Effects of N-acetylcysteine on the inflammatory response and bacterial translocation in a model of intestinal obstruction and ischemia in rats

Purpose: To evaluate effect of N-acetylcysteine (NAC) associated with Ringer lactate or hypertonic saline in inflammation and bacterial translocation on experimental intestinal obstruction (IO). Methods: Wistar rats was subjected to IO. Six or 24 hours after, rats were subjected to enterectomy and fluid resuscitation: IO, RL (subjected to the same procedures but with fluid resuscitation using Ringer's lactate solution); RLNAC (added NAC to Ringer's solution); and HSNAC (surgical procedure + fluid reposition with 7.5% hypertonic saline and NAC). After 24 h, tissues were collected to cytokines, bacterial translocation, and histological assessments. Results: In kidney, interleukin-1beta (IL-1beta) was lower in the groups with fluid resuscitation compared to IO group. The RLNAC showed lower levels compared to the RL. Interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-alpha), and (IFN-gamma) were lower in the treatment groups than in IO. In lung, IL-1beta and IL-6 were lower in RLNAC compared to IO. IL-10 was lower in RL, RLNAC and HSNAC compared to IO. TNF-alpha was higher in HSNAC compared to both RL and RLNAC. Bacterial translocation was observed in all animals of IO group. In kidneys, inflammation and congestion degrees were lower in HSNAC compared to RL. In lungs, inflammation levels were higher in RLNAC compared with the sham group. Conclusions: The data indicates that NAC associated with RL can promote a decrease in the inflammatory process in the kidneys and lungs in rats, following intestinal obstruction and ischemia in rats.

Remote ischemic conditioning protects against testicular ischemiareperfusion injury in rats

Purpose To evaluate the effect of remote ischemic conditioning associated to N-acetylcysteine (NAC) on testicular ischemiareperfusion (IR) injury in rats. Methods Twenty-five adult male Wistar rats were randomly distributed into five experimental groups (n=5), as follows: Sham, IR, Perconditioning (PER), NAC and PER+NAC. Two-hour ischemia was induced by rotating the left testis 720° to clockwise direction, followed by 4 hours of reperfusion. Perconditioning was performed by three I/R cycles of 10 min each on the left limb, 30 min before reperfusion. N-acetylcysteine (150 mgkg) was administered 30 min before reperfusion. Results Statistical differences were observed in MDA levels between I/R group with all groups (p 0.01), in addition there was statistical difference between PER and Sham, and PER+ NAC groups (p 0.05) in plasma. Conclusions The protective effect of perconditioning isolated in the reduction of lipid peroxidation related to oxidative stress was demonstrated. However, when Perconditioning was associated with NAC, there was no protective effect against testicular injury of ischemia and reperfusion.(AU)

Histological analysis of the intestinal wall of newborn rats submitted to hypoxia and reoxygenation to evaluate the protective effect of N-Acetylcysteine

Purpose To evaluate the effect of N-Acetylcysteine (NAC) in newborn rats submitted to hypoxia and reoxygenation (H/R) conditions in an experimental model of necrotizing enterocolitis. Methods Eight pregnant rats and their 70 cubs were used (5 groups) and exposed to H/R conditions and received NAC at different times. The animals in the H/R groups were placed in a gas chamber (100% CO2) for 10 minutes and then reoxygenated for 10 minutes (100% O2), twice a day for the first three days of life, with a six-hour span between events. On the third day of life, the animals were anesthetized, laparotomized and the intestines were resected. Results The H/R and NAC groups showed changes in the intestinal wall in relation to the number, height and width of the villi when compared to the control group (p 0.0001), but with better preservation of structures in the NAC group. There were no differences between groups regarding the number (%) of mitoses. Conclusion The administration of NAC decreased the lesions in the intestinal wall of rats submitted to H/R, therefore suggesting that this drug can be used to prevent the development of necrotizing enterocolitis in newborns.(AU)

Non-surgical treatment of guttural pouch empyema with presence of chondroids in a filly

Background: Guttural pouch empyema in horses is a disease described by the accumulation of purulent/mucopurulent exudate, which with chronification of the disease can become chondroids, affecting horses of any age and not presenting breed predisposition. The main cause of empyema is upper respiratory infection, associated or not with failure in the defense mechanisms, as well as drainage to the guttural pouch of retropharyngeal lymph node abscesses; the main pathogen related to this condition is Streptococcus equi. This paper aims to describes a case of a filly that presented a mucopurulent nasal discharge, five months of evolution, and irresponsive to antibiotic therapy. Case: A 2.5-year-old quarter filly was referred to the veterinary hospital presenting a 5 months evolution mucopurulent nasal discharge, irresponsive to gentamicin and ceftiofur, and later doxycycline, acetylcysteine and clenbuterol that were instituted on the farm. Throw the endoscopic examination of the upper respiratory tract, was observed the presence of mucopurulent content and chondroids inside the right guttural pouch. This material was collected and sent for culture and antibiogram tests. Streptococcus equi was isolated, and was only sensitive to ceftiofur. The treatment included the guttural pouches flushes with warm saline solution (0.9%) associated with Lauryl Dietylene Glycol Ether Sulfate Sodium (28%) and acetylcysteine (10%). In addition to topical treatment, 5 mg/kg of ceftiofur was administered intramuscularly daily for 7 days. After 10 flushes of the guttural pouch, was observed a total absence of chondroid and mucopurulent contents. Discussion: The treatment of the guttural pouch empyema can be performed either by conservative methods or by the surgical drainage. Among the benefits of the conservative treatment are the absence of the risks...

