title: Effects of Antioxidant Supplements (BioPQQ™) on Cerebral Blood Flow and Oxygen Metabolism in the Prefrontal Cortex.
abstract: Pyrroloquinoline quinone (PQQ) is a quinone compound originally identified in methanol-utilizing bacteria and is a cofactor for redox enzymes. At the Meeting of the International Society on Oxygen Transport to Tissue (ISOTT) 2014, we reported that PQQ disodium salt (BioPQQ™) improved cognitive function in humans, as assessed by the Stroop test. However, the physiological mechanism of PQQ remains unclear. In the present study, we measured regional cerebral blood flow (rCBF) and oxygen metabolism in prefrontal cortex (PFC), before and after administration of PQQ, using time-resolved near-infrared spectroscopy (tNIRS). A total of 20 healthy subjects between 50 and 70 years of age were administered BioPQQ™ (20 mg) or placebo orally once daily for 12 weeks. Hemoglobin (Hb) concentration and absolute tissue oxygen saturation (SO2) in the bilateral PFC were evaluated under resting conditions using tNIRS. We found that baseline concentrations of hemoglobin and total hemoglobin in the right PFC significantly increased after administration of PQQ (p < 0.05). In addition, decreases in SO2 level in the PFC were more pronounced in the PQQ group than in the placebo group (p < 0.05). These results suggest that PQQ causes increased activity in the right PFC associated with increases in rCBF and oxygen metabolism, resulting in enhanced cognitive function.
authors.affiliation: Niigata Research Laboratory, Mitsubishi Gas Chemical Co., Inc., Tokyo, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Nakano
authors.affiliation: Department of Electrical and Electronic Engineering, NEWCAT Research Institute, College of Engineering, Nihon University, 1 Nakagawara, Tokusada, Tamuramachi, Koriyama, Fukushima Prefecture, 963-8642, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Murayama
authors.affiliation: Department of Electrical and Electronic Engineering, NEWCAT Research Institute, College of Engineering, Nihon University, 1 Nakagawara, Tokusada, Tamuramachi, Koriyama, Fukushima Prefecture, 963-8642, Japan.
authors.forename: Lizhen
authors.initials: L
authors.lastname: Hu
authors.affiliation: Niigata Research Laboratory, Mitsubishi Gas Chemical Co., Inc., Tokyo, Japan.
authors.forename: Kazuto
authors.initials: K
authors.lastname: Ikemoto
authors.affiliation: CX Medical Japan Co., Inc., Tokyo, Japan.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Uetake
authors.affiliation: Department of Electrical and Electronic Engineering, NEWCAT Research Institute, College of Engineering, Nihon University, 1 Nakagawara, Tokusada, Tamuramachi, Koriyama, Fukushima Prefecture, 963-8642, Japan. sakatani.kaoru@nihon-u.ac.jp.|Department of Neurological Surgery, School of Medicine, Nihon University, Tokyo, Japan. sakatani.kaoru@nihon-u.ac.jp.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Sakatani
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000975:Antioxidants / Q000008:administration & dosage*; D015415:Biomarkers / Q000097:blood; D001783:Blood Flow Velocity; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D010092:Oximetry / Q000379:methods; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000187:drug effects*; D010108:Oxyhemoglobins / Q000378:metabolism; D045542:PQQ Cofactor / Q000008:administration & dosage*; D017397:Prefrontal Cortex / Q000098:blood supply* / Q000187:drug effects* / Q000378:metabolism; D019265:Spectroscopy, Near-Infrared; D014041:Tokyo
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D010108:Oxyhemoglobins; D045542:PQQ Cofactor; D010100:Oxygen
keywords: NIRS; Prefrontal cortex; Pyrroloquinoline quinone; Stroop test; Working memory