97 resultados para PROTECTIVE EFFECT
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)
Resumo:
The aim of this study was to test a novel phytocompound in an experimental model of antitumor-induced immunosuppression. Five groups of mice were considered: young (Y) and aged (A) that were given intraperitoneally 10 doses of cyclophosphamide (CPX, 25mg/kg/bw) or CPX plus (150 mg/kg/bw) of the nutraceutical DTS (Denshichi-Tochiu-Sen), and control. After sacrifice, macrophage chemotaxis and serum levels of IFN-gamma, IL-2, and GM-CSF were determined. Liver and urinary bladder were examined histologically, as were the liver and kidney for redox enzymes. CPX significantly decreased macrophage chemotaxis and all cytokines (p < 0.05, A >> Y). DTS restored macrophage function and cytokine concentration (p < 0.001) and partly improved the necro-inflammatory score and substance P receptor expression in the bladder and the redox status in liver and kidney (p < 0.05). Such data suggest that DTS effectively prevents CPX-induced immune suppression and oxidative-inflammatory damage, which are particularly enhanced in aged organisms.
Resumo:
Purpose. Histological aspects were considered in order to evaluate the in vivo photoprotective effect of a w/o microemulsion containing quercetin against UVB irradiation-induced dermal damages. The toxicity in cell culture and the potential skin irritation resulting from topical application of this formulation were investigated. Methods. Mouse dorsal surfaces were treated topically with 300 mg of the unloaded and quercetin-loaded (0.3%, w/w) microemulsions before and after exposure to UVB (2.87 J/cm(2)) irradiation. The untreated control groups irradiated and non-irradiated were also evaluated. UVB-induced histopathological changes as well as the photoprotective effect of this formulation were evaluated considering the parameters of infiltration of inflammatory cells, epidermis thickening (basale and spinosum layers) and collagen and elastic fiber contents. The cytotoxicity of the reported formulation was evaluated in L929 mice fibroblasts by MTT assay and the skin irritation was investigated after topical application of both unloaded and quercetin-loaded microemulsions once a day for 15 days. Results. The results demonstrated that the w/o microemulsion containing quercetin reduced the incidence of histological skin alterations, mainly the connective-tissue damage, induced by exposure to UVB irradiation. This suggests that protective effects of this formulation against UV-induced responses are not secondary to the interference of UV transmission (i.e., blocking the UVB radiation from being absorbed by the skin), as is usually implied with UVB absorbers and sunscreens, but is instead due to different biological effects of this flavonoid. Furthermore, by evaluating the cytotoxic effect on L929 cells and histological aspects such as infiltration of inflammatory cells and epidermis thickness of hairless mice, the present study also demonstrated the lack of toxicity of the proposed system. Conclusion. Based on these mice models, a detailed characterization of the w/o microemulsion incorporating quercetin effects as a photochemoprotective agent on human skin is presented.
Resumo:
Carbon dioxide (CO(2)) has been used in the food industry as an antimicrobial agent. This study aimed to investigate whether CO(2) pneumoperitoneum might act similarly as an antimicrobial agent in the infected peritoneal cavity. Peritonitis was induced in 58 rats by intraabdominal injection of an Escherichia coli inoculum (6 x 105 colony-forming units [CFU]/ml). Control rats were injected with saline solution. The rats were randomly divided into four groups: rat control (RC, n = 15), bacterial inoculation control (BIC, n = 10), bacterial inoculation and laparotomy (BIL, n = 17), and bacterial inoculation and CO(2) pneumoperitoneum (BIP, n = 16). The survival rates and histopathologic changes in the abdominal wall muscles, spleen, liver, intestines, and omentum were evaluated, and the samples were classified as ""preserved"" or ""inflamed"" (acute inflammation or tissue regeneration). The survival rates for the four groups were as follows: RC (100%), BIP (75%), BIL (53%), and BIC (30%). With regard to survival rates, statistically significant differences were observed between the following groups: RC and BIC (p = 0.0009), RC and BIL (p = 0.0045), BIP and BIC (p = 0.0332), and RC and BIP (p = 0.0470). No significant differences regarding survival rates were observed between the BIL and BIC groups or between the BIP and BIL groups. With regard to the number of inflamed samples per group, a statistically significant difference was observed between the BIC and RC groups and the BIL and RC groups (p = 0.05). Carbon dioxide pneumoperitoneum has a protective effect against bacterial peritonitis induced in rats.
