Modification of phospholipids fatty acid composition in reuber H35 hepatoma cells: Effect on HMG-CoA reductase activity

2003 ◽  
Vol 90 (3) ◽  
pp. 586-591 ◽  
Author(s):  
M. Carmen García-Pelayo ◽  
Eduardo García-Peregrín ◽  
Marina Martínez-Cayuela
2006 ◽  
Vol 84 (1) ◽  
pp. 102-111 ◽  
Author(s):  
Monica P Polo ◽  
Margarita G de Bravo

Monoterpenes have multiple pharmacological effects on the metabolism of mevalonate. Geraniol, a dietary monoterpene, has in vitro and in vivo anti-tumor activity against several cell lines. We have studied the effects of geraniol on growth, fatty-acid metabolism, and mevalonate metabolism in the human hepatocarcinoma cell line Hep G2. Up to 100 µmol geraniol/L inhibited the growth rate and 3-hydroxymethylglutaryl coenzyme A reductase (HMG-CoA) reductase activity of these cells. At the same concentrations, it increased the incorporation of cholesterol from the medium in a dose-dependent manner. Geraniol-treated cells incorporated less 14C-acetate into nonsaponifiable lipids, inhibiting its incorporation into cholesterol but not into squalene and lanosterol. This is indicative of an inhibition in cholesterol synthesis at a step between lanosterol and cholesterol, a fact confirmed when cells were incubated with 3H-mevalonate. The incorporation of 3H-mevalonate into protein was also inhibited, whereas its incorporation into fatty acid increased. An inhibition of Δ5 desaturase activity was demonstrated by the inhibition of the conversion of 14C-dihomo-γ-linolenic acid into arachidonic acid. Geraniol has multiple effects on mevalonate and lipid metabolism in Hep G2 cells, affecting cell proliferation. Although mevalonate depletion is not responsible for cellular growth, it affects cholesterogenesis, protein prenylation, and fatty-acid metabolism.Key words: geraniol, Hep G2, HMG-CoA reductase, mevalonate, fatty acids.


1985 ◽  
Vol 54 (03) ◽  
pp. 563-569 ◽  
Author(s):  
M K Salo ◽  
E Vartiainen ◽  
P Puska ◽  
T Nikkari

SummaryPlatelet aggregation and its relation to fatty acid composition of platelets, plasma and adipose tissue was determined in 196 randomly selected, free-living, 40-49-year-old men in two regions of Finland (east and southwest) with a nearly twofold difference in the IHD rate.There were no significant east-southwest differences in platelet aggregation induced with ADP, thrombin or epinephrine. ADP-induced platelet secondary aggregation showed significant negative associations with all C20-C22 ω3-fatty acids in platelets (r = -0.26 - -0.40) and with the platelet 20: 5ω3/20: 4ω 6 and ω3/ ω6 ratios, but significant positive correlations with the contents of 18:2 in adipose tissue (r = 0.20) and plasma triglycerides (TG) (r = 0.29). Epinephrine-induced aggregation correlated negatively with 20: 5ω 3 in plasma cholesteryl esters (CE) (r = -0.23) and TG (r = -0.29), and positively with the total percentage of saturated fatty acids in platelets (r = 0.33), but had no significant correlations with any of the ω6-fatty acids. Thrombin-induced aggregation correlated negatively with the ω3/6ω ratio in adipose tissue (r = -0.25) and the 20: 3ω6/20: 4ω 6 ratio in plasma CE (r = -0.27) and free fatty acids (FFA) (r = -0.23), and positively with adipose tissue 18:2 (r = 0.23) and 20:4ω6 (r = 0.22) in plasma phospholipids (PL).The percentages of prostanoid precursors in platelet lipids, i. e. 20: 3ω 6, 20: 4ω 6 and 20 :5ω 3, correlated best with the same fatty acids in plasma CE (r = 0.32 - 0.77) and PL (r = 0.28 - 0.74). Platelet 20: 5ω 3 had highly significant negative correlations with the percentage of 18:2 in adipose tissue and all plasma lipid fractions (r = -0.35 - -0.44).These results suggest that, among a free-living population, relatively small changes in the fatty acid composition of plasma and platelets may be reflected in significant differences in platelet aggregation, and that an increase in linoleate-rich vegetable fat in the diet may not affect platelet function favourably unless it is accompanied by an adequate supply of ω3 fatty acids.


EDIS ◽  
2017 ◽  
Vol 2017 (6) ◽  
Author(s):  
Geoffrey M. Meru ◽  
Yuqing Fu ◽  
Dayana Leyva ◽  
Paul Sarnoski ◽  
Yavuz Yagiz

This article aims to summise production and nutrition aspects of pumpkin seed. Specifically, it focuses on health benefits of the seeds, production practices and provides data on the oil, protein and fatty acid composition of 35 pumpkin accessions.  


Author(s):  
Tereza Metelcová ◽  
Markéta Vaňková ◽  
Hana Zamrazilová ◽  
Milena Hovhannisyan ◽  
Eva Tvrzická ◽  
...  

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