Joanna Piasecka-Zelga

Oxidative stress induced in rat liver by anticancer drugs doxorubicin, paclitaxel and docetaxel

PURPOSE Oxidative stress generated by anticancer drugs in non-targeted tissues, is considered as a significant factor responsible for their severe side effects, e.g. cardiotoxicity, neurotoxicity and hepatotoxicity. Lack of data on the effect of concurrent administration of commonly used anticancer drugs: doxorubicin (DOX), paclitaxel (PTX) and docetaxel (DTX) on normal tissue, prompted us to examine the markers of oxidative stress in the liver of rats treated with these drugs. MATERIAL/METHODS Male Wistar rats of average weight 200 g were injected intraperitoneally (i.p.) with 10 mg/kg of body weight (b.w.) of DOX, PTX and DTX. The drugs were given alone or in combinations DOX+taxane. The activities of superoxide dismutase (SOD), catalase (CAT), low molecular weight and total thiols and thiobarbituric acid-reactive substances (TBARS) were estimated. RESULTS Combination of two drugs generated greater changes than single agents. Concurrent administration of DOX and PTX increased SOD activity and TBARS, decreased the amount of low molecular weight and total thiols, but did not cause any changes in the activity of catalase. Combination of DOX and DTX induced similar changes except for the activity of catalase, which decreased after the treatment. Of the three drugs only DTX significantly decreased the activity of SOD. However, both taxanes increased the activity of catalase. Although a decrease in concentration of -SH groups, depletion of glutathione and an increase of TBARS were observed after treatment with single drugs, the changes were not statistically significant. CONCLUSION Concurrent administration of DOX and taxane induced enhanced oxidative stress in comparison to single drugs, which suggests their synergistic prooxidant mode of action in liver.

Quercetin attenuates oxidative stress in the blood plasma of rats bearing DMBA-induced mammary cancer and treated with a combination of doxorubicin and docetaxel.

The development of side-effects during doxorubicin-docetaxel (DOX-DTX) chemotherapy is considered as related to generation of oxidative stress by DOX. The addition of docetaxel potentiates this effect. Thus, antioxidants are assumed as a promising remedy for neutralizing deteriorating effects of reactive oxygen species (ROS) in pathological conditions and polyphenolic antioxidants are suitable candidates for such a therapeutic approach. We evaluated the ability of quercetin to attenuate oxidative stress developed during the process of DMBA carcinogenesis and DOX-DTX chemotherapy in the blood plasma of rats bearing mammary tumors. We have found that quercetin significantly improved the plasma nonenzymatic antioxidant capacity (NEAC) and reduced lipid peroxidation, which suggest the beneficial effect of flavonoid. The inclusion of quercetin to the DOX-DTX chemotherapy was also advantageous. A considerable decrease of carbonyls and lipid peroxidation products (TBARS) and improvement of the endogenous antioxidant defense system (an increase of NEAC, thiols and SOD activity) were observed compared to rats treated with DOX-DTX chemotherapy. These results suggest that quercetin could protect blood plasma constituents against oxidative damage evoked by DOX and DTX.

Immunological determinants in a murine model of toluene diisocyanate-induced asthma

ObjectivesDiisocyanates (DIC) are highly reactive, low-molecular-weight chemicals which are the leading cause of occupational asthma (OA). The aim of the study was to analyze certain aspects of the pathogenesis of allergic inflammation in the airways induced by toluene diisocyanate (TDI) in an experimental model in mice.Materials and MethodsThe experiment was carried out on 50 female BALB/cJ/Han/IMP mice, which were exposed by inhalation (intranasal and in the inhalation chamber) to toluene diisocyanate (2,4-TDI). After the experiment, the bronchoalveolar lavage fluid (BALF) was collected from the animals, and the composition of the induced inflammatory cells, and the concentrations of certain cytokines (IL-4, IL-5, TNF-α) were evaluated.ResultsThe total number of cells in BALF of the examined group of mice was significantly higher compared to the control mice. There was also a significant increase in neutrophils and eosinophils in the study group compared to the controls. The number of lymphocytes and macrophages did not differ significantly between the two groups. A statistically significant increase in the level of TNF-α was shown to occur in the group exposed to toluene diisocyanate in comparison to the control group. The concentration of IL-4 increased in the study group, compared to the control one, but the differences did not reach the level of significance, p > 0.05. Such difference was not observed for IL-5.ConclusionsWe developed a murine model of TDI-induced asthma which caused the influx of inflammatory cells like eosinophils and neutrophils in the bronchoalveolar lavage fluid (BALF) in the TDI-treated mice. The increase of the concentration of some proinflammatory cytokines (TNF-α, IL-4) in BALF from the exposed mice was also observed.

