Alternative Model-Based Safety Assessment of a Celtis iguanaea Standardized Spray-Dried Extract

Abstract The Celtis iguanaea (Jacq.) Sarg., Cannabaceae, standardized spray-dried extract, underwent acute safety evaluation using a range of alternative toxicological models in alignment with Organization for Economic Co-operation and Development Test Guidelines. Acute aquatic toxicity was assessed using the Artemia salina lethality test (LC 50 418.4 μg/ml) and the zebrafish ( Danio rerio ) embryo toxicity test (OECD TG 236; LC 50 1116.0 μg/ml). According to the Globally Harmonized System aquatic toxicity categories, C. iguanaea spray-dried extract is classified as non-hazardous (LC 50 > 100 μg/ml). In vitro assays included cytotoxicity (methyl thiazolyl tetrazolium assay –in WI-38 and HaCaT cells; resazurin in Caco-2 and HT-29 cells), cell adhesion genotoxicity (comet assay; OECD TG 489), and mutagenicity (cytokinesis-block micronucleus assay; OECD TG 487). Celtis iguanaea spray-dried extract showed no cytotoxic, genotoxic, or mutagenic effects up to 250 μg/ml and enhanced HaCaT cell viability and adhesion at higher concentrations (100 μg/ml), suggesting potential support for wound healing. No antimicrobial activity was observed against Candida spp., ESKAPE pathogens, or bacteria associated with urinary tract infections (MIC > 1024.0 μg/ml). This weight-of-evidence assessment supports the safe use of C. iguanaea spray-dried extract in topical or oral formulations and provides data suitable for regulatory hazard characterization and acute risk assessment. Graphical Abstract