Effects of Spinach Leaf Protein Concentrate on the Serum Cholesterol and Amino Acid Concentrations in Rats Fed a Cholesterol-free Diet.

Abstract

SummaryThe effects of spinach leaf protein concentrate (SPPC) on serum and liver lipid concentrations and on serum free amino acid concentrations were examined in rats fed a cholesterol-free diet contain ing 2 and 10% fats. The serum total cholesterol, triacylglycerol and phospholipid concentrations in the rats fed an SPPC diet containing 2% corn oil were significantly lower than those of the rats fed a corresponding casein diet. When 10% corn oil or lard was used, the serum cholesterol lowering effect of the SPPC became insignificant, but the serum and liver triacylglycerol concentrations were kept at significantly lower levels. Both the amounts of fecal neutral steroids and bile acids were significantly higher in the rats fed the SPPC than those of the casein-fed rats. The concentrations of serum threonine, serine, glutamine, glycine, cystine, and isoleucine were significantly higher in the rats fed the SPPC diet contain ing 2% corn oil compared with those of the control rats, but when the dietary fat was raised to 10%, only glycine showed a higher serum concentration. These results indicate that the SPPC has a stronger cho lesterol-lowering effect at a lower dietary fat level, 2%, and the activity is partly due to the inhibition of intestinal absorption of cholesterol and bile acid, and partly due to an increase in the concentration of some of the serum amino acids. Key Words spinach leaf protein concentrate, cholesterol-lowering effect Plant protein has received much attention because it generally exerts a hypo cholesterolemic effect compared with animal protein. Soybean, sunflower, rice and pea protein isolates (1-10), and Italian ryegrass and alfalfa protein concentrates (11) are the representative plant proteins shown to have a hypocholesterolemic effect when compared with casein. However, the cholesterol-lowering effect of other plant protein isolates, especially the vegetable protein isolates with high purity, have not yet been fully examined. Spinach leaf protein concentrate (SPPC)

Effects of Cabbage Leaf Protein Concentrate on the Serum and Liver Lipid Concentrations in Rats.

“…It has been reported that proteins derived from plant-origin, such as soybean, sunflower, rice, spinach and radish protein isolates (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11), produce activity to maintain lower serum cholesterol concentrations as compared to those of animal proteins such as casein. These reports suggest that some other plant proteins may also have hypocholesterolemic activity; however, the influence of vegetable proteins which are consumed daily on the serum and liver lipid levels has not yet been fully examined.…”

“…These reports suggest that some other plant proteins may also have hypocholesterolemic activity; however, the influence of vegetable proteins which are consumed daily on the serum and liver lipid levels has not yet been fully examined. We have previously demonstrated that spinach leaf protein isolate, as compared to casein, had hypocholesterolemic and hypolipidemic activities, and that the supplement of methionine to the spinach leaf protein isolate diet improved the nutritive value without loss of the cholesterol-lowering effect (10,11).…”

Short‐ and Long‐term Effects of Corn Oil on Serum Lipid and Lipoprotein and Visceral Abdominal Fat Pad Parameters of Rats

“…1996). Satoh et al . (1995) believed that these effects were because of the linoleic acid in corn oil.…”

“…So far, the effects of low and high levels of corn oil on the abdominal adipose mass and serum lipid and lipoprotein status in rats have been evaluated (Hill et al . 1992, 1993; Satoh et al . 1995; Djuric et al .…”

Hypocholesterolaemic effect of the oleoresin of Capsicum annum L. in gerbils (Meriones hurrianae Jerdon)

“…The lowering of serum and tissue cholesterol and triglycerides following concurrent CO feeding could be due to increased catabolism and thus may help in the prevention of aortic lesions in atherogenic diet fed gerbils ( Table 2). The possible mechanism for the prevention of hyperlipidaemia may be that oleoresin ingestion decreased the intestinal obsorption of exogenous cholesterol and increased the bile acid excretion (Malinow et al, 1980;Satoh et al, 1995). This could stimulate the catabolism of cholesterol in the liver by a feedback mechanism (Havel, 1988).…”