Food components inhibiting recombinant human histidine decarboxylase activity.
Histidine decarboxylase (HDC) catalyzes histamine formation from histidine. Histamine is a bioactive amine acting as a neurotransmitter as well as a chemical mediator. Phenolic food components have been tested for their ability to inhibit recombinant human HDC. Epicatechin gallate (ECG) was found to be a potent inhibitor as it inhibited HDC activity in a competitive manner with Ki = 10 muM against l-histidine. Epigallocatechin gallate (EGCG) showed time-dependent inhibition which disappeared under anaerobic conditions. It is probable that time-dependent inhibition could be due to the result of autoxidation of EGCG. The initial burst observed for EGCG suggests that EGCG itself is involved in HDC inhibition as observed for ECG. Our present results have shown that the tested food components can inhibit HDC activity. This inhibition likely affects histamine biosynthesis and possibly leads to controlling the biological action induced by histamine. Therefore, those food components exhibiting HDC inhibitory activity might be potentially useful in controlling histamine-induced biological actions.
Nitta
Yoko
Y
Department of Food Science and Nutrition, Faculty of Human Life and Environment, Nara Women's University, Kitauoya Nishi Machi, Nara 630-8506, Japan. nitta@ cc.nara-wu.ac.jp
Kikuzaki
Hiroe
H
Ueno
Hiroshi
H
D002392:Catechin / Q000031:analogs & derivatives / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005502:Food; D005504:Food Analysis; D006632:Histamine / Q000378:metabolism; D006639:Histidine / Q000378:metabolism; D006640:Histidine Decarboxylase / Q000037:antagonists & inhibitors*; D006801:Humans; D007700:Kinetics; D011994:Recombinant Proteins
D004791:Enzyme Inhibitors; D011994:Recombinant Proteins; D006639:Histidine; D006632:Histamine; D002392:Catechin; C062669:epicatechin gallate; C045651:epigallocatechin gallate; D006640:Histidine Decarboxylase