Hypolipidaemic effects of potato protein and fish protein in pigs

Abstract

This study was performed to assess the effects of potato protein and fish protein on concentrations of lipids in plasma and lipoproteins and the expression of genes involved in lipid metabolism in pigs used as an animal model. Therefore, 27 young male pigs with an average body weight of 22 kg were fed diets supplemented with protein extracted from potatoes (containing 849 g protein/kg dry matter), Alaska Pollack fillet as a source of fish protein (containing 926 g crude protein/kg dry matter) or casein which was used as control, for 3 weeks. Diets were formulated to supply identical amounts of each protein to the pigs by the three protein sources, namely 116 g/day in first week and 150 g/day in the second and third week. Pigs fed potato protein had lower concentrations of cholesterol in plasma and LDL than pigs fed casein (p < 0.05); no effect was observed on concentrations of HDL cholesterol and triglycerides. Pigs fed fish protein had lower cholesterol concentrations in plasma, LDL and HDL, and lower triglyceride concentrations in triglyceride-rich lipoproteins than pigs fed casein (p < 0.05). mRNA concentrations of genes involved in bile acid synthesis and cholesterol uptake were higher in pigs fed fish protein than in pigs fed casein (p < 0.05); no effect on these genes was observed in pigs fed potato protein. Expression of genes involved in lipogenesis and fatty acid oxidation was not altered by fish protein. In conclusion, this study shows that fish protein and potato protein lower plasma cholesterol concentrations in pigs. The hypocholesterolaemic effect of fish protein might be in part caused by a stimulation of bile acid synthesis; the reason for the hypocholesterolaemic effect of potato protein requires further elucidation.

Response of young pigs to feeding potato protein and potato fibre - nutritional, physiological and biochemical parameters

“…The greater absorption was accompanied by higher blood levels of triglycerides in pigs fed on PPC than on CAS while the total cholesterol concentration did not differ. These findings are contradictory to the hypolipidaemic effect of potato protein observed in rats (De Schrijver, 1990) and its hypocholesterolaemic but not hypolipidaemic, effect found in pigs (Spielmann et al, 2009). Pigs and not rats, are considered as a better model of lipid metabolism when related to humans.…”

“…The animals fed on cereal diet containing PPC as the only protein source had similar feed intake and growth rate, and even slightly better feed conversion than piglets fed on casein-supplemented diet. Absence of negative effect of potato protein on growth performance of older pigs (initial body weight 22 kg) was found also by Spielmann et al (2009) who fed diets containing casein, fish meal or potato protein at the level increased from 15 to 19.4% during 21 days of experiment. Potato protein appeared to be a good substitute of fish meal when fed at 6% level to piglets of the initial body weight 7.5 kg (Sardi et al, 2005) and when fed at 8% level with faba beans as the protein source for growing-finishing pigs (Sundrum et al, 2000).…”

“…Relative weights of liver and pancreas were slightly greater in pigs fed on PPC than on CAS diets which may indicate for a greater metabolic activity of these organs. The enlargement of liver was found also by Spielmann et al (2009) in pigs fed similar amounts of PPC while progressive hypertrophy of liver and pancreas was observed in chickens fed increasing amounts of PPC (Tuśnio et al, submitted to publication). Changes of liver weight are considered as the manifestation of hepatoxic effects of glycoalkaloids (Friedman et al, 1996) while hypertrophy of pancreas may reflect stimulatory effect of trypsin inhibiting activity on pancreatic secretion.…”

Effects of Various Dietary Arginine and Lysine Concentrations on Plasma and Liver Cholesterol Concentrations in Rats

“…[1][2][3][4][5][6][8][9][10]. It has been hypothesized that effects of these proteins on cholesterol metabolism, i.e.…”

“…It has been reported many times that protein isolated from soybeans has hypocholesterolaemic effects in laboratory animals, pigs and humans when compared to casein [2,[5][6][7] . Recently, it has been found that proteins extracted from sweet lupins [8] and peas [9] as well as from fish as a source of a protein of animal origin [10][11][12] also have beneficial effects on the cholesterol metabolism of rats and pigs.…”