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Journal Article 2010; 31(Suppl 2): 101-104 PubMed PMID: 21187839 Citation  Keywords:  Antioxidants:pharmacology, Ascorbic Acid:pharmacology, Copper:pharmacology, Cysteamine:pharmacology, Dose-Response Relationship, Drug, Glutathione:pharmacology, Hyaluronic Acid:metabolism, Hydrogen Peroxide:metabolism, Hydroxides:metabolism, Oxidation-Red.   

OBJECTIVE: This study presents the results of antioxidative and pro-oxidative efficacy of cysteamine and D-penicillamine (D-pen) in comparison to L-glutathione (L-GSH) on high-molar-mass hyaluronan (HA) degradation by cupric ions plus ascorbic acid.

METHODS: The substance tested was applied in the degradative system cupric ions plus ascorbate: (i) before the reaction onset or also (ii) 1 h after the reaction started. The results obtained were compared with that one recorded by using the degradative system in the absence of the substance tested. To monitor HA degradation kinetics, rotational viscometry was applied. Moreover, the standard ABTS and DPPH assays were used.

RESULTS: By using the method of rotational viscometry, D-pen showed dual effect: initial inhibitory effect on •OH radicals was changed to a pro-oxidative one in the dose and time dependent manner. Both L-GSH and cysteamine were recorded to be more effective scavengers of •OH radicals than D-pen. Cysteamine demonstrated to be an excellent scavenger also of alkoxyl- and peroxyl- type radicals. Based on IC50 values, gained by ABTS assay, it is evident that D-pen showed higher radical scavenging capacity compared to cysteamine. Similar results were observed also in DPPH assay, although in this assay less effective radical scavenging capacities of both substances tested were recorded.

CONCLUSIONS: On the basis of the results obtained, it can be stated that D-pen can produce hydrogen peroxide or •OH radicals and can inhibit the production of these oxidants. Our results showed that both L-GSH and cysteamine are similarly effective in inhibiting of HA degradation. Moreover, cysteamine demonstrated to be a significant inhibitor of alkoxyl- and peroxyl- type radicals generated from C-type macroradical of HA....

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Journal Article 2006; 27(Suppl 2): 180-182 PubMed PMID: 17159810 Citation  Keywords:  Animals, Copper:pharmacology, Fatty Acids, Unsaturated:metabolism, Lipoxygenase:metabolism, Lipoxygenase Inhibitors:pharmacology, Models, Biological, Organometallic Compounds:pharmacology, Rats,.   

OBJECTIVES: Lipoxygenases (EC 1.13.11.12, LOX) catalyze the hydroperoxidation of polyunsaturated fatty acids (PUFA). This reaction leads to the production of conjugated hydro peroxide dienes of PUFA. In animals, LOX generate leukotriens (LT) and lipoxins, which belong to inflammatory mediators. It is believed that restricting LT synthesis by inhibition of LOX would have therapeutic utility for the treatment of a variety of inflammatory conditions (e.g. asthma, rheumatoid arthritis, psoriasis).

METHODS & RESULTS: The process of production and elimination of radical intermediates in vitro can be monitored by determination of LOX activity. We assessed the concentration of PUFA hydroperoxides in our system with LOX-catalyzed enzyme reaction spectrophotometrically. The inhibition of LOX activity (LOX from cytosol fraction of rat lungs) with selected N-salicylideneaminoalkanoatocopper(II) complexes was tested. In our experiments, all compounds tested showed an inhibitory effect on LOX catalyzed hydroperoxidation of PUFA. Cu(II) (from CuSO(4).5H(2)O dilution) ions also inhibited this enzyme reaction, but all compounds studied had a 10 times higher anti-LOX activity. The most effective of these complexes was monohydrate aqua-(N-salicylidene-L-a-alaninato)copper(II) complex [Cu(sal-L-alpha-ala)(H(2)O)].H(2)O with IC(50) 1.86 x 10(-4) mol/l.

CONCLUSIONS: These complexes are known for their anti-phlogistic and radioprotective properties and they can be classified as potential anti-radical compounds. The structure of these complexes is similar to the active site of Cu,Zn-SOD (superoxide dismutase) and superoxide radical scavenger activity of these complexes is known. We found that these copper complexes were capable to inhibit LOX activity, which may be related with their anti-radical properties....

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