Effect of Dietary Phosphatidylinositol on Cholesterol Metabolism in Zucker (fa/fa) Rats

Abstract

Recent studies have shown that dietary phospholipids, especially phosphatidylcholine and phosphatidylserine, have various beneficial biological effects. However, there are not enough data concerning the physiological function of dietary phosphatidylinositol (PI). The metabolic syndrome, a cluster of metabolic abnormalities such as dyslipidemia, diabetes mellitus, and hypertension, is widespread and increasingly prevalent diseases in industrialized countries. In the present study, we evaluated that the effect of dietary PI on cholesterol metabolism in metabolic syndrome model Zucker (fa/fa) rats. For 4 weeks, rats were fed semisynthetic diets containing either 7% soybean oil or 5% soybean oil plus 2% PI. Dietary PI prevented the mild hypercholesterolemia and hepatic cholesterol accumulation in Zucker (fa/fa) rats. These effects were attributable to an increased fecal bile acid excretion and to the tendencies of decreased ACAT1 mRNA level and increased CYP7A1 mRNA level in the liver. Additionally, dietary PI markedly increased microsomal PI content in the liver of Zucker (fa/fa) rats. Our study suggests that dietary PI normalizes cholesterol metabolism through the enhancement of fecal bile acid excretion in the metabolic syndrome model rats.

Toxicity studies of Asahi Kasei PI, purified phosphatidylinositol from soy lecithin

“…In the organ weights, a decrease in the relative liver weight was observed in the males in the 1,000 mg/kg group (Table 3). This change was considered to be the effect of pharmacological action of Asahi Kasei PI -terol and lipid metabolisms, and consistent with a previ- ous report by Shirouchi et al (2008Shirouchi et al ( , 2009. They showed that in male Zucker rats, which develop nonalcoholic fatty liver disease associated with obesity, 4-week dietary Asahi Kasei PI lowered the liver weight, hepatic and serum lipid levels, and hepatic injury markers in serum -ment of hepatomegaly and hepatic steatosis.…”

Phospholipid fingerprints of milk from different mammalians determined by 31P NMR: Towards specific interest in human health

“…The question that has to be addressed is the optimal dose and the specific PL classes to be selected. SM given at a dose of 205 mg/d reduces intestinal cholesterol absorption in mice by 85% (Eckhardt et al, 2002), cholesterol metabolism is normalised in Zucker rats fed 2% PI by weight in the diet (Shirouchi et al, 2009), and feeding rats 2% PE by weight in the diet (equivalent to about 1 g per day in humans) reduces blood cholesterol levels (Imaizumi et al, 1991). PC exhibits hepatoprotective effects by reducing alcohol-induced hepatocyte apoptosis, inhibiting fibrosis, and reducing hepatic steatosis when orally administrated in rats at a dose of 2-6% by weight in the diet (Cohn et al, 2008).…”

“…Phosphatidylserine (PS) is particularly important during the development of the central nervous system (De Simone, Ajmone-Cat, & Minghetti, 2004), and dietary supplementation improves cognition in humans (Pepeu, Pepeu, & Amaducci, 1996). Phosphatidylethanolamine (PE) or phosphatidylinositol (PI) exert hypocholesterolemic effects in rats (Imaizumi, Sekihara, & Sugano, 1991;Shirouchi et al, 2009). Other classes are involved in inflammatory responses (lysophosphatidylcholine (LPC), sphingomyelin (SM)) or in chemoattraction (cardiolipin, LPC) (Chaurio et al, 2009).…”

Dietary plasmalogen increases erythrocyte membrane plasmalogen in rats

“…It has been known that dietary phospholipids cause decrease of plasma cholesterol probably due to inhibition of intestinal cholesterol absorption [6,9,10]. There is a report that dietary PE, but not dietary PC, caused a decreases of phospholipid, cholesterol and apolipoprotein A-1 in rat blood plasama [11].…”