Copper and zinc status in adjuvant-arthritic rat: studies on blood, liver, kidneys, spleen and inflamed paws

Copper(II) complexes as potential anticancer and Nonsteroidal anti-inflammatory agents: In vitro and in vivo studies

Copper-based compounds are promising entities for target-specific next-generation anticancer and NSAIDS therapeutics. In lieu of this, benzimidazole scaffold plays an important role, because of their wide variety of potential functionalizations and coordination modes. Herein, we report three copper complexes 1-3 with benzimidazole-derived scaffolds, a biocompatible molecule, and secondary ligands viz, 1-10-phenanthroline and 2,2'-bipyridyl. All the copper complexes have been designed, synthesized and adequately characterized using various spectroscopic techniques. In-vitro, human serum albumin (HSA) binding was also carried out using fluorescence technique and in-silico molecular modeling studies, which exhibited significant binding affinities of the complexes with HSA. Furthermore, copper complexes 1-3 were tested for biological studies, i.e., anticancer as well as NSAIDS. In vitro cytotoxicity results were carried out on cultured MCF-7 cell lines. To get the insight over the mechanism of action, GSH depletion and change in lipid peroxidation were tested and thus confirmed the role of ROS generation, responsible for the cytotoxicity of the complexes 1-3. Moreover, the copper complexes 1-3 were tested for potential to act as NSAIDS on albino rats and mice in animal studies in-vivo. Additionally, we also predicted the mechanism of action of the copper complexes 1-3 using molecular modeling studies with COX-2 inhibitor.

In vivo assessment of newly synthesized achiral copper(ii) and zinc(ii) complexes of a benzimidazole derived scaffold as a potential analgesic, antipyretic and anti-inflammatory

Two new complexes of copper(ii) and zinc(ii) were synthesized and characterized using various spectroscopic techniques. The newly synthesized compounds were screened for analgesic, antipyretic and anti-inflammatory activities.

Evaluation of the anti-inflammatory and analgesic effects of Cu(II) and Zn(II) complexes derived from 2-(naphthalen-1-yloxy)-N'-(1-(pyridin-2-1)ethylidene) acetohydrazide

New Cu(II) and Zn(II) complexes of 2-(naphthalen-1-yloxy)-N'-(1-(pyridin-2-yl)ethylidene) acetohydrazide (HA2PNA) have been prepared and characterized by elemental analyses, spectral (IR, UV-visible, ESR and 1H NMR) as well as magnetic and thermal measurements. According to the data, the complexes assigned the formulae: [Cu(A2PNA)2]H2O and [Zn(A2PNA)(OAc)(H2O)], respectively. IR data revealed that the ligand acts as before ONN and after morever ONN mononegative tridentate via deprotonated carbonyl oxygen (CO) and both (CN)imine and (CN)pyridine nitrogen atoms. The bond lengths, bond angles, HOMO, LUMO, dipole moment and charges on the atoms have been calculated by using density functional theory (DFT) at B3LYP level with 6-31G and 6-31G(d,p) basis sets to confirm the geometry of the ligand and the investigated complexes. Also, the kinetic parameters were determined for each thermal degradation stage of the complexes using Coats-Redfern and Horowitz-Metzger methods. Moreover, the complexes have been tested for anti-inflammatory and analgesic activity in rat model of collagen adjuvant arthritis and compared with piroxicam. All the compounds showed a significant anti-inflammatory and analgesic effect versus piroxicam.

Effect of green tea extract and vitamin C on oxidant or antioxidant status of rheumatoid arthritis rat model

