Antioxidant enzymes, hematology and histology of spleen in Nile tilapia fed supplemented diet with natural extracts challenged with Aeromonas hydrophila.

This study investigated the effects of dietary supplementation with the extrats of propolis and Aloe barbadensis (aloe) on the antioxydant enzime activity, hematology and histology of the spleen of Nile tilapia challenged with Aeromonas hydrophila. Seventy two juvenile Nile tilapia were divided in four treatments and three replicates and fed extract mixture for 15 days: fish fed supplemented diet with 1% of the mixture of extracts of propolis and aloe (1:1) injected with phosphate-buffered saline (PBS); fish fed suplemented diet with 1% of the mixture of extracts of propolis and aloe (1:1) injected with the A. hydrophila, fish fed supplemented diet with the mixture of propolis extracts and aloe, injected with PBS and injected with A. hydrophila. The influence of the supplementation of propolis and Aloe extracts on the immunomodulation in tilapias was observed by the evaluation of the survival of the animals after challenge with A. hydrophila. Non-supplemented fish had a 44.5% survival rate and those supplemented with 1% of the mixture of extracts showed 55.6% survival 7 days after challenge. The supplemented animals also showed a significant increase in the number of lymphocytes in the evaluation of the blood parameters and, consequently, in the histopathological evaluation, presented greater presence of centers of melanomacrophages. In addition, the activity of the antioxidant enzymes glutathione reductase (GR) in the spleen presented a significant difference in fish supplemented with 1% of the extracts mixture, being superior in the animals injected with PBS when compared to those challenged with A. hydrophila.

Effect of dietary supplementation with propolis and Aloe barbadensis extracts on hematological parameters and parasitism in Nile tilapia.

This study evaluated the influence of diet supplementation with propolis and Aloe barbadensis on hematological parameters and parasitism in tilapia. One hundred and eighty fish were distributed among 12 water tanks forming four treatments: fish supplemented with a 1:1 mixture of 0%, 0.5%, 1% and 2% propolis and aloe extracts. After the fish had been fed on the experimental diets for 15 and 21 days, blood samples were taken and parasites collected. The monogeneans Cichlidogyrus sclerosus, C. halli, C. thurstonae and Scutogyrus longicornis were identified in the gills. Between the sampling times, there were increases in the numbers of erythrocytes, leukocytes, thrombocytes and lymphocytes, as observed after 21 days, possibly due to the stress level over the course of the assay and/or accumulation of substances in the organism. Supplementation with the mixture of propolis and aloe for 15 days showed the highest efficacy against the parasites. This was possibly due to the association between the two compounds. The results demonstrated that supplementation with mixtures of extracts did not produce hematological alterations and also favored a significant reduction in the number of gill parasites. The best results were achieved after 15 days of feeding with a diet with 0.5% and 1% supplementation with the extract mixture, which increased efficiency by 83 and 85% respectively.

Effect of dietary supplementation with propolis and Aloe barbadensis extracts on hematological parameters and parasitism in Nile tilapia / Efeito da suplementação dietária com extratos de própolis e Aloe barbadensis sobre parâmetros hematológicos e parasitismo em tilápia do Nilo

This study evaluated the influence of diet supplementation with propolis and Aloe barbadensis on hematological parameters and parasitism in tilapia. One hundred and eighty fish were distributed among 12 water tanks forming four treatments: fish supplemented with a 1:1 mixture of 0%, 0.5%, 1% and 2% propolis and aloe extracts. After the fish had been fed on the experimental diets for 15 and 21 days, blood samples were taken and parasites collected. The monogeneans Cichlidogyrus sclerosus, C. halli, C. thurstonae and Scutogyrus longicornis were identified in the gills. Between the sampling times, there were increases in the numbers of erythrocytes, leukocytes, thrombocytes and lymphocytes, as observed after 21 days, possibly due to the stress level over the course of the assay and/or accumulation of substances in the organism. Supplementation with the mixture of propolis and aloe for 15 days showed the highest efficacy against the parasites. This was possibly due to the association between the two compounds. The results demonstrated that supplementation with mixtures of extracts did not produce hematological alterations and also favored a significant reduction in the number of gill parasites. The best results were achieved after 15 days of feeding with a diet with 0.5% and 1% supplementation with the extract mixture, which increased efficiency by 83 and 85% respectively.

Este estudo avaliou a influência da alimentação de tilápias com dieta suplementada com extratos de própolis e Aloe barbadensis sobre os parâmetros hematológicos e parasitismo. Setenta e dois peixes foram distribuídos em 12 tanques, formando 4 tratamentos: peixes suplementados na dieta com extrato de própolis e aloe (0%, 0,5%, 1% e 2%). Após 15 e 21 dias de alimentação com dietas experimentais foram realizadas coletas de sangue e parasitos. Os monogeneas Cichlidogyrus sclerosus, C. halli, C. thurstonae e Scutogyrus longicornis foram identificados nas brânquias. Entre os períodos de coleta, observou-se aumento nos valores de eritrócitos, leucócitos, trombócitos e linfócitos, após 21 dias de alimentação, o que pode significar estresse ao longo do período experimental e/ou acúmulo dos produtos no organismo.A suplementação com a mistura de própolis e aloe, por 15 dias, apresentou melhor eficácia frente parasitos, possivelmente, devido à associação dos compostos. Os resultados demonstram que a suplementação com a mistura dos extratos não alterou os parâmetros hematológicos, além de favorecer redução significativa no número de parasitos branquiais. Os melhores resultados foram obtidos em 15 dias de alimentação com a dieta suplementada com 0,5% e 1% da mistura dos extratos, respectivamente por 83% e 85% de eficiência.

Leukocyte phagocytosis and lysozyme activity in Nile tilapia fed supplemented diet with natural extracts of propolis and Aloe barbadensis.

Although there is evidence on the benefits in the use of immunostimulants in aquaculture, there are few commercial products being used. This study evaluated the use of natural substances as potential sources for the production of immunostimulants. Propolis and Aloe barbadensis have been widely studied and its extracts have different chemical constituents responsible for antimicrobial, anti-inflammatory and immunostimulant. Tilapia juveniles were fed for two weeks with diets supplemented mix of propolis extracts and aloe (1:1) in different concentrations: 0.5, 1 e 2%. After the experimental period, fish blood was collected for hematoimmunological as follows : hematocrit, total plasma protein, erythrocytes (RBC), leukocytes (WBC), differential leukocyte count, phagocytic activity, serum lysozyme activity, and serum antimicrobial activity, serum antimicrobial activity (evaluated against Aeromonas hydrophila, Enterococcus durans and Escherichia coli). Except for higher number of thrombocytes in 1%-supplemented fish, the rest did not show significant difference.