Lipid peroxidation and its measurement
Roger L. McMullen in Antioxidants and the Skin, 2018
Arachidonic acid is an omega-6 fatty acid that is incorporated into the structure of many phospholipids in eukaryotic cells. In normal metabolic circumstances it is converted to prostaglandins by the enzyme cyclooxygenase (COX). However, during lipid peroxidation arachidonic acid may be converted by a free radical mechanism (COX is not involved) to prostaglandin-like compounds, which belong to the family of isoprostanes and are toxic. Figure 5.11 shows a common F2-isoprostane that is often used as a probe of isoprostane formation. The F2-isoprostanes have become accepted as key biomarkers of oxidative stress in vivo and are usually present in tissues or fluids suffering from oxidative damage at elevated concentrations.103–108
Prolactin Regulation of Membrane Fluidity and Prostaglandin Formation
James A. Rillema in Actions of Prolactin on Molecular Processes, 1987
Direct alteration of the hepatic plasma membrane lipids may be achieved in vivo by dietary means. As discussed in an earlier section, the proportion of unsaturated fatty acids in membrane is one of the determinants of lipid microviscosity. Arachidonic acid, a polyunsaturated fatty acid, is an important constituent of most mammalian cells, and is synthesized in animals from linoleic acid. The latter, a dienoic acid, is not synthesized in animal tissue and, hence, is dietary “essential”. By feeding a diet deficient in essential fatty acids (EFA) for a long period, one may induce dramatic alterations in lipid composition of tissue membranes. In an earlier study, female C3H mice maintained on an EFA-deficient diet showed a time-related loss of hepatic PRL binding which was less than 50% after 32 weeks of treatment.155,156 Furthermore, treatment of EFA-deficient mice with exogenous PRL did not reverse this loss in hepatic PRL binding.156 As anticipated, the lipid microviscosity of hepatic membranes obtained from EFA-deficient mice was greater than control values (Figure 2). These results suggested that changes in membrane lipid microviscosity are inversely related to the number of accessible PRL binding sites, and that EFA are required for the maintenance of PRL receptors and physiological values of lipid microviscosity.
Complementary and integrative treatments I
Kathleen A. Kendall-Tackett in Depression in New Mothers, 2016
EPA and DHA were also used to treat major depression during pregnancy (Su et al., 2008). In this study, 36 pregnant women with major depression participated in a randomized clinical trial comparing a placebo to 3.4 g EPA/DHA (2.2 g DHA, 1.2 g EPA). Compared to the placebo group, subjects in the EPA/DHA group had significantly lower depression scores on the Hamilton Rating Scale for Depression at 6 and 8 weeks than the placebo group, and had a higher (although non-significant) remission rate. EPA and DHA were well tolerated and there were no adverse effects for either mother or baby. The authors noted that this treatment was likely effective because it halted the arachidonic acid cascade. Arachidonic acid is a long-chain, omega-6 fatty acid and is proinflammatory (see Figure 14.1). People with mood disorders often have higher levels of arachidonic acid in their plasma than do those without mood disorders.
The potential for metabolomics in the study and treatment of major depressive disorder and related conditions
Published in Expert Review of Proteomics, 2020
Jiajia Duan, Peng Xie
A study of metabolomics, based on GC-MS in the PFC of an LPS-induced mouse model of depression, identified 20 differential metabolites associated with lipid metabolism, such as arachidonic acid and ethanolamine, which were increased, and cholesterol, which was decreased [61]. Another metabolomics study, using GC-MS in the hippocampus of a CUMS-induced rat model of depression, showed the dysregulated metabolism of fatty acids, including hexadecane, arachidonic acid, methyl palmitoleate, and 2-monopalmitin, and glycerophospholipids, including phosphorylethanolamine and ethanolamine [46]. Arachidonic acid is a polyunsaturated fatty acid found among the phospholipids of the cell membranes, which can mediate an inflammatory response. Decreased cholesterol levels can influence the development of cholinergic-rich brain areas and cholinergic transmission [63]. These results indicated that lipid metabolism disturbances are associated with the etiology of depression.