Elevated free radical generation in inflamed joints and impaired antioxidant system has been implicated in rheumatoid arthritis (RA). Green tea extracts (GTE) have been shown to reduce inflammation in inflammatory arthritis murine model. This study investigates possible mechanisms by which vitamin C and GTE protect joints in RA rat model. This study included forty adult male rats that were divided into four groups (10 rats each); control group, collagen II induced RA group (CII), CII treated with vitamin C (CII + Vit C) and CII treated with GTE (CII + GTE) in physiology laboratory, Assiut University, Egypt. After 45 days of treatment, plasma levels of lipid peroxides (LPO), nitric oxide (NO), ceruloplasmin (CP), superoxide dismutase (SOD), uric acid (UA) and glutathione (GSH) were detected using colorimetric methods, PGE(2) using ELISA and copper (Cu) and zinc (Zn) using spectrometer. In CII group, levels of LPO, NO, PGE(2), UA, CP, Cu were higher while SOD, GSH, Zn were lower than controls. In groups treated with vitamin C and GTE, levels of SOD, GSH were increased while levels of LPO, NO, PGE(2), Cu, CP were decreased compared with CII group. Levels of UA were decreased and Zn increased in GTE treated group compared with CII group. GTE treated group showed higher Zn and low Cu levels compared with vitamin C treated group. This study suggests proper GTE and vitamin C intake may effectively normalize the impaired oxidant/antioxidant system and delaying complication of RA.

Copper and zinc intake and serum levels in patients with juvenile rheumatoid arthritis

OBJECTIVE

To evaluate the copper and zinc intake and serum levels in patients with juvenile rheumatoid arthritis (JRA), considering the pauci and polyarticular types, the disease activity and duration, the number of inflamed joints and the use of corticosteroids therapy.

DESIGN

Cross-sectional study with control group.

SETTING

Outpatients of the pediatric rheumatology public health clinic, of the Universidade Federal de São Paulo/Escola Paulista de Medicina, Brazil.

SUBJECTS

Forty-one patients with JRA were evaluated and 23 patients' brothers, as a control group.

INTERVENTIONS

Copper and zinc intake evaluation by Food Register method. Copper and zinc serum levels by atomic absorption spectrophotometry.

RESULTS

The disease activity did not determine difference in copper (P=0.624) and zinc (P=0.705) intake, being predominantly below the Recommended Dietary Allowances. The serum copper in relation to control was statistically greater (P=0.018), showing that the number of inflamed joints is statistically significantly related with its variation (P=0.001). The serum zinc was not different either in relation to control (P=0.940) or to the disease characteristics.

CONCLUSIONS

The evaluation of copper intake seems to be of fundamental importance. It may influence the efficiency of the organic serum response. More research is needed to indicate, with security, adequate zinc intake.

Secretory sphingomyelinase

Several physiologic and pathophysiologic processes in which sphingomyelinases (SMases) have been implicated may involve extracellular sphingomyelin (SM) hydrolysis. A candidate enzyme for these processes is a recently discovered SMase called secretory SMase, or S-SMase. S-SMase arises from the acid sphingomyelinase (ASM) gene via differential protein trafficking of a common protein precursor; this precursor can be targeted to either lysosomes or the Golgi secretory pathway. S-SMase is activated by physiologic levels of Zn2+, although the S-SMase from endothelial cells, which secrete abundant amounts of the enzyme, is partially Zn2+-independent. S-SMase functions best at acid pH but can hydrolyze certain physiologic substrates, such as atherogenic lipoproteins, at neutral pH. In endothelial cells, the secretion of S-SMase is regulated at the level of protein trafficking by inflammatory cytokines. Current work implicates a role for S-SMase in atherogenesis, and future work will be directed at understanding the potential roles of S-SMase in other processes, such as ceramide-mediated cell-signaling and the host inflammatory response.

Serum zinc and copper in active rheumatoid arthritis: correlation with interleukin 1 beta and tumour necrosis factor alpha

Serum zinc and copper levels and serum interleukin 1 beta (IL1 beta) and tumour necrosis factor alpha (TNF alpha) levels were evaluated in 57 female patients with active rheumatoid arthritis (RA) to investigate a possible role of IL1 beta and TNF alpha on zinc and copper homeostasis in RA. Serum zinc levels were significantly lower and serum copper levels significantly higher in RA patients when compared with osteoarthritis or asymmetrical psoriatic oligoarthritis patients and with normal controls. No differences were observed in serum IgM rheumatoid factor positive and serum IgM rheumatoid factor negative patients as regards serum zinc and copper concentration. In RA patients the erythrocyte sedimentation rate and acute-phase proteins correlated negatively with serum zinc and positively with serum copper. IL1 beta and TNF alpha were found to correlate negatively with zinc and positively with copper in RA patients. Lower levels of zinc may be due to an accumulation of zinc-containing proteins in the liver and in the inflamed joints in RA. Elevated serum copper levels seem to be linked to the increased synthesis of ceruloplasmin by the liver.