Resumo:
Indomethacin administration in animals increases permeability of the small intestine, leading to inflammation that mimics Crohn`s disease. Nonsteroidal anti-inflammatory drugs increase the permeability of the intestinal epithelial barrier and should therefore be used with caution in patients with Crohn`s disease. We analyzed the protective effects of octreotide and the tumor necrosis factor-alpha inhibitor infliximab in a rat model of indomethacin-induced enterocolitis. Male Wistar rats received 20 mg of infliximab or 10 mu g of octreotide 24 h prior to injection with indomethacin. Intestinal permeability was analyzed using Cr-51-ethylenediaminetetraacetic acid clearance. No microscopic or macroscopic alterations were observed in the rats receiving infliximab or octreotide, both of which increased permeability (P < 0.001 versus controls). Our macroscopic and microscopic findings might be related to the low specificity of infliximab and suggest that cytokines affect the intestinal epithelial barrier, as evidenced by the protective effect that infliximab had on the permeability parameters evaluated.
Resumo:
We investigated the effects of the antioxidant N-acetylcysteine (NAC) on early outcomes of deceased donor renal transplantation. Between April 2005 and June 2008, adult primary graft recipients of deceased renal donors were assigned to treatment (n = 38) or control (n = 36) groups and evaluated for 90 days and one year after renal transplantation. The treatment group received NAC orally (600 mg twice daily) from day 0 to 7 postoperatively. Renal function was determined by serum creatinine, MDRD and Cockcroft-Gault estimated GFR (eGFR), delayed graft function (DGF) and dialysis free Kaplan-Meier estimate curve. Serum levels of thiobarbituric acid reactive substances (TBARS), were employed as markers of oxidative stress. The NAC group displayed a lower mean serum creatinine during the first 90 days (P = .026) and at 1 year after transplantation (P = .005). Furthermore, the NAC group showed a higher mean eGFR throughout the first 90 days and at 1 year. DGF was lower among the NAC group (P = .017) and these recipients required fewer days of dialysis (P = .012). Oxidative stress was significantly attenuated with NAC (P < .001). Our results suggested that NAC enhanced early outcomes of deceased donor renal transplantation by attenuating oxidative stress.
Resumo:
Background/Aims. The transcription factor nuclear factor-kappa B (NF-kappa B) exerts a pivotal role in the pathogenesis of hepatic ischemia/reperfusion (I/R) injury. Caffeic acid phenyl ester (CAPE), a potent and specific NF-kappa B inhibitor, presents protective effects on I/R injury in some tissues. This study aimed to evaluate the effect of CAPE on hepatic I/R injury in rats. Materials and methods. Wistar rats were submitted to a sham operation, 60 min ischemia, or 60 min ischemia plus saline or CAPE treatment followed by 6 h reperfusion. Liver tissue injury was evaluated by alanine aminotransferase, aspartate aminotransferase, and tissue glutathione measurement, and histological damage score. Apoptotic hepatocytes were determined by the transferase-mediated dUTP-biotin nick-end labeling assay. Hepatic neutrophil accumulation was assessed by the naphthol method. Lipid peroxidation and NF-kappa B activation were evaluated by 4-hydroxynonenal and NF-kappa B p65 immunohistochemistry, respectively. Results. Animals submitted to ischemia showed a marked increase of alanine aminotransferase and aspartate aminotransferase after reperfusion, but with lower levels in CAPE group. Tissue glutathione content declined gradually during ischemia to reperfusion and was partially recovered with CAPE treatment. The histological damage score, apoptosis index, and neutrophil infiltration, as well as 4-hydroxynonenal and NF-kappa B p65 nuclear labeling, were higher in the liver of animals submitted to I/R compared to the ischemia group. However, the CAPE treatment significantly reduced all of these alterations. Conclusions. CAPE was able to protect the liver against normothermic I/R injury in rats. This effect may be associated with the inhibition of the NF-kappa B signaling pathway and decrease of the acute inflammatory response following I/R in the liver. (C) 2008 Elsevier Inc. All rights reserved.
