Low-linoleic acid diet and oestrogen enhance the conversion of α-linolenic acid into DHA through modification of conversion enzymes and transcription factors

• Published in: British journal of nutrition Vol. 121; no. 2; pp. 137 - 145
• Main Authors: Kim, Donghee, Choi, Jeong-Eun, Park, Yongsoon
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 28.01.2019
• Subjects: alpha-Linolenic Acid - metabolism; Animals; Chains; Conversion; Corn oil; Desaturase; Diet; Dietary intake; Docosahexaenoic Acids - biosynthesis; Drug Synergism; Eicosapentaenoic Acid - biosynthesis; Energy; Enzymes; Estrogens - administration & dosage; Fatty Acid Desaturases - metabolism; Fatty Acid Elongases - metabolism; Fatty acids; Fatty Acids - analysis; Fatty liver; Female; Fish oils; Gene Expression; Linoleic acid; Linoleic Acid - administration & dosage; Linolenic acid; Lipids; Liver; Liver - chemistry; Liver - enzymology; Liver - metabolism; Low protein diet; Metabolism; Molecular Nutrition; Nutrient deficiency; Nutrition; Oils & fats; Ovariectomy; Peroxisome proliferator-activated receptors; Phospholipids - blood; Phospholipids - chemistry; Polyunsaturated fatty acids; PPAR-beta - genetics; Proteins; Rats; Rats, Wistar; Rodents; Sterol regulatory element-binding protein; Transcription factors; Low-linoleic acid diet; Conversion enzymes; Oestrogen; α-Linolenic acid; ACOX1 acyl-coenzyme A oxidase 1; LA linoleic acid; ELOVL elongase of very long fatty acid; ALA α-linolenic acid; E 17β-oestradiol-3-benzoate; FADS fatty acid desaturase; SREBP1 sterol regulatory element binding protein 1; ER oestrogen receptor
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1017/S0007114518003252

Conversion of α-linolenic acid (ALA) into the longer chain n-3 PUFA has been suggested to be affected by the dietary intake of linoleic acid (LA), but the mechanism is not well known. Therefore, the purpose of this study was to evaluate the effect of a low-LA diet with and without oestrogen on the fatty acid conversion enzymes and transcription factors. Rats were fed a modified American Institute of Nutrition-93G diet with 0% n-3 PUFA or ALA, containing low or high amounts of LA for 12 weeks. At 8 weeks, the rats were injected with maize oil with or without 17β-oestradiol-3-benzoate (E) at constant intervals for the remaining 3 weeks. Both the low-LA diet and E significantly increased the hepatic expressions of PPAR-α, fatty acid desaturase (FADS) 2, elongase of very long chain fatty acids 2 (ELOVL2) and ELOVL5 but decreased sterol regulatory element binding protein 1. The low-LA diet, but not E, increased the hepatic expression of FADS1, and E increased the hepatic expression of oestrogen receptor-α and β. The low-LA diet and E had synergic effects on serum and liver levels of DHA and on the hepatic expression of PPAR-α. In conclusion, the low-LA diet and oestrogen increased the conversion of ALA into DHA by upregulating the elongases and desaturases of fatty acids through regulating the expression of transcription factors. The low-LA diet and E had a synergic effect on serum and liver levels of DHA through increasing the expression of PPAR-α.