Abstract Background The neutrophil-to-lymphocyte (NLR), monocyte-to-lymphocyte (MLR), platelet-to-lymphocyte ratio (PLR), and red blood cell distribution width (RDW) have been previously studied as predictors of survival in different malignancies. Objective The aim of this study was to evaluate the predictive value of these hematologic inflammatory biomarkers for patients with brain metastases (BM). Methods We reviewed a consecutive cohort of patients at Instituto do Cancer do Estado de São Paulo (ICESP-FMUSP) from 2011 to 2016 with ≥ 1 BM treated primarily by surgical resection. The primary outcome was 1-year survival. We optimized the NLR, MLR, PLR, and RDW cutoff values, preserving robustness and avoiding overestimation of effect size. Results A total of 200 patients (mean age 56.1 years; 55.0% female) met inclusion criteria. Gross-total resection was achieved in 89.0%. The median (quartiles) preoperative and postoperative KPS scores were 60 (50-80) and 80 (60-90), respectively. Preoperative NLR was significantly associated with survival (HR 2.66, 95% CI: 1.17-6.01, p = 0.019). A NLR cutoff value of 3.83 displayed the most significant survival curve split. Conclusions Preoperative NLR is an independent predictor of survival in newly diagnosed BM. We propose a cutoff value of 3.83 for preoperative NLR testing may be clinically useful as predictor of poor survival in this population. The wide accessibility of the NLR favors its inclusion in clinical decision-making processes for BM management.

Resumo Antecedentes Os neutrófilos para linfócitos (NLR), monócitos para linfócitos (MLR), proporção de plaquetas para linfócitos (PLR) e largura de distribuição de glóbulos vermelhos (RDW) foram previamente estudados como preditores de sobrevivência em diferentes malignidades. Objetivo O objetivo deste estudo foi avaliar o valor preditivo desses biomarcadores inflamatórios hematológicos para pacientes com metástases cerebrais (MB). Métodos Nós revisamos uma coorte consecutiva de pacientes no Instituto do Câncer do Estado de São Paulo (ICESP-FMUSP) de 2011 a 2016 com ≥ 1 MB tratados principalmente por ressecção cirúrgica. O desfecho primário foi a sobrevida em 1 ano. Otimizamos os valores de corte de NLR, MLR, PLR e RDW, preservando a robustez e evitando superestimação do tamanho do efeito. Resultados Um total de 200 pacientes (idade média de 56,1 anos; 55,0% mulheres) preencheram os critérios de inclusão. A ressecção grosseira total foi obtida em 89,0%. A mediana (quartis) dos escores KPS pré-operatório e pós-operatório foram 60 (50–80) e 80 (60–90), respectivamente. O NLR pré-operatório foi significativamente associado à sobrevida (HR 2,66, IC 95%: 1,17–6,01, p = 0,019). Um valor de corte de NLR de 3,83 exibiu a divisão da curva de sobrevivência mais significativa. Conclusões O NLR pré-operatório é um preditor independente de sobrevida em MBs recém-diagnosticados. Propomos que um valor de corte de 3,83 para o teste de NLR pré-operatório pode ser clinicamente útil como preditor de baixa sobrevida nesta população. A ampla acessibilidade do NLR favorece sua inclusão nos processos de tomada de decisão clínica para o gerenciamento de BM.

