effect of oxidized fat in food on lipoprotein oxidation 9.5.2012 | jukka-pekka suomela department of...
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Effect of oxidized fat in food on lipoprotein oxidation
9.5.2012 | Jukka-Pekka Suomela
Department of Biochemistry and Food Chemistry
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BackgroundFat oxidation
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(autoxidation)
This proton ripped off from anotherfatty acid molecule
BackgroundFat oxidation
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BackgroundFat oxidation
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Breakdown of hydroperoxides
BackgroundFat oxidation
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Photosensitizedoxidation of linoleicacid
Autoxidation oflinoleic acid
(Buettner, Molecular targets of photosensitization)
In addition, enzymatic oxidation is possible inbiological systems…
BackgroundFat oxidation
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Background“Basic” indicators of fat oxidation
peroxide value (PV, POV) Fat oxidation gives birth to peroxides that are
measured with a method based on the ability of peroxides to release iodine from potassium jodide
Titration of the relased iodine with Na2S2O3-liuoksella
p-anisidine value (p-AV) Measures the amount of secundary oxidation products
(aldehydes, ketones) in oil spectrophotometric determination at 350 nm
Fats get rancid also hydrolytically!
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BackgroundOxidation products from dietary fats to the body –
lipoproteins and atherosclerosis
Witztum, J.L. Lancet 344: 793-795
Oxidized lipoproteins seem to increase the risk of atherosclerosis LDL Chylomicrons, VLDL, and their remnants?
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BackgroundClassification of lipoproteins
chylomicrons formed in small intestine
very low density lipoproteins (VLDL) formed in liver
intermediate density lipoproteins (IDL) formed from VLDL
low density lipoproteins (LDL) formed from IDL
high density lipoproteins (HDL) formed in liver and small intestine
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Durrington, P.N. Hyperlipidaemia: Diagnosis and Management. 2nd edition.
London: Butterworth-Heinemann; 1995.
BackgroundClassification of lipoproteins
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BackgroundMetabolism of lipoproteins
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BackgroundFormation of foam cells
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BackgroundAtherosclerotic plaque
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BackgroundLipoproteins transport oxidized lipids
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BackgroundFood and oxidized lipoproteins
Staprans, I. et al. Arterioscler Thromb 14: 1900-1905
In various studies, dietary oxidized lipids have increased the oxidation of chylomicrons and VLDL
food small intestine lipoproteins other tissues… What? Where? Why?
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Aim of the research
1. To study the effect of oxidized dietary oil on the amount of oxidized lipids in porcine lipoproteins
2. To identify the molecular structures of oxidized triacylglycerols (TAGs) in porcine chylomicrons and VLDL
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Oxidation of fatty acids within glycerolipids
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Study protocols
STUDY 1 3 groups of 3 pigs; 14%
sunflower seed oil in the feed Peroxide value of the oil:
group 1: 1 meq O2/kg oil
group 2: 84 meq O2/kg oil
group 3: 223 meq O2/kg oil
STUDY 2 2 groups of 10 pigs; 16%
sunflower seed oil in the feed Peroxide value of the oil:
group 1: 1 meq O2/kg oil
group 2: 190 meq O2/kg oil
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Methods
1. Determination of the oxidation level of pig lipoproteins BDC (baseline diene conjugation) spectrophotometrically
2. Identification of the molecular structures of oxidized TAGs in chylomicrons and VLDL: Separation of lipid classed by TLC (thin layer chromatography) Further separation by RP-HPLC (reversed-phase liquid
chromatography) Detectors:
ESI-MS ELSD UV (DNPH derivatives of core aldehydes)
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MethodsIdentification of molecular structures, TLC
TAGOxidizedTAG
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(MeOH / i-Pr) (80 / 20, by vol)
0,85 ml / min20 min
(MeOH / i-Pr) (20 / 80, by vol)
SOLVENT GRADIENT:
Discovery HS C18 5 m, 250 mm x 4.6 mm i.d.
