The Level of Isoprostanes as a Non-invasive Marker for in vivo Lipid Peroxidation in Secondary Progressive Multiple Sclerosis

Oxidative stress leads to lipid peroxidation and may contribute to the pathogenesis of lesions in multiple sclerosis (MS), an autoimmune disease characterized by inflammatory as well as degenerative phenomena. Isoprostanes are prostaglandin-like compounds which are formed by free radical catalysed peroxidation of arachidonic acid esterified in membrane phospholipids. They are a new class of sensitive specific markers for in vivo lipid peroxidation. In this study 26 patients (15 females and 11 males; mean age 48.2 ± 15.2 year; mean disease duration 10.0 ± 6.5 year) with secondary progressive MS (SPMS) and 12 healthy controls were enrolled. In patients with multiple sclerosis the lipid peroxidation as the level of urine isoprostanes and the level of thiobarbituric acid reactive species (TBARS) in plasma were estimated. Moreover, we estimated the total antioxidative status (TAS) in plasma. It was found that the urine isoprostanes level was over 6-fold elevated in patients with SPMS than in control (P < 0.001). In SPMS patients TBARS level was also statistically higher than in controls (P < 0.01). However, we did not observed any difference of TAS level in serum between SPMS patients and controls (P > 0.05). In patients with SPMS the lipid peroxidation and oxidative stress measured as the increased level of isoprostanes was observed. Thus, we suggest that the level of isoprostanes may be used as non-invasive marker for a determination of oxidative stress what in turn, together with clinical symptoms, may determine an specific antioxidative therapy in SPMS patients

Thrombin inhibitory activity of some polyphenolic compounds

Thrombin, also known as an active plasma coagulation factor II, belongs to the family of serine proteases and plays a crucial role in blood coagulation process. The process of thrombin generation is the central event of the hemostatic process and regulates blood coagulant activity. For this reason, thrombin inhibition is key to successful novel antithrombotic pharmacotherapy. The aim of our present study was to examine the effects of the well-known polyphenolic compounds on the activity of thrombin, by characterization of its interaction with selected polyphenols using different biochemical methods and biosensor BIAcore analyses. Only six compounds, cyanidin, quercetin, silybin, cyanin, (+)-catechin and (−)-epicatechin, of all examined in this study polyphenols caused the inhibition of thrombin amidolytic activity. But only three of the six compounds (cyanidin, quercetin and silybin) changed thrombin proteolytic activity. BIAcore analyses demonstrated that cyanidin and quercetin caused a strong response in the interaction with immobilized thrombin, while cyanin and (−)-epicatechin induced a low response. Lineweaver–Burk curves show that used polyphenol aglycones act as competitive thrombin inhibitors. Our results suggest that polyphenolic compounds might be potential structural bases and source to find and project nature-based, safe, orally bioavailable direct thrombin inhibitors.This work was supported by Grant 545/485 and Grant 506/810 from the University of Lodz

The effect of pre-incubation of Allium cepa L. roots in the ATH-rich extract on Pb uptake and localization

The positive influence of anthocyanin (ATH) on toxic metal-treated plant material is well documented; however, it is still not explained if it is caused by changes in element absorption and distribution. Therefore, detailed analysis of the effect of the ATH-rich extract from red cabbage leaves on Pb uptake and localization at morphological, anatomical and ultrastructural level was the goal of this study. Two-day-old adventitious roots of Allium cepa L. (cv. Polanowska) were treated for 2 h with the aqueous solution of Pb(NO3)2 at the concentration of 100 μM with or without preliminary incubation in the anthocyanin-rich extract from Brassica oleracea L. var. capitata rubra leaves (250 μM, 3 h). The red cabbage extract did not change the total Pb uptake but it enhanced the translocation of accumulated metal from roots to shoots. Within the pretreated roots, more Pb was deposited in their basal part and definitely smaller amount of the metal was bound in the apoplast of the outer layers of cortex cells. The ultrastructural analysis (transmission electron microscopy and X-ray microanalysis) revealed that the ATH-rich extract lowered the number of Pb deposits in intracellular spaces, cell wall and cytoplasm of root meristematic cells as well as in such organelles important to cell metabolism as mitochondria, plastids and nucleus. The Pb deposits were preferably localised in those vacuoles where ATH also occurred. This sequestration of Pb in vacuoles is probably responsible for reduction of metal cytotoxicity and consequently could lead to better plant growth.This work was supported by the grant of the University of Lodz, no. 505/04038

Melatonin Redox Activity. Its Potential Clinical Application in Neurodegenerative Disorders.

Neurodegeneration is the hallmark of many chronic progressive neurogical disorders characterized by specific clinical, morphological and biochemical features. Central nervous system is very sensitive to oxidative stress, which is considered as a key factor of neurodegenerative disorders. Therefore, many therapeutical strategies are focused on molecules with redox activity to re-establish the equilibrium between pro and antioxidants. Due to the fact that melatonin readily crosses the blood- brain-barrier, concomitant with its safety profile at the highest dosages makes this dietary supplement very useful in possible clinical application in neurodegeneration. Melatonin is currently marketed in several countries as a dietary supplement with no prescription. Clinical trials have shown different effectiveness of melatonin supplementation in several disorders, including neurodegenerative disorders. Melatonin has unique biochemical properties such as scavenging of hydroxyl, carbonate, alkoxyl, peroxyl and aryl cation radicals and stimulation of activities main antioxidative enzymes (glutathione peroxidase, superoxide dismutase etc.). Moreover, it can suppress nitric oxide synthase. The present paper highlighted the potential clinical role of melatonin in main neurodegenerative diseases including Alzheimer disease, Parkinson disease, amylotrophic lateral sclerosis and multiple sclerosis. Moreover, in this review the main molecular aspects of melatonin in brain cell protection and survival mechanisms were discussed. Therefore, melatonin is regarded as a potential therapeutical agent in clinical application in neurodegenerative disorders, but this findings needs to be confirmed by the larger, more well-designed clinical trials

Peroxynitrite a strong biological oxidant

As demonstrated in recent years, one of the major factors of oxidative stress, generated in the circulatory system, in both acute and chronic pathological conditions, is peroxynitrite (ONOO –) [4]. Peroxynitrite is a strong biological oxidant and nitrating compound, generated in vivo from a rapid reaction of two relatively less reactive, but commonly found, of free radicals: nitrogen monoxide (NO ) and superoxide (O2–) [8]. This reaction occurs spontaneously and is not catalyzed by any enzyme. A fundamental reaction of ONOO – in biological systems is its fast reaction with carbon dioxide (k = 5,7 ź 104 M–1 s–1) and yields a short-lived intermediate, nitrosoperoxycarbonate (ONOOCO 2 –), which homolyzes leads to the formation of carbonate (CO 3–) and nitrogen dioxide (NO 2) radicals (yield ~35%) [29, 30] (Fig. 1), which are one-electron oxidants. ONOO – is responsible for oxidative modifications in a wide variety of biomolecules and is capable to induce of nitrative changes in sulfur and aromatic amino acids, especially 3-nitrotyrosine and dityrosine formation [17] (Fig. 2). This article describes the formation, reactivity and biological action of peroxynitrite