In vitro protective effects of Paeonia mascula subsp. hellenica callus extract on human keratinocytes.

Natural ingredients have been used to improve the state of health in humans. The genus Paeonia has been studied only limited yet it's reported to have many activities such as antioxidant and anti-inflammatory. To this context, here we focused on an endemic Paeonia species in Attica.

Polyphenol-hydrogen peroxide reactions in skin: In vitro model relevant to study ROS reactions at inflammation.

Antioxidants are important to protect and maintain biological barriers, such as the skin. Antioxidant effects are often assessed using clinical trials, however these tests are costly and time consuming. In this work we introduce a skin membrane-covered oxygen electrode (SCOE) as an in vitro tool for monitoring HO and antioxidant reactions in skin.

Harmonizing lipidomics: NIST interlaboratory comparison exercise for lipidomics using SRM 1950-Metabolites in Frozen Human Plasma.

As the lipidomics field continues to advance, self-evaluation within the community is critical. Here, we performed an interlaboratory comparison exercise for lipidomics using Standard Reference Material (SRM) 1950-Metabolites in Frozen Human Plasma, a commercially available reference material. The interlaboratory study comprised 31 diverse laboratories, with each laboratory using a different lipidomics workflow.

Increased Plasma Levels of Select Deoxy-ceramide and Ceramide Species are Associated with Increased Odds of Diabetic Neuropathy in Type 1 Diabetes: A Pilot Study.

Plasma deoxy-sphingoid bases are elevated in type 2 diabetes patients and correlate with the stage of diabetic distal sensorimotor polyneuropathy; however, associations between deoxy-sphingolipids (DSL) and neuropathy in type 1 diabetes have not been examined. The primary aim of this exploratory pilot study was to assess the associations between multiple sphingolipid species including DSL and free amino acids and the presence of symptomatic neuropathy in a DCCT/EDIC type 1 diabetes subcohort. Using mass spectroscopy, plasma levels of DSL and free amino acids in DCCT/EDIC type 1 diabetes participants (n = 80), with and without symptoms of neuropathy, were investigated.

Amperometric monitoring of quercetin permeation through skin membranes.

Transdermal delivery of quercetin (QR, 3,3',4',5,7-pentahydroxyflavone), a natural flavonoid with a considerable antioxidant capacity, is important for medical treatment of, e.g., skin disorders.

Targeting (cellular) lysosomal acid ceramidase by B13: design, synthesis and evaluation of novel DMG-B13 ester prodrugs.

Acid ceramidase (ACDase) is being recognized as a therapeutic target for cancer. B13 represents a moderate inhibitor of ACDase. The present study concentrates on the lysosomal targeting of B13 via its N,N-dimethylglycine (DMG) esters (DMG-B13 prodrugs).

Sphingolipid analysis by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).

Sphingolipid (SPL) metabolism (Fig. 1) serves a key role in the complex mechanisms regulating cellular stress responses to environment. Several SPL metabolites, especially ceramide (Cer), sphingosine (Sph) and sphingosinel-phosphate (S1P) act as key bioactive molecules governing cell growth and programmed cell death (Fig.

Blood sphingolipidomics in healthy humans: impact of sample collection methodology.

We used a HPLC-MS/MS methodology for determination of a basic metabolomic profile (18:1,18:0 sphingoid backbone, C(14)-C(26) N-acyl part) of "normal" sphingolipid levels in human serum and plasma. Blood was collected from healthy males and nonpregnant females under fasting and nonfasting conditions with and without anticoagulants. Sphingolipids analyzed included sphingoid bases, sphingosine and dihydrosphingosine, their 1-phosphates (S1P and dhS1P), molecular species (C(n)-) of ceramide (Cer), sphingomyelin (SM), hexosylceramide (HexCer), lactosylceramide (LacCer), and Cer 1-phosphate (Cer1P).

Comprehensive quantitative analysis of bioactive sphingolipids by high-performance liquid chromatography-tandem mass spectrometry.