Non-surgical treatment of guttural pouch empyema with presence of chondroids in a filly

Background: Guttural pouch empyema in horses is a disease described by the accumulation of purulent/mucopurulent exudate, which with chronification of the disease can become chondroids, affecting horses of any age and not presenting breed predisposition. The main cause of empyema is upper respiratory infection, associated or not with failure in the defense mechanisms, as well as drainage to the guttural pouch of retropharyngeal lymph node abscesses; the main pathogen related to this condition is Streptococcus equi. This paper aims to describes a case of a filly that presented a mucopurulent nasal discharge, five months of evolution, and irresponsive to antibiotic therapy. Case: A 2.5-year-old quarter filly was referred to the veterinary hospital presenting a 5 months evolution mucopurulent nasal discharge, irresponsive to gentamicin and ceftiofur, and later doxycycline, acetylcysteine and clenbuterol that were instituted on the farm. Throw the endoscopic examination of the upper respiratory tract, was observed the presence of mucopurulent content and chondroids inside the right guttural pouch. This material was collected and sent for culture and antibiogram tests. Streptococcus equi was isolated, and was only sensitive to ceftiofur. The treatment included the guttural pouches flushes with warm saline solution (0.9%) associated with Lauryl Dietylene Glycol Ether Sulfate Sodium (28%) and acetylcysteine (10%). In addition to topical treatment, 5 mg/kg of ceftiofur was administered intramuscularly daily for 7 days. After 10 flushes of the guttural pouch, was observed a total absence of chondroid and mucopurulent contents. Discussion: The treatment of the guttural pouch empyema can be performed either by conservative methods or by the surgical drainage. Among the benefits of the conservative treatment are the absence of the risks...(AU)

The examination of the nephroprotective effect of montelukast sodium and N-acetylcysteine n renal schemia with dimercaptosuccinic acid imaging in a placebo-controlled rat model

Purpose To determine the nephroprotective effect of NAC and Montelukast Sodium administration against the development of renal damage associated with long warm renal ischemia. Methods Twenty-seven rats were randomly divided into 3 study groups, which received NAC, montelukast and placebo, and 3 rats were included in the sham-treated control group. Medications were given 3 days before the procedure. DMSA renal scintigraphy was performed before and after surgery. The right renal pedicle was occluded for 45 min to induce ischemia and then subjected to reperfusion for 6 h (I/R groups). Results On pathological examination, the mean pathological scores of the montelukast and NAC groups were significantly lower than those of the placebo group. (p 0.05). In biochemical examination, significant differences were found in all parameter levels between the placebo group and the montelukast and NAC groups. (p 0.05) When postoperative DMSA renal scintigraphy measurements and renal function levels were compared, significant differences were found between the montelukast and NAC groups and the placebo and sham groups. Conclusion The administration of NAC and montelukast sodium was seen to have a nephroprotective effect against the development of renal damage associated with warm renal ischemia.(AU)

Impact of in vitro fertilization by refrigerated versus frozen buffalo semen on developmental competence of buffalo embryos

The objective of this study was to evaluate the fertility of buffalo semen for in vitro embryo production (IVEP) by comparing the effectiveness of refrigerated versus frozen semen. Three OPU sessions were held at 30-day intervals. For oocyte fertilization three buffalo bulls were used, one per session. At each OPU-IVEP session, one ejaculate was collected and divided into two equal aliquots. Each aliquot was either refrigerated at 5ºC/24 hours or frozen. A TRIS extender containing 10% low density lipoproteins, 0.5% lecithin and 10 mM acetylcysteine was used adding 7% glycerol for freezing. Sperm motility/kinetic was evaluated by CASA and sperm membrane integrity by the hypoosmotic swelling test. The evaluations were performed at 0 h (post final dilution at 37ºC), at 4 and 24 hs post-incubation at 5ºC and post-thaw. At 24 hs incubation and immediately post thaw sperm cells were used for in vitro fertilization of buffalo oocytes equally distributed between both groups. Cleavage rates and embryo development were followed. The embryo/matured and embryo/cultured rates were 25.4 x 14.0% and 29.4 x 18.5% (P 0.05), for chilled and frozen semen, respectively. It is concluded that cooled semen can be used for in vitro embryo production in buffalo and that a better efficiency may be expected for cooled compared to frozen semen.

Impact of in vitro fertilization by refrigerated versus frozen buffalo semen on developmental competence of buffalo embryos

The objective of this study was to evaluate the fertility of buffalo semen for in vitro embryo production (IVEP) by comparing the effectiveness of refrigerated versus frozen semen. Three OPU sessions were held at 30-day intervals. For oocyte fertilization three buffalo bulls were used, one per session. At each OPU-IVEP session, one ejaculate was collected and divided into two equal aliquots. Each aliquot was either refrigerated at 5ºC/24 hours or frozen. A TRIS extender containing 10% low density lipoproteins, 0.5% lecithin and 10 mM acetylcysteine was used adding 7% glycerol for freezing. Sperm motility/kinetic was evaluated by CASA and sperm membrane integrity by the hypoosmotic swelling test. The evaluations were performed at 0 h (post final dilution at 37ºC), at 4 and 24 hs post-incubation at 5ºC and post-thaw. At 24 hs incubation and immediately post thaw sperm cells were used for in vitro fertilization of buffalo oocytes equally distributed between both groups. Cleavage rates and embryo development were followed. The embryo/matured and embryo/cultured rates were 25.4 x 14.0% and 29.4 x 18.5% (P 0.05), for chilled and frozen semen, respectively. It is concluded that cooled semen can be used for in vitro embryo production in buffalo and that a better efficiency may be expected for cooled compared to frozen semen.(AU)

