Reactivity of active center analogs of Cu2Zn2 superoxide dismutase on activated polymorphonuclear leukocytes

Severe antioxidase deficiency in human semen samples with pathological spermiogram parameters

Spermatozoa of 103 ejaculates from infertile patients and fertile healthy individuals were separated from seminal plasma and purified on Percoll gradient to determine the activities of superoxide dismutase (SOD) and catalase (CAT) in seminal plasma as well as in spermatozoal supernatants after hypotonic disintegration of the sperm plasma membrane. Out of collected specimens, a subgroup of ejaculates from 40 individuals was examined whose female partners had developed malignant processes in the cervix uteri (oncological subgroup). All sperm samples were classified into normal and pathological semen samples according to WHO criteria. While no significant differences of SOD levels were detected in seminal plasma of patients with primary infertility, a catalase deficiency seemed to be associated with combined sperm pathology-oligoasthenoteratozoospermia (OAT). Liberated concentrations of both SOD and catalase were diminished by 10-70% in the oncological subgroup compared to normozoospermia. In four OAT samples obtained from infertile males of the oncological subgroup, total depletion from both antioxidases was observed. A lack of sufficient antioxidase protection in cases of severe sperm pathology (OAT) may also lead to cervical dysplasia.

Hepatoprotective reactivity of a copper-di-Schiffbase active centre analogue of Cu2Zn2 superoxide dismutase

1. The anti-inflammatory and hepatoprotective efficacy of CuPu(Py)2 ((N,N'-bis(2-pyridyl-methylene)-1,4-butanediamine) (N,N',N",N")-Cu2+), a serum-stable, copper-di-Schiffbase active centre analogue of Cu2Zn2 superoxide dismutase was tested in male NMNR mice suffering from endotoxin/galactosamine-induced hepatitis. 2. Parameters including the activities of serum transaminases and sorbitol-dehydrogenase as well as the levels of reactive oxygen and nitrogen intermediates which were used to quantify the disease activity. 3. A dose-dependent inhibition of hepatic enzyme release was noted in the presence of 0.1-10 mg/kg of CuPu(Py)2. 4. The release of transaminases from damaged liver cells was reduced by 68% and paralleled the reduction of serum levels of nitric oxides. 5. Elevated levels of reactive oxygen species were normalized to those healthy controls. 6. The copper-free apochelate Pu(Py)2, which is unable to dismutate superoxide, did not display any anti-inflammatory reactivity.

Effects of allopurinol on in vivo suppression of arthritis in mice and ex vivo modulation of phagocytic production of oxygen radicals in whole human blood

Recently, we demonstrated elevated levels of xanthine oxidase in serum of patients with various inflammatory and autoimmune rheumatic diseases. The present study reports the antiarthritic efficacy of the xanthine oxidase inhibitor and immunosuppressant allopurinol in DBA/1xB10A(4r) mice suffering from peroxochromate-induced arthritis. A profound dose-dependent suppression of arthritis was noted (P < 0.001). The ED50 was 80 +/- 14 mumol/kg/day. The arthritis index correlated positively to the phagocytic production of oxygen radicals (r2 > 0.672) and negatively to the concentrations of allopurinol (r2 = 0.915). Ex vivo, allopurinol and various conventional antirheumatic drugs were screened for the inhibition of 12-O-tetradecanoylphorbol-13-acetate-stimulated whole human blood chemiluminescence. The concentrations of antirheumatic drugs required to inhibit the chemiluminescence by 50% were compared to the therapeutic doses administered to rheumatic patients. While D-penicillamine and cis-platinum(II) increased the phagocytic generation of superoxide, nonsteroidal antiinflammatory drugs (NSAIDs), steroids, and slow-acting antirheumatic drugs (SAARDs) inhibited the whole blood chemiluminescence in a dose-dependent manner. Therapeutic doses of NSAIDs, SAARDs, or steroids inhibited the phagocytic generation of reactive oxygen species by 10-50%. In addition to well-known mechanisms of action of NSAIDs and SAARDs, our results support the hypothesis that most common anti-rheumatic drugs act also by modulating the levels of reactive oxygen species, which serve important mediator and signal transduction functions in inflammatory and autoimmune diseases. Pharmacologically safe antioxidants like allopurinol, which simultaneously modify the oxidative burst of phagocytes, inhibit xanthine oxidase, and display immunosuppressive effects may well be suited to control the consequences of chronic phagocytic hyperreactivity in rheumatic patients.

