Dietary lysine requirements of Colossoma macropomum (Cuvier, 1818) based on growth performance,hepatic and intestinal morphohistology and hematology

Veterinary Research Communications - This study aimed to determine the dietary lysine requirements of juvenile Colossoma macropomum tambaqui based growth performance, hepatic and intestinal...     

Antitumor activity of three benzopyrans isolated from Hypericum polyanthemum

In the present study we have investigated the in vitro antitumor effects of three benzopyrans, 6-isobutyryl-5,7-dimethoxy-2,2-dimethylbenzopyran (1), 7-hydroxy-6-isobutyryl-5-methoxy-2,2-dimethylbenzopyran (2) and 5-hydroxy-6-isobutyryl-7-methoxy-2,2-dimethylbenzopyran (3) isolated from Hypericum polyanthemum. The three compounds tested demonstrated potent growth inhibitory activity at 40 microg/ml (<25% control growth) in the NCI-H460, HT-29 and U-373MG human cell lines. Determination of cell cycle distribution demonstrated that the antiproliferative effect of the three benzopyrans could be associated to alterations in the cell cycle phase distribution. Treatment with the IC50 of the three compounds induced an arrested in S phase. Only in cells treated with compound 3 did the percentage of sub-G1 population increase up to 9%, suggesting that this compound induced more cell death than the others. Consistent with sub-G1 analysis, appreciable oligonucleosomal DNA fragmentation was only observed in the NCI-H460 cell line treated with compound 3. From these results it can be suggested that despite no differences among the cytotoxicity of the three compounds, it was observed that the mechanism of their antiproliferative effects appears to be different.     

Effect of Different Media and Protein Source on Equine Gametes: Potential Impact During In Vitro Fertilization

Equine in vitro fertilization (IVF) is still inconsistent. In the present work, we studied how modified Whitten's (MW) medium and Tissue Culture Medium 199 (TCM) added with Foetal Bovine Serum (FBS; 10% v/v) or Bovine Serum Albumin (BSA; 7 mg/ml) affected equine gametes to subsequently run IVF trials. Compact (Cp) and expanded (Ex) cumuli equine oocytes were matured and placed in TCM or MW supplemented with BSA or FBS for 18–20 h (no sperm added). In Ex oocytes, TCM‐199 added with FBS or BSA resulted in higher metaphase II (MII) rates (75.7% and 62.7%, respectively) than MW added with BSA (54%) or FBS (52.2%; p < 0.05); this was not observed for Cp oocytes. Equine sperm were capacitated in the same media at 10 × 10⁶ sperm/ml for 4 h at 37°C; total motility and protein tyrosine phosphorylation (PY) were evaluated. While motility remained unchanged, TCM or MW added with FBS enhanced the number of sperm showing PY‐stained tails (25 ± 4.8% and 31 ± 6.6%; mean ± SEM, respectively) over BSA supplemented media (3 ± 1.2% and 11.7 ± 1.1%) for TCM and MW (p < 0.05). In view of the previous results, sperm were capacitated in TCM + FBS and MW + BSA (control); IVF trials were run in the same media supplemented with 200 ng/ml of progesterone, but no fertilization occurred. Our results show that TCM + FBS enhances Ex equine oocyte's meiotic competence over MW + BSA and TCM or MW added with FBS successfully induce equine PY over media supplemented with BSA.     

Curcuma longa supplementation in the diet of Astyanax aff. bimaculatus in preparation for transport

The physiological state of fish before transportation is an important aspect to be observed when reduction in losses due to mortality is aimed. Various preparative procedures for transport are reported, but little is known about the use of additives in fish diet. In this study, we aimed to evaluate the effect of dietary turmeric (Curcuma longa) supplementation on the tolerance of juvenile Astyanax aff. bimaculatus to transportation stress. The experimental design consisted of six treatments: 0, 20, 40, 60, 80 and 100.0 g kg^?1 turmeric. Fish weighing 0.83 ± 0.04 g were distributed in 24 80‐L aquaria at a density of 0.5 fish L^?1 and were fed to satiation three times a day for 60 days. After this period, fish were transported for 24 h in plastic bags (15 fish per bag). Using a discontinuous linear response plateau (LRP) model, the lowest estimated concentration of turmeric that maximized the survival rate was 16.67 g kg^?1. Quadratic effects of turmeric on blood lactate levels were observed, and the estimated concentration of turmeric required to minimize blood lactate levels was 64.7 g kg^?1. We observed quadratic effects of turmeric on superoxide dismutase activity and the concentration of malondialdehyde in fish gills and the turmeric concentrations required to minimize the transport stress effects on these variables were 42.50 and 83.33 g kg^?1, respectively. Thus, dietary supplementation with turmeric enhanced the tolerance of juvenile A. aff. bimaculatus to transportation stress.     

