Background: The roles of active oxygen metabolites and anti-oxidative defen
ses in aspirin (ASA)-induced gastric damage have been little studied.
Aim: We determined the effects of aspirin (400 mg b.d.) with or without vit
amin C (480 mg b.d.) for 3 days on gastric mucosa in human volunteers.
Methods: Gastric injury was assessed endoscopically; gastric blood flow, re
active oxygen release (quantified by chemiluminescence), lipid peroxidation
, myeloperoxidase, superoxide dismutase and glutathione peroxidase activity
and intragastric vitamin C content were measured. Expression of superoxide
dismutase and glutathione peroxidase mRNAs was assayed semi-quantitatively
Results: ASA produced erosions, a marked increase in chemiluminescence, lip
id peroxidation, and myeloperoxidase activity. It also resulted in a suppre
ssion of gastric blood flow, intragastric vitamin C levels, superoxide dism
utase and glutathione peroxidase activities. The addition of vitamin C sign
ificantly attenuated gastric damage and reversed the effects of ASA on thes
e parameters. Superoxide dismutase and glutathione peroxidase mRNAs were de
creased in ASA-treated subjects; the addition of vitamin C restored their r
Conclusions: (i) free radical-induced lipid peroxidation and suppression of
antioxidizing enzymes play an important role in gastric damage induced by
aspirin; (ii) increased myeloperoxidase activity suggests activated neutrop
hils to be the major source of these radicals; (iii) vitamin C protects aga
inst ASA-induced damage due to its anti-oxidizing activity.