Suppression of arthritis by an active center analogue of Cu2Zn2-superoxide dismutase

The anti-arthritic and anti-inflammatory efficacy of CuPu(Py)2 ([N,N'-bis(2-pyridylmethylene)-1,4-butanediamine] (N,N',N",N"))-Cu(II), a serum-stable active center analogue of Cu2Zn2-superoxide dismutase (SOD; EC 1.15.1.1), was tested in male DBA/1 x B10A (4R) mice suffering from potassium-peroxochromate-induced (PIA) or collagen type II-induced arthritis (CIA). Parameters including the arthritis index, the plasma SOD activity, and the inhibition of phagocytic responses in unseparated blood were used for the assessment of disease activity. A dose-dependent suppression of arthritis was noted in both models. The ED50 was 2.5 +/- 0.4 mumol/kg/day of CuPu(Py)2 for PIA and 4.0 +/- 1.1 mumol/kg/day for CIA. The arthritis index correlated with both the levels of reactive oxygen species (ROS) generated by phorbol ester-activated neutrophils and monocytes in unseparated blood (r = 0.892) and the SOD-like activity in plasma (r = 0.857). CuPu(Py)2 inhibited also the lipoplysaccharide-induced release of tumor necrosis factor alpha from human monocytes and neutrophils in a dose-dependent manner. Unlike SOD, which exerts successful anti-rheumatic activity mainly upon intra-articular injection, the SOD-mimic CuPu(Py)2 can be applied systemically. Non-proteinaceous low molecular weight antioxidases may well be suited to control oxidative stress-derived damage in rheumatic diseases by modulation of ROS-dependent signal transduction pathways.

Reactivity of an active center analog of Cu2Zn2superoxide dismutase in murine model of acute and chronic inflammation

The antiinflammatory efficacy of CuPu(Py)2 ([[N,N'-bis(2-pyridylmethylene)-1,4-butanediamine] (N,N',N'',N''')]-Cu2+), a serum stable active center analog of Cu2Zn2superoxide dismutase (SOD), was tested in vitro and in vivo in male Wistar rats suffering from potassium peroxochromate-induced inflammation. Parameters including 99mTc gamma-scintigraphic imaging, the arthritis score, the plasma superoxide dismutase activity, the inhibition of plasma sulfhydryl depletion as well as mitogenic and phagocytic responses were used to quantify the disease activity. All parameters improved impressively during the treatment with CuPu(Py)2 and resembled those of healthy animals after 21 days. The arthritis score was inhibited by 80% (P > 0.001) and the plasma SOD activity enhanced by 380% (P > 0.001). The depletion of plasma sulfhydryls and the leukocytic responses to concanavalin A, tetradecanoylphorbolacetate, and lipopolysaccharide were significantly reduced (P > 0.001) and correlated well with the arthritis score. The collapse of antioxidant defenses in human plasma as well as the depolymerization of hyaluronic acid was mimicked in vitro and successfully inhibited by CuPu(Py)2. Oxidant-induced injury of plasma components during the aqueous decay of potassium peroxochromate were demonstrated to activate the oxidative burst of phagocytes in human blood. The role of impaired pro- and antioxidant balances in the etiology of inflammatory and autoimmune rheumatic diseases is discussed.

