Resveratrol attenuates doxorubicin-induced toxicity during in vitro culture of mouse-isolated preantral follicles.

The aims of this study were to evaluate the doxorubicin concentration that induces toxic effects on in vitro culture of isolated mouse secondary follicles and to investigate whether resveratrol can inhibit or reduce this toxicity. Secondary follicles were isolated and cultured for 12 days in control medium (α-MEM+) or in α-MEM+ supplemented with doxorubicin (0.1 µg/ml) or different concentrations of resveratrol (0.5, 2, or 5 µM) associated with doxorubicin (0.1 µg/ml) (experiment 1). For experiment 2, follicles were cultured in α-MEM+ alone or supplemented with doxorubicin (0.3 µg/ml) or different concentrations of resveratrol (5 or 10 µM) associated or not with doxorubicin (0.3 µg/ml) (experiment 2). The endpoints analyzed were morphology (survival), antrum formation, follicular diameter, mitochondrial activity, glutathione (GSH) levels and DNA fragmentation. In the first experiment, doxorubicin (0.1 µg/ml) maintained survival and antrum formation similar to the control, while 5 µM resveratrol showed increased parameters, maintained mitochondrial activity and increased GSH levels compared to the control. In the second experiment, doxorubicin (0.3 µg/ml) reduced survival, antrum formation and follicular diameter compared to the control. Resveratrol at a concentration of 10 µM attenuated the damage caused by doxorubicin by improving follicular survival and did not present DNA fragmentation. In conclusion, supplementation of the in vitro culture medium with 0.3 µg/ml doxorubicin reduced the survival and impaired the development of mouse-isolated preantral follicles. Resveratrol at 10 µM reduced doxorubicin-induced follicular atresia, without DNA fragmentation in the follicles.

Intestinal morphometry and performance of broiler chickens subjected to diets with buriti oil / [Morfometria intestinal e desempenho de frangos de corte submetidos a dietas com óleo de buriti]

This study aimed to evaluate the productive performance, carcass yield, and intestinal morphometry of broiler chickens subjected to diets with the inclusion of buriti oil. Buriti oil is an energy food that can be used in chicken feed to replace soybean oil, which has a high cost in production, also has its anti-inflammatory, antioxidant, and antimicrobial properties, which can provide benefits in chicken feed. 180 male broilers of the Ross lineage were used, distributed in a completely randomized design with 3 treatments and 6 replicates of 10 birds per experimental unit. The experimental phase took place from 14 to 28 days and levels 0; 0.75 and 1.50% of buriti oil were added to the corn and soybean-based feed. It can be inferred that the buriti oil-based diets in the diet with insertion of levels of 0%, 0.75% and 1.50% did not differ significantly for the productive performance variables, but in relation to the productive yield there was a significant difference for carcass yield accompanied by greater disposition of abdominal fat, thigh and heart fat, a common effect in the use of oils. Although no statistical differences were observed for most of the variables in the assessment of intestinal morphometry, there was an increase in the crypt depth of the duodenum and ileum and an increase in the muscle layer of the duodenum and jejunum, which may have been caused by some injury to the intestine and not by direct effect of buriti oil. In the other variables there was no difference between treatments and it is concluded that buriti oil did not harm the performance, yield and intestinal morphometry of broiler chickens from 14 to 28 days of age.

Objetivou-se, com essa pesquisa, avaliar o desempenho produtivo, o rendimento de carcaça e a morfometria intestinal de frangos de corte com dietas submetidas à inclusão do óleo de buriti. Trata-se de um alimento energético que pode ser utilizado na alimentação de frangos visando substituir o óleo de soja, o qual apresenta alto custo na produção. O óleo de buriti ainda possui suas propriedades anti-inflamatórias, antioxidantes, antimicrobianas, podendo conferir benefícios na alimentação de frangos. Foram utilizados 180 frangos de corte machos, da linhagem Ross, distribuídos em um delineamento inteiramente ao acaso, com três tratamentos e seis repetições de 10 aves por unidade experimental. A fase experimental ocorreu de 14 a 28 dias, e os níveis 0%, 0,75% e 1,50% de óleo de buriti foram inseridos na ração à base de milho e soja. Pode-se inferir que as dietas à base de óleo de buriti na dieta com inserção dos níveis de 0%, 0,75% e 1,50% não diferiram significativamente para as variáveis de desempenho produtivo, mas, em relação ao rendimento produtivo, houve uma diferença significativa para o rendimento de carcaça, acompanhado de maior disposição de gordura abdominal, gordura de sobrecoxa e coração, efeito comum na utilização de óleos. Apesar de não serem observadas diferenças estatísticas para a maioria das variáveis na avaliação da morfometria intestinal, houve aumento na profundidade de cripta do duodeno e do íleo, bem como aumento da camada muscular