Antioxidants such as vitamin C and vitamin E
may inhibit lipid peroxidation. An alternative method employs the isotope effect on lipid peroxidation of deuterated polyunsaturated fatty acids (PUFAs) at the methylene bridges (bis-allylic sites) between double bonds, which leads to the inhibition of the chain reaction.
How can we control and reduce lipid peroxidation?
Antioxidants such as vitamin C and vitamin E
may inhibit lipid peroxidation. An alternative method employs the isotope effect on lipid peroxidation of deuterated polyunsaturated fatty acids (PUFAs) at the methylene bridges (bis-allylic sites) between double bonds, which leads to the inhibition of the chain reaction.
What causes high lipid peroxides?
Elevated concentrations of lipid peroxides are often found in patients with common diseases such as
atherosclerosis, diabetes
, cancer or neurodegenerative diseases including Parkinson’s and Alzheimer’s disease.
How do you reduce lipid oxidation?
Among the many methods employed for controlling lipid oxidation,
use of antioxidants
is the most effective, convenient and economical means. Food manufacturers world-wide use antioxidants to stabilize food lipids and thus preventing quality deterioration of the products.
How does hydrogen peroxide affect lipid peroxidation?
The results of the present study reveal a clear dose dependent increase in the production of MDA upon treatment with hydrogen peroxide.
Ion radicals generated during oxidative stress leads
to a chain reaction called lipid peroxidation. … H
2
O
2
gives a Fenton reaction in the presence of Fe
2 +
.
Is lipid peroxidation reversible?
Peroxidation of polyunsaturated fatty acids occurs as a consequence of double bond weakening, production of conjugated dienes, O
2
addition, peroxy radical formation, and H
+
loss from lipid. Because cells do not have mechanisms to dispose of these byproducts,
lipid peroxidation is considered irreversible
[45].
Why are lipid peroxides bad?
The lipid peroxidation (LPO) products are
highly reactive and display marked biological effects
, which, depending upon their concentration, cause selective alterations in cell signaling, protein and DNA damage, and cytotoxicity.
How does lipid oxidation occur?
Lipid oxidation can occur by
either enzymatic or nonenzymatic catalysis
. Nonenzymatic reaction mechanisms can involve catalysis by H
2
O
2
, heme iron from myoglobin, nonheme iron, or salts. Antioxidants (e.g., nitrite, ascorbic acid, phenols, or alpha-tocopherol) are effective lipid oxidation inhibitors.
Why does lipid oxidation occur?
Auto-oxidation occurs
in the presence of oxygen
and is described as the auto-catalytic generation of free radicals. It is initiated when a hydrogen atom is abstracted in the presence of initiators such as light, heat, metals or oxygen, forming a lipid radical, which reacts with oxygen making a lipid peroxide radical.
What are the three stages of lipid oxidation?
The overall process of lipid peroxidation consists of three steps:
initiation, propagation, and termination
[31, 36, 37].
How is lipid peroxidation tested?
The most commonly used test is called a
TBARS Assay
(thiobarbituric acid reactive substances assay). Thiobarbituric acid reacts with malondialdehyde to yield a fluorescent product. However, there are other sources of malondialdehyde, so this test is not completely specific for lipid peroxidation.
What are the effects of lipid oxidation in food?
Lipid oxidation of foods gives
rise to formation of unhealthy compounds
, negatively affects sensory properties of foods and is an important contributor to reduced shelf life and food waste. In order to meet current nutritional recommendations, the content of polyunsaturated fatty acids in foods must be increased.
What chemical species leads to the process of lipid peroxidation?
Lipid peroxidation has been attributed to an increase in
reactive oxygen species (e.g., O2− , OH•, and H2O2)
resulting from, for example, increased lipoxygenase activity and decreased activities of protective enzymes such as catalase, ascorbate peroxidase, (cytosolic) superoxide dismutase, and glutathione-S-transferase …
How does lipid peroxidation affect protein function?
Besides forming DNA lesions, the reactive aldehydes resulting from lipid peroxidation are also capable of
easily forming protein adducts
. However, if such protein damage occurs in the photoreceptor outer region, the permanent renewal of the outer segments will clear away and replace the damaged proteins.
How do you induce lipid peroxidation?
Lipid peroxidation induced by
iron ions
, organic hydroperoxides, halogenated hydrocarbons, redox cycling drugs, glutathione depleting chemicals, ethanol, heavy metals, ozone, nitrogen dioxide and a number of miscellaneous compounds, e.g. hydrazines, pesticides, antibiotics, are mentioned.
What is the importance of lipid peroxidation?
Lipid peroxidation-derived aldehydes play a major role in human health and disease as they
act as important signaling intermediates in modulating cellular physiological function via regulating various transcription factors
(Fig. 32.6).