Resumo:
Objective. To evaluate the antiinflammatory effects of RC-3095 in 2 experimental models of arthritis, collagen-induced arthritis (CIA) and antigen-induced arthritis (AIA), and to determine the mechanisms of action involved. Methods. RC-3095 was administered daily to mice with CIA and mice with AIA, after induction of disease with methylated bovine serum albumin. Disease incidence and severity were assessed using a clinical index and evaluation of histologic features, respectively. In mice with CIA, gastrin-releasing peptide receptor (GRPR) was detected by immunohistochemical analysis, while in mice with AIA, migration of neutrophils, presence of glycosaminoglycans, and lymphocyte proliferation, determined using the MTT assay, were assessed. Expression of cytokines interleukin-17 (IL-17), IL-1 beta, and tumor necrosis factor alpha (TNF alpha) was evaluated in all mouse knees using enzyme-linked immunosorbent assay. Treg cell production was assessed by flow cytometry in the joints of mice with AIA. Results. In mice with AIA, administration of RC-3095 reduced neutrophil migration, mechanical hypernociception, and proteoglycan loss. These findings were associated with inhibition of the levels of all 3 proinflammatory cytokines, decreased lymphocyte proliferation, and increased Treg cell numbers. In the CIA model, treatment with RC-3095 led to a significant reduction in arthritis clinical scores and the severity of disease determined histologically. Synovial inflammation, synovial hyperplasia, pannus formation, and extensive erosive changes were all dramatically reduced in the arthritic mice treated with RC-3095. Furthermore, arthritic mice treated with RC-3095 showed a significant reduction in the concentrations of IL-17, IL-1 beta, and TNF alpha, and showed a diminished expression of GRPR. Conclusion. These findings suggest that the GRP pathway has a significant role in chronic arthritis, and its inhibition can be explored as a possible therapeutic strategy in rheumatoid arthritis.
Resumo:
We investigated the effect of an extract from a helminth (Ascaris suum) in zymosan-induced arthritis (ZYA) or collagen-induced arthritis (CIA). Rats and mice, respectively, received 1 mg and 0.1 mg zymosan intra-articularly (i.a.). Test groups received an A. suum extract either per os (p.o.) or intraperitoneally (i.p.) 30 min prior to i.a. zymosan. Controls received saline. Hypernociception was measured using the articular incapacitation test. Cell influx, nitrite, and cytokine levels were assessed in joint exudates. The synovia and distal femoral extremities were used for histopathology. Cartilage damage was assessed through determining glycosaminoglycan (GAG) content. DBA/1J mice were subjected to CIA. The test group received A. suum extract i.p. 1 day after CIA became clinically detectable. Clinical severity and hypernociception were assessed daily. Neutrophil influx was determined using myeloperoxidase activity. The A. suum extract, either i.p. or p.o., significantly and dose-dependently inhibited cell influx and hypernociception in ZYA in addition to reducing GAG loss and ameliorating synovitis. The A. suum extract reduced i.a. levels of NO, interleukin-1 beta (IL-1 beta), and IL-10 but not tumor necrosis factor alpha (TNF-alpha) in rats subjected to ZYA while reducing i.a. IL-10, but not IL-1 beta or TNIT-alpha, levels in mice. Clinically, mice subjected to CIA treated with the A. suum extract had less severe arthritis. Hypernociception, myeloperoxidase activity, and synovitis severity were significantly reduced. These data show that a helminth extract given p.o. protects from arthritis severity in two classical arthritis models. This A. suum effect is species independent and functions orally and parenterally. The results show clinical and structural benefits when A. suum extract is given either prophylactically or therapeutically.
