title: Pyrroloquinoline Quinone (PQQ) Prevents Cognitive Deficit Caused by Oxidative Stress in Rats.
abstract: The effects of pyrroloquinoline quinone (PQQ) and coenzyme Q(10) (Co Q(10)), either alone or together, on the learning ability and memory function of rats were investigated. Rats fed a PQQ-supplemented diet showed better learning ability than rats fed a CoQ(10)-supplemented diet at the early stage of the Morris water maze test. The combination of both compounds resulted in no significant improvement in the learning ability compared with the supplementation of PQQ alone. At the late stage of the test, rats fed PQQ-, CoQ(10)- and PQQ + CoQ(10)-supplemented diets showed similar improved learning abilities. When all the groups were subjected to hyperoxia as oxidative stress for 48 h, rats fed the PQQ- and CoQ(10) supplemented diets showed better memory function than the control rats. The concurrent diet markedly improved the memory deficit of the rats caused by oxidative stress. Although the vitamin E-deficient rats fed PQQ or CoQ(10) improved their learning function even when subjected to hyperoxia, their memory function was maintained by PQQ rather than by CoQ(10) after the stress. These results suggest that PQQ is potentially effective for preventing neurodegeneration caused by oxidative stress, and that its effect is independent of either antioxidant's interaction with vitamin E.
authors.affiliation: Division of Biological Chemistry, Shibaura Institute of Technology, 3-7-5 Toyosu, Kohtoh-ku, Tokyo 135-8548, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Ohwada
authors.forename: Hironobu
authors.initials: H
authors.lastname: Takeda
authors.forename: Makiko
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Hirosi
authors.initials: H
authors.lastname: Isogai
authors.forename: Masahiko
authors.initials: M
authors.lastname: Nakano
authors.forename: Masao
authors.initials: M
authors.lastname: Shimomura
authors.forename: Koji
authors.initials: K
authors.lastname: Fukui
authors.forename: Shiro
authors.initials: S
authors.lastname: Urano