Toxicological evaluation and mycochemical characterisation of aqueous extract of Schizophyllum commune

Growing demand for Schizophyllum commune Fr. reflects its pharmaceutical and nutraceutical potential, although its safety profile remains underexplored despite long-standing traditional use. This study aimed to evaluate the in vitro cytotoxicity, in vivo acute and subacute oral toxicity, and mycochemical composition of the aqueous extract of S. commune (AESC). Cytotoxicity was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on human gastric adenocarcinoma (AGS) and human hepatocellular carcinoma (HepG2) cell lines. Acute toxicity was evaluated in Sprague-Dawley rats given a single oral dose of 5000 mg/kg bw, while subacute toxicity involved daily oral doses of 250, 500, and 1000 mg/kg bw for 28 days. Parameters including clinical signs, body weight, relative organ weight, food and water intake, and haematological, biochemical, and histopathological changes were monitored throughout the study. Mycochemical characterisation was performed using qualitative screening tests and liquid chromatography–quadrupole time-of-flight mass spectrometry (LC–QTOF–MS). The MTT assay indicated minimal cytotoxicity, with half-maximal inhibitory concentration (IC50) values exceeding 1000 µg/mL for both AGS and HepG2 cells. No mortality or adverse signs occurred in the acute toxicity study, indicating a median lethal dose (LD50) greater than 5000 mg/kg bw. Similarly, the subacute study showed no adverse effects at any tested dose in either sex, with a no-observed-adverse-effect level (NOAEL) greater than 1000 mg/kg bw. Qualitative screening revealed no detectable levels of major secondary metabolite classes, while LC–QTOF–MS profiling identified amino acids, fatty acids, and low-abundance phenolic compounds as the predominant constituents of AESC. These findings confirm a favourable safety profile of AESC, supporting further evaluation for gastro- and hepato-protective applications.