Removal and killing of multispecies endodontic biofilms by N-acetylcysteine

Removal of bacterial biofilm from the root canal system is essential for the management of endodontic disease. Here we evaluated the antibacterial effect of N-acetylcysteine (NAC), a potent antioxidant and mucolytic agent, against mature multispecies endodontic biofilms consisting of Actinomyces naeslundii, Lactobacillus salivarius, Streptococcus mutans and Enterococcus faecalis on sterile human dentin blocks. The biofilms were exposed to NAC (25, 50 and 100 mg/mL), saturated calcium hydroxide or 2% chlorhexidine solution for 7 days, then examined by scanning electron microscopy. The biofilm viability was measured by viable cell counts and ATP-bioluminescence assay. NAC showed greater efficacy in biofilm cell removal and killing than the other root canal medicaments. Furthermore, 100 mg/mL NAC disrupted the mature multispecies endodontic biofilms completely. These results demonstrate the potential use of NAC in root canal treatment.(AU)

An experimental study on the preventive effects of N-acetyl cysteine and ozone treatment against contrast-induced nephropathy

Purpose: To compare the preventive effects of N-acetyl cysteine (NAC), ozone preconditioning and ozone treatment against contrast-induced nephropathy (CIN) in an experimental rat model. Methods: Thirty adult male Wistar rats were randomly distributed into five groups (n=6 for each group). Group I served as control and Group II had only contrast agent, while Group III received NAC and Group IV received intraperitoneal ozone 6 hours before and 6 hours after introduction of contrast agent. Ozone treatment was applied for 5 days after the contrast agent was introduced in Group V. After induction of CIN, groups were compared in terms of serum levels of urea, creatinine, neutrophil gelatinase associated lipocalin, protein carbonyl, total antioxidant capacity (TAC) as well as degree of renal injury at histopathologic level. Results: Groups II-V displayed more obvious histopathological alterations such as hemorrhage and renal tubular injury compared with Group I. TAC (p=0.043) and creatinine (p=0.046) levels increased significantly in Group II after the intervention. In Group III, protein carbonyl level diminished remarkably (p=0.046), while creatinine level was increased (p=0.046) following the intervention. TAC level was higher in Group IV (p=0.028) and Group V (p=0.026) following the procedure. Conclusion: The N-acetyl cysteine and ozone treatment may alleviate the biochemical and histopathological deleterious effects of contrast-induced nephropathy via enhancement of total antioxidant capacity and decreasing oxidative stress.(AU)

Cytotoxic activity of Androctonus australis hector venom and its toxic fractions on human lung cancer cell line

Background: Several studies have showed that animal venoms are a source of bioactive compounds that may inhibit the growth of cancer cells, which makes them useful agents for therapeutic applications. Recently, it was established that venom toxins from scorpions induced cytotoxic, antiproliferative and apoptogenic effects on cancer cells. Therefore, the present study aims to investigate the cytotoxic activity of Androctonus australis hector (Aah) scorpion venom and its toxic fractions (FtoxG-50 and F3) on NCI-H358 human lung cancer cells. Methods: The cytotoxic and antiproliferative activities were estimated using MTT assay, lactate dehydrogenase release and clonogenic assays. Apoptosis was evaluated by Hoechst 33258 staining, DNA fragmentation assay and caspase-3 activity. Oxidative stress was analyzed by reactive oxygen species, nitric oxide, malondialdehyde and protein carbonyl levels along with assessment of antioxidant status. In addition, alteration of mitochondrial membrane potential was analyzed by JC1 fluorescent dye. Results: The present findings showed that F3 fraction was more cytotoxic towards NCI-H358 lung cancer cells with an IC50 of 27.05 ± 0.70 μg/mL than venom alone (396.60 ± 1.33 μg/mL) and its toxic fraction FtoxG-50 (45.86 ± 0.91 μg/mL). Nevertheless, F3 fraction was not cytotoxic at these concentrations on normal human lung fibroblast MRC-5 cells. Inhibition of NCI-H358 cell proliferation after F3 fraction exposure occurred mainly by apoptosis as evidenced by damaged nuclei, significant DNA fragmentation level and caspase-3 activation in a dose dependent manner. Moreover, F3 fraction enhanced oxidative and nitrosative stress biomarkers and dissipated mitochondrial membrane potential in lung cancer cells along with significant depletion in cellular enzymatic and non-enzymatic antioxidants. Further, the apoptosis induced by F3 fraction was markedly prevented by the antioxidant N-acetylcysteine (NAC) suggesting the potential mechanism of oxidative stress. Conclusion: These findings suggest that F3 fraction could induce apoptosis in lung cancer cells through involvement of oxidative stress and mitochondrial dysfunction. Hence, these properties make F3 fraction a promising candidate for development of new anticancer agents.(AU)

Cytotoxic activity of Androctonus australis hector venom and its toxic fractions on human lung cancer cell line