Resumo:
Background and purpose: Calendula officinalis flowers have long been employed time in folk therapy, and more than 35 properties have been attributed to decoctions and tinctures from the flowers. The main uses are as remedies for burns (including sunburns), bruises and cutaneous and internal inflammatory diseases of several origins. The recommended doses are a function both of the type and severity of the condition to be treated and the individual condition of each patient. Therefore, the present study investigated the potential use of Calendula officinalis extract to prevent UV irradiation-induced oxidative stress in skin. Methods: Firstly, the physico-chemical composition of marigold extract(ME) (hydroalcoholic extract)was assessed and the in vitro antioxidant efficacy was determined using different methodologies. Secondly, the cytotoxicity was evaluated in L929 and HepG2 cells with the MTT assay. Finally, the in vivo protective effect of ME against UVB-induced oxidative stress in the skin of hairless mice was evaluated by determining reduced glutathione (GSH) levels and monitoring the secretion/activity of metalloproteinases. Results and conclusions: The polyphenol, flavonoid, rutin and narcissin contents found in ME were 28.6 mg/g, 18.8 mg/g, 1.6 mg/g and 12.2 mg/g, respectively and evaluation of the in vitro antioxidant activity demonstrated a dose-dependent effect of ME against different radicals. Cytoxicity experiments demonstrated that ME was not cytotoxic for L929 and HepG2 cells at concentrations less than or equal to of 15 mg/mL However, concentrations greater than or equal to 30 mg/mL, toxic effects were observed. Finally, oral treatment of hairless mice with 150 and 300 mg/kg of ME maintained GSH levels close to non-irradiated control mice. In addition, this extract affects the activity/secretion of matrix metalloproteinases 2 and 9 (MMP-2 and -9) stimulated by exposure to UVB irradiation. However, additional studies are required to have a complete understanding of the protective effects of ME for skin. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
Resumo:
The aim was to analyze the protective effects of titanium, zirconium and hafnium tetrafluorides on erosion of pellicle-free and pellicle-covered enamel and dentine in vitro. Eight groups of 20 specimens each of bovine enamel and bovine dentine were prepared. Half the specimens in each group were immersed in human saliva for 2 h for pellicle formation. Specimens were then left untreated (controls) or were treated for 120 s with TiF(4), ZrF(4) or HfF(4) solutions (0.4 or 1%) or 1.25% AmF/NaF gel. All specimens were eroded by exposure to hydrochloric acid, pH 2.6, for 25 min. Cumulative calcium release into the acid was monitored in consecutive 30-second intervals for 5 min, then at 2-min intervals up to a total erosion time of 25 min using the Arsenazo III procedure. Data were analyzed by ANOVA. 1% TiF(4) solution offered the best protective effect, especially in dentine (reduction of calcium loss about 50% at 25 min). 1% ZrF 4, 1% HfF 4 and 0.4% TiF(4) also reduced calcium loss, but to a lesser extent. Long-term effects were limited to dentine, while reduction of enamel erosion (about 25%) was restricted to 1-min erosion. The fluoride gel had a protective effect only in dentine. The efficacy of the tetrafluorides was influenced by the presence of the pellicle layer, in that the protection against dentine erosion by TiF(4) and ZrF(4) was greater on pellicle-covered specimens. Tetrafluoride solutions, especially 1% TiF(4), could decrease dental erosion, but were more effective on dentine than on enamel. Copyright (C) 2008 S. Karger AG, Basel.
Resumo:
Background: It has been speculated that the biostimulatory effect of Low Level Laser Therapy could cause undesirable enhancement of tumor growth in neoplastic diseases. The aim of the present study is to analyze the behavior of melanoma cells (B16F10) in vitro and the in vivo development of melanoma in mice after laser irradiation. Methods: We performed a controlled in vitro study on B16F10 melanoma cells to investigate cell viability and cell cycle changes by the Tripan Blue, MTT and cell quest histogram tests at 24, 48 and 72 h post irradiation. The in vivo mouse model (male Balb C, n = 21) of melanoma was used to analyze tumor volume and histological characteristics. Laser irradiation was performed three times (once a day for three consecutive days) with a 660 nm 50 mW CW laser, beam spot size 2 mm(2), irradiance 2.5 W/cm(2) and irradiation times of 60s (dose 150 J/cm(2)) and 420s (dose 1050 J/cm(2)) respectively. Results: There were no statistically significant differences between the in vitro groups, except for an increase in the hypodiploid melanoma cells (8.48 +/- 1.40% and 4.26 +/- 0.60%) at 72 h postirradiation. This cancer-protective effect was not reproduced in the in vivo experiment where outcome measures for the 150 J/cm(2) dose group were not significantly different from controls. For the 1050 J/cm(2) dose group, there were significant increases in tumor volume, blood vessels and cell abnormalities compared to the other groups. Conclusion: LLLT Irradiation should be avoided over melanomas as the combination of high irradiance (2.5 W/cm(2)) and high dose (1050 J/cm(2)) significantly increases melanoma tumor growth in vivo.
