Anti-inflammatory activity of copper salicylates applied to rats percutaneously in dimethyl sulphoxide with glycerol

Cupric yersiniabactin is a virulence-associated superoxide dismutase mimic

Many Gram-negative bacteria interact with extracellular metal ions by expressing one or more siderophore types. Among these, the virulence-associated siderophore yersiniabactin (Ybt) is an avid copper chelator, forming stable cupric (Cu(II)-Ybt) complexes that are detectable in infected patients. Here we show that Ybt-expressing E. coli are protected from intracellular killing within copper-replete phagocytic cells. This survival advantage is highly dependent upon the phagocyte respiratory burst, during which superoxide is generated by the NADPH oxidase complex. Chemical fractionation links this phenotype to a previously unappreciated superoxide dismutase (SOD)-like activity of Cu(II)-Ybt. Unlike previously described synthetic copper-salicylate (Cu(II)-SA) SOD mimics, the salicylate-based natural product Cu(II)-Ybt retains catalytic activity at physiologically plausible protein concentrations. These results reveal a new virulence-associated adaptation based upon spontaneous assembly of a non-protein catalyst.

Effects of copper, iron and zinc on oedema formation induced by phospholipase A2

1. Intradermal or subplantar injection of soluble snake venom phospholipase A2 (PLA2) evoked a brisk inflammatory response, with cutaneous vascular permeability increase and paw oedema. 2. These inflammatory processes are mainly the result of arachidonic acid cascade activation and mast cell degranulation. 3. Copper, iron and zinc have an inhibitory effect on vascular permeability increase and paw oedema induced by PLA2. 4. Copper and iron could have not only a direct effect on PLA2 but on enzymes of arachidonic acid cascade. 5. However, zinc have a moderate antiinflammatory activity. This effect could be the result to inhibit PLA2 induced mast cell degranulation.

[The modification of the mechanically loaded periodontium during orthodontically induced tooth movement with nonsteroidal anti-inflammatory agents in an animal experiment]

In a total of 123 female adult Wistar rats the first upper molar was moved by orthodontics for more than 28 days. This orthodontically stimulated tooth movement was influenced by local application of Cu-salicylate, Cu-indomethacin or epsilon-Aminocapronacid. The application of Cu-salicylate and Cu-indomethacin caused reduced tooth movement, a decrease in osteoclasts in the pressure region of the periodontium, and an increase of hydroxyproline in the desmodont. Generally, the local application of Cu-nonsteroidal antiphlogistics seems to stabilize the experimentally induced tooth movement.

Irritancy and anti-inflammatory activity of bis(eta 5-cyclopentadienyl)titanium(IV) complexes in rats

Dichloro-bis(eta 5-cyclopentadienyl)titanium(IV) and some related complexes were compared with cis-dichlorodiammineplatinum(II) in rats for acute anti-inflammatory activity against carrageenan paw oedema, anti-arthritic activity against developing and established adjuvant-induced polyarthritis, immunosuppressant activity in a local graft-vs. host assay, irritant effects at sites of administration (paw, skin, peritoneum) and nephro- and gastro-toxicities. These titanium complexes, like cisplatin and its hydrolysis products, in vivo exhibited both anti-inflammatory and anti-arthritic activity as well as immunosuppressant effects. Nephro- and gastro-toxicity were much less severe than in rats given platinum complexes. In vitro they selectively inhibited [3H]thymidine incorporation by isolated thymocytes and prevented the germination of radish seeds. When given intraperitoneally, the anti-inflammatory activity may partly be due to a counter-irritant phenomenon since the titanium derivatives elicited an acute peritoneal effusion if they were injected towards the omentum. However, when injected subcutaneously or applied in dimethylformamide or dimethylsulfoxide to the skin, they manifested both anti-inflammatory and anti-arthritic activity without irritancy or much local skin damage. They might therefore have the potential of being useful drugs, especially if released slowly.

Biodistribution of 64Cu in inflamed rats following administration of two anti-inflammatory copper complexes

64Cu was administered in two anti-inflammatory formulations to normal rats and to rats with 2 forms of local inflammation, namely (a) an acute paw oedema (elicited with carrageenan) or (b) a chronic granulomatous response to an implanted irritant (Mycobacterium tuberculosis in a polyurethane sponge). The copper formulations used were (i) a slow release one consisting of Cu(II) salicylate applied dermally with ethanol/DMSO and (ii) short acting hydrophilic complex (Cu(I)Cu(II)-penicillamine)5- given subcutaneously. Three types of changes in copper biodistribution with these forms of inflammation were discerned based on determination of 64Cu and copper content in the following organs: inflammatory locus (foot or sponge implant), kidney, liver, spleen, adrenals, brain, blood, thymus, heart, and skin (site of application). The most evident changes were in the kidneys, liver, spleen, adrenals, thymus and serum from animals with chronic granulomatous inflammation. In contrast, a short term acute inflammatory stress (carrageenan paw oedema) had little effect. While copper D-penicillamine (applied subcutaneously) appeared to move as a bolus through the animals, the results with the percutaneous copper salicylate formulation are consistent with it providing a slow release source of copper(II). Exogenous 64Cu from both formulations was sequestered at inflammatory sites (relative to serum). This may partly explain how applied copper complexes can be anti-inflammatory.

Biodistribution of 64Cu in rats after topical application of two lipophilic anti-inflammatory Cu(II) formulations

64Cu(II) is extensively absorbed and excreted, mainly in the faeces, when applied to the skin of rats as complexes with (a) salicylate in ethanol with dimethylsulphoxide and glycerol or (b) phenylbutazone in dimethyl sulphoxide and glycerol, previously found to be anti-inflammatory. 64Cu distribution paralleled that observed after administering aqueous 64Cu-salicylate i.m. It is concluded that copper(II) can pass rapidly through the dermal barriers when applied with an appropriate cupriphore and presented in a medium with low water content.

Copper and ceruloplasmin (Cp) concentrations during the acute inflammatory process in the rat

We have measured the concentration of copper and ceruloplasmin in serum of rats with carrageenan foot-oedema and in serum and exudate of rats with carrageenan pleurisy. Both serum copper and ceruloplasmin were found to increase in both models of inflammation. In these experimental conditions we have shown a strong positive correlation between copper and ceruloplasmin, in the serum of both normal and inflamed rats.

Lipophilic copper(II) formulations: some correlations between their composition and anti-inflammatory/anti-arthritic activity when applied to the skin of rats

Copper complexes of phenols related to salicylic acid were prepared in DMSO and applied to the shaved dorsal skin of rats. The following activities were assayed: (i) suppression of the carrageenan or hydroxylapatite paw oedemas; (ii) reduction of chronic inflammation in established adjuvant arthritis; (iii) local skin toxicity. Cu(II) was an essential component. Some limited structure-activity correlations were made among alternative cupriphores. DMSO solutions of copper complexes were more potent than their solutions in ethanol. Glycerol was a beneficial additive. Reducing the acidity of some copper salicylate formulations also reduced their potency. Niflumic acid and phenylbutazone were effective non-salicylate transcutaneous cupriphores.

Anti-inflammatory properties of copper implants in the rat paw edema: a preliminary study

Metallic copper has been shown to possess anti-inflammatory activity in the carrageenan foot paw edema of the rat, when applied in the form of an implant. The implant was installed two months before the edema was induced. It is postulated that the anti-inflammatory activity is due to dissolved copper from the implant.