Is the use of turmeric in the diet safe for fish?

With this study, we aimed to assess the safety of using Curcuma longa in fish feed. Juvenile Astyanax aff. bimaculatus (0.83 ± 0.04 g) were kept in 24 80‐L aquaria, at a density of 0.5 fish L^?1 for 60 days. Six diets supplemented with 0.0, 20.0, 40.0, 60.0, 80.0 and 100.0 g kg^?1 were evaluated. Histopathological analysis of the gills showed that there was an increasing linear effect of turmeric on the frequency of lamellar aneurysm, hypertrophy of mucous cells, oedema and necrosis. There was a quadratic effect of turmeric supplementation on the frequency of fusion and disruption of secondary lamellae, vacuolation and hypertrophy of the epithelial cells, and the estimated values to minimize these variables were 4.63, 25.93 and 24.46 g kg^?1 respectively. There was a quadratic effect of turmeric on the gills index (I_BRA), and the estimated value to minimize this index was 30.23 g kg^?1. No effect of turmeric on the frequency of histopathological changes and organ index in fish liver was observed. Thus, we conclude that turmeric is not hepatotoxic for A. aff. bimaculatus; however, its use is safe at concentrations up to 30.23 g kg^?1 diet as a function of its gill toxic effect at higher doses.     

The bone degenerative processes in senile fishes from Holocene Brazilian shell mounds

Zooarchaeological collections from shell mounds in Rio de Janeiro (2,470–4,632 cal BP) contain a high prevalence of swollen fish bones belonging to the Atlantic spadefish (Chaetodipterus faber), crevalle jack (Caranx hippos) and fat snook (Centropomus parallelus). Given the lack of knowledge of the bone degenerative process in senile fishes, this study analysed hyperostotic bone in zooarchaeological and modern specimens to obtain high‐resolution morphology and microstructure reconstruction. We used microCT as well as X‐ray diffraction to characterize the crystallographic changes associated with fish senility. Our results showed that trabecular microstructures in hyperostotic bones were consistent with estimated values of the per cent bone volume‐to‐total volume ratio (BV/TV) and were greater than 60% in cortical bone. Hyperostotic bones indicated a high radiograph density, and X‐ray diffractograms showed a decrease in hydroxyapatite [Ca₁₀(PO₄)₆(OH)₂] and calcite (CaCO₃) neocrystallization. These crystalline and density changes revealed an advanced stage of fish senile and indicate the vulnerability of ageing fish populations.     

<Emphasis Type="Italic">Curcuma longa</Emphasis> as additive in the diet for <Emphasis Type="Italic">Astyanax aff. bimaculatus</Emphasis>

The aim of the present study was to evaluate the effect of turmeric (Curcuma longa) as additive in the diet for Astyanax aff. bimaculatus. Fish (0.83 ± 0.04 g) were fed, for 60 days, with six diets containing 0.0, 20.0, 40.0, 60.0, 80.0, and 100.0 g turmeric kg^?1 feed. There was an increasing linear effect of turmeric on the thickness of the muscular layer, and height and width of the folds of the intestine. In the liver, a quadratic effect was observed of turmeric on the percentage of hepatocyte cytoplasm and a decreasing linear effect on the percentage of sinusoid capillaries. A quadratic effect was also observed of turmeric on the liver glycogen. There was no effect of turmeric on the antioxidant activity in the liver, carcass composition or productive performance of the fish. Thus, we concluded that Curcuma longa has trophic effects on the epithelium and the muscular layer of the intestine of A. aff. bimaculatus. Additionally, low levels of Curcuma longa cause increased deposition of liver glycogen and high levels cause reduction.     

Influence of net cage fish cultures on the diversity of the zooplankton community in the Furnas hydroelectric reservoir, Areado, MG, Brazil

The aim of this study was to examine the influence of the net cage system of fish culture on the composition, abundance and diversity of the zooplankton community. Comparisons were made between three collection points located near a group of 30 net cages, with individual volumes of approximately 4 m³, containing newly hatched, young and adult Nile tilapia, positioned in an arm of the Furnas hydroelectric reservoir; point 1 was in the limnetic region and points 2 and 3 were upstream and downstream of the cages, respectively, near the bank. The sampling was carried out at all three points from July to December, 2005. The composition of the zooplankton community differed among the points analysed. The lowest diversity was recorded at point 1. Point 2, upstream of the cages, was characterized by greater species richness and higher density of organisms pertaining to the Rotifera group. The results of the study suggest that variations in the composition and abundance of Rotifera and Cladocera are a consequence of the impact of net cage fish culture, although the magnitude of the variations is small.