Phytosterol oxidation products in enriched foods: Occurrence, exposure, and biological effects

2015 ◽  
Vol 59 (7) ◽  
pp. 1339-1352 ◽  
Author(s):  
Birgit Scholz ◽  
Sabine Guth ◽  
Karl-Heinz Engel ◽  
Pablo Steinberg
Keyword(s):  
Biological Effects ◽  
Oxidation Products ◽  
Phytosterol Oxidation Products

scholarly journals Qualitative and quantitative comparison of the cytotoxic and apoptotic potential of phytosterol oxidation products with their corresponding cholesterol oxidation products

2005 ◽  
Vol 94 (3) ◽  
pp. 443-451 ◽  
Author(s):  
Eileen Ryan ◽  
Jay Chopra ◽  
Florence McCarthy ◽  
Anita R. Maguire ◽  
Nora M. O'Brien
Keyword(s):  
Cell Line ◽  
Biological Effects ◽  
Oxidation Products ◽  
Cholesterol Oxidation ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Cholesterol Oxidation Products ◽  
Phytosterol Oxidation Products ◽  
Induced Apoptosis ◽  
Β Carotene

Phytosterols contain an unsaturated ring structure and therefore are susceptible to oxidation under certain conditions. Whilst the cytotoxicity of the analogous cholesterol oxidation products (COP) has been well documented, the biological effects of phytosterol oxidation products (POP)have not yet been fully ascertained. The objective of the present study was to examine the cytotoxicity of β-sitosterol oxides and their corresponding COP in a human monocytic cell line (U937), a colonic adenocarcinoma cell line (CaCo-2) and a hepatoma liver cell line (HepG2). 7β-Hydroxysitosterol, 7-ketositosterol, sitosterol-3β,5α,6β-triol and a sitosterol-5α,6α-epoxide–sitosterol-5β,6β-epoxide (6:1) mixture were found to be cytotoxic to all three cell lines employed; the mode of cell death was by apoptosis in the U937 cell line and necrosis in the CaCo-2 and HepG2 cells. 7β-Hydroxysitosterol was the only β-sitosterol oxide to cause depletion in glutathione, indicating that POP-induced apoptosis may not be dependent on the generation of an oxidative stress. A further objective of this study was to assess the ability of the antioxidants α-tocopherol, γ-tocopherol and β-carotene to modulate POP-induced cytotoxicity in U937 cells. Whilst α/γ-tocopherol protected against 7β-hydroxycholesterol-induced apoptosis, they did not confer protection against 7β-hydroxysitosterol-or 7-ketositosterol-induced toxicity, indicating that perhaps COP provoke different apoptotic pathways than POP. β-Carotene did not protect against COP- or POP-induced toxicity. In general, results indicate that POP have qualitatively similar toxic effects to COP. However, higher concentrations of POP are required to elicit comparable levels of toxicity.

Phytosterol Oxidation Products: Their Formation, Occurrence, and Biological Effects

2009 ◽  
Vol 25 (2) ◽  
pp. 157-174 ◽  
Author(s):  
Eileen Ryan ◽  
Florence McCarthy ◽  
Anita Maguire ◽  
Nora O'Brien
Keyword(s):  
Biological Effects ◽  
Oxidation Products ◽  
Phytosterol Oxidation Products

scholarly journals 5α,6α-Epoxyphytosterols and 5α,6α-Epoxycholesterol Increase Oxidative Stress in Rats on Low-Cholesterol Diet

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Tomasz Wielkoszyński ◽  
Jolanta Zalejska-Fiolka ◽  
Joanna K. Strzelczyk ◽  
Aleksander J. Owczarek ◽  
Armand Cholewka ◽  
...  
Keyword(s):  
Redox State ◽  
Glutathione Transferase ◽  
Conjugated Dienes ◽  
Oxidation Products ◽  
Paraoxonase 1 ◽  
Cholesterol Oxidation ◽  
Cholesterol Diet ◽  
Phytosterol Oxidation Products ◽  
Reduced Activity ◽  
Low Cholesterol

Objective. Cholesterol oxidation products have an established proatherogenic and cytotoxic effect. An increased exposure to these substances may be associated with the development of atherosclerosis and cancers. Relatively little, though, is known about the effect of phytosterol oxidation products, although phytosterols are present in commonly available and industrial food products. Thus, the aim of the research was to assess the effect of 5α,6α-epoxyphytosterols, which are important phytosterol oxidation products, on redox state in rats. Material and Methods. The animals were divided into 3 groups and exposed to nutritional sterols by receiving feed containing 5α,6α-epoxyphytosterols (ES group) and 5α,6α-epoxycholesterol (Ech group) or sterol-free feed (C group). The levels of malondialdehyde (MDA), conjugated dienes (CD), and ferric reducing antioxidant potential (FRAP) were assayed in the plasma; anti-7-ketocholesterol antibodies and activity of paraoxonase-1 (PON1) were determined in serum, whereas the activity of catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), S-glutathione transferase (GST), and superoxide dismutase (SOD) were assayed in RBCs. Results. During the experiment, the levels of lipid peroxidation products increased, such as CD and anti-7-ketocholesterol antibodies. At the same time, the plasma levels of FRAP and serum activity of PON1 decreased alongside the reduced activity of GPx, GR, and SOD in RBCs. There was no effect of the studied compounds on the plasma MDA levels or on the activity of CAT and GST in RBCs. Conclusions. Both 5α,6α-epoxyphytosterols and 5α,6α-epoxycholesterols similarly dysregulate the redox state in experimental animal model and may significantly impact atherogenesis.

scholarly journals Analysis of Sterol Oxidation Products in Foods

2004 ◽  
Vol 87 (2) ◽  
pp. 441-466 ◽  
Author(s):  
Francesc Guardiola ◽  
Ricard Bou ◽  
Josep Boatella ◽  
Rafael Codony
Keyword(s):  
Gas Chromatography ◽  
Liquid Chromatography ◽  
Sample Preparation ◽  
State Of The Art ◽  
The State ◽  
Oxidation Products ◽  
Cholesterol Oxidation ◽  
Cholesterol Oxidation Products ◽  
Phytosterol Oxidation Products ◽  
Adequate Method

Abstract The main aspects related to the analysis of sterol oxidation products (SOP) in foods are comprehensively reviewed. Special emphasis is placed on the critical and controversial points of this analysis because these points affect crucial analytical parameters such as precision, accuracy, selectivity, and sensitivity. The effect of sample preparation and the conditions of quantification by gas chromatography and liquid chromatography on these parameters are also reviewed. The results show that, in order to choose an adequate method to analyze SOP in a certain food, the analyst must consider its SOP concentration and matrix complexity. The term SOP includes both cholesterol oxidation products (COP) and phytosterol oxidation products (POP). The state of the art of COP and POP analysis is quite different; many more studies have dealt with the analysis of COP than of POP. However, most of the results presented here about COP analysis may be extrapolated to POP analysis because both groups of compounds show similar structures and characteristics.

Sign in / Sign up

Export Citation Format

Share Document