Resumo Contexto A lesão de isquemia e reperfusão contribui para a morbidade após procedimentos de revascularização. Juntamente com a reperfusão precoce, o condicionamento tecidual através de breves episódios de isquemia e reperfusão é considerado a melhor abordagem para limitar o dano tecidual. Apesar disso, os mecanismos do condicionamento isquêmico remoto são pouco compreendidos, o que pode levar a uma aplicação incorreta. Objetivos Avaliar se o condicionamento isquêmico remoto funciona no coração e no cérebro através do aprimoramento da defesa antioxidante das células e se é uma resposta sustentada ou temporária. Métodos Vinte e um ratos Wistar foram divididos em três grupos (n = 7): SHAM, no qual não foi realizado condicionamento isquêmico; RIC 10, no qual 10 minutos após o protocolo de condicionamento isquêmico, foi realizada a coleta dos órgãos; e RIC 60, no qual 60 minutos após o protocolo de condicionamento isquêmico, foi realizada a coleta dos órgãos. O protocolo de condicionamento isquêmico remoto consistiu em três ciclos de 5 minutos de isquemia, seguidos de 5 minutos de perfusão no membro posterior esquerdo, com duração total de 30 minutos. Amostras foram usadas para medir a capacidade antioxidante do tecido. Resultados O condicionamento isquêmico remoto aumentou a capacidade antioxidante do coração e do cérebro após 10 minutos (0,746 ± 0,160/0,801 ± 0,227 mM/L) quando comparado ao SHAM (0,523 ± 0,078/0,404 ± 0,124 mM/L) . Sessenta minutos após o condicionamento isquêmico remoto, não foi detectado aumento da capacidade antioxidante do coração ou do cérebro (0,551 ± 0,073/0,455 ± 0,107 mM/L). Conclusões O condicionamento isquêmico remoto melhora temporariamente as defesas antioxidantes do coração e do cérebro em ratos Wistar.

Abstract Background Ischemia-reperfusion injury contributes to morbidity after revascularization procedures. Along with early reperfusion, tissue conditioning by alternating intervals of brief ischemia-reperfusion episodes is considered the best approach to limit tissue damage. Remote ischemic conditioning is conducted remotely, in tissues other than those under ischemia. Despite this, remote ischemic conditioning protection mechanisms are poorly understood, which can lead to misapplication. Objectives To assess whether remote ischemic conditioning works in the heart and brain through enhancement of cells’ antioxidant defenses and whether the response is sustained or temporary. Methods Twenty-one male Wistar rats were assigned to three groups (n = 7): SHAM: same procedure as the other groups, but no remote ischemic conditioning was carried out. RIC 10: heart and brain were harvested 10 minutes after the remote ischemic conditioning protocol. RIC 60: heart and brain were harvested 60 minutes after the remote ischemic conditioning protocol. The remote ischemic conditioning protocol consisted of 3 cycles of 5 min left hindlimb ischemia followed by 5 min left hindlimb perfusion, lasting 30 min in total. Heart and brain samples were used to measure the tissue antioxidant capacity. Results Remote ischemic conditioning increased heart and brain antioxidant capacity after 10 minutes (0.746 ± 0.160/0.801 ± 0.227 mM/L) when compared to SHAM (0.523 ± 0.078/0.404 ± 0.124 mM/L). No enhancement of heart or brain antioxidant capacity was detected 60 minutes after remote ischemic conditioning (0.551 ± 0.073/0.455 ± 0.107 mM/L). Conclusions Remote ischemic conditioning temporarily enhances heart and brain antioxidant defenses in male Wistar rats.

RESUMO Racional: O melhor sítio para implante esplênico não foi definido, principalmente avaliando a funcionalidade do implante. Objetivo: Avaliar os efeitos do implante esplênico autógeno subcutâneo na sobrevida de ratos esplenectomizados. Métodos: Foram estudados 21 ratos alocados aleatoriamente em três grupos (n=7): grupo 1 - manipulação da cavidade abdominal e preservação do baço; grupo 2 - esplenectomia total; grupo 3 - esplenectomia e implante do tecido retirado no subcutâneo. Os animais foram acompanhados por 90 dias pós-operatórios. Resultados: Houve mortalidade maior nos grupos 2 (p=0,0072) e 3 (p=0,0172) em relação ao grupo 1. Não houve diferença entre os grupos 2 e 3 (p=0,9817). Conclusão: O implante esplênico no subcutâneo é ineficaz na sobrevida de ratos submetidos à esplenectomia.

