Neurochemical Research

, Volume 32, Issue 3, pp 489–495 | Cite as

Pyrroloquinoline Quinone is a Potent Neuroprotective Nutrient Against 6-Hydroxydopamine-Induced Neurotoxicity

  • Hirokazu Hara
  • Hideaki Hiramatsu
  • Tetsuo Adachi
Original Paper


Pyrroloquinoline quinone (PQQ), which is an essential nutrient, has been shown to act as an antioxidant. Reactive oxygen species (ROS) are thought to be responsible for neurotoxicity caused by the neurotoxin 6-hydroxydopamine (6-OHDA). In this study, we investigated the ability of PQQ to protect against 6-OHDA-induced neurotoxicity using human neuroblastoma SH-SY5Y. When SH-SY5Y cells were exposed to 6-OHDA in the presence of PQQ, PQQ prevented 6-OHDA-induced cell death and DNA fragmentation. Flow cytometry analysis using the ROS-sensitive fluorescence probe, dihydroethidium, revealed that PQQ reduced elevation of 6-OHDA-induced intracellular ROS. In contrast to PQQ, antioxidant vitamins, ascorbic acid and α-tocopherol, had no protective effect. Moreover, we showed that PQQ effectively scavenged superoxide, compared to the antioxidant vitamins. Therefore, our results suggest the protective effect of PQQ on 6-OHDA-induced neurotoxicity is involved, at least in part, in its function as a scavenger of ROS, especially superoxide.


Pyrroloquinoline quinone Antioxidant 6-Hydroxydopamine Oxidative stress Neuroprotection 



This work was supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan (HHa).


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Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Hirokazu Hara
    • 1
  • Hideaki Hiramatsu
    • 1
  • Tetsuo Adachi
    • 1
  1. 1.Department of Clinical PharmaceuticsGifu Pharmaceutical UniversityGifuJapan

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