Modulation of the innate immune response,antioxidant system and oxidative stress during acute and chronic stress in pacu (Piaractus mesopotamicus)

Fish Physiology and Biochemistry - Stress is an energy-demanding process, as well as the responses of the innate immune system, that impose a metabolic overload on cellular energy production, which...     

Protein supplementation to early lactation dairy cows grazing tropical grass: Performance and ruminal metabolism

This experiment was designed to evaluate the effects of different concentrate crude protein (CP) concentration on performance, metabolism and efficiency of N utilization (ENU) on early-lactation dairy cows grazing intensively managed tropical grass. Thirty cows were used in a ten replicated 3 × 3 Latin square design. The treatments consisted of three levels of concentrate CP: 7.9%, 15.4%, and 20.5% offered at a rate of 1 kg (as-fed basis)/3 kg of milk. The cows fed low and medium CP had negative balance of rumen degradable protein and metabolizable protein. Increasing CP tended to linearly increase DMI, 3.5% FCM and milk casein, and linearly increased the yields of milk fat and protein. Increasing CP linearly increased the intake of N, the concentration of rumen NH₃–N, and the losses of N in milk, urine, and feces. Increasing dietary CP linearly increased the molar proportion of butyrate but had no effect on the other rumen VFAs and no effect on microbial yield. In conclusion, feeding a concentrate with 20.5% of CP to early-lactation dairy cows grazing tropical grasses, leading to a 17.8% CP diet, tended to increase DMI, increased the yield of 3.5% FCM and the milk N excretion, and decreased ENU by 32%.     

A new steroidal saponin with antiinflammatory and antiulcerogenic properties from the bulbs of Allium ampeloprasum var. porrum

A new steroidal saponin was isolated from the bulbs of Allium ampeloprasum var. porrum L. On the basis of chemical evidence, comprehensive spectroscopic analyses and comparison of known compounds, its structure was established as (3β,5α,6β,25R)-6-[(β-d-glucopyranosyl)oxy]-spirostan-3-yl O-β-d-glucopyranosyl-(1→2)-O-[β-D-glucopyranosyl-(1→3)]-β-d-galactopyranoside (1). Results of the present study indicated that the steroidal saponin showed haemolytic effects in the in vitro assays and demonstrated antiinflammatory activity and gastroprotective property using in vivo models.     

First successful frozen semen of the maned wolf (Chrysocyon brachyurus)

This study aimed to describe successful cryopreservation of sperm from maned wolves (Chrysocyon brachyurus). Three ejaculates from 2 maned wolves were collected by digital manipulation of the penis and evaluated subjectively, centrifuged and frozen in BotuCrio^® (Botupharma, Botucatu, Brazil) or Tris–yolk egg extender. Spermatozoa were thawed at 37ºC/30s or 70ºC/4s and evaluated for kinetics, morphology, plasma and acrosome membrane integrity, mitochondrial potential, hydrogen peroxide, superoxide anion and lipid peroxidation. From 5 thawed samples, two had sperm total motility >55% (56.0% and 64.0%) and progressive motility ~35% (35% and 40%), both frozen with Tris–yolk egg. Plasma and acrosome membrane integrity decreased and percentage of sperm defects increased post-thawing. We concluded that is possible to freeze spermatozoa from maned wolves using semen collection and processing methods applied for domestic dogs.     

Evaluation of the Antioxidant and Antimicrobial Activity of Protein Hydrolysates and Peptide Fractions Derived from Colossoma macropomum and Their Effect on Ground Beef Lipid Oxidation