ABSTRACT Background: The best site for splenic implant was not defined, mainly evaluating the functionality of the implant. Aim: To evaluate the effects of autogenous splenic implantation on the subcutaneous tissue in the survival of splenectomized rats. Method: Twenty-one randomly assigned rats were studied in three groups (n=7): group 1 - manipulation of the abdominal cavity and preservation of the spleen; group 2 - total splenectomy; group 3 - splenectomy and implant of the tissue removed in the subcutaneous. The animals were followed for 90 days postoperatively. Results: There was a higher mortality in groups 2 (p=0.0072) and 3 (p=0.0172) in relation to group 1. There was no difference between groups 2 and 3 (p=0.9817). Conclusion: The splenic implant in the subcutaneous is ineffective in the survival of rats submitted to splenectomy.

Resumo Anastomoses vasculares são procedimentos comuns realizados por grande parte dos cirurgiões e cujo treinamento ocorre principalmente em seres humanos, contrariando os princípios éticos vigentes. Esse fato se deve, sobretudo, à carência e ao alto custo relacionados aos atuais modelos de treinamento. Assim, este estudo visa avaliar a viabilidade de três vegetais para a realização de anastomoses vasculares. Foram utilizadas cinco unidades de cebolinha, vagem e feijão-verde. Em cada uma tentou-se realizar uma anastomose término-terminal. Conseguiu-se a realização da anastomose apenas na vagem e no feijão-verde. Contudo, por apresentar uma menor espessura, o feijão-verde assemelhou-se mais aos vasos humanos.

Abstract Vascular anastomoses are common procedures and are performed by most surgeons. Training is primarily conducted in human beings, which violates current ethical principles. This is because current training models are expensive and in short supply. This study was designed to investigate the feasibility of three vegetable models of vascular anastomosis. Five units each of scallions, green beans, and yardlong beans were used. An end-to-end anastomosis was attempted with each specimen. Anastomoses were only successful in green beans and yardlong beans. Since they are narrower, the yardlong beans are the most similar to human vessels.

Abstract Purpose: To compare the continuous and interrupted suture technique on femoral artery on rats after vessel repair and 14 days after. Methods: Twenty rats were operated randomly divided into two group matched according to the suture technique used: interrupted or continuous. We performed a femoral anastomosis on the right femoral artery. We analyzed weight, arterial caliber, anastomosis time and patency after vessel repair and 14 days after. Results: There was no significant difference between groups in the weight (p=0.64), diameter of the femoral artery (p=0.95) and patency (p=1.00). The time spent in the anastomosis was 451 seconds in the continuous group and 718 seconds in the interrupted group, presenting significant difference (p<0.01). Conclusion: The continuous suture technique shows a similar patency rates than interrupted technique, however with a shorter time to perform the anastomosis.

Abstract Purpose: To evaluate if combination of perconditioning and postconditioning provides improved renal protection compared to perconditioning alone in a model of renal reperfusion injury. Methods: Thirty rats were assigned into 6 groups: normality; sham; ischemia and reperfusion; postconditioning; perconditioning; perconditioning + postconditioning. Animals were subjected to right nephrectomy and left renal ischemia for 30 minutes. Postconditioning consisted of 3 cycles of 5 min renal perfusion followed by 5 min of renal ischemia after major ischemic period. Perconditioning consisted of 3 cycles of 5 min hindlimb ischemia followed by 5 min of hindlimb perfusion contemporaneously to renal major ischemic period. After 24 hours, kidney was harvested and blood collected to measure urea and creatinine. Results: Perconditioning obtained better values for creatinine and urea level than only postconditioning (p<0.01); performing both techniques contemporaneously had no increased results (p>0.05). Regarding tissue structure, perconditioning was the only technique to protect the glomerulus and tubules (p<0.05), while postconditioning protected only the glomerulus (p<0.05). Combination of both techniques shows no effect on glomerulus or tubules (p>0.05). Conclusions: Perconditioning had promising results on ischemia and reperfusion induced kidney injury, enhanced kidney function and protected glomerulus and tubules. There was no additive protection when postconditioning and perconditioning were combined.

