Yoshinori Suzuki, Masashi Ishihara, Tetsuya Segami and Mikio Ito (*)
Department of Pharmacology, Faculty of Pharmacy, Meijo University, 150
Yagotoyama, Tenpaku-ku, Nagoya 468-8503, Japan
(*) To whom correspondence should be addressed.
Abstract: When free radical-scavenging activities of quercetin,
alpha-tocopherol, nifedipine and tetracycline were measured by an electron
spin resonance technique, all test compounds (10-5 to 10-3
M) scavenged both superoxide anions and hydroxyl radicals. The oral administration
of quercetin (50 and 100 mg/kg), alpha-tocopherol (8 and 16 mg/kg), nifedipine
(20 and 40 mg/kg) or tetracycline (10 and 20 mg/kg) markedly prevented the
HCI plus ethanol-induced gastric mucosal injury and the increase in the
content of thiobarbituric acid-reactive substances in the injured mucosa
in rats. In addition, quercetin (25, 50 and 100 mg/kg), alpha-tocopherol
(4, 8 and 16 mg/kg), nifedipine (10, 20 and 40 mg/kg) and tetracycline (5,
10 and 20 mg/kg), given orally, twice daily for 14 consecutive days from
the day after acetic acid injection, dose-dependently promoted the ulcer
healing and inhibited the increase in the content of thiobarbituric acid-reactive
substances in the ulcerated mucosa. These results indicate that quercetin,
alpha-tocopherol, nifedipine and tetracycline possess gastric cytoprotective
and gastric ulcer healing-promoting actions. In addition, the free radical-scavenging
properties of these compounds may be partly related to their anti-ulcer
effects.
Keywords: Antioxidant, Gastric cytoprotection, Gastric ulcer, Free radical