There has been a recent explosion in research concerning novel bioactive sphingolipids (SPLs) such as ceramide (Cer), sphingosine (Sph), and sphingosine 1-phosphate (Sph-1P) and this has necessitated the development of accurate and user-friendly methodology for analyzing and quantitating the endogenous levels of these molecules. ESI/MS/MS methodology provides a universal tool used for detecting and monitoring changes in SPL levels and composition from biological materials. Simultaneous ESI/MS/MS analysis of sphingoid bases (SBs), sphingoid base 1-phosphates (SB-1Ps), ceramides (Cers), ceramide 1-phosphates (Cer-1P), glucosyl/galactosyl-ceramides (Glu-Cers), and sphingomyelins (SMs) is performed on a Thermo Fisher Scientific triple quadrupole mass spectrometer operating in a multiple reaction monitoring (MRM) positive ionization mode.

Novel analogs of D-e-MAPP and B13. Part 2: signature effects on bioactive sphingolipids.

Novel isosteric analogs of the ceramidase inhibitors (1S,2R)-N-myristoylamino-phenylpropanol-1 (d-e-MAPP) and (1R,2R)-N-myristoylamino-4'-nitro-phenylpropandiol-1,3 (B13) with modified targeting and physicochemical properties were developed and evaluated for their effects on endogenous bioactive sphingolipids: ceramide, sphingosine, and sphingosine 1-phosphate (Cer, Sph, and S1P) in MCF7 cells as determined by high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS). Time- and dose-response studies on the effects of these compounds on Cer species and Sph levels, combined with structure-activity relationship (SAR) data, revealed 4 distinct classes of analogs which were predominantly defined by modifications of the N-acyl-hydrophobic interfaces: N-acyl-analogs (class A), urea-analogs (class B), N-alkyl-analogs (class C), and omega-cationic-N-acyl analogs (class D). Signature patterns recognized for two of the classes correspond to the cellular compartment of action of the new analogs, with class D acting as mitochondriotropic agents and class C compounds acting as lysosomotropic agents.

The human FA2H gene encodes a fatty acid 2-hydroxylase.

2-Hydroxysphingolipids are a subset of sphingolipids containing 2-hydroxy fatty acids. The 2-hydroxylation occurs during de novo ceramide synthesis and is catalyzed by fatty acid 2-hydroxylase (also known as fatty acid alpha-hydroxylase). In mammals, 2-hydroxysphingolipids are present abundantly in brain because the major myelin lipids galactosylceramides and sulfatides contain 2-hydroxy fatty acids.

The relaxin-like factor is a hormone.

The relaxin-like factor (RLF) circulates in the bloodstream of humans, interacts with a membrane protein with all the characteristics of ligand-receptor binding, and must therefore be considered a hormone by definition. The polyclonal antibody raised against synthetic human RLF showed no crossreactivity to other structurally related hormones, like insulin and relaxin. The sensitivity of this assay (ED50 at 100 pM) allowed the direct measurement of RLF concentrations in serum.

Relaxin receptors in mice: demonstration of ligand binding in symphyseal tissues and uterine membrane fragments.

A monocomponent, high specific activity, carrier-free porcine relaxin tracer (125I) has made it possible for us to demonstrate relaxin receptors in the symphysis pubis, uterus, and ovary via autoradiography. The receptors are concentrated in the symphyseal ligament and the peripheral layers of uterus and ovary. Specific relaxin binding was observed in crude membrane preparations of uteri, ovaries, and brain, whereas crude membranes of leg muscle and kidney showed only nonspecific binding.

Accumulation of tetrahydrofolates in human plasma after leucovorin administration.

Reduced folates in plasma after i.v. and oral leucovorin administration were estimated by a ternary complex assay based on the incorporation of CH2FH4 into a stable complex with Lactobacillus casei thymidylate synthase and [3H]FdUMP.

Biosynthesis, metabolism and regulation of steroid hormones secretion in the placental phase of gestation in the rat.

The regulation of biosynthesis of steroid hormones in the pre-placental stage and in placental phase of pregnancy in the rat is described. On the ground of our own studies a concept of an ovarian-placental unit in the rat has been formulated. This unit is characterized by coupled biosynthesis and secretion of steroid hormones in the placental stage of rat pregnancy.