Several studies have showed that animal venoms are a source of bioactive compounds that may inhibit the growth of cancer cells, which makes them useful agents for therapeutic applications. Recently, it was established that venom toxins from scorpions induced cytotoxic, antiproliferative and apoptogenic effects on cancer cells. Therefore, the present study aims to investigate the cytotoxic activity of Androctonus australis hector (Aah) scorpion venom and its toxic fractions (FtoxG-50 and F3) on NCI-H358 human lung cancer cells. Methods: The cytotoxic and antiproliferative activities were estimated using MTT assay, lactate dehydrogenase release and clonogenic assays. Apoptosis was evaluated by Hoechst 33258 staining, DNA fragmentation assay and caspase-3 activity. Oxidative stress was analyzed by reactive oxygen species, nitric oxide, malondialdehyde and protein carbonyl levels along with assessment of antioxidant status. In addition, alteration of mitochondrial membrane potential was analyzed by JC1 fluorescent dye. Results: The present findings showed that F3 fraction was more cytotoxic towards NCI-H358 lung cancer cells with an IC50 of 27.05 ± 0.70 g/mL than venom alone (396.60 ± 1.33 g/mL) and its toxic fraction FtoxG-50 (45.86 ± 0.91 g/mL). Nevertheless, F3 fraction was not cytotoxic at these concentrations on normal human lung fibroblast MRC-5 cells. Inhibition of NCI-H358 cell proliferation after F3 fraction exposure occurred mainly by apoptosis as evidenced by damaged nuclei, significant DNA fragmentation level and caspase-3 activation in a dose dependent manner. Moreover, F3 fraction enhanced oxidative and nitrosative stress biomarkers and dissipated mitochondrial membrane potential in lung cancer cells along with significant depletion in cellular enzymatic and non-enzymatic antioxidants. Further, the apoptosis induced by F3 fraction was markedly prevented by the antioxidant N-acetylcysteine (NAC) suggesting the potential mechanism of oxidative stress. Conclusion: These findings suggest that F3 fraction could induce apoptosis in lung cancer cells through involvement of oxidative stress and mitochondrial dysfunction. Hence, these properties make F3 fraction a promising candidate for development of new anticancer agents.(AU)

Cytotoxic activity of Androctonus australis hector venom and its toxic fractions on human lung cancer cell line

Several studies have showed that animal venoms are a source of bioactive compounds that may inhibit the growth of cancer cells, which makes them useful agents for therapeutic applications. Recently, it was established that venom toxins from scorpions induced cytotoxic, antiproliferative and apoptogenic effects on cancer cells. Therefore, the present study aims to investigate the cytotoxic activity of Androctonus australis hector (Aah) scorpion venom and its toxic fractions (FtoxG-50 and F3) on NCI-H358 human lung cancer cells. Methods: The cytotoxic and antiproliferative activities were estimated using MTT assay, lactate dehydrogenase release and clonogenic assays. Apoptosis was evaluated by Hoechst 33258 staining, DNA fragmentation assay and caspase-3 activity. Oxidative stress was analyzed by reactive oxygen species, nitric oxide, malondialdehyde and protein carbonyl levels along with assessment of antioxidant status. In addition, alteration of mitochondrial membrane potential was analyzed by JC1 fluorescent dye. Results: The present findings showed that F3 fraction was more cytotoxic towards NCI-H358 lung cancer cells with an IC50 of 27.05 ± 0.70 g/mL than venom alone (396.60 ± 1.33 g/mL) and its toxic fraction FtoxG-50 (45.86 ± 0.91 g/mL). Nevertheless, F3 fraction was not cytotoxic at these concentrations on normal human lung fibroblast MRC-5 cells. Inhibition of NCI-H358 cell proliferation after F3 fraction exposure occurred mainly by apoptosis as evidenced by damaged nuclei, significant DNA fragmentation level and caspase-3 activation in a dose dependent manner. Moreover, F3 fraction enhanced oxidative and nitrosative stress biomarkers and dissipated mitochondrial membrane potential in lung cancer cells along with significant depletion in cellular enzymatic and non-enzymatic antioxidants. Further, the apoptosis induced by F3 fraction was markedly prevented by the antioxidant N-acetylcysteine (NAC) suggesting the potential mechanism of oxidative stress. Conclusion: These findings suggest that F3 fraction could induce apoptosis in lung cancer cells through involvement of oxidative stress and mitochondrial dysfunction. Hence, these properties make F3 fraction a promising candidate for development of new anticancer agents.

