Harvesting Season and Botanical Origin Interferes in Production and Nutritional Composition of Bee Pollen

ABSTRACT We aimed to evaluate the frequency of bee pollen production, its botanical origin and chemical composition when collected in different seasons. Our results indicate that higher proteins (22.80 ± 3.09%) and flavonoids (2789.87 ± 1396.00 μg 100g-1) levels were obtained in the winter season, which also showed greater pollen production (134.50 ± 35.70 grams) and predominance of the Myrtaceae family. As for spring we found high concentrations of lipids (4.62 ± 2.26%) and low ash content (2.22 ± 0.39%). Regarding the amino acid composition and vitamin C content, we found no differences between the averages throughout the seasons. Our results highlight the importance of understanding not only the botanical origin and the chemical composition of bee pollen, but also the harvesting frequency of this product by bees, so that it becomes possible to supplement the colonies in times of natural food resources shortage.

Harvesting Season and Botanical Origin Interferes in Production and Nutritional Composition of Bee Pollen.

We aimed to evaluate the frequency of bee pollen production, its botanical origin and chemical composition when collected in different seasons. Our results indicate that higher proteins (22.80 ± 3.09%) and flavonoids (2789.87 ± 1396.00 µg 100g-1) levels were obtained in the winter season, which also showed greater pollen production (134.50 ± 35.70 grams) and predominance of the Myrtaceae family. As for spring we found high concentrations of lipids (4.62 ± 2.26%) and low ash content (2.22 ± 0.39%). Regarding the amino acid composition and vitamin C content, we found no differences between the averages throughout the seasons. Our results highlight the importance of understanding not only the botanical origin and the chemical composition of bee pollen, but also the harvesting frequency of this product by bees, so that it becomes possible to supplement the colonies in times of natural food resources shortage.

Activity of Brazilian propolis against Aeromonas hydrophila and its effect on Nile tilapia growth, hematological and non-specific immune response under bacterial infection

ABSTRACT The effect of the ethanolic extract of propolis (EEP) on Aeromonas hydrophila was analyzed by determination of minimum inhibitory concentration (MIC). Then, the effects of crude propolis powder (CPP) on growth, hemato-immune parameters of the Nile tilapia, as well as its effects on resistance to A. hydrophila challenge were investigated. The CPP (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0%) was added to the diet of 280 Nile tilapia (50.0 ± 5.7 g fish-1). Hemato-immune parameters were analyzed before and after the bacterial challenge. Red blood cell, hematocrit, hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and hydrogen peroxide (H2O2) and nitric oxide (NO) were evaluated. The MIC of the EEP was 13% (v/v) with a bactericidal effect after 24 hours. Growth performance was significantly lower for those fish fed diets containing 2.5 and 3% of CPP compared to the control diet. Differences in CPP levels affected fish hemoglobin, neutrophils number and NO following the bacterial challenge. For others parameters no significant differences were observed. Our results show that although propolis has bactericidal properties in vitro, the addition of crude propolis powder to Nile tilapia extruded diets does not necessarily lead to an improvement of fish health.

Activity of Brazilian propolis against Aeromonas hydrophila and its effect on Nile tilapia growth, hematological and non-specific immune response under bacterial infection.

The effect of the ethanolic extract of propolis (EEP) on Aeromonas hydrophila was analyzed by determination of minimum inhibitory concentration (MIC). Then, the effects of crude propolis powder (CPP) on growth, hemato-immune parameters of the Nile tilapia, as well as its effects on resistance to A. hydrophila challenge were investigated. The CPP (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0%) was added to the diet of 280 Nile tilapia (50.0 ± 5.7 g fish-1). Hemato-immune parameters were analyzed before and after the bacterial challenge. Red blood cell, hematocrit, hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and hydrogen peroxide (H2O2) and nitric oxide (NO) were evaluated. The MIC of the EEP was 13% (v/v) with a bactericidal effect after 24 hours. Growth performance was significantly lower for those fish fed diets containing 2.5 and 3% of CPP compared to the control diet. Differences in CPP levels affected fish hemoglobin, neutrophils number and NO following the bacterial challenge. For others parameters no significant differences were observed. Our results show that although propolis has bactericidal properties in vitro, the addition of crude propolis powder to Nile tilapia extruded diets does not necessarily lead to an improvement of fish health.

Effects of Brazilian and Bulgarian propolis on bactericidal activity of macrophages against Salmonella Typhimurium.

Propolis has been used in folk medicine since ancient times due to its many biological properties, such as antimicrobial, antiinflammatory, antioxidant, immunomodulatory activities, among others. Macrophages play an important role in the early phase of Salmonella infection. In this work, macrophages were prestimulated with Brazilian or Bulgarian propolis and subsequently challenged with Salmonella Typhimurium at different macrophage/bacteria ratio. After 60 min of incubation, cells were harvested with Triton-X to lyse the macrophages. To assess the bactericidal activity, the number of colony-forming units (CFU) of S. typhimurium was determined by plating 0.1 mL in Mueller Hinton agar. After 24 h, CFU were counted, and the percentage of bactericidal activity was obtained. Propolis from Brazil and Bulgaria enhanced the bactericidal activity of macrophages, depending on its concentration. Brazilian propolis seemed to be more efficient than that from Bulgaria, because of their different chemical composition. In Bulgaria, bees collect the material mainly from the bud exudate of poplar trees, while in Brazil, Baccharis dracunculifolia DC. was shown to be the main propolis source. Our data also showed that the increased bactericidal activity of macrophages involved the participation of oxygen (H(2)O(2)) and nitrogen (NO) intermediate metabolites.