RESUMO Racional: O desfecho satisfatório na abordagem cirúrgica da obesidade deve contemplar, além da perda de peso, alteração significativa nas comorbidades preexistentes e na qualidade de vida dos pacientes. Objetivo: Avaliar a qualidade de vida no pós-operatório tardio de pacientes submetidos à cirurgia de gastrectomia vertical por videolaparoscopia. Métodos: Foi aplicado o questionário "Bariatric Analysis and Reporting Outcome System" (BAROS) em pacientes submetidos à gastrectomia vertical por videolaparoscopia. Resultados: Foram avaliados 47 pacientes, entre 21 e 60 anos de idade. O IMC médio antes da operação era 43,06±5,87 kg/m². A média percentual de redução do excesso de peso após foi de 85,46±23,6%. A pontuação obtida pelos pacientes no questionário sobre a melhora na qualidade de vida evidenciou resultado excelente (36,17%), ótimo (40,43%), bom (21,28%) e razoável (2,13%). Houve melhora clínica após a operação em todas as comorbidades investigadas. Conclusão: A perda de peso foi fundamental para a melhoria na qualidade de vida e proporcionou resolução ou a melhora clínica em todas as comorbidades investigadas.

ABSTRACT Background: Mesenteric ischemia is a challenging diagnosis. Delay in diagnosis can lead to extent bowel necrosis and poor outcomes. Ischemia and reperfusion syndrome plays an important role in this scenario. Aim: To access effects of different post-conditioning cycles on mesenteric ischemia-reperfusion syndrome. Method: Twenty-five rats were assigned into five groups: Sham, used to establish normal parameters; control group, submitted to mesenteric ischemia for 30 min; in groups GP3, GP1 and GP30, ischemia was followed by post-conditioning protocol, which consisted of 1 cycle of 3 min (GP3), 3 cycles of 1 min (GP1) or 6 cycles of 30 s (GP30), respectively. Ileum samples were harvested after one hour of reperfusion. Intestinal mucosal injury was evaluated through histopathological analysis. Results: The average of mesenteric injury degree was 0 in the sham group, 3.6 in the control group, 3.4 in GP3, 3.2 in GP1, and 3.0 in GP30; villous length average was 161.59 in sham group, 136.27 in control group, 135.89 in GP3, 129.46 in GP1, and 135.18 in GP30. Was found significant difference between sham and other groups (p<0.05); however, there was no difference among post-conditioning groups. Conclusion: Post-conditioning adopted protocols were not able to protect intestinal mucosa integrity after mesenteric ischemia and short term reperfusion.

Resumo Os vasos femorais de 80 ratos foram identificados e dissecados. O comprimento e o diâmetro externo da artéria e da veia femoral foram mensurados com o auxílio de um microscópio e um sistema de magnificação por vídeo. Esses parâmetros foram correlacionados com o peso do animal. O comprimento de ambos os vasos femorais foi de 14,33 mm, e a média do diâmetro das artérias foi de 0,65 mm, e das veias, de 0,81 mm. Na nossa amostra, o peso dos animais se correlacionou apenas com o diâmetro da veia femoral.

Abstract The right femoral vessels of 80 rats were identified and dissected. External lengths and diameters of femoral arteries and femoral veins were measured using either a microscope or a video magnification system. Findings were correlated to animals’ weights. Mean length was 14.33 mm for both femoral arteries and femoral veins, mean diameter of arteries was 0.65 mm and diameter of veins was 0.81 mm. In our sample, rats’ body weights were only correlated with the diameter of their femoral veins.

