Glucomannan- and glucomannan plus spirulina-enriched pork affect liver fatty acid profile, LDL receptor expression and antioxidant status in Zucker fa/fa rats fed atherogenic diets

Abstract

We evaluated the effects of glucomannan or glucomannan plus spirulina-restructured pork (RP)
on liver fatty acid profile, desaturase/elongase enzyme activities and oxidative status of Zucker fa/
fa rats for seven weeks. Control (C), glucomannan (G) and glucomannan/spirulina (GS)-RP; HC
(cholesterol-enriched control), HG and HGS (cholesterol-enriched glucomannan and glucomannan/
spirulina-RP) experimental diets were tested. Increased metabolic syndrome markers were
found in C, G and GS rats. Cholesterol feeding increased liver size, fat, and cholesterol and
reduced antioxidant enzyme levels and expressions. Cholesterolemia was lower in HG and HGS
than in HC. GS vs. G showed higher stearic but lower oleic levels. SFA and PUFA decreased while
MUFA increased by cholesterol feeding. The arachidonic/linoleic and docosahexaenoic/alphalinolenic
ratios were lower in HC, HG, and HGS vs. C, G, and GS, respectively, suggesting a
delta-6-elongase-desaturase system inhibition. Moreover, cholesterol feeding, mainly in HGS,
decreased low-density-lipoprotein receptor expression and the delta-5-desaturase activity and
increased the delta-9-desaturase activity. In conclusion, the liver production of highly unsaturated
fatty acids was limited to decrease their oxidation in presence of hypercholesterolaemia.
Glucomannan or glucomannan/spirulina-RP has added new attributes to their functional properties
in meat, partially arresting the negative effects induced by high-fat-high-cholesterol feeding
on the liver fatty acid and antioxidant statuses.