POTENCIAL TERAPÊUTICO DA COENZIMA-Q10 E N-ACETILCISTEÍNA NA INTOXICAÇÃO EXPERIMENTAL POR PARACETAMOL EM RATOS WISTAR

O paracetamol (PAR) é um medicamento muito utilizado na medicina e na veterinária como analgésico e antipirético, frequentemente envolvido em quadros de intoxicação. O objetivo do estudo foi avaliar o potencial terapêutico da coenzima Q10 (CoQ10) e da N-acetilcisteína (NAC) em modelo de intoxicação por PAR. Foram utilizados 31 ratos adultos, divididos aleatoriamente em cinco grupos. O grupo controle negativo (CON-) recebeu por via oral (VO) 1ml de NaCl 0,9%. Os demais grupos receberam 1,2g /kg de PAR por VO, em dose única. O grupo controle positivo (CON+) recebeu apenas o PAR, como acima descrito. O grupo NAC recebeu 800 mg/kg de NAC por via intraperitoneal (IP), 1h após a administração de PAR. O quarto grupo (CoQ10) recebeu, 1h e 12h após a intoxicação, CoQ10 (10 mg/kg por via IP). E o quinto grupo (NAC+CoQ10) recebeu a associação: NAC (800 mg/Kg IP) e CoQ10 (10mg/kg IP). Transcorridas 12 horas, os animais foram submetidos à eutanásia para a obtenção de amostras direcionadas para as avaliações hematológicas, bioquímicas, avaliações de lesões em DNA e avaliações histopatológicas. Não foram observadas alterações relevantes na hematologia, bioquímica renal e lesões em DNA, contudo foi possível constatar por meio de microscopia óptica, lesões significativas em hepatócitos nos grupos CON+ e NAC, associadas com o aumento de AST. O grupo que recebeu apenas a CoQ10 como tratamento apresentou lesões hepáticas discretas, assim como aumento brando de AST, o que sugere que a sua utilização, de forma individualizada, exerce um efeito hepatoprotetor frente à hepatotoxicidade induzida por PAR.

Acetaminophen (APAP) is a widely used drug in medicine and veterinary medicine as an analgesic and antipyretic and it is frequently involved in intoxications. The study aimed to evaluate the therapeutic potential of coenzyme Q10 (CoQ10) and N-acetylcysteine (NAC) in a model of APAP intoxication. 31 adult Wistar rats were randomly divided into five groups. The negative control group (CON-) received orally (PO) 1 ml of 0.9% NaCl. The other groups received 1.2 g/kg of PAR, PO, single dose. The positive control group (CON +) received only APAP as previously described. The NAC group received 800 mg/kg of NAC, intraperitoneal injection (IP), 1 hour after the APAP administration. The fourth group (CoQ10) received Q-10 (10 mg /kg, intraperitoneal injection- IP) after 1 hour and 12 hours after intoxication. And the fifth group (NAC + Q10) received NAC (800 mg /kg, IP) and Q-10 (10 mg/kg, IP). After 12 hours, the animals were euthanized to collect samples and send them to hematological, biochemical, histopathological, and DNA assessments. No relevant alterations were observed in hematology, kidney biochemistry, and comet assay, however, it was possible to conjecture through optic microscopy significant damage in hepatocytes of NAC and CON+ groups, correlated to the increased AST values. The group that only received CoQ10 as treatment presented discreet hepatic damage as a mild increase of AST, suggesting that the sole use of CoQ10 has a hepatoprotective effect when facing hepatotoxicity induced by APAP.

The effect of n-acetylcysteine on hepatic histomorphology during hypothermic preservation

To evaluate the NAC effects on liver hypothermic preservation at different time intervals. For this, we used livers of male Wistar rats weighing between 250 and 300g, undergoing preservation in Ringer solution at 4°C for up to 24 hours. Tissue samples were obtained at four moments of preservation for histological examination by hematoxylin and eosin staining: T0 = beginning of preservation, T12 = 12 hours, T18 = 18 hours and T24 = 24 hours. Will be analyzed vacuolation, hepatic apoptosis by optical microscopy and parenchymal. The results showed a progressive increase in hepatic injury in both groups and showed that NAC was effective at T0. The parenchyma preservation was better in the NAC group and no difference when vacuolization of the cells. Hypothermic preservation, over time, causes changes in the hepatic parenchyma with increased apoptosis, loss of architecture, vacuolization, culminating in severe injury. The administration of N-acetylcysteine protects against preservation liver injury.(AU)

OTIMIZAÇÃO DO PERFIL DE SEGURANÇA DA NIMESULIDA ATRAVÉS DA ASSOCIAÇÃO COM HEPATOPROTETOR

Autor: Amanda Godoi Elias Orientador: Luciana Grazziotin Rossato Grando Passo Fundo, 30 de Setembro de 2019 Os antiinflamatórios juntamente com os antibióticos são as causas mais frequentes de lesões hepáticas induzidas por drogas. A nimesulida é um potente antiinflamatório, muito utilizado por ter seus efeitos rápidos e duradouros, porém é um medicamento que tem alto risco de hepatotoxicidade. Diante deste contexto, o objetivo deste trabalho foi avaliar os efeitos de hepatoprotetores sobre os mecanismos hepatotóxicos induzidos pela nimesulida visando propor uma formulação mais segura. Inicialmente, fizemos um estudo in vitro através do modelo de cultura celular HepG2 para testar três possíveis hepatoprotetores: N-acetilcisteína, o Ginkgo biloba e a L-carnitina. Neste estudo constatamos que tanto N-acetelcisteína como o Gingko biloba tem bom potencial para antagonizar a citotoxicidade induzida pela nimesulida. Diante disso, selecionamos a N-acetilcisteína devido ao seu potencial antioxidante e maior experiência clínica em seu uso como antídoto de intoxicações hepatotóxicas. O estudo in vivo foi realizado utilizando 24 ratos Wistar machos como modelo animal. Os animais foram divididos em 4 grupos (6 animais por grupo): Controle que receberam solução salina; nimesulida 100mg/kg/dia de nimesulida; nimesulida e N-acetilcisteína 100mg/kg/dia de cada e Nacetilcisteína 100mg/kg/dia de N-acetilcisteína. Os tratamentos foram administrados por via oral (gavagem), durante o estudo dois animais do grupo que recebeu somente nimesulida morreram, após apresentar um emagrecimento progressivo. Com relação ao peso relativo dos animais, os que receberam nimesulida somente, apresentaram um menor ganho de peso com relação aos controles (p<0.0001) e a associação de nimesulida com N-acetilcisteína apresentou um ganho de peso significativamente maior quando comparado ao grupo que recebeu somente a nimesulida (p<0.05). Nas análises de histopatologia dos fígados, o grupo que recebeu somente nimesulida apresentou muitas lesões de degeneração e necrose, enquanto que no grupo que recebeu associação de nimesulida e N-acetilcisteína essas lesões foram de menor intensidade. Não houve alterações significativas em nenhum dos grupos com relação aos biomarcadores sanguíneos de lesão hepática e nem ocorrência de stress oxidativo nos fígados. Neste trabalho, pela primeira vez os efeitos da N-acetilcisteína como hepatoprotetor na lesão hepática induzida pela nimesulida foi demonstrado. Apesar dos excelentes resultados deste hepatoprotetor como antídoto em outras intoxicações, há uma proteção parcial na associação da nimesulida com Nacetilcisteína.

