2003 Fiscal Year Final Research Report Summary

BIO-MODULATING FUNCTIONS OF TRANS ISOMERS OF POLYUNSATURATED FATTY ACIDS ORIGINATING FROM MARINE LIVES

Research Project

Project/Area Number	13460091
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Research Field	Fisheries chemistry
Research Institution	Kyoto University
Principal Investigator	HIRATA Takashi KYOTO UNIVERSITY, GRADUATE SCHOOL OF AGRICULTURE, PROFESSOR, 農学研究科, 教授 (40273495)
Co-Investigator(Kenkyū-buntansha)	ARAI Hirofumi YAMAGUCHI UNIVERSITY, FACULTY OF MEDICINE, INSTRUCTOR, 医学部, 助手 (70295848) FUKUNAGA Kenji KANSAI UNIVERSITY, FACULTY OF ENGINERING, ASSOCIATE PROFESSOR, 工学部, 助教授 (30278634)
Project Period (FY)	2001 – 2003
Keywords	EPA / TRANS ISOMER / OXIDATION / LOX / INFLAMMATION / MELANOMA
Research Abstract	Production and functions of EPA trans isomers were investigated. (1) EPA ethyl ester trans isomers showed higher oxidative stability compared with its all cis isomer both in hydrophilic and hydrophobic solvents. The trans isomers also showed higher resistant against 15-LOX than the all cis isomer. The structural and polar difference between isomers seemed to be responsible for their stability properties. (2) Production of LTB4, a mediator of inflammation, in rat peritoneal exudate cells was not affected by the trans isomers very much. Judging from fatty acid analysis of phospholipids in the cell membrane, the trans isomers seem to be difficult to be incorporated into the membrane. 5-LOX more easily modified the trans isomers to produce LTB4. These results suggested that intake of the trans isomers lead to induction of different physiological functions from the all cis isomer. (3) Conventional cooking temperature did not convert the all cis isomer into the trans isomers. While AMVN, a radical emitter, also produced no trans isomer, NO2 very easily induced the isomer at room temperature suggesting that the possible formation of the trans isomers proceeds in vivo anal nitrite as food additives may induce formation of the trans acids during food processing. (4) Melanin formation in mouse Bl6 melanoma cells were significantly suppressed by both all cis isomer and trans isomers of EPA.