The objective of this study was to obtain protein hydrolysate from the mechanically separated meat of blackfin pacu to evaluate the influence by ultrafiltration in the antioxidant and antimicrobial activities of the peptide fractions obtained and to apply in ground beef to evaluate the lipid stability. The enzymatic hydrolysis was performed using the enzyme Protamex (pH 7.0, 60°C) for 240 min. The protein hydrolysate was fractionated by ultrafiltration. Then, the antioxidant capacity of the protein hydrolysate and the peptide fractions were evaluated in vitro by the methods of 2,2’-azinobis (3-ethylbenzothiazoline sulfonic acid) radical capture, 2,2-diphenyl-1-picrylhydrazyl radical-scavenging assay, reducing power, and hydroxyl radical scavenging activity. The antimicrobial activity of the samples was evaluated by disc-diffusion against Staphylococcus aureus and Escherichia coli. After evaluation, the peptide fractions did not present higher bioactivities than that shown for the hydrolysate. The protein hydrolysate was applied to ground beef, where the substances reactive to thiobarbituric acid and color were evaluated during 7 days of storage at 4°C. Lipid oxidation was reduced up to 60.9% and there was no modification of the natural coloration. Thus, the protein hydrolysate can be used as an alternative source of antioxidant for the preservation of refrigerated meats.     

Evaluation of Macroalgae Sulfated Polysaccharides on the Leishmania (L.) amazonensis Promastigote

The sulfated polysaccharides from Solieria filiformis (Sf), Botryocladia occidentalis (Bo), Caulerpa racemosa (Cr) and Gracilaria caudata (Gc) were extracted and extensively purified. These compounds were then subjected to in vitro assays to evaluate the inhibition of these polysaccharides on the growth of Leishmania (L.) amazonensis promastigotes. Under the same assay conditions, only three of the four sulfated polysaccharides were active against L. amazonensis, and the polysaccharide purified from Cr was the most potent (EC₅₀ value: 34.5 μg/mL). The polysaccharides derived from Bo and Sf demonstrated moderate anti-leishmanial activity (EC₅₀ values of 63.7 μg/mL and 137.4 μg/mL). In addition, we also performed in vitro cytotoxic assays toward peritoneal macrophages and J774 macrophages. For the in vitro cytotoxicity assay employing J774 cells, all of the sulfated polysaccharides decreased cell survival, with CC₅₀ values of 27.3 μg/mL, 49.3 μg/mL, 73.2 μg/mL, and 99.8 μg/mL for Bo, Cr, Gc, and Sf, respectively. However, none of the sulfated polysaccharides reduced the cell growth rate of the peritoneal macrophages. These results suggest that macroalgae contain compounds with various chemical properties that can control specific pathogens. According to our results, the assayed sulfated polysaccharides were able to modulate the growth rate and cell survival of Leishmania (L.) amazonensis promastigotes in in vitro assays, and these effects involved the interaction of the sulfated polysaccharides on the cell membrane of the parasites.     

Subclinical leptospirosis may impair athletic performance in racing horses

The infection by Leptospira in horses, in both its acute disease and subclinical forms, is very common, particularly in endemic regions. Therefore, the objective of this study was to evaluate the effects of subclinical leptospirosis in the athletic performance of racing thoroughbred horses. Athletic performance of 119 racing Thoroughbred horses from Rio de Janeiro, Brazil, was calculated by assigning a point value for the results in racing (performance index (PI)), and serology for leptospirosis was conducted. A total of 85 (71.4?%) horses showed reactive titers (??100), and of which 52 had high titers (34 with 400 and 18 with ??800). Although those animals had high titers against Leptospira, no clinical signs associated with leptospirosis were observed. Seventeen (89.5?%) out of the 19 horses with substandard performance were seroreactive with high titers, in contrast with 35?% of seroreactivity in horses with good athletic performance (P?<?0.0001). Additionally, seroreactivity to leptospirosis was more often observed in horses with substandard athletic performance in contrast to those with good performance (P?<?0.0001, odds ratio 15.8). The Average PI of this group increased to 133?% after treatment (P?<?0.0001). Leptospirosis may impair performance in racing horses, and antibiotic therapy may improve the performance of affected animals.     

Morphological and physiological parameters influence the use efficiency of nitrogen and phosphorus by Eucalyptus seedlings

New Forests - Morpho-physiological characteristics in Eucalyptus species can determine N (NUE) and P (PUE) use efficiency and, consequently, the plant's responses to fertilization. The study...