Effects of instant coffee consumption on oxidative DNA damage, DNA repair, and redox system in mouse liver.
To examine the effects of instant coffee consumption on cancer risk, we analyzed the oxidative DNA damage levels and the DNA repair and redox systems in the livers of coffee-fed mice. Three-week-old male ICR mice were fed with/without 0.1% (w/v) instant coffee solution. At 2, 4, and 8 mo, the levels of 8-hydroxydeoxyguanosine (8-OH-dG), a major form of oxidative DNA damage, and the expression of mouse 8-OH-dG repair-associated genes and redox system-associated genes, the SOD activity, and the LPO level were analyzed. Simultaneously, half of the mice were fed a low vitamin (LV) diet (autoclaved diet) to disturb the defense system against oxidative stresses. As a result, the 8-OH-dG level was increased in the livers of LV diet (+ water)-fed mice for 8 mo, in comparison to those of the 0 M control mice and normal diet (+ water)-fed mice. However, no significant differences between water drinking and coffee drinking were observed, in terms of the 8-OH-dG level. In addition, the 8-OH-dG repair-associated gene expression, the SOD activity, and the LPO level also showed no significant differences between water drinking and coffee drinking in all mouse groups. On the other hand, among the redox system-associated genes, only the expression of GPx1 was changed. These results suggest that instant coffee consumption has little, if any, effect on the risk of liver cancer due to oxidative stresses.
Morii
H
H
Graduate School of Environmental Engineering, The Univ. of Kitakyushu, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0135, Japan.
Kuboyama
A
A
Nakashima
T
T
Kawai
K
K
Kasai
H
H
Tamae
K
K
Hirano
T
T
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D001361:Avitaminosis / Q000378:metabolism; D001835:Body Weight; D003069:Coffee / Q000009:adverse effects*; D004249:DNA Damage; D004260:DNA Repair / Q000235:genetics*; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000032:analysis; D004032:Diet; D005511:Food Handling; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism; D015227:Lipid Peroxidation; D008099:Liver / Q000737:chemistry / Q000378:metabolism*; D008113:Liver Neoplasms / Q000453:epidemiology; D008297:Male; D008315:Malondialdehyde / Q000032:analysis; D051379:Mice; D008813:Mice, Inbred ICR; D018384:Oxidative Stress / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D013997:Time Factors; D000094765:Glutathione Peroxidase GPX1
D003069:Coffee; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D008315:Malondialdehyde; D000080242:8-Hydroxy-2'-Deoxyguanosine; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D003849:Deoxyguanosine; D000094765:Glutathione Peroxidase GPX1; C000722068:Gpx1 protein, mouse