Avaliação da capacidade protetora da piperina (extraída a partir das sementes de Piper nigrum L.), sobre parâmetros relacionados ao sistema imune de frangos de corte intoxicados experimentalmente por aflatoxina B1

Abstract

Aflatoxins are toxic products from molds secondary metabolism, usually found in grains and feed. Aflatoxin B1 (AFB1) is the type produced in major quantity and possesses the greatest toxic potential. Among the effects produced in layer and broiler chickens intoxication, can be mentioned, the productivity decrease due to reduction in body weight gain and laying eggs reduction, liver lesions with alterations in hepatic enzymes levels, chromosomes damage, carcinogenesis and immunosuppression leading to increase in susceptibility to infections and vaccinal response decrease. In the other hand, piperine is a natural product extracted from black pepper (Piper nigrum L.) and own citoprotective properties, showed by its antioxidative and antiapoptotic capacity, moreover it possesses immunoprotective effects against many immunotoxic products. Therefore, this research aimed to contribute to the knowledge of immunoprotective ability of piperine added in feed, assessing possible effects under immunological parameters in broiler chickens intoxicated by AFB1. To perform the study 60 male broiler chickens, 7 days old, were divided into four groups (n=15), control group (soya oil), AFB1 group (0,5 mg AFB1/kg of body weight, orally ), piperine group (60ppm on feed) and ppiperine-AFB1 group (piperine 60ppm and 0,5mg/kg of body weight ). All groups were vaccinated against Newcastle disease virus at 9 and 28 days old. Initially, the control and AFB1 groups were examined aiming the determination of AFB1 concentration (0,5 mg /kg) ability in broiler chickens intoxication, by the liver necropsy and weighing, AST and GGT enzymes dosage, citotoxic effects assessment on bone marrow (PCE frequency), micronucleus research in red blood cells. Once the toxic effect of AFB1 as determined in broiler chickens, were evaluated the piperine ability in suppress the immutoxic effects of AFB1, by necropsy, weighing and histophatological analyses of the lymphoid organs (thymus, bursa of Fabricius and spleen), total and differential circulating leukocytes counts, and vaccinal response to Newcastle disease virus. AFB1 concentration used in this study was able to promote broiler chicken intoxication, showed by the decrease in body weight gain, hepatic alterations, ( weight increase and liver aspect alterations and AST and GGT hepatic enzymes), bone marrow damage (reduce in PCE frequency) and increase in micronucleus presence in red blood cell. This concentration of AFB1 was able to promote damages in birds thymus, showed by the reduce in the organ weight, and macroscopic and microscopic alterations. The toxic effect on bone marrow and thymus promoted marcable leucopeny, with significant reduce in circulating lymphocytes and heterophils. The toxic effects of AFB1 on vaccinal response were not evident as much as other immune parameters studied. The administration of piperine in chicks feed was able to avoid the AFB1 immunotoxic effects in all aspects evaluated in this study.