Inhibition in vitro linoleic acid peroxidation and haemolysis by caffeoyltryptophan

• Published in: Phytochemistry (Oxford) Vol. 47; no. 7; pp. 1215 - 1218
• Main Authors: Ohnishi, Motoyo, Morishita, Hideko, Toda, Shizuo, Yase, Yoshiro, Kido, Ryo
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01-04-1998; Elsevier
• Subjects: Animals; Antioxidants - chemistry; Antioxidants - pharmacology; Biological and medical sciences; Caffeic Acids - chemistry; Caffeic Acids - pharmacology; Chemical constitution; Feeding. Feeding behavior; Free Radical Scavengers - chemistry; Free Radical Scavengers - pharmacology; Fundamental and applied biological sciences. Psychology; Hemolysis - drug effects; Linoleic Acid - metabolism; Lipid Peroxidation - drug effects; Male; Mice; Plant physiology and development; Tryptophan - analogs & derivatives; Tryptophan - chemistry; Tryptophan - pharmacology; Vertebrates: anatomy and physiology, studies on body, several organs or systems; free radical; Caffeoyltryptophan; haemolysis; peroxidation; coffee; Hemolysis; Coffea; Red blood cell; Antioxidant; Coffee; In vitro; Biological activity; Caffeic acid; Free radical; Feeding; Dose activity relation; α-Aminoacid; Dicotyledones; Angiospermae; Rubiaceae; Plant origin; Spermatophyta; Indole derivatives; Peroxidation
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/S0031-9422(97)00754-1

Antioxidant activities of caffeoyltryptophan were investigated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging system, the superoxide anion generation system and the superoxide anion-mediated linoleic acid peroxidation system. At 10 μM, caffeoyltryptophan showed greater scavenging activity on DPPH than
dl-
α-tocopherol or ascorbic acid. DPPH radical scavenging activity of caffeoyltryptophan increased dose-dependently at concentrations ranging from 1 to 50 μM; 1 mol of caffeoyltryptophan reacted with
ca 4 mol of radical.
Caffeoyltryptophan caused 80% inhibition of superoxide anion generation at 50 μM. The inhibitory activity of caffeoyltryptophan was as strong as that of 5-caffeoylquinic acid. Caffeoyltryptophan inhibited the formation of conjugated diene from linoleic acid. The inhibitory activity increased in the order caffeic acid <5-caffeoylquinic acid < caffeoyltryptophan <
dl-
α-tocopherol.
Effects on the
in vitro haemolysis and peroxidation of mouse erythrocytes induced by H
2O
2 were also examined. Caffeoyltryptophan exhibited strong inhibitory activities; Tryptophan was ineffective in these systems. These data suggest that caffeoyltryptophan may be a natural antioxidant in the human diet and, as such, may intervene in toxicological processes that are mediated by radical mechanisms.