Predictive serum biomarkers of patients with cerebral infarction
Published in Neurological Research, 2022
Yan Kong, Yu-qing Feng, Ya-ting Lu, Shi-sui Feng, Zheng Huang, Qian-yi Wang, Hui-min Huang, Xue Ling, Zhi-heng Su, Yue Guo
Arachidonic acid (AA) is a type of unsaturated fatty acid that has the widest distribution and highest content in the human body. It is the precursor of many important active cardiovascular and cerebrovascular substances in the human body. A variety of AA metabolites that are regulated by AA metabolism genes are related to the formation of atherosclerotic plaques and the pathogenesis of cerebral infarction. The metabolism of AA is always dynamic, and once its balance is destroyed, atherosclerosis and cerebral infarction occur. AA is involved in three metabolic pathways: cyclooxygenase, lipoxygenase, and cytochrome P450 (CYP) [24,25]. Among these, the third metabolic pathway, CYP cyclooxygenase, catalyzes AA into epoxyeicosatrienoic acids (EETs), which has functions of anti-inflammation, lowering of blood pressure, attenuation of ischemia-reperfusion injury of the myocardium, and reduction of the infarct area of the myocardium and brain tissue [26]. Cerebral inflammation plays a crucial role in the pathophysiology of ischemic stroke and involves all stages of the ischemic cascade [27]. We showed that the level of 5,6-epoxy-8,11,14-eicosatrienoic acid in the serum of patients with cerebral infarction was significantly higher than that of the control group. We hypothesized that AA is converted into EET under the catalysis of the CYP2 enzyme to a greater degree with the occurrence of cerebral inflammation during cerebral infarction. Therefore, AA metabolism dysfunction may be another pathogenesis of cerebral infarction. Patients with cerebral infarction may be treated by stabilizing AA metabolism.
Olive oil and oleic acid-based self nano-emulsifying formulation of omega-3-fatty acids with improved strength, stability, and therapeutics
Published in Journal of Microencapsulation, 2021
Abhay Tharmatt, Shubham Thakur, Amrinder Singh, Manjot Kaur, Navid Reza Shahtaghi, Divay Malhotra, Subheet Kumar Jain
Nutrients are an integral component of the human body and are of prime importance for maintaining a healthy lifestyle (Simopoulos 2011). Their deficiencies directly affect individuals regardless of their age. Polyunsaturated fatty acids such as omega-3 (Ω-3) and omega-6 (Ω-6) are the essential fatty acids that have distinct functions. The Ω-3 and Ω-6 fatty acids are converted from their precursors of 18 C fatty acids viz alpha-linolenic acid (ALA) (18:3n-3) and linoleic acid (LA) (18:2n-6) within the body, although these long-chain fatty acids are present even in their preformed state in natural sources. The rich vegetable oils of the crop, such as sunflower, soya, canola, corn, safflower, or cotton, are found to be rich in Ω-6-fatty acids especially LA. Whereas, flaxseed oil, walnut, pomegranate, chia, and green leafy vegetables contain Ω-3-fatty acids especially ALA (Sinclair et al. 2002). Moreover, red meat, ham, egg yolks, and human milk contains arachidonic acid (AA) (Beare-Rogers et al. 2001), while Docosahexaenoic acid (DHA) and Eicosapentaenoic acid (EPA) are majorly synthesised by marine algae and are present in marine foods such as salmon, tuna, sardines, etc. (Simopoulos 2011).
Related Knowledge Centers
- Arachidic Acid
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- Chemical Structure
- Eicosatetraenoic Acid
- Peanut Oil
- Phosphatidylethanolamine
- Phospholipid
- Polyunsaturated Fat
- Omega-6 Fatty Acid
- Cis–Trans Isomerism