This article is available online at http://www.jlr.org functions, in addition to structural roles ( 1 ); consequently lipidomic studies have become fundamental for understanding their contribution to health and disease. Mass spectrometry (MS), with its capability of providing structural information, has been the main method of choice in lipidomic studies. Recent technological advances in mass spectrometers, including increased sensitivity, higher mass accuracy, higher scan speeds, and the ability to acquire in both positive and negative mode in one run have resulted in the increased popularity of MS as a detection technique for biomolecules in recent years. This has enabled the mapping of lipids present in fl uids and cells, leading to better understanding of the role of the different lipid classes in the pathophysiology of diseases.A critical step in lipidomic analysis is lipid extraction with an appropriate organic solvent mixture (solvent system) prior to MS detection. The solvent system should be capable of effectively extracting lipids representative of the sample under study without bias, inducing or promoting the degradation of lipids, or introducing contamination by nonlipid components such as sugars, peptides, and amino acids. Therefore, the success in the identifi cation and profi ling of lipids is critically dependent on the efficiency of the extraction step. The performance of the lipid extraction for a given sample (tissue, cell, or fl uid) with a particular solvent system depends on the partitioning of the

Lipid peroxidation products like malondialdehyde, 4-hydroxynonenal and F 2 -isoprostanes are widely used as markers of oxidative stress in vitro and in vivo . This study reports the results of a multi-laboratory validation study by COST Action B35 to assess inter-laboratory and intra-laboratory variation in the measurement of lipid peroxidation. Human plasma samples were exposed to UVA irradiation at different doses (0, 15 J, 20 J), encoded and shipped to 15 laboratories, where analyses of malondialdehyde, 4-hydroxynonenal and isoprostanes were conducted. The results demonstrate a low within-day-variation and a good correlation of results observed on two different days. However, high coeffi cients of variation were observed between the laboratories. Malondialdehyde determined by HPLC was found to be the most sensitive and reproducible lipid peroxidation product in plasma upon UVA treatment. It is concluded that measurement of malondialdehyde by HPLC has good analytical validity for inter-laboratory studies on lipid peroxidation in human EDTA-plasma samples, although it is acknowledged that this may not translate to biological validity.

Increased exposure to nicotine contributes to the development of cardiac dysfunction by promoting oxidative stress, fibrosis, and inflammation. These deleterious events altogether render cardiac myocytes more susceptible to acute cardiac insults such as ischemia-reperfusion (I/R) injury. This study sought to elucidate the role of angiotensin II type I (AT1) receptors in cardiac injury resulting from prolonged nicotine administration in a rat model. Male Sprague-Dawley rats were given nicotine (0.6 mg/kg ip) for 28 days to induce cardiac dysfunction, alone or in combination with the AT1 receptor antagonist, irbesartan (10 mg/kg, po). Vehicle-treated rats were used as controls. Rat hearts isolated from each experimental group at study endpoint were examined for changes in function, histology, gene expression, and susceptibility against acute I/R injury determined ex vivo. Rats administered nicotine alone exhibited significantly increased cardiac expression of angiotensin II and angiotensin-converting enzyme (ACE) in addition to elevated systolic blood pressure (SBP) and heart rate. Furthermore, nicotine administration markedly reduced left ventricular (LV) performance with concomitant increases in myocardial oxidative stress, fibrosis, and inflammation. Concomitant treatment with irbesartan attenuated these effects, lowering blood pressure, heart rate, oxidative stress, and expression of fibrotic and inflammatory genes. Importantly, the irbesartan-treated group also manifested reduced susceptibility to I/R injury ex vivo. These findings suggest that AT1 receptors play an important role in nicotine-induced cardiac dysfunction, and pharmacological approaches targeting cardiac AT1 receptors may thus benefit patients with sustained exposure to nicotine.

These observations indicate the protective effect of roselle on cardiac dysfunction in OB and OB+MI rats, which suggest its potential to be developed as a nutraceutical product for obese and obese patients with MI in the future.

The syntheses and bioactivities of symmetrical curcumin and its analogues have been the subject of interest by many medicinal chemists and pharmacologists over the years. To improve our understanding, we have synthesized a series of unsymmetrical monocarbonyl curcumin analogues and evaluated their effects on prostaglandin E2 production in lipopolysaccharide-induced RAW264.7 and U937 cells. Initially, compounds 8b and 8c exhibited strong inhibition on the production of PGE2 in both LPS-stimulated RAW264.7 (8b, IC50=12.01μM and 8c, IC50=4.86μM) and U937 (8b, IC50=3.44μM and 8c, IC50=1.65μM) cells. Placing vanillin at position Ar2 further improved the potency when both compounds 15a and 15b significantly lowered the PGE2 secretion level (RAW264.7: 15a, IC50=0.78μM and 15b, IC50=1.9μM while U937: 15a, IC50=0.95μM and 15b, IC50=0.92μM). Further experiment showed that compounds 8b, 8c, 15a and 15b did not target the activity of downstream inflammatory COX-2 mediator. Finally, docking simulation on protein targets COX-2, IKK-β, ERK, JNK2, p38α and p38β were performed using the conformation of 15a determined by single-crystal XRD.