Author: Amanda Godoi Elias Advisor: Luciana Grazziotin Rossato Grando Passo Fundo, 30 de Setembro de 2019 Anti-inflamatory drugs, together with antibiotics, are the most relevant cause of druginduced hepatotoxicity. Nimesulide is a potent anti-inflammatory, which presents rapid and last-longing effects and also a high risk of hepatotoxicity. Thus, the aim of this work was to enhance nimesulide safety profile through the association with an hepatoprotector. First, we performed an in vitro study using HepG2 cell line model to test 3 possible hepatoprotectors: Nacetylcisteine, Gingko biloba, and L-carnitine. N-acetylcysteine and G. biloba show promisor results, then we selected N-acetylcysteine due to its board antioxidant effect and clinical experience as an antidote of hepatotoxicity. In vivo study was performed using 24 male Wistar rats, divided in 4 groups (6 animals/group): Control (receiving saline solution), Nimesulide 100mg/kg/day, Nimesulide 100mg/kg/day + N-acetylcysteine 100mg/kg/day, and Nacetylcysteyne 100mg/kg/day alone. Treatments were given through gavage, daily, for 15 days. During the study, 2 rats treated with nimesulide died after present a progressive weight-loss. Animals treated with nimesulide alone present lower body weight gain compared to control (p<0.0001and the association of nimesulide and N-acetylcysteine group presents higher body weight gain compared to nimesulide alone (p<0.05). Liver histology revealed hepatic lesions with degeneration and necrosis in animals receiving nimesulide. Rats treated with the association of nimesulide+N-acetylcysteine present hepatic lesions less pronounced. Liver, heart and spleen of animals treated with nimesulide show higher relative mass when compared to control. This change is reverted by the association with nimesulide only in hearts. It was not observed significant differences between groups in biochemical biomarkers or oxidative stress parameters. To the best our knowledge, we show for the first time the protection elicited by Nacetylcysteine against nimesulide-induced hepatotoxicity. Despite excellent effects of Nacetylcysteine used as antidote in other drug-induced hepatotoxicity, the protection obtained here is only partial.

N-acetylcysteine improves morphologic and functional aspects of ovarian grafts in rats

To evaluate morphological and functional aspects of the ovarian graft in transplanted rats treated with NAC. Female Wistar rats, virgin, 3 to 4 months old, weighing 200-250 grams were used in experiments. The rats have been kept in proper sanitary conditions, receiving food and water ad libitum. Five groups (n=10, each) were constituted: 4 groups treated subcutaneously with NAC, at doses of 150, 300, 600 and 1200 mg/kg (NAC150, NAC300, NAC600 and NAC1200, respectively), one hour of before the ovarian transplantation and control group (GTx) - treated with physiological solution and submitted to ovarian transplantation. The rats were anesthetized and submitted to autologous left ovarian transplantation, without anastomosis in retroperitoneum, and contralateral oophorectomy. During follow-up of 4 or 15 days, the estrous cycle was evaluated by vaginal smears to determine cycle regularity. At the end of 4th or 15th days, rats were re-anesthetized and blood and graft were obtained to estradiol analysis and morphological assessment. Data were analysed by One Way Analysis of Variance (ANOVA) or ANOVA on ranks complemented by Student-Newman-Keuls test. RESULTS: At 4th day, viable follicles in the graft did not altered by NAC treatments. The NAC300 and NAC600 groups showed increasing in follicle atresia (p=0.012) compared to GTx and NAC1200 group. At 15th day, 50% of GTx, NAC150, and NAC300 rats showed regular oestrous cycle; 83% of NAC600 and 100% of NAC1200 rats returned to regular cycle. NAC1200 group showed increasing in primordial follicle compared to GTx, NAC150 or NAC300 (p=0.011). NAC did not interfere in estradiol levels after 4 or 15 days of transplantation. In autologous ovarian transplantation, high dose of NAC promotes graft viability with recovery of estrous cycle.(AU)

Comparação entre dois protocolos de tratamento de ceratoconjuntivite seca experimentalmente induzida em coelhos / Comparison of two treatment protocols of experimentally induced keratoconjunctivitis sicca in rabbits

