Dissertação

Efeitos da suplementação com antioxidantes sobre as alterações oxidativas cerebrais e pulmonares em malária murina

During malaria infection, Plasmodium may provoke high oxidative stress, resulting in oxidative damage, and may lead to the development of severe malaria, such as cerebral and pulmonary malaria. Furthermore, the involvement of reactive oxygen species and antioxidant defenses in the physiopathological...

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Autor principal: GOMES, Bruno Alexandre Quadros
Grau: Dissertação
Idioma: por
Publicado em: Universidade Federal do Pará 2017
Assuntos:
Acesso em linha: http://repositorio.ufpa.br/jspui/handle/2011/9188
Resumo:
During malaria infection, Plasmodium may provoke high oxidative stress, resulting in oxidative damage, and may lead to the development of severe malaria, such as cerebral and pulmonary malaria. Furthermore, the involvement of reactive oxygen species and antioxidant defenses in the physiopathological phenomena of disease has been discussed, as well as the potential benefit of antioxidant supplements. Hence, from the antioxidant sources that would be suitable, two are particularly interesting: N-acetylcysteine (NAC) and mushroom Agaricus sylvaticus. Thus, the aim of this study was to investigate the potential benefit NAC and Agaricus sylvaticus supplementation against oxidative changes in murine malaria caused by Plasmodium berghei. Two-hundred male mice (Mus musculus) were randomly divided into 20 groups, as following: Groups I-V (positive control); Groups VI-X (negative control); Groups XI-XV: (infected and treated with N-acetylcysteine animals); Groups XVI-XX: (infected and treated with Agaricus sylvaticus animals). Them, brain, lung, and blood samples were collected after 1, 3, 5, 7, or 10 days after infection for malondialdehyde (MDA), trolox equivalente antioxidant capacity (TEAC), nitrites and nitrates (NO) measurement, and parasitemia rate evaluation. Results show that parasitemia increased progressively with evolution of disease, and that was a significant decrease from 7th to 10 th day of infection in both antioxidant supplemented groups. Total antioxidant capacity was higher in supplemented animal’s groups, in that Agaricus sylvaticus treated animals presented a most pronuncied effect in lung samples, with progressive increase along with the days of infection. At the same time, pulmonary MDA levels in the Agaricus sylvaticus and NAC groups showed similar between themselves and with positive control. On the other hand, the cerebral MDA in antioxidants supplemented groups increased during infection, but not in a progressive way. Besides, in the Agaricus sylvaticus groups, MDA levels were lower than NAC, particularly in 5th day of infection. Thus, oxidative damage were most pronounced in pulmonary tissue than brain and related to lipid peroxidation. However, Agaricus sylvaticus was found to be more effective in preventing lipid peroxidation in brain and lung. In addition, pulmonary NO levels were increased in Nacetylcysteine supplemented animals in relationship to Agaricus sylvaticus from 3rd to 10th days of study, progressively increasing, and Agaricus sylvaticus supplemented animals presented similar NO levels to negative control groups. NAC also induced cerebral NO synthesis, but not in a progressive way. In addition, positive and negative control groups show similar cerebral NO levels. Probabily Agaricus sylvaticus and NAC act in two distinct mechanisms in attempt to defeat infection, and can be helpful in the adjuvant therapy of malaria.