Effects of salicylate-copper complex on the metabolic activation in phagocytizing granulocytes

Possible implementation of salicylate anions in lead detoxification

The water-soluble coordination polymer of formula {[Pb(Sal)₂(H₂O)]_n} (SaLead), was obtained from the reaction between Pb(NO₃)₂ and the potassium salt of salicylic acid (SalH), an anti-inflammatory drug, which is also use as food preservation, in cosmetics etc. The compound was characterized by melting point, Attenuated Total Reflectance-Fourier Transform Infra-Red (ATR-FTIR) spectroscopy and X-ray diffraction crystallography (XRD) in solid state and in solution by Ultra Violet (UV) and ¹H NMR spectroscopies. The binding affinity of SalK to Pb(II) ions towards SaLead was determined in order to examine its possible implementation in lead detoxification. The in vitro non-toxic behaviour of SalK and its complex SaLead was evaluated against normal human fetal lung fibroblast cells (MRC-5). The corresponding IC₅₀ values are 260 ± 13 and > 1600 μM respectively. The non-genotoxic in vitro activity of SaLead was confirmed with the micronucleus (MN) assay, while its in vivo non-toxicity behaviour was evaluated with Allium cepa and Artemia salina assays.

Modulation of polymorphonuclear leukocyte responsiveness by copper (II)2 (niflumate)4

Antiinflammatory activities and modulations of PMNL responses produced by treatment with tetrakis-mu-2-[3-(trifluoromethyl)-phenyl]aminonicotinatodicopper (II) [Cu(II)2(niflumate)4] and niflumic acid were studied in isologous serum-induced rat pleurisy. Doses of 10 or 30 mg/kg (35 or 106 mumol/kg) of niflumic acid or Cu(II)2(niflumate)4 (8 or 23 mumol/kg) caused significant (p < 0.01) reductions in pleural exudate and number of polymorphonuclear leukocytes (PMNLs) in the exudate. While both doses of Cu(II)2(niflumate)4 produced significant dose-related reductions in both parameters, only the higher dose of niflumic acid produced a significant dose-related reduction in both parameters. Boyden chamber measurements of N-formyl-methionyl-leucyl-phenylalanine (f-MLP) chemotaxis by PMNLs incubated with 10 or 30 micrograms/ml niflumic acid (35 or 106 nmol/ml) or Cu(II)2(niflumate)4 (8 or 23 nmol/ml) were significantly (p < 0.01 to p < 0.001) decreased in dose-related fashions. Chemotaxis of PMNLs from pleuritic rats treated orally with 10 or 30 mg/kg niflumic acid or Cu(II)2(niflumate)4 was significantly (p < 0.001) inhibited by the larger dose of niflumic acid and both doses of Cu(II)2(niflumate)4. Opsonized zymosan (OZ)-stimulated chemiluminescence (CL) of PMNLs from pleuritic rats treated orally with these same doses of niflumic acid or Cu(II)2(niflumate)4 was only significantly (p < 0.05 or p < 0.01 respectively) decreased by the larger doses. Superoxide (O2-) production by these cells was significantly decreased by the larger dose of niflumic acid (p < 0.05) while both doses of Cu(II)2(niflumate)4 produced significant (p < 0.05 to p < 0.01) decreases.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition by superoxide dismutase-mimetic copper complexes of phorbol ester-induced respiratory burst in human granulocytes

Two superoxide dismutase-mimetic lipophilic copper complexes, Cu(II)2(indomethacin)4 [Cu(II)2(indo)4] and Cu(II)2(3,5-diisopropylsalicylate)4 [Cu(II)2(3,5-DIPS)4], were tested for their effects on the respiratory burst of intact human granulocytes and on xanthine oxidase, under conditions where superoxide and hydrogen peroxide were generated. The effect of the copper complexes on these enzyme systems (as opposed to their dismutase effect on superoxide) was determined by measuring oxygen uptake with an oxygen meter. It was found that, after a short delay, both systems were inhibited markedly by micromolar amounts of these complexes. This inhibition was prevented by treatment with EDTA or catalase if added prior to starting the reaction. Similar inhibitory effects were seen using copper sulfate. It appears that these lipophilic SOD-mimetic compounds can, in the presence of H2O2 and O2-, give rise to a species that can inhibit some component of the respiratory burst oxidase or protein kinase C in intact granulocytes and xanthine oxidase in solution. The observed decrease in O2- levels observed upon addition of these compounds is likely due to inhibition of the source and not to their SOD-mimetic properties.