Elevated levels of xanthine oxidase in serum of patients with inflammatory and autoimmune rheumatic diseases

Sera of patients with various inflammatory and autoimmune rheumatic diseases were screened for the presence of xanthine oxidase (XOD) and compared to sera from healthy donors and patients with nonrheumatic diseases including AIDS, internal diseases, and different carcinomas. Up to 50-fold higher levels of XOD were detected in rheumatic sera (P < 0.001). In addition, serum sulfhydryls (SH) were determined as sensitive markers of oxidative stress. The SH status in rheumatic patients was diminished by 45-75% (P < 0.001) and inversely correlated to the concentration of serum XOD (R = 0.73), suggesting a causal interrelation. The depletion of serum sulfhydryls by the oxyradical-producing XOD/acetaldehyde system was mimicked successfully ex vivo in human serum from healthy donors. Cortisone treatment of patients suffering from systemic lupus erythematosus and rheumatoid arthritis impressively normalized elevated XOD concentrations in rheumatic sera to those of healthy controls. The participation of xanthine oxidase in the depletion of serum antioxidants in rheumatic patients is discussed in the light of substrate availability and Km values.

Reactive nitrogen intermediates, antinuclear antibodies and copper-thionein in serum of patients with rheumatic diseases

Sera from 354 patients with various inflammatory and autoimmune rheumatic diseases were screened for the presence of reactive nitrogen intermediates, antinuclear antibodies and the anti-oxidase copper-thionein (Cu-thionein), and compared to sera from healthy donors and patients with non-rheumatic diseases including AIDS, various internal as well as neurological diseases and carcinoma of different organs. When compared to healthy individuals, the levels of nitric oxides in sera from patients with autoimmune rheumatic diseases were elevated by 240-600% (P < 0.01). The status of reactive nitrogen intermediates (NOx, RNI) in sera from donors with inflammatory rheumatic diseases was increased by 170-540%, but was also significantly enhanced in sera of patients with non-rheumatic diseases, indicating a general inflammatory mechanism that is predominantly triggered by inducible nitric oxide (NO) syntheses of phagocytes. All rheumatic sera were dramatically depleted of the anti-oxidase Cu-thionein (P < 0.001), a powerful consumer of hydroxyl radicals and singlet oxygen and an efficient superoxide dismutase. The NOx levels were positively correlated with the serum titers of antinuclear antibodies (r = 0.77) and negatively correlated with Cu-thionein levels (r = 0.94), reflecting a high steady-state concentration of free radicals generated during inflammatory and autoimmune rheumatic diseases.

Copper-dependent antioxidase defenses in inflammatory and autoimmune rheumatic diseases

Gel-filtered sera of patients with various inflammatory and autoimmune rheumatic diseases (N = 354) were screened for the presence of the inflammation marker Cu-thionein. The concentrations of Cu-thionein were significantly diminished in patients with connective tissue diseases (P < 0.001). Sera of patients suffering from inflammatory rheumatic diseases were almost totally depleted of this low-molecular-weight copper protein that exerts pronounced superoxide dismutase activity and scavenges effectively hydroxyl radicals and singlet oxygen. Cortisone treatment of patients with rheumatoid arthritis, systemic lupus erythematosus, and polymyalgia rheumatica replenished impressively the serum concentration of Cu-thionein. The partial oxidation of the EPR-silent Cu(I)-chromophore to Cu(II)/Cu(I)-thionein, which is essential for the catalytic dismutation of superoxide, was monitored by electron paramagnetic resonance in the presence of activated neutrophils and monocytes. Release of Cu-thionein during the oxidative burst of peripheral blood monocytes was demonstrated in vitro. The role of prooxidant-antioxidant imbalances in the pathogenesis of rheumatic diseases is discussed.

