Protection of pyrroloquinoline quinone against methylmercury-induced neurotoxicity via reducing oxidative stress

Free Radic Res. 2009 Mar;43(3):224-33. doi: 10.1080/10715760802677348.


Pyrroloquinoline quinone (PQQ) is a novel redox cofactor and also exists in various foods. In vivo as well as in vitro experimental studies have shown that PQQ functions as an essential nutrient or antioxidant. Methylmercury (MeHg), as a highly toxic environmental pollutant, could elicit central nervous system (CNS) damage. Considering the antioxidant properties of PQQ, this study was aimed to evaluate the effect of PQQ on MeHg-induced neurotoxicity in the PC12 cells. The results showed that, after pre-treatment of PC12 cells with PQQ prior to MeHg exposure, the MeHg-induced cytotoxicity was significantly attenuated and then the percentage of apoptotic cells and the arrest of S-phase in cell cycle were correspondingly reduced. Moreover, PQQ significantly decreased the production of ROS, suppressed the lipid peroxidation and increased the antioxidant enzyme activities in PC12 cells exposed to MeHg. These observations highlighted the potential of PQQ in offering protection against MeHg-induced neuronal toxicity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Catalase / metabolism
  • Cell Cycle / drug effects
  • Cell Survival / drug effects
  • Cells, Cultured
  • Glutathione Peroxidase / metabolism
  • Lipid Peroxidation / drug effects
  • Mercury Poisoning, Nervous System / metabolism
  • Mercury Poisoning, Nervous System / pathology
  • Mercury Poisoning, Nervous System / prevention & control*
  • Methylmercury Compounds / toxicity*
  • Neurons / drug effects
  • Neurons / metabolism
  • Neurons / pathology
  • Oxidative Stress / drug effects*
  • PC12 Cells
  • PQQ Cofactor / pharmacology*
  • Rats
  • Superoxide Dismutase / metabolism


  • Methylmercury Compounds
  • PQQ Cofactor
  • Catalase
  • Glutathione Peroxidase
  • Superoxide Dismutase