O objetivo deste estudo foi avaliar e comparar a eficácia de dois protocolos de tratamento de ceratoconjuntivite seca (CCS) experimentalmente induzida em coelhos: uma formulação oftálmica tópica composta por álcool polivinílico 1,4%, adicionado com acetilcisteína 10% e pilocarpina 1% (AAP), e outro protocolo com o uso do óleo de semente de linhaça (OL) tópico em forma de colírio, durante 12 semanas. Foram utilizados 15 coelhos machos, adultos, da raça Nova Zelândia, alocados aleatoriamente em três grupos: grupo C (controle), grupo AAP (formulação oftálmica) e grupo L (OL tópica). Os animais foram avaliados semanalmente pelo teste lacrimal de Schirmer, teste de fluoresceína e teste de Rosa Bengala; uma vez por mês, pelo exame de citologia esfoliativa ocular; ao final do experimento, pela análise histopatológica da córnea e conjuntiva. Os resultados demonstraram que houve um aumento maior na produção lacrimal quando utilizada a formulação oftálmica, e uma resolução mais rápida das úlceras de córnea, bem como diminuição no número de células desvitalizadas quando utilizado o óleo de semente de linhaça, além de aumento no número de células caliciformes em ambos os grupos de tratamento. A associação desses dois protocolos pode ser no futuro uma alternativa no tratamento da CCS.(AU)

The objective of this study was to evaluate and compare the effectiveness of two treatment protocol of experimentally induced keratoconjunctivitis sicca (KCS) in rabbits, a topical ophthalmic formulation composed by 1.4% povinilic alcohol added with 10% acetylcysteine and 1% pilocarpine (AAP) and another protocol with the topical use of the linseed seed oil (LO) in eye drop form f or 12 weeks. Fifteen male New Zealand white rabbits were aleatory allocated in 3 groups: Group C (Control), Group AAP (ophthalmic formulation) and Group L (LO topical). The animals were evaluated weekly using the Schirmer's tear test, fluorescein test and Rose Bengal test monthly for ocular cytology, and at the end of the experiment for histopathological analysis of cornea and conjunctive. The results demonstrated that there was a larger increase in the tear production when the ophthalmic formulation was us ed and a faster rapid resolution of corneal ulcers and decrease in the number of devitalized cells when linseed seed oil was used, besides an increase in the number of caliciform cells in both treatment groups. The association of those two protocols can be a future alternative in the treatment of KCS.(AU)

"Sêmen refrigerado e seu potencial de uso na inseminação artificial de búfalas ( Bubalus Bubalis )"

A exploração da bubalinocultura tem crescido constantemente nos últimos anos. Neste contexto, o uso de biotécnicas da reprodução como a inseminação artificial em tempo fixo (IATF), aspiração folicular (OPU) e produção in vitro de embriões (PIVE), têm se mostrado factíveis em bubalinos, embora ainda com uma eficiência reduzida e com pouca aplicação comercial comparado a outras espécies animais. Isto se deve a características particulares da espécie, como dificuldade de identificação do estro e à complicação em condicionar touros para a coleta de sêmen com a vagina artificial, principalmente animais adultos. Somados a isto, mesmos os animais após o condicionamento e coleta de sêmen, não mantém uma constância na produção de ejaculados com qualidade, chegando mesmo a interromper a produção de sêmen sem um motivo aparente. Em parte, esses problemas foram solucionados com a elaboração de protocolos que permitam o uso da IA sem a necessidade de detecção do estro, ou seja, em tempo fixo (IATF). Já o conhecimento da dinâmica folicular nessa espécie possibilitou o desenvolvimento de protocolos para controlar as fases folicular e luteínica do ciclo estral e, por fim, a ovulação. A combinação destes tratamentos de sincronização da ovulação permite o uso da inseminação artificial durante todo o ano, possibilitando o ganho genético e a distribuição da concepção e dos partos conforme a demanda do mercado. No entanto, a inseminação artificial em bubalinos, que tem como base o uso do sêmen congelado, apresenta alguns gargalos como: a falta de sêmen no mercado nacional; touros com genética superior, mas que não resistem ao processo de congelamento; injúrias causadas aos espermatozoides durante o processo de congelamento, que pode causar um decréscimo de até 60% na viabilidade da população espermática em bubalinos e a existência de deficiências básicas de manejo nas propriedades. Face ao exposto, esse estudo tem o objetivo de testar a eficácia do sêmen refrigerado e congelado na IATF nos períodos reprodutivos favorável e desfavorável, assim como na fertilização in vitro para melhorar as taxas de fertilidade, estudar a expressão dos comportamentos sexuais de touros bubalinos e, a aplicação de técnicas de manejo racional durante o período de coleta de sêmen com a vagina artificial, visando facilitar o condicionamento e coleta de sêmen, bem como desenvolver novos extensores para o sêmen de búfalos. Os resultados obtidos com as inseminações artificiais durante o período reprodutivo favorável e desfavorável mostraram taxa de prenhez superior para o sêmen refrigerado. Resultado este que também foi obtido com a PIVE. Quanto ao comportamento dos touros, verificou-se que estes animais são passíveis de condicionamento para a coleta de sêmen com vagina artificial á campo. Após diversos testes foi verificado que o diluidor TRIS com 10% de LDL, acrescido de 0,5% de lecitina de soja e com a adição de 10 mM do antioxidante acetilcisteína apresentou os melhores resultados de longevidade e fertilidade in vitro.