The superoxide dismutase-like activity of some copper(II) complexes derived from tridentate Schiff bases

Oxygen free radicals are the final or intermediate products of many metabolic reactions. Of greatest significance to the organism are superoxide anion radical (O2-.), hydrogen peroxide (H2O2), hydroxyl radical (.OH), singlet oxygen (1O2) etc. A proper ratio between both production and breakdown of oxy-radicals is essential for the maintenance of a dynamic equilibrium of vital processes. The superoxide dismutases protect cells against toxic influence of the superoxide. In addition, some square-pyramidally pentacoordinated copper(II) complexes, derived from tridentate Schiff bases of the N-salicylideneaminoalcanoate type, show remarkable SOD-like activity. A selected set of complexes of this type have been tested: potassium [aqua-(N-salicylideneglutamato) cuprate] (L- and D,L-form), potassium [(isothiocyanato)-(N-salicylideneglycinato) cuprate], potassium [(isothiocyanato)-(N-salicylidene-D,L-alaninato) cuprate], potassium [(isothiocyanato)-(N-salicylidene-beta-alaninato) cuprate] and potassium [(isocyanato)-(N-salicylideneglycinato) cuprate]. Our results suggest that the copper complexes are not only antioxidants, but may also possess anti-inflammatory, cytostatic and radioprotective properties.

Oxidant-dependent metabolic activation of polycyclic aromatic hydrocarbons by phorbol ester-stimulated human polymorphonuclear leukocytes: possible link between inflammation and cancer

Oxidants, such as those generated by metabolically activated phagocytes in inflammation, have been implicated in the metabolic activation of carcinogens, and in this study we demonstrate that the interaction of (+/-)-trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (BP 7,8-dihydrodiol) with phorbol ester-stimulated polymorphonuclear leukocytes (PMNs) results in the generation of both a chemiluminescent intermediate and one that covalently binds to DNA. Cu(II)(3,5-diisopropylsalicylic acid)2 (CuDIPS), a biomimetic superoxide dismutase, and azide, a myeloperoxidase inhibitor, inhibited both of these reactions, indicating a dependency on oxygen-derived oxidants in these hydrocarbon-activation processes. Concordant with the formation of a carcinogen-DNA adduct, the admixture of BP 7,8-dihydrodiol and phorbol ester-stimulated PMNs elicited mutagenesis in Salmonella typhimurium strain TA100. 7,8-Dihydro-BP and BP cis-7,8-dihydrodiol were also mutagenic, whereas derivatives lacking a double bond at the 9,10 position were not. These results demonstrate that oxidants generated by metabolically stimulated PMNs can activate penultimate polycyclic aromatic hydrocarbons to a genotoxic metabolite and further defines a role for inflammation in carcinogenesis.

Some new data to the toxicological effects of paraquat and the therapy

1. Substances previously tested therapeutically were studied to obtain evidence on the pathomechanism in mice of paraquat, the active ingredient of Gramoxon, connected with the radicals formed from molecular oxygen, and also to extend the therapeutic possibilities. 2. The effects of these substances were assessed on the basis of the 72-hr survival rate and the percentage ratio of the wet lung weight to the overall body weight. 3. Other toxicological parameters too were followed. 4. Our present investigations indicate that, in agreement with our earlier results, besides reduced glutathione and ascorbic acid, vitamin E and C-ase are of the greatest importance from the aspect of the protection against paraquat toxicity. 5. In addition to those listed, other materials too, e.g. antifibrotic substances, naturally possess considerable detoxicating properties too.

Zinc, copper, and manganese in immune function and experimental oncogenesis

Dietary deficiency of trace metals among human populations, once thought to be exceedingly rare, has recently gained attention as a potential public health problem. The consumption of highly refined and heavily processed foods reduces the trace element content of the diet. The higher trace element requirements of pregnancy, lactation, growth, development, and chronic disease may further contribute to states of marginal trace metal nutriture. Experimental animal studies have demonstrated that even marginal trace element deprivation during critical periods of growth and development or, alternately, during prolonged deficiency in adults can significantly alter immunologic function. Furthermore, trace metal nutriture has been shown to affect initiation and progression of a large variety of neoplasia. Studies of the interaction of trace metal nutriture and cancer have, however, suffered from many methodological inconsistencies as well as failures to define and quantitate the trace element content of diets and the host alterations in response to neoplastic challenge. Similarly, there has been little information in the critical area of marginal and moderate trace metal deficiency, i.e., those experimentaL situations most analogous to deficiencies that may occur in human populations. In this review, an attempt is made first to place in perspective experimental data relevant to these issues, and second to emphasize the desirability of further investigation in this critical area of human nutrition.