title: Pyrroloquinoline quinone is a potent neuroprotective nutrient against 6-hydroxydopamine-induced neurotoxicity.
abstract: 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 alpha-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.
authors.affiliation: Department of Clinical Pharmaceutics, Gifu Pharmaceutical University, 5-6-1 Mitahora-higashi, Gifu 502-8585, Japan. harah@gifu-pu.ac.jp
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Hara
authors.forename: Hideaki
authors.initials: H
authors.lastname: Hiramatsu
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Adachi
mesh_terms: D001205:Ascorbic Acid / Q000494:pharmacology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects*; D005434:Flow Cytometry; D016166:Free Radical Scavengers / Q000494:pharmacology; D006801:Humans; D009447:Neuroblastoma; D018696:Neuroprotective Agents / Q000494:pharmacology*; D009498:Neurotoxins / Q000633:toxicity*; D016627:Oxidopamine / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D045542:PQQ Cofactor / Q000494:pharmacology*; D013481:Superoxides / Q000378:metabolism; D024502:alpha-Tocopherol / Q000494:pharmacology
chemical_list: D016166:Free Radical Scavengers; D018696:Neuroprotective Agents; D009498:Neurotoxins; D013481:Superoxides; D045542:PQQ Cofactor; D016627:Oxidopamine; D024502:alpha-Tocopherol; D001205:Ascorbic Acid