Recent research has uncovered the detrimental effects of 6-PPD quinone (6-PPDQ), a byproduct of tire antioxidants, on the citric acid cycle in Caenorhabditis elegans (C. elegans), a model organism. Published in Environmental Chemistry and Ecotoxicology, the study demonstrates that even at low, environmentally relevant concentrations (0.1–10 μg/L), 6-PPDQ significantly reduces key intermediates and enzyme expressions critical for the citric acid cycle, a fundamental metabolic pathway.
The citric acid cycle is essential for converting carbohydrates, fats, and proteins into energy. The study found that 6-PPDQ exposure led to a decrease in metabolites such as citric acid and α-ketoglutarate, alongside suppressing genes responsible for their production. This disruption not only impairs energy production but also affects the synthesis of vital biomolecules, indicating a broader impact on cellular health.
Further findings reveal that 6-PPDQ exposure reduces acetyl CoA and pyruvate levels, crucial for initiating the citric acid cycle. This reduction was linked to decreased expressions of specific genes, exacerbating the cycle's disruption and leading to mitochondrial dysfunction. Interestingly, the study suggests that sodium pyruvate treatment could mitigate some of these toxic effects, offering a potential avenue for addressing 6-PPDQ exposure.
This research underscores the growing concern over 6-PPDQ's environmental presence and its potential health risks. By elucidating the mechanisms through which 6-PPDQ disrupts metabolic processes, the study calls for further investigation into its implications for both ecosystems and human health. The full study can be accessed here.