Anti-tumor potential of nitroxyl derivative Pirolin in the DMBA-induced rat mammary carcinoma model: A comparison with quercetin

BACKGROUND Considering the role of oxidative stress in carcinogenesis, we investigated the effect of synthetic antioxidant Pirolin (3-carbamoyl-2,2,5,5-tetramethylpyrroline-1-oxyl) on breast cancer progression. Since the anticancer drugs may cause cardiotoxicity due to oxidative stress in the heart muscle, we also evaluated Pirolin performance in heart tissue and compared its effect with that of the natural dietary flavonoid quercetin. METHODS Sprague-Dawley rats were administered with 7,12-dimethylbenz(a)anthracene (DMBA) and then treated ip with an antioxidant (each at a dose of 10mg/kg b.w.) for 14 days. The histopathology of tumors, their size and multiplicity were assesed. The effect of antioxidants on heart tissue was evaluated by the oxidative stress markers and poly (ADP-ribose) polymerase 1 (PARP 1) cleavage. RESULTS The median number of tumors and their volume, at the end of the study, were considerably smaller in both antioxidant-treated groups. We found a better antioxidative performance of quercetin in the heart, since a restoration of the GSH pool and decreased amount of hydroperoxides were observed. Antioxidants did not prevent cardiomyocytes from apoptosis. CONCLUSION The attenuation of tumor progression by Pirolin was comparable with the action of quercetin. No negative changes were observed in the heart of animals after Pirolin treatment. Thus, its use in targeting deregulated redox pathways should be further studied.

Effect of inhaled toluene diisocyanate on local immune response based on murine model for occupational asthma

Abstract Highly reactive, low-molecular-weight diisocyanates (DIC) are the most commonly identified cause of occupational asthma (OA). Animal/clinical studies of DIC asthma have been more limited compared with atopic asthma, and an understanding of DIC pathogenesis is less clear. The aim of this study was to investigate in a mouse model, toluene diisocyanate (TDI, as 2,4-TDI isomer)-induced inflammatory reactions/cytokine profile changes in the lungs and accompanying changes in lymph node lymphocyte sub-populations. The study used female BALB/cJ/Han/IMP mice that were exposed first intra-nasally and then in an inhalation chamber to TDI or air. After the final exposure, bronchoalveolar lavage fluid (BALF) was collected and changes induced in inflammatory cell composition, levels of key cytokines (i.e. IL-4, TNFα, IFNγ), and lymphocyte sub-population profiles within auricular lymph nodes, were evaluated. Total number of cells in the BALF of treated mice was significantly higher than in control mice BALF. There was also a significant increase in BALF neutrophil and eosinophil levels with TDI mice compared to in controls; lymphocyte and macrophage numbers did not significantly differ. A significant increase in BALF levels of TNFα and IFNγ was also noted in mice exposed to TDI relative to levels in controls. BALF IL-4 levels were also increased, but the change from control was not significant. Lastly, the levels/percentages of CD3+CD4+ (T-helper [TH]) lymphocytes significantly increased in the lymph nodes of TDI-exposed groups while those of the CD3+CD8+ cells decreased as compared to in control mice. These studies, the first to assess TDI-induced changes in levels of three key cytokines in BALF in conjunction with changes in local lymph nodes following first an intra-nasal and then a general inhalation exposure to a low-level of TDI, confirm that TDI inhalation induces a pathology manifested by airway inflammation, TH cell-derived cytokine production, and shifts in lymph node lymphocytes sub-populations toward increases in TH cells.

Partial protection from organophosphate-induced cholinesterase inhibition by metyrapone treatment