Neutrophil behavior following exposure to in vivo or in vitro zinc in normal and acutely-inflamed rats: studies on lysozyme secretion, superoxide anion release and platelet adhesion

The mechanism was studied of the anti-inflammatory effect of oral zinc (114 mg/kg/day of elemental metal, given for 14 days) on the development of the carrageenan-induced paw oedema of the rat, and the impact of in vivo treatment on the activity of neutrophils isolated from the blood of inflamed and non-inflamed animals. The effects of the in vitro incubation with the metal on either non-inflamed or inflamed neutrophils coming from zinc-untreated rats were also examined. It was found that the administration of oral zinc inhibited markedly the process of ex vivo adhesion of the cells obtained from the inflamed rats (an observation confirmed by the in vitro experiments). In vitro release of lysozyme and superoxide anion productions were measured: in the absence of zinc, the 30' of pre-incubation carried out before stimulating with PMA did not influence the cell's reactivity of the non-inflamed neutrophils. It was, on the contrary, capable of significantly reducing that of the inflamed ones. As a consequence, it is quite difficult to properly interpret the data obtained studying the activity of the cells exposed to the metal in vitro.

Human vascular endothelial cells are a rich and regulatable source of secretory sphingomyelinase. Implications for early atherogenesis and ceramide-mediated cell signaling

We recently reported that macrophages and fibroblasts secrete a Zn2+-dependent sphingomyelinase (S-SMase), which, like lysosomal SMase, is a product of the acid SMase gene. S-SMase may cause subendothelial retention and aggregation of lipoproteins during atherogenesis, and the acid SMase gene has been implicated in ceramide-mediated cell signaling, especially involving apoptosis of endothelial cells. Because of the central importance of the endothelium in each of these processes, we now sought to examine the secretion and regulation of S-SMase by vascular endothelial cells. Herein we show that cultured human coronary artery and umbilical vein endothelial cells secrete massive amounts of S-SMase (up to 20-fold more than macrophages). Moreover, whereas S-SMase secreted by macrophages and fibroblasts is almost totally dependent on the addition of exogenous Zn2+, endothelium-derived S-SMase was partially active even in the absence of added Zn2+. Secretion of S-SMase by endothelial cells occurred both apically and basolaterally, suggesting an endothelial contribution to both serum and arterial wall SMase. When endothelial cells were incubated with inflammatory cytokines, such as interleukin-1beta and interferon-gamma, S-SMase secretion by endothelial cells was increased 2-3-fold above the already high level of basal secretion, whereas lysosomal SMase activity was decreased. The mechanism of interleukin-1beta-stimulated secretion appears to be through increased routing of a SMase precursor protein through the secretory pathway. In summary, endothelial cells are a rich and regulatable source of enzymatically active S-SMase, suggesting physiologic and pathophysiologic roles for this enzyme.

Effect of Santolina oblongifolia on ACII-immunized animals

The therapeutic effect of organic extracts of Santolina oblongifolia in adjuvant-carrageenan-induced inflammation (ACII) in Wistar rats was investigated. The present study concerns the effect of the extracts on serum copper (Cu) and zinc (Zn) levels, and on hindpaw swelling and ankle joint widths of arthritic animals. Compared with controls, the arthritic animals showed an increase in serum Cu levels, while serum Zn was decreased. The altered levels of trace elements in arthritic animals were significantly normalized in the chronic phase of the disease after treatment with most of the extracts of S. oblongifolia. Additionally, administration of the extracts significantly decreased the clinical signs of inflammation. The results of the present investigation indicated that these extracts could offer a partial protective action against changes induced by ACII in Wistar rats.