Bubalinoculture exploitation has been growing steadily in recent years. In this context, the use of reproductive biotechniques such as fixed-time artificial insemination (FTAI), follicular aspiration (OPU) and in vitro embryo production (IVP) have been shown to be feasible in buffaloes, although still with reduced efficiency and with little commercial application compared to other animal species. This is due to particular characteristics of the species, such as difficulty in identifying the estrus and the complication in conditioning bulls for the collection of semen with the artificial vagina, mainly adult animals. Added to this, even the animals after the conditioning and collection of semen, does not maintain a constancy in the production of ejaculates with quality, even interrupting the production of semen without an apparent reason. In part, these problems have been solved with the elaboration of protocols that allow the use of AI without the need of detection of estrus, that is, in fixed time (FTAI). Already the knowledge of the follicular dynamics in this species allowed the development of protocols to control the follicular and luteal phases of the estrous cycle and, finally, ovulation. The combination of these ovulation synchronization treatments allows the use of artificial insemination throughout the year, allowing the genetic gain and distribution of conception and delivery according to market demand. However, artificial insemination in buffaloes, which is based on the use of frozen semen, presents some bottlenecks such as: the lack of semen in the national market; bulls with superior genetics, but that do not resist the freezing process; injuries caused to the spermatozoa during the freezing process, which can cause up to 60% decrease in the viability of the sperm population in buffaloes and the existence of basic management deficiencies in the properties. In the light of the above, this study aims to test the efficacy of refrigerated and frozen semen on FTAI in favorable and unfavorable reproductive periods, as well as in vitro fertilization to improve fertility rates, to study the expression of sexual behavior of buffalo bulls and, the application of rational management techniques during the period of collection of semen with the artificial vagina, aiming to facilitate the conditioning and collection of semen, as well as to develop new extensors for buffaloes semen. The results obtained with the artificial inseminations during the favorable and unfavorable reproductive period showed superior pregnancy rate for the refrigerated semen. This result was also obtained with IVP. Regarding the behavior of the bulls, it was verified that these animals can be conditioned for the collection of semen with artificial vagina in the field. After several tests it was verified that the TRIS diluent with 10% LDL plus 0.5% soy lecithin and with the addition of 10 mM of the antioxidant acetylcysteine showed the best longevity and fertility results in vitro.

Effect of N-acetylcysteine in liver ischemia-reperfusion injury after 30% hepatectomy in mice / Efeito da N-acetilcisteína na lesão hepática por isquemia e reperfusão após 30% de hepatectomia em camundongos

PURPOSE: Evaluate the effect of N-acetylcysteine in liver remnant after hepatectomy associated to ischemia-reperfusion injury in mice. METHODS: Male adult BALB/c mice, weighing 20-22g were used. Animals were anesthetized with ketamine (70 mg/kg) and xylazine (10 mg/kg); received N-acetylcysteine (150 mg/kg, H-IR-NAC group) or vehicle (H-IR group). Surgical procedures were performed under 10X magnification. Partial hepatectomy (30%) was followed by ischemia-reperfusion injury (30 minutes of ischemia and 60 minutes of reperfusion). Blood sample and liver tissue were removed before animal was euthanized. AST and ALT were evaluated in blood samples and histomorphological analyses were performed in remnant liver. Groups were compared by Mann-Whitney test, and it was considered significant when p<0.05. RESULTS: Biochemical evaluations showed reduced levels of ALT in NAC group (H-IR-NAC=376±127U/l vs H-IR=636±39U/l, p=0.023). AST was similar (p=0.456). H-IR group showed hepatic tissue with preserved architecture, large area of steatosis, vascular congestion and rare mitogenic activity. NAC group showed hepatic tissue with small area of steatosis, vascular congestion and elevated mitogenic activity, evidenced by increased binuclear cells (H-IR-NAC=15.88±0.52 vs H-IR=7.4±0.37, p<0.001). CONCLUSION: N-acetylcysteine promotes enzymatic and morphological protection against hepatectomy and ischemia-reperfusion injury.(AU)

OBJETIVO: Investigar se a N-acetilcisteína promove proteção do remanescente hepático após ressecção associada à isquemia e reperfusão do fígado em camundongos. MÉTODOS: Foram utilizados 12 camundongos BALB/c, machos, pesando entre 20-22g. Os animais foram anestesiados com quetamina (70mg/kg) e xilazina (10mg/kg); receberam a N-acetilcisteína (150mg/kg, grupo H-IR-NAC) ou controle (grupo H-IR). Os procedimentos cirúrgicos ocorreram na magnificação de 10X. A lesão por isquemia e reperfusão (30 minutos de isquemia e 60 minutos de reperfusão) foi precedida pela hepatectomia de 30%. Foram utilizados como parâmetro de avaliação: a bioquímica sangüínea (AST e ALT) e a histologia do fígado (coloração de hematoxilina-eosina). Para avaliação estatística empregou-se o teste de Mann-Whitney e o nível de significância foi 5%. RESULTADOS: Na avaliação bioquímica houve redução no nível de ALT no grupo tratado (H-IR-NAC=376±127 U/l vs H-IR=636±39 U/l, p=0,023). AST foi similar (p=0,456). Na histologia, o grupo H-IR apresentou um tecido hepático com arquitetura preservada, com grandes áreas de infiltração gordurosa, presença de congestão vascular e de alguma atividade mitótica; o grupo com a N-acetilcisteína apresentou menor infiltração gordurosa e congestão vascular, maior atividade mitótica, evidenciada pela quantidade elevada de células binucleadas (H-IR-NAC=15,88±0,52 vs H-IR=7,4±0,37, p<0,001). CONCLUSÃO: A N-acetilcisteína promove proteção ao fígado, do ponto de vista morfológico e enzimático, após hepatectomia associada à isquemia e reperfusão.(AU)