BackgroundOrganophosphates are cholinesterase (ChE) inhibitors with worldwide use as insecticides. Stress response, evidenced by a dramatic and relatively long-lasting (several hours) rise in the plasma glucocorticoid concentration is an integral element of the organophosphate (OP) poisoning symptomatology. In rodents, corticosterone (CORT) is the main glucocorticoid. There are several reports suggesting a relationship between the stressor-induced rise in CORT concentration (the CORT response) and the activity of the cerebral and peripheral ChE. Thus, it seems reasonable to presume that, in OP intoxication, the rise in plasma CORT concentration may somehow affect the magnitude of the OP-induced ChE inhibition. Metyrapone (MET) [2-methyl-1,2-di(pyridin-3-yl)propan-1-one] blocks CORT synthesis by inhibiting steroid 11β-hydroxylase, thereby preventing the CORT response. Chlorfenvinphos (CVP) [2-chloro-1-(2,4-dichlorophenyl) ethenyl diethyl phosphate] is an organophosphate insecticide still in use in some countries.Material and MethodsThe purpose of the present work was to compare the CVP-induced effects — the rise of the plasma CORT concentration and the reduction in ChE activity — in MET-treated and MET-untreated rats. Chlorfenvinphos was administered once at 0.0, 0.5, 1.0 and 3.0 mg/kg i.p. Metyrapone, at 100 mg/kg i.p., was administered five times, at 24-h intervals. The first MET dose was given two hours before CVP.ConclusionThe following was observed in the MET-treated rats: i) no rise in plasma CORT concentration after the CVP administration, ii) a reduced inhibition and a faster restitution of blood and brain ChE activities. The results suggest that MET treatment may confer significant protection against at least some effects of OP poisoning. The likely mechanism of the protective MET action has been discussed.

Tissue reaction to the nickel implants in the guinea pigs

ObjectivesThe aim of the study was the assessment of local tolerance to nickel implants during 9 months observation in guinea pigs sensitized to nickel before implantation and non-sensitized ones.Materials and MethodsThree groups of guinea pigs were included in the study: 10 sensitized to nickel by the guinea pig maximization test; 10 previously non-sensitized and 10 in control group. In 20 animals (except control group) the nickel implants were inserted in the muscle of the back. After 9 months of observation, the animals were patch-tested with 5% nickel sulfate. Also percentage of eosinophils in peripheral blood was examined. Next, the tissue surrounding the implant and skin from the area of patch tests were collected for the histological examination.ResultsIn 70% of previously sensitized animals, the patch test confirmed the sensitivity to nickel. In 60% of previously non-sensitized animals, a positive reaction to nickel occurred. The results of patch tests in control group were negative. Percentage of eosinophils in peripheral blood was fourfold higher in animals sensitized to nickel than in control group. In histological examination, in the tissue surrounding the implant a dissimilarity concerning the intensity of cellular infiltration was observed between animals previously allergic and non-allergic to nickel. In the 2 of 10 previously sensitized guinea pigs quite severe inflammatory reactions in the inside of connective tissue capsule were noted which may indicate a local allergic reaction. The histological images of skin collected from the positive patch test site corresponded with the typical allergic contact dermatitis.ConclusionsNickel implants may cause primary sensitization to nickel. The nature of the histological changes in the tissues around the implants in guinea pigs sensitized to nickel may correspond to an allergic reaction. The examination of percentage of eosinophils in blood of guinea pigs may be useful in assessing the allergenic activity of metal alloys containing nickel.

An in vivo biocompatibility study of surgical meshes made from bacterial cellulose modified with chitosan

Bacterial cellulose modified with chitosan (MBC) is an innovative biomaterial used in regenerative medicine which may potentially improve treatment outcomes mesh for hernia repair surgery by facilitating better absorption in native tissue with less risk of mesh-related infections. The aim of the present study was to evaluate the biocompatibility of mesh based on MBC, and determine whether immunological reactions occur due to hypersensitivity to the implants. Forty five Imp:WIST rats were randomly assigned to be implanted with one of three mesh types: simple polypropylene mesh (n = 15), mesh modified by bacterial cellulose only (n = 15) and MBC mesh (n = 15) and evaluated after one and three months following intramuscular implantation. For MBC mesh, basic toxicological studies, i.e. Acute Dermal Irritation, Intradermal Reactivity and Acute Sensitization (GPMT), were also carried out on 9 Imp:BN albino rabbits and 15 Imp:D-H guinea pigs. The lowest immune response and the highest degree of fibroplasia were observed for MBC mesh both after one and three months after implantation. Toxicological studies classified the tested MBC mesh as a barely perceptible irritant with no signs of sensitization or allergic reactions observed during the studies. The findings indicate that MBC mesh does not irritate, does not sensitize and does not cause hypersensitivity in the implant site, and therefore presents a low risk of provoking such reactions in humans.

Acute dermal toxicity and sensitization studies of novel nano-enhanced UV absorbers

Acute dermal toxicity and sensitization studies of novel nano‐enhanced UV absorbers: Joanna Piasecka‐Zelga, et al. Institute of Occupational Medicine, Research Laboratory for Medicine and Veterinary Products in the GMP Quality System, Poland