Physiological Activity of Docosahexaenoic Acid

Abstract

(Nishi-Ohnuma 4-4-1, Sagamihara-shi, Kanagawa-ken,-7229) Docosahexaenoic Acid (DHA) has important physiological activities, such as reduction of the plasma cholesterol and triglyceride, lowering effect of systolic blood pressure, anti-inflama-tory and anti-tumor activities, etc. Recent studies also strongly suggest that DHA plays a key role in the brain and retina. DHA commonly exists in fish oil obtained from sardines, mackerels, menhadens, etc. Usually, however, it contains DHA at a relatively low level (5-10%) and many other polyunsaturated fatty acids, and thus isolation of pure DHA from fish oil is quite difficult. Recently, we found that (1) orbital fat of a bonito (Katsuwonus) and a tuna (Thunnus) fish was an excellent source of DHA, (2) DHA content in the total fatty acids of the orbital fat isolated from a bonito and a tuna fish was 42% and 30%, respectively, and (3) DHA existed as trigly-ceride in both cases. Purification of DHA was examined after ethanolysis of orbital fat oil obtained from a tuna fish, and resulted in 95%-99% purity of DHA-ethyl ester by a new method using Ag ion. Thus, finding of the excellent source and the purification procedure will greatly accelerate the research on DHA. 1 ‚Í ‚ ¶ ‚ß ‚É •Å‹ß,ƒh ƒRƒTƒwƒLƒTƒGƒ"Ž_(DHA)‚É ŠÖ‚· ‚éOE¤ ‹ † ‚ª •i "W‚µ‚Ä-ˆ ‚Ä‚¢ ‚é•B ‚µ‚©‚µ‚È‚ª ‚ç,ƒq ƒg‚Ì OE'•N‚̈ێN‚̈ێ•, '• •i ‚É'Î ‚· ‚é •H•i ‚AE‚µ‚Ä‚ÌDHA‚Ì-ðŠ",‚ ‚é ‚¢ ‚Í Ž¾ •a ‚Ì-\-h,-\ OEã‚â Ž¡-à ‚É'Î ‚· ‚éˆã‚éˆã-ò•i ‚AE‚µ‚Ä‚ÌDHA ‚Ì-ðŠ" ‚ÉŠÖ‚· ‚é•î •ñ ‚Í ‚Ü‚¾•[ •ª ‚AE ‚Í OE¾ ‚¦ ‚È‚¢•B‰h-{ ƒo ƒ‰ ƒ"ƒX‚É‚¨‚¯ƒX‚É‚¨‚¯ ‚é-û Ž‰ •H•i ‚AE‚µ‚Ă̈ʂAE‚µ‚Ä‚ÌˆÊ 'u•t ‚¯,P/S"ä ‚ân-3/n-6ƒo ƒ‰ ƒ"ƒX‚É‚¨‚¯ƒX‚É‚¨‚¯ ‚éDHA‚Ì "K•³-Ê "™‚ɂ‚¢ ‚Ä‚Í,-{"Á•W• † ‚Ì '¼•e ‚ð,‚Ü ‚½'¼‚ÌDHA‚Ì '• •à ‚àŽQ •AE‚³ ‚ê ‚½‚¢•B-{•e ‚Å‚Í,DHAOE¤ ‹ † ‚Ì •Å•V‚Ì ƒgƒs ƒbƒNƒY‚ð ‚¢ ‚-‚‚©•E ‚¢•ã ‚° ‚Ä•Ð‰î ‚³ ‚¹ ‚Ä'Õ ‚-‚±‚AE‚AE ‚· ‚é•B 2 DHA OE¤‹ † ‚AE‚» ‚Ì "wOEi 1970"N 'ã,‹› •H' †•S ‚Ì ƒGƒXƒLƒ‚ •[ ‚â "ú-{ •l ‚É‚¨‚¢‚É‚¨‚¢ ‚Ä OEOE •ð •« ‚Ì Ž¾ •a ‚ª •-‚È‚¢Ž-‚©‚ç,‹›-û•¬•ª "Á‚ɃCƒRƒTƒy ƒ" ƒ^ƒGƒ"Ž_(EPA)‚â ƒhƒRƒTƒwƒLƒTƒGƒ"Ž_(DHA)‚Ì OE¤ ‹ † ‚ª "-"W‚µ‚½•BEPA‚É ŠÖ‚µ‚Ä‚Í,1980"N 'ã ‚ae ‚è‹›-û ‚ae ‚è 'Š •o ‚µ‚½EPA(•ƒ "x-ñ25%)‚Ì ƒJ ƒvƒZƒ‹ ‚ª OE'•N•H•i ‚AE ‚µ‚Ä"Ì "" ‚³ ‚ê,‚Ü ‚½•ð "N‚É‚ÍEPAƒG ƒ` ƒ‹ ƒGƒXƒe ƒ‹(•ƒ "x90%)‚ªˆã‚ªˆã-ò•i ‚AE‚µ‚Ä•ã Žs ‚³ ‚ê ‚½•B‚» ‚µ‚Ä‚» ‚Ì OEã •Å‹ß ‚É‚È ‚è,‚³ ‚ç‚É‚ae ‚è•d-v ‚È‚à ‚¤‚ЂAE ‚Â‚Ì ‹›-û•¬•ª ‚AE‚µ‚Ä ƒhƒRƒTƒwƒLƒTƒGƒ"Ž_(DHA)‚ª '•-Ú ‚³ ‚ê‚Ä-ˆ‚½•B Docosahexaenoic acid (C22:6) Icosapentaenoic acid (C26:5) DHA‚Í •ã ‚ÉŽ¦ ‚·-l‚ȉ» Šw•\ '¢ ‚ð-L ‚· ‚én-3OEn ‚Ì 'Y 'f •"22,"ñ •d OE‹• ‡6‚© •Š‚ð-L ‚· ‚é •‚ "x•s-O˜a Ž‰-bŽ_‚̈êbŽ_‚Ìˆê Ží ‚Å‚ ‚é •B 202