Aurothiomalate as Preventive and Chain‐Breaking Antioxidant in Radical Degradation of High‐Molar‐Mass Hyaluronan

Abstract

The potential anti- or pro-oxidative effects of a disease-modifying antirheumatic drug, aurothiomalate, to protect high-molar-mass hyaluronan against radical degradation were investigated along with L-glutathione - tested in similar functions. Hyaluronan degradation was induced by the oxidative system Cu(II) plus ascorbate known as the Weissberger's oxidative system. The time- and dose-dependent changes of the dynamic viscosity of the hyaluronan solutions were studied by the method of rotational viscometry. Additionally, the antioxidative activity of aurothiomalate expressed as a radical-scavenging capacity based on a decolorization 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay was inspected. At the higher concentrations tested, L-glutathione showed excellent scavenging of (.) OH and peroxyl-type radicals, however, at the lowest concentration applied, its pro-oxidative effect was revealed. The effects of aurothiomalate on hyaluronan degradation were similar to that of L-glutathione, however, at the lowest concentration tested, no significant pro-oxidant effect was observed.

Hyaluronan and synovial joint: function, distribution and healing

“…High molecular weight hyaluronan samples were exposed to free-radical chain degradation reactions induced by ascorbate in the presence of Cu(II) ions, the so called Weissberger's oxidative system. The concentrations of both reactants [ascorbate, Cu(II)] were comparable to those that may occur during an early stage of the acute phase of joint inflammation (see Figure 6) (Banasova et al, 2011; Valachova et al, 2011; Soltes et al, 2006a; Soltes et al, 2006b; Stankovska et al, 2004; Soltes et al, 2006c; Soltes et al, 2007; Valachova et al, 2008; 2009; 2010; 2011; 2013; Hrabarova et al, 2009, 2011; Rapta et al, 2009; 2010; Surovcikova-Machova et al, 2012; Banasova et al, 2011; Drafi et al, 2010; Fisher & Naughton, 2005). …”

“…Generation of H 2 O 2 by Weissberger's system from ascorbate and Cu(II) ions under aerobic conditions (Valachova et al, 2011)…”

“…Effect of A) l -penicillamine, B) l -cysteine and C) bucillamine with different concentrations (50, 100 µM) on HA degradation induced by the oxidative system containing 1.0 µM CuCl 2 + 100 µM ascorbic acid (Valachova et al, 2011). …”

Impact of Ergothioneine, Hercynine, and Histidine on Oxidative Degradation of Hyaluronan and Wound Healing

“…Dynamic viscosity of the reaction mixture (8 mL) containing HA (2 mg/mL), ascorbate (100 µmol/L) along with Cu(II) ions (1 µmol/L) in the absence and presence of the examined compounds (10, 50, and 100 µmol/L) was reported by a Brookfield LVDV-II+PRO digital rotational viscometer (Brookfield Engineering Labs., Middleboro, MA, USA). The parameters of the measurement were: Temperature 25.0 ± 0.1 • C, shear rate of 237.6 s −1 , 180 rpm, data report every 3 min within 5 h [37,38].…”

Antioxidative properties of Sambacus nigra extracts

“…Brought to you by | New York University Bobst Library Technical Services Authenticated Download Date | 6/8/15 12:06 PM 0.15 M aqueous NaCl) containing HA (2.5 mg mL −1 ), ascorbate (100 M) plus Cu(II) ions (1 M) in the absence and in the presence of elderberry extracts 2006 and 2012 (1 mg mL −1 , 10 mg mL −1 and 100 mg mL −1 ) was monitored by a Brookfield LVDV-II+PRO digital rotational viscometer (Brookfield Engineering Labs., Middleboro, MA, USA) at (25.0 ± 0.1) • C and at the shear rate of 237.6 s −1 for 5 h in a Teflon cup reservoir (Valachová et al, 2011). The elderberry extracts as potential protective agents were introduced into the HA reaction system before or 1 h after the HA degradation started.…”