Multiple lipoxygenase sequence alignments and structural modeling of the enzyme/substrate interaction of the cucumber lipid body lipoxygenase suggested histidine 608 as the primary determinant of positional specificity. Replacement of this amino acid by a less-space-filling valine altered the positional specificity of this linoleate 13-lipoxygenase in favor of 9-lipoxygenation. These alteration...

Nanotitanium dioxide particle (nTiO2) inhalation has been reported to induce lung parenchymal injury. After inhalation of nTiO2, we monitored changes in 5-lipoxygenase, endothelial nitric oxide synthase (eNOS), and inducible nitric oxide synthase (iNOS) mRNA in rat lung tissue. Lung function parameters include specific airway resistance (SRaw), peak expiratory flow rate (PEF), functional residu...

Although it is now recognized that low levels of reactive oxygen species (ROS) are required for the mitogenic response, mitogen-induced signalling pathways that regulate ROS generation in non-phagocytic cells remain largely uncharacterized. Using a real-time assay for measuring hydrogen peroxide (H(2)O(2)) formation, we analysed H(2)O(2) release in human HaCaT keratinocytes in response to lysop...

Some of the metabolites of arachidonic acid formed in the lipoxygenase and cyclooxygenase pathways stimulate insulin release. We studied the relative importance of each of these pathways in the modulation of glucose-induced insulin release by using inhibitors of arachidonate metabolism. Perfusion of the isolated rat pancreas with two chemically different inhibitors of cyclooxygenase, flurbiprof...

Purpose: To study the structure-activity relationships of synthetic multifunctional sulfides through evaluation of lipoxygenase and anti-bacterial activities. Methods: S-substituted derivatives of the parent compound 5-(1-(4-chlorophenylsulfonyl) piperidin-3yl)-1, 3, 4-oxadiazole-2-thiol were synthesized through reaction with different saturated and unsaturated alkyl halides in DMF medium, with...

The metabolism of radiolabeled arachidonic acid in epithelium, stroma, and endothelium was studied in normal and cryogenically lesioned rabbit corneas. The synthesis of cyclooxygenase- and lipoxygenase-reaction products, as well as the incorporation of arachidonic acid in phospholipids and neutral lipids, was followed by in vitro incubation (60 min) of corneas obtained 2 hr, 5 days, and 15 days...

Cyclooxygenase and 5-lipoxygenase are enzymes that catalyze important inflammatory pathways, suggesting that dual cyclooxygenase/lipoxygenase inhibitors should be more efficacious as anti-inflammatory medicines with lower side effects than the currently available nonsteroidal anti-inflammatory drugs. Many plants from the family Asteraceae have anti-inflammatory activities, which could be exerte...