Continuous and discontinuous multi-generational disturbances of tetrabromobisphenol A on longevity in Caenorhabditis elegans

Tetrabromobisphenol A (TBBPA) is one of the most prevalently used brominated flame retardants. Due to its persistence, it is predominantly found in environmental matrices and has the potential to generate multi-generational toxicity. However, knowledge of its adaptive response or long-term residual effect in multi-generations, and molecular mechanisms remain understudied. In the current study, the model animal nematode Caenorhabditis elegans (C. elegans) was exposed to TBBPA at environmentally realistic concentrations (0.1-1000 μg L-1) for four consecutive generations (G0 to G3). Degenerative age-related multiple endpoints including lifespan, locomotion behaviors, growth, reproduction, oxidative stress-related biochemical responses, cell apoptosis, and stress related gene expressions were assessed in the continuous exposure generations (G0 and G3) and the discontinuously exposed generations (T3 and T'3). The results showed that changes in degenerative age-related response monitored four generations varied in direction and magnitude depending on the TBBPA concentrations, and the response intensify ranked as G0 > T'3/G3 > T3. TBBPA at 1 μg L-1 dosage was detected as the lowest observed effect concentration in multi-biomarkers. The underlying mechanism of aging phenotypes was that reactive oxygen species accumulation led to cell apoptosis regulated by gene ape-1, and confirmed catalase enzyme and superoxide dismutase activity played a crucial role in the detoxification process of TBBPA at the molecular level. This study provided insights into the underlying mechanism of TBBPA-interfered longevity and its environmental multi-generational potential risks.