Resumo:
The free H(2)xspa ligands [xspa = pspa, Clpspa, tspa or fspa where p = 3-(phenyl), Clp = 3-(2-chlorophenyl), t = 3-(2-thienyl), f = 3-(2-furyl) and spa = 2-sulfanylpropenoato], their Zn(II) complexes of formula [HQ](2)[Zn(xspa)(2)] (HQ=diisopropylammonium) and the Cd(II) equivalents were prepared and characterized by elemental analysis and by IR, Raman and NMR ((1)H, (13)C) spectroscopy. X-Ray studies of the crystal structures of [HQ](2)[Zn(pspa)(2)], [HQ](2)[Zn(Clpspa)2], [HQ](2)[Zn(tspa)(2)] and [HQ](2)[Zn(fspa)(2)] show that the zinc atom is coordinated to two O atoms and two S atoms of the ligands in a distorted tetrahedral ZnO(2)S(2) environment. In the structures of [HQ](2)[Cd(pspa)(2)] and [HQ](2)[Cd(Clpspa)(2)] the cadmium atom is coordinated to three S atoms and two carboxylato O atoms of the ligands in a distorted trigonal bipyramidal environment. The interchange of ligands between Zn( II) and Cd( II) was studied by (113)Cd NMR spectroscopy. The in vitro protective effect of H(2)xspa and their Zn( II) complexes against Cd toxicity was investigated using the human hepatocarcinoma HepG2 cell line and the pig renal proximal tubule LLC-PK1 cell line. The incorporation of Zn( II) was found to be relevant in the case of H(2)pspa, with an increase observed in the cell viability of the LCC-PK1 cells with respect to the value for the free ligand.
Resumo:
Background: The aim of the present study was to evaluate the protective effects of the 4-anilinoquinazoline derivative PD153035 on cardiac ischemia/reperfusion and mitochondrial function. Methodology/Principal Findings: Perfused rat hearts and cardiac HL-1 cells were used to determine cardioprotective effects of PD153035. Isolated rat heart mitochondria were studied to uncover mechanisms of cardioprotection. Nanomolar doses of PD153035 strongly protect against heart and cardiomyocyte damage induced by ischemia/reperfusion and cyanide/aglycemia. PD153035 did not alter oxidative phosphorylation, nor directly prevent Ca(2+) induced mitochondrial membrane permeability transition. The protective effect of PD153035 on HL-1 cells was also independent of AKT phosphorylation state. Interestingly, PD153035 activated K(+) transport in isolated mitochondria, in a manner prevented by ATP and 5-hydroxydecanoate, inhibitors of mitochondrial ATP-sensitive K(+) channels (mitoK(ATP)). 5-Hydroxydecanoate also inhibited the cardioprotective effect of PD153035 in cardiac HL-1 cells, demonstrating that this protection is dependent on mitoK(ATP) activation. Conclusions/Significance: We conclude that PD153035 is a potent cardioprotective compound and acts in a mechanism involving mitoK(ATP) activation.
Resumo:
In this study we assessed the protective effect of topical application of Pothomorphe umbellata extract on ultraviolet B (UVB)-induced skin lesion parameters in hairless mouse epidermis. A single dose of UVB irradiation (0.23 kJ/m(2)) resulted in a significant decrease in thymine dimer-positive cells and apoptotic sunburn cells, with an increase in p53 and proliferating cell nuclear antigen-positive cells in the epidermis. After 5 weeks (total dose 13.17 kJ/m(2)) and 15 weeks (total dose 55.51 kJ/m(2)) of irradiation, P. umbellata treatment inhibited the hyperplasic response and induced an increase in p53-positive cells. These findings suggest that P. umbellata extract affords protection against UVB-induced skin lesions.
Resumo:
The dibenzylbutyrolactone lignan (-)-hinokinin (HK) was obtained by partial synthesis from (-)-cubebin, isolated from the dry seeds of the pepper, Piper cubeba. In view of the trypanocidal activity of HK and its potential as a lead compound for drug development, evaluation of its possible genotoxic activity is required. We have tested HK for possible genotoxicity and evaluated the compound`s effect on the activity of the clastogens doxorubicin (DXR) and methyl methanesulfonate (MMS) in the micronucleus (MN) assay with Chinese hamster lung fibroblast V79 cells. HK alone did not induce MN, at concentrations up to 128 mu M. In combined treatments, HK reduced the frequency of MN induced by MMS. With respect to DXR, HK exerted a protective effect at lower concentrations, but at higher concentrations it potentiated DXR clastogenicity. (C) 2010 Elsevier B.V. All rights reserved.