RESUMO Objetivo: avaliar os efeitos do bloqueio da regulação do tônus vascular por meio do uso da lidocaína na técnica de pós-condicionamento isquêmico na síndrome de isquemia e reperfusão renal em ratos. Métodos: trinta e cinco ratos foram randomizados em sete grupos de cinco animais: Grupo 1- Controle; Grupo 2- Isquemia e Reperfusão; Grupo 3- Isquemia, Reperfusão e Solução Salina; Grupo 4- Pós-condicionamento Isquêmico; Grupo 5- Pós-condicionamento Isquêmico e Solução Salina; Grupo 6- Lidocaína; Grupo 7- Pós-condicionamento Isquêmico e lidocaína. Com exceção do grupo controle, todos os demais foram submetidos à isquemia renal de 30 minutos. Nos grupos de pós-condicionamento, foi realizado o ciclo de isquemia e reperfusão de cinco minutos cada, aplicado logo após a isquemia principal. Nos grupos salina e lidocaína foram instiladas as substâncias numa taxa de duas gotas por minuto. Para comparar os grupos, foram dosados os níveis séricos de ureia e creatinina e análise histopatológica renal. Resultados: os grupos pós-condicionamento e pós-condicionamento + lidocaína apresentaram uma redução nos valores de ureia e creatinina. O grupo lidocaína apresentou apenas uma redução nos valores de creatinina. Na análise histopatológica, apenas os grupos submetidos ao pós-condicionamento isquêmico apresentaram redução do grau de necrose tubular. Conclusão: a lidocaína não bloqueou os efeitos do pós-condicionamento na síndrome de isquemia e reperfusão renal, mas conferiu melhor na proteção glomerular quando aplicada em conjunto com o pós-condicionamento isquêmico.

ABSTRACT Objective: to evaluate the effects of blocking the regulation of vascular tone on the ischemia and reperfusion syndrome in rats through the use of lidocaine in the postconditioning technique. Methods: we randomized 35 rats into seven groups of five animals: Group 1- Control; Group 2- Ischemia and Reperfusion; Group 3- Ischemia, Reperfusion and Saline; Group 4- Ischemic Postconditioning; Group 5- Ischemic Postconditioning and Saline; Group 6- Lidocaine; Group 7- Ischemic Postconditioning and Lidocaine. Except for the control group, all the others were submitted to renal ischemia for 30 minutes. In postconditioning groups, we performed ischemia and reperfusion cycles of five minutes each, applied right after the main ischemia. In saline and lidocaine groups, we instilled the substances at a rate of two drops per minute. To compare the groups, we measured serum levels of urea and creatinine and also held renal histopathology. Results: The postconditioning and postconditioning + lidocaine groups showed a decrease in urea and creatinine values. The lidocaine group showed only a reduction in creatinine values. In histopathology, only the groups submitted to ischemic postconditioning had decreased degree of tubular necrosis. Conclusion: Lidocaine did not block the effects of postconditioning on renal ischemia reperfusion syndrome, and conferred better glomerular protection when applied in conjunction with ischemic postconditioning.

ABSTRACT PURPOSE: To verify the publication rate of the abstracts presented at the XII Brazilian Congress of Experimental Surgery. METHODS: We performed a cross-sectional study that evaluated if the abstracts accepted for presentation at the XII Brazilian Congress of Experimental Surgery were published in periodics. The information was acquired using the Scielo, Medline / Pubmed, LILACS and Google Scholar databases. RESULTS: From all the abstracts presented, only 77 (40.52%) were published in scientific journals. Of this total, 14 (18.18%) were published prior to the conference 35 (45.45%) in the same year that occurred congress, 56 (72.72%) in the period 2011-2013 and 63 (81, 81%) between the Congress and the year 2015. Regarding the geographical distribution of summaries, 42 (22%) were from the northern region, 19 (10%) from the Northeast, 8 (4%) Midwest, 116 (61%) from the Southeast and 5 (3%) from the south. CONCLUSION: The publication rate of the abstracts presented at the XII Brazilian Congress of Experimental Surgery was 40,52%, most from the state of Sao Paulo.

