Effect of dietary linoleate/alpha-linolenate balance on experimentally induced gastric injury in rats.
Rats were fed diets containing different ratios of linoleate (18:2 n-6) to alpha-linolenate (18:3 n-3), and the severity of gastric injury induced by ethanol, ischemia/reperfusion and water-immersion stress was compared. On decreasing the 18:2 n-6/18:3 n-3 ratios in the diets, the proportion of arachidonic acid (20:4 n-6) decreased and that of eicosapentaenoic acid (20:5 n-3) increased in the phospholipids of the gastric mucosa, which was associated with decreased mucosal prostaglandin E2 content. Mucosal injury in all the three experimental models was exacerbated significantly in the diet group fed 18:2 n-6/18:3 n-3 ratio of 0.25 (perilla oil) as compared with the groups fed dietary oils with 18:2 n-6/18:3 n-3 ratios of 2.7 (mixture of perilla and safflower oils) and 127 (safflower oil). This adverse effect induced by perilla oil diet was not observed when rats were pretreated with a mild irritant (20% ethanol) prior to challenge with a strong irritant (absolute ethanol). Furthermore, an 18:2 n-6/18:3 n-3 ratio of as low as 1 was found to be in a safe range in the water-immersion stress ulcer model. Thus, oils with very low n-6/n-3 ratios, for example perilla oil, could be used without the risk of the observed adverse effects on experimental gastric injury in people of industrialized countries ingesting foods with n-6/n-3 ratios of above 4. A decrease in the n-6/n-3 ratios to 2 or below is still recommended for the prevention of chronic diseases in the elderly related to atherosclerosis and inflammation.
Matsuba
S
S
First Department of Internal Medicine, Nagoya City University Medical School, Japan.
Itoh
M
M
Joh
T
T
Takeyama
H
H
Dohi
N
N
Watanabe
S
S
Okuyama
H
H
D000818:Animals; D004032:Diet; D004042:Dietary Fats, Unsaturated / Q000378:metabolism / Q000494:pharmacology*; D015232:Dinoprostone / Q000032:analysis / Q000378:metabolism; D004195:Disease Models, Animal; D000431:Ethanol; D005227:Fatty Acids / Q000032:analysis; D005744:Gastric Acid / Q000378:metabolism; D005753:Gastric Mucosa / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D019787:Linoleic Acid / Q000378:metabolism / Q000494:pharmacology*; D008297:Male; D010434:Pepsin A / Q000032:analysis / Q000378:metabolism; D010743:Phospholipids / Q000737:chemistry / Q000378:metabolism; D010938:Plant Oils / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury; D013276:Stomach Ulcer / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D017962:alpha-Linolenic Acid / Q000378:metabolism / Q000494:pharmacology*
D004042:Dietary Fats, Unsaturated; D005227:Fatty Acids; D010743:Phospholipids; D010938:Plant Oils; D017962:alpha-Linolenic Acid; D000431:Ethanol; D019787:Linoleic Acid; D010434:Pepsin A; D015232:Dinoprostone