Stable superoxide dismutase (SOD)-mimetic ternary human serum albumin-Cu(II)(3,5-diisopropylsalicylate)2/Cu(II)2(3,5-diisopropylsalicylate)4 complexes in tissue distribution of the binary complex

Copper(II)2(3,5-diisopropylsalicylate)4 [Cu(II)2(3,5-DIPS)4] has been found to have antiinflammatory, antiulcer, anticancer, anticonvulsant, antimutagenic, antidiabetic, analgesic, and radiation protection and recovery activities. It has also been found to reduce ischemia-reperfusion injury. Because of these activities it was of interest to understand how this compound is transported in the body to affected tissues. Evidence supporting the suggested formation of ternary human serum albumin (HSA)-Cu(II)(3,5-DIPS)2 or Cu(II)2(3,5-DIPS)4 complexes was obtained using ultraviolet spectrophotometry, dialysis, and atomic absorption spectrophotometry or atomic emission spectroscopy. Superoxide dismutase (SOD)-mimetic activity was also determined using the xanthine/xanthine oxidase/cytochrome c system. Ultraviolet spectra of aqueous solution mixtures of Cu(II)2(3,5-DIPS)4 in equilibrium with 2Cu(II)(3,5-DIPS)2 and HSA as well as aqueous solutions of solid Cu(II)2(3,5-DIPS)4 obtained by stirring the solid with an aqueous solution of HSA showed no obvious change in absorbance to indicate ternary complex formation. However, comparison of ultraviolet spectra taken before and after dialysis supports the suggested bonding of Cu(II)(3,5-DIPS)2 or Cu(II)2(3,5-DIPS)4 to HSA. Comparison of copper concentrations before and after dialysis also supports the suggested bonding of Cu(II)(3,5-DIPS)2 or Cu(II)2(3,5-DIPS)4 to HSA. Based upon these data it is plausible that Cu(II)(3,5-DIPS)2 or Cu(II)2(3,5-DIPS)4 form stable ternary complexes with HSA. These stable ternary complexes were also found to have SOD-mimetic activity.

Antiinflammatory reactivity of copper(I)-thionein

In unseparated human blood the reactivity of yeast copper (I)-thionein on TPA-activated polymorphonuclear leukocytes was evaluated and compared with low Mr copper chelates exerting Cu2Zn2 superoxide dismutase mimetic activity. Cu, 18 microM, in the form of Cu-thionein was sufficient to inhibit the superoxide production of activated human blood phagocytes by 50%. Furthermore, the scavenging of hydroxyl radicals and singlet oxygen by Cu(I)-thionein was determined, using the 2-deoxyribose fragmentation assay induced by decaying K3CrO8 and the NADPH oxidation caused by UVA illuminated psoralen, respectively. The inhibitory reactivity of Cu-thionein in both assays was compared with that of serum proteins including albumin, ceruloplasmin, transferrin, and ferritin. The galactosamine/endotoxin-induced hepatitis in male NMRI mice was used to evaluate the antiinflammatory reactivity of Cu-thionein in vivo. The serum copper, superoxide dismutase, and sorbitol dehydrogenase concentrations, as well as the activity of polymorphonuclear leukocytes in unseparated blood seemed most appropriate to quantify the protective capacity of Cu-thionein in the course of an oxidative stress-dependent liver injury. The intraperitoneal application of 32.5 mumols/kg thionein-Cu limited this damage to 45%.

Anticarcinogenic reactivity of copper-dischiffbases with superoxide dismutase-like activity

CuPu(Py)2 and CuPu(Im)2, two novel dischiffbase coordinated low Mr active centre analogues of Cu2Zn2 superoxide dismutase, were shown to effectively catalyze the production of hydroxyl radicals in the presence and absence of TPA-activated polymorphonuclear leukocytes. These stable copper chelates exhibited a pronounced anticarcinogenic reactivity in male Sprague Dawley rats implanted with Walker 256 carcinosarcoma cells. When four doses of 5 mumol/kg CuPu(Py)2 and CuPu(Im)2, respectively, were administered intratumorally, reduction in tumor size, delay of metastasis and a significant increase in survival of the hosts were observed, resulting in 75% of total remissions. 60% of the animals recovered totally from the carcinosarcoma, when CuPu(Py)2 was applicated intravenously.