. The optimal in vitro wound-healing effect was observed at 500 µg mL⁻¹, achieving 40% wound closure at 32 h. Label-free quantitative proteomic analysis by UHPLC-HRMS identified 83 differentially expressed proteins, including upregulation of tissue repair-related factors such as plasminogen and FHL2, alongside modulation of cell-cycle regulation and mRNA transport pathways. In vivo zebrafish caudal fin regeneration assays demonstrated maximal regenerative activity at 200 µg mL⁻¹ (p < 0.001 vs. control). Overall, these findings demonstrate that B. utriformis polysaccharides are safe bioactive compounds that promote key biological processes involved in tissue regeneration, supporting their potential application as natural wound-healing agents.

Natural fungal polysaccharides are increasingly explored as bioactive compounds capable of orchestrating complex regenerative responses during tissue repair. This study aimed to evaluate the in vivo wound-healing efficacy and molecular mechanisms of a topical polysaccharide formulation derived from Bovistella utriformis (Calvatin 2%) using complementary murine, zebrafish, and proteomic approaches. Phylogenetic analysis based on ITS sequences confirmed the taxonomic identity of the Chilean specimen. In a murine full-thickness excisional wound model, Calvatin 2% significantly accelerated wound contraction and re-epithelialization compared to both saline and base-cream controls, achieving near-complete closure by day 10. Label-free quantitative proteomic analysis of wound tissue by UHPLC-HRMS identified 2432 high-confidence proteins, with 171 upregulated and 153 downregulated proteins in the Calvatin versus control comparison (p < 0.01). Functional enrichment revealed strong activation of innate immune response, complement activation, coagulation cascades, and acute-phase response pathways, while lipid metabolism, mitochondrial energy production, and muscle-related processes were significantly downregulated. KEGG pathway analysis further highlighted complement and coagulation cascades and neutrophil extracellular trap formation as the most prominently affected pathways. In a zebrafish laser-induced wound model, Calvatin induced early and sustained regenerative responses, reaching over 93% wound closure by 18 days post-lesion, significantly outperforming both PBS and vehicle-treated groups. Chronic oral administration of polysaccharides did not induce major hepatic inflammatory responses, supporting systemic safety. Overall, these findings indicate that B. utriformis polysaccharides are associated with modulation of immune- and repair-related pathways together with tissue reprogramming processes that may contribute to accelerated cutaneous regeneration, positioning Calvatin as a promising bioactive formulation for wound-healing applications.

Neurodegenerative diseases are currently raising their prevalences and new preclinical low-cost investigations of drug design are urging. This systematic review extensively overviews strategies that use zebrafish assays to investigate modulations of mitochondrial function as new therapies against these diseases. The review was performed following an electronic search of different databases (PubMed, Embase, Scopus and Web of Science) after the PRISMA procedure. Articles published in the English language were identified and screened based on the keywords used: mitochondrial metabolism, therapy, neurodegenerative diseases and zebrafish. Following 176 entries, exclusion criteria reduced the record to 34 final studies. These studies investigate 24 natural, 6 semisynthetic, 5 synthetic and 2 compounds of not-determined origin to ameliorate 9 prevalent diseases: ARSACS, Alzheimer’s, Parkinson’s, Huntington’s diseases, Leigh and Wolfram syndromes, Amyotrophic lateral sclerosis, Limb – girdle muscular dystrophy 2G and hyperglycemia-associated amnesia. Most studies, 22, are focused on potential therapies against Parkinson´s disease that modulate mitochondrial activity in response to endoplasmic reticulum stress/unfolded protein response (4 cases), ubiquitin-dependent mitophagy and receptor-mediated mitophagy (5 cases), or iNOS/NO pathway (1 cases) among others. To conclude, zebrafish have become an effective model for screening potential drugs for neurodegenerative diseases with symptomatology difficult to replicate in rodent models.