Multi-Endpoint Toxicological Assessment of the Food Additive Triammonium Citrate: Differential Responses in Colorectal Cancer Cells and Non-Neoplastic Colon Fibroblasts.

Abstract

Triammonium citrate (TAC; E380) is used as a food additive, making characterization of its effects in malignant and non-neoplastic colon-derived cells relevant to applied toxicology. We conducted a multi-endpoint assessment of 0.5- to 2.0-mg/mL TAC in KRASG13D-mutant, mismatch repair-deficient HCT116 colorectal carcinoma cells and non-neoplastic CCD-18Co colon fibroblasts. Exposure durations were endpoint-specific (60 min, 24 h, or 48 h), and endpoints included viability, primary DNA damage, micronucleus frequency, nuclear division, clonogenic survival, and wound closure. Microbial assays tested antimicrobial and membrane-disruptive activity; docking was exploratory. The clearest differential response occurred at 2.0 mg/mL after 48 h, when viability was 8.80% ± 2.14% in HCT116 cells and 49.52% ± 11.50% in CCD-18Co cells. Primary DNA damage increased in both models, with the largest numerical comet response in HCT116 cells at 2.0 mg/mL. HCT116 clonogenic survival decreased to 29.0% ± 4.8% at 2.0 mg/mL after a 24-h exposure and 9-day recovery. Micronucleus frequency did not increase in either cell line, although the nuclear division index decreased in both at 2.0 mg/mL after 48 h, indicating cytostasis. TAC also reduced wound closure in both models. No microbial growth inhibition was detected at 0.5-2.0 mg/mL, and no membrane leakage was detected in Staphylococcus aureus up to 200 mg/mL. Docking generated hypotheses involving PFK-1, KRAS, and PARP-1 but did not establish binding or target engagement. Collectively, these findings demonstrate pronounced HCT116 cytotoxicity together with primary DNA damage in both models, without detectable chromosome-level damage, and provide a basis for mechanistic investigation.