Zinc reduces the hyperalgesia and upregulation of NGF and IL-1 beta produced by peripheral inflammation in the rat

The effect of systemic zinc administration on the inflammatory hyperalgesia induced by intraplantar injections of either complete Freund's adjuvant (CFA) or bacterial endotoxin/lipopolysaccharide (LPS) in a hindpaw of adult rats was investigated. CFA injection resulted in mechanical and thermal hyperalgesia and an elevation in the levels of interleukin-1 beta (IL-1 beta) and nerve growth factor (NGF) in the ipsilateral hindpaw. Zinc treatment (20 nmole) significantly reduced sensitivity in the early phase of the inflammation and diminished the increase in the levels of IL-1 beta and NGF without affecting paw swelling. Intraplantar LPS injection also produced mechanical hyperalgesia and this too was reduced by zinc administration in a dose-dependent fashion (0.1-20 nmoles). Our results indicate that zinc has an analgesic action during early inflammation and that this may be the consequence of reducing levels of the inflammatory cytokine IL-beta and the growth factor NGF.

The utility of chelating agents as antidotes for nephrotoxicity of gold sodium thiomalate in adjuvant-arthritic rats

The effects of 2,3-dimercaptopropane sulphonate (DMPS) and N-(2-mercapto-2-methylpropanoyl)-L-cysteine (bucillamine) against the renal damage induced by gold sodium thiomalate (AuTM) in adjuvant-arthritic rats were studied. Arthritic rats induced by adjuvant using Mycobacterium butyricum were injected intraperitoneally with a chelating agent (0.6 mmol/kg) immediately after intramuscular injection of AuTM (0.066 mmol/kg) every other day for 21 days. Treatment with DMPS and bucillamine prevented increases in the urinary excretion of protein, aspartate aminotransferase, and glucose and blood urea nitrogen level after AuTM injection. AuTM prevented the increase in both adjuvant-injected and uninjected hind-feet volumes. The prevention of these inflamed lesions by AuTM was not affected by DMPS and bucillamine. These chelating agents decreased the gold concentration in the kidney and liver after AuTM administration, but did not affect the hepatic and renal concentrations of copper, zinc, iron, and calcium except the renal copper level after AuTM. These findings suggest that DMPS and bucillamine are very useful antidotes for gold toxicity.

Wasting in adjuvant-induced arthritis and its relationship to plasma zinc, copper and liver metallothionein

The appearance of joint inflammation (JI) 14 days after the injection of adjuvant (AJ) in the tail of rats is associated with a cachectic syndrome which is characterised by marked weight loss (WL). The degree of weight loss was examined in relation to the extent of change in other markers of inflammation including increased plasma copper (pCu), decreased plasma zinc (pZn) and increased hepatic metallothionein (hMT). At 14 days post-AJ injection, arthritic rats showed the following changes, relative to the controls: body weight, 12% decrease, pZn, 50% decrease; pCu, 90% increase and hMT, 11-fold increase (all p < 0.001). Significant relationships were observed between JI, WL, pZn and hMT. The following coefficients of determination (r2) were observed; JI and WL, -0.530, JI and pZn, -0.485; JI and hMT, 0.286; WL and hMT, -0.510 (all p < 0.007). There was a strong relationship between the decreased pZn and increased hMT; r2 = 0.456 (p < 0.001). While increased pCu was clearly associated with AJ-arthritis in these rats, there was no quantitative relationship between the extent of change in pCu and the other parameters measured (r2 all < 0.01). The highest correlation observed was between pZn and WL (r2 = 0.637, p < 0.001). While the initial depression of pZn may be the result of increased hepatic hMT levels, longer term reductions in pZn levels are linked to systemic inflammation, the degree of arthritis and associated weight loss.

Copper and zinc body levels in inflammation: an overview of the data obtained from animal and human studies

The development of acute and chronic inflammatory processes induces, in the laboratory animal, a net accumulation of both copper and zinc in many body compartments, the inflamed area included. In rheumatoid arthritis, as well as in animal models, only plasma zinc concentration seems to be significantly correlated with disease severity, while the increase in total plasma copper could be described as an "all or nothing" phenomenon. Moreover, in rheumatoid arthritis, it appears that the disease develops and progresses without being linked to either copper or zinc deficiency conditions. Thus, it seems reasonable to suggest that a rationale for the use of copper and/or zinc in the treatment of inflammatory disorders can only be drawn from the intrinsic pharmacological properties of such trace elements, rather than from the need for their repletion.