COLUMN:
MethodsIdentification of molecular structures, HPLC
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HPLC
130 l/min850 l/min
720 l/min
UV/ELSD
ESI MS
MethodsIdentification of molecular structures, HPLC
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Methods
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ResultsStudy 1
0
5
10
15
Time point 1 Time point 2
BD
C (
mol
/L)
Group 1
Group 2
Group 3
Chylomicrons
0
1
2
3
4
5
6
Time point 1 Time point 2
BD
C (
mol
/L)
Group 1
Group 2
Group 3
VLDL
LDL
0
5
10
15
20
25
Time point 1 Time point 2
BD
C (
mol
/L)
Group 1
Group 2
Group 3
a
b
Group 1: 1 meq O2/kg oilGroup 2: 84 meq O2/kg oilGroup 3: 223 meq O2/kg oil
Time point 1: 3 hr after mealTime point 2: 4 hr after meal
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ResultsStudy 1
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Estimated proportions of oxidized TAGs of the total lipids of the test oils and chylomicronsa
Group 1b Group 3c
Oil 0.2 Oil 6.2
Time point 3 h Time point 3 h Pig 1 0.0 Pig 7 0.4Pig 2 0.1 Pig 8 0.4Pig 3 0.2 Pig 9 1.9
Time point 4 h Time point 4 h Pig 1 0.0 Pig 7 0.6 Pig 2 0.3 Pig 8 1.1 Pig 3 0.3 Pig 9 1.2
aResults as g/100 g total lipids.bPeroxide value of the oil used in feed: 1 meq O2/kg.cPeroxide value of the oil used in feed: 223 meq O2/kg.
ResultsStudy 1
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Typically only one fatty acid residue of a TAG molecule was oxidized in the identified molecules
Among oxidized TAG structures were: hydroxides epoxides ketones aldehydes (9:0, 12:1)
Hydroperoxides were not found
ResultsStudy 1
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0
5
10
15
20
25
30
35
Time point 1 Time point 2
BD
C (
mo/
L)
Group 1
Group 2a
b
Chylomicrons
0
5
10
15
20
25
30
35
Time point 1 Time point 2
BD
C (
mol
/L)
Group 1
Group 2
VLDL
0
5
10
15
20
25
30
35
Time point 1 Time point 2
BD
C (
mol/L)
Group 1
Group 2
LDL
Group 1: 1 meq O2/kg oilGroup 2: 190 meq O2/kg oil
0
10
20
30
40
50
60
70
80
Time point 1 Time point 2
BD
C (
mol
/L)
Group 1
Group 2
Plasma
a
b
ResultsStudy 2
Time point 1: 3 hr after mealTime point 2: 4 hr after meal
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Estimated proportions of oxidized TAGs of the total lipids of the test oils, chylomicrons, and VLDLa
Group 1b Group 2c
Oil 0.0 Oil 6.4
Chylomicrons
Time point 3 h 0,8 ± 0,7a Time point 3 h 2,0 ± 0,6b
Time point 4 h 0,8 ± 0,9a Time point 4 h 2,4 ± 0,7b
VLDLTime point 3 h 0,1 ± 0,1 Time point 3 h 0,2 ± 0,2Time point 4 h 0,1 ± 0,1a Time point 4 h 0,2 ± 0,1b
aResults as g/100 g total lipids.bPeroxide value of the oil used in feed: 1 meq O2/kg.cPeroxide value of the oil used in feed: 190 meq O2/kg.
ResultsStudy 2
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ResultsStudy 2
Typically only one fatty acid residue of a TAG molecule was oxidized in the identified molecules
Among oxidized TAG structures were: hydroxides epoxides ketones aldehydes (9:0, 12:1)
Hydroperoxides were not found
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Conclusions
Diet containing oxidized sunflower oil increased lipid oxidation in lipoproteins
Oxidized fats are partly transported to the circulation Effect of vitamin E?
Several oxidized molecular structures derived from TAGs were found in chylomicrons and VLDL Method was not optimized to extensively oxidized
structures
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Literature
Suomela, J.-P., Ahotupa, M., Sjövall, O., Kurvinen, J.-P., & Kallio, H. (2004) Diet and lipoprotein oxidation: analysis of oxidized triacylglycerols in pig lipoproteins. Lipids 39: 639–647, DOI: 10.1007/s11745-004-1277-4
Suomela, J.-P., Ahotupa, M., and Kallio, H. (2005) Triacylglycerol oxidation in pig lipoproteins after a diet rich in oxidized sunflower seed oil. Lipids 40: 437–444, DOI: 10.1007/s11745-005-1402-4
Ahotupa, M., Suomela, J.-P., Vuorimaa, T., and Vasankari, T. (2010) Lipoprotein-specific transport of circulating lipid peroxides. Ann Med 42: 521–529, DOI: 10.3109/07853890.2010.510932
Tarvainen, M., Phuphusit, A., Suomela J.-P., Kuksis, A., and Kallio H. (2012) Effects of antioxidants on rapeseed oil oxidation in an artificial digestion model analyzed by UHPLC−ESI−MS. J Agric Food Chem, DOI: 10.1021/jf2050944. E-pub ahead of print.
Kanner, J., Gorelik, S., Sirota, R., & Kohen, R. (2012) Protection by polyphenols of postprandial human plasma lipid oxidative modification: the stomach as a bioreactor. J Agric Food Chem, DOI: 10.1021/jf300193g. E-pub ahead of print.