Racional: As instruções aos autores são a principal comunicação entre os pesquisadores e as políticas editoriais. Um dos itens obrigatórios que devem conter é sobre a parte ética, para evitar que novas pesquisas que realizem abusos com os incluídos na pesquisa sejam publicadas e estimuladas. Objetivo: Verificar os quesitos éticos das instruções aos autores de revistas cirúrgicas nacionais. Método: Treze revistas escolhidas aleatoriamente do campo cirúrgico foram selecionadas. As instruções aos autores foram analisadas com base em protocolo de pesquisa contendo seis itens que devem obrigatoriamente conter nas instruções aos autores. Resultados: A média da pontuação do grupo de revistas gerais foi semelhante que o grupo de revistas sobre especialidades cirúrgicas (3,66±0,57vs 3,30±1,15, p=0,6154). Quando cada quesito ético foi comparado entre os grupos, não houve diferença significativa entre os quesitos estudados (p>0,05). Conclusão: Houve respeito pela maioria dos quesitos éticos avaliados, sem diferença entre as revistas de cunho geral ou especializadas.

Background: The instructions to authors are the only means of communication between researchers and the editorial standards of a scientific journal. One of the mandatory items to be contained therein is about the ethical part, to prevent new research to carry out abuses with the enrolled on the research are published and stimulated. Aim: To verify the ethical questions on the guidelines of Brazilian surgical journals Method: Thirteen selected journals were divided into two groups: general surgery (n=3), and surgical specialty (n=10). The instructions to authors were analyzed by the quote of ethical requirements based on a specific research protocol, ranging from zero to six points. Results: The average score of the general surgery group was similar than that of the surgical specialty group (3.66±0.57 vs 3.30±1.15, p=0.6154). When each ethical requirement was compared between the groups, there was no significant difference between the ethical requirements (p<0.05). Conclusion: There was respect for most ethical questions evaluated, with no difference between the journals of general or specialty surgery.

Resumo As veias femorais de 30 ratas da linhagem Wistar foram estudadas por método histológico com objetivo de investigar a presença de válvulas. Na análise histológica não foram identificadas projeções do endotélio ou recessos valvares que poderiam sugerir a presença de válvulas venosas nessa espécie de animal.

Abstract The femoral veins of 30 female rats of the Wistar lineage were studied using histological methods with the objective of determining whether they have valves. Histological analysis did not detect any endothelial projections or valve recesses that would suggest the presence of venous valves in this species of animal.

Racional: A utilização de telas nas herniorrafias foi grande revolução na área cirúrgica; contudo, elas trouxeram algumas dificuldades, como grande área de fibrose, maior dor pós-operatória e risco de infecção. A busca por novas substâncias que minimizem esses efeitos deve ser estimulada. As plantas medicinais se destacam por apresentaram conjunto de princípios ativos que podem atuar em todos esses problemas. Objetivo: Verificar se o óleo de copaíba influência no reparo de defeitos abdominais em ratos corrigidos com tela de Vicryl®. Método: Vinte e quatro ratas Wistar foram submetidas a um defeito abdominal e corrigidos com tela de Vicryl®. Elas foram distribuídas em dois grupos: controle e copaíba via gavagem, administrada durante sete dias após a operação. A análise dos animais ocorreu nos dias 8, 15 e 22 de pós-operatório. Foi analisada a quantidade de aderências e feita análise microscópica da tela. Resultados: Não houve diferença estatística em relação à quantidade de aderências. Todos os animais tiveram sinais de inflamação aguda. No grupo controle, houve menor quantidade de macrófagos nos animais do dia 8 em relação aos demais dias e maior quantidade de necrose no dia 8 do que no dia 22. No grupo copaíba, o número de gigantócitos aumentou em relação aos dias analisados. Conclusão: O óleo de copaíba mostrou melhora na resposta inflamatória acelerando o seu início; contudo, não interferiu na quantidade de aderências abdominais ou fibras colágenas.

