Lipid Peroxidtion Products In Vivo
Valerian E. Kagan in Lipid Peroxidation In Biomembranes, 1988
Figure 1 illustrates the most essential and relatively well-studied ways of transforming the intermediates of the free-radical lipid peroxidation. For the sake of simplicity, all possible reactions of one type have not been presented, nor have all structural and positional isomers of the LP0 products. Moreover, a large number of components formed in vitro and in vivo by the interaction of intermediate LP0 products with intracellular components (e.g., with antioxidants) are not considered at all as they are not sufficiently studied, with the exception of lipofuscin-like fluorescent pigments. A more detailed description of the mechanisms of the reactions involving the participation of intermediates of free-radical oxidation of lipids is given in References 1 to 6.
Functional foods in lipid-lowering and coronary prevention
Dr Allan Gaw, James Shephard in Lipids and Atherosclerosis Annual 2003, 2003
Introduction For the past couple of decades nutritionists have concentrated on developing guidelines to reduce or prevent the incidence of coronary heart disease (CHD), such as low-fat, low-salt, and high-fibre diets in addition to ways to reduce excess body weight. More recently, functional foods have gained popularity as a means of retarding the onset and progression of cardiovascular disease. The emphasis has ceased to be solely on measures to reduce plasma lipids-today’s research also investigates ways in which diet may affect risk factors such as lipoprotein oxidation, platelet aggregation, thrombotic mechanisms, plaque formation and cardiac arrhythmias. Other areas of enquiry have included epidemiological studies of various diets from around the world, such as the Mediterranean diet, as well as of specific vitamins, minerals and essential fatty acids.
Lipid guidelines come of age?
Dr Allan Gaw, James Shephard in Lipids and Atherosclerosis Annual 2003, 2003
Introduction In the beginning there was only opinion, usually strongly held. Then there was evidence, and after evidence came guidelines. And the medical profession were divided: some regarded guidelines as a good thing created by experts in their field who spent long hours sifting through the results of clinical trials in order to help the rest of us make evidence-based treatment decisions, while others considered guidelines a straitjacket or worse, a form of cookbook medicine designed primarily to curtail clinical freedom. Those for and those against guidelines are unlikely ever to be completely reconciled, but even the hardened sceptic would probably concede that guidelines in general, and lipid guidelines in particular, are now coming of age.
Influence of liquid lipid content on the properties of puerarin-loaded lipid nanoparticles
Published in Journal of the Chinese Advanced Materials Society, 2014
Xiaofen Hu, Yuyan Zhang, Jiehong Yang, Haitong Wan
The present study described the fabrication and characterization of puerarin-loaded lipid nanoparticles with blends of glyceryl monostearate (solid lipid phase) and DELIOS® MCT (liquid lipid phase) as the lipid matrices. Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) were prepared via controlling the ratio of liquid lipid to solid lipid. The drug–lipid compatibility was evaluated via theoretical calculation of solubility parameters and X-ray diffraction analysis. The influence of liquid lipid content on the particle size, morphology, stability, drug loading properties of the lipid nanoparticles and in vitro release behavior of puerarin was investigated. Both SLN and NLC exhibited good stability and spherical shapes, and no significant difference in particle size occurred for the NLC series. The drug loading capacity and entrapment efficiency of the lipid nanoparticles were affected with increasing the liquid lipid content, and the presence of liquid lipid had a positive effect on improved drug payload. The in vitro release behavior of puerarin was intimately associated with the constituent of the lipid matrix. A sustained release of puerarin from NLC was observed in the selected experimental time window. The results of the current study displayed the application potential of NLC as nano-sized delivery carriers for puerarin.
HPLC Separation of Acyl Lipid Classes
Published in Journal of Liquid Chromatography & Related Technologies, 2007
Identification of complex acyl lipids ideally includes the normal‐phase HPLC to separate the acyl lipid classes followed by reversed‐phase HPLC to separate the molecular species of a lipid class. Both polar lipid classes and non‐polar lipid classes have been separated by normal‐phase HPLC, mostly on silica and diol columns using binary gradients. The tentative identification of lipid classes can be made by HPLC retention times and the co‐chromatography with lipid class standards. Various normal‐phase HPLC systems separating lipid classes are reviewed here.
An Experimental Model to Study the Impact of Lipid Oxidation on Contact Lens Deposition
Published in Current Eye Research, 2017
Burkhardt S. Schuett, Thomas J. Millar
ABSTRACT Purpose: This study was to establish a controlled in vitro test system to study the effect of lipid oxidation on lipid deposition on contact lenses. Methods: Fatty acids with varying degree of unsaturation were oxidized using the Fenton reaction. The degree of lipid oxidation and the lipid moieties formed during the oxidation were identified and estimated by various lipid staining techniques following separation with thin-layer chromatography, and by measuring thiobarbituric acid reactive substances or peroxides in solution. Two different silicone hydrogel-based contact lenses (Balafilcon A and Senofilcon A) were incubated with fatty acids laced with radioactive tracer oxidized to varying degrees, and the amount of lipid deposition was measured using unoxidized lipid samples as controls. Results: The Fenton reaction together with the analytical methods to analyze the lipid oxidation can be used to control oxidation of lipids to a desired amount. In general, saturated fatty acids are not oxidized, the monounsaturated oleic acid produced peroxides while poly-unsaturated lipids initially produced peroxides and then fragmented into reactive aldehydes. Incubation with mildly oxidized lipids (most likely lipid peroxides) resulted in increased lipid deposition on Balafilcon A lenses compared to unoxidized lipids, but this was not observed for Senofilcon A lenses. Further oxidation of the lipids (carbon chain breakup) on the other hand resulted in diminished lipid deposition for both contact lens types. Conclusions: This study provides a method for inducing and controlling lipid oxidation so that the effect of lipid oxidation on contact lens binding can be compared. It could be shown that the degree of lipid oxidation has different effects on the lipid deposition on different contact lens types.