Background: The use of meshes in hernia surgical repair promoted revolution in the surgical area; however, some difficulties had come, such as a large area of fibrosis, greater postoperative pain and risk of infection. The search for new substances that minimize these effects should be encouraged. Medicinal plants stand out due possible active ingredients that can act on these problems. Aim: To check the copaiba oil influence in the repair of abdominal defects in rats corrected with Vicryl(c) mesh. Method: Twenty-four Wistar rats were submitted to an abdominal defect and corrected with Vicryl(c) mesh. They were distributed into two groups: control and copaíba via gavage, administered for seven days after surgery. The analysis of the animals took place on 8, 15 and 22 postoperative days. It analyzed the amount of adhesions and microscopic analysis of the mesh. Results: There was no statistical difference regarding the amount of adhesions. All animals had signs of acute inflammation. In the control group, there were fewer macrophages in animals of the 8th compared to other days and greater amount of necrosis on day 8 than on day 22. In the copaiba group, the number of gigantocytes increased compared to the days analyzed. Conclusion: Copaiba oil showed an improvement in the inflammatory response accelerating its beginning; however, did not affect the amount of abdominal adhesions or collagen fibers.

PURPOSE: To evaluate the effect of fasting on gastric emptying in mice.METHODS:Twenty-eight mice were distributed into three study groups: a normal group (N=4): normal standard animals; a total fasting group (N=12): subjected to food and water deprivation and a partial fasting group (N=12): subjected to food deprivation only. The fasting groups were subdivided into three subgroups of four animals each, according to the date of euthanasia: 24, 48 and 72 hours. Was analyzed: the gastric volume, degree of the gastric wall distention and the presence of food debris in gastrointestinal tract.RESULTS:The mean gastric volume was 1601 mm3in the normal group, 847 mm3in total fasting group and 997 mm3in partial fasting group. There was difference between the fasting groups in any analyzed period (p<0.05). Regarding the presence of food debris in the gastrointestinal tract and the degree of distension of the stomach, there was no difference between the groups that underwent total or partial fasting (p>0.05).CONCLUSION:Total fasting or only-solids deprivation does not induce gastric emptying in mice.

PURPOSE: To investigate the copaiba oil on the hepatic damage induced by acetaminophen, comparing against corn oil. METHODS: Fifty four rats were distributed into nine study groups (N=6): control group, that didn't receive the acetaminophen; Acetaminophen Group, that only received the acetaminophen; Prophylactic Copaiba Group 1, that received copaiba oil two hours before the acetaminophen; Prophylactic Copaiba Group 7, that received copaiba oil seven days, once by day, before the acetaminophen; Therapy Copaiba Group, that received the copaiba oil two hours after the acetaminophen, the corn's groups were similar than copaiba oil groups; and N-Acetyl-Cysteine Group, that received the N-Acetyl-Cysteine two hours after the acetaminophen. Euthanasia was performed after 24 hours. The serum levels transaminases, bilirubin and canalicular enzymes were analyzed. RESULTS: The prophylactic copaiba group 7, therapy copaiba group and N-Acetyl-Cysteine Group showed amounts of AST and ALT similar to the control group; and the prophylactic copaiba group 1 and corn's groups showed similar levels to the acetaminophen group. There was no significant difference between the groups regarding the amount of alkaline phosphatase and ɤ GT (p>0.05). The therapy copaiba group showed the highest levels of total bilirubin and was statistically different from the other groups (p<0.01). CONCLUSIONS: Copaiba oil administered prophylactically for seven days and therapeutically 2 hours after the acetaminophen acute intoxication offered a potential hepato protection against paracetamol-induced hepatic damage, normalizing the biochemical parameters similarly to N-Acetyl-Cysteine, and the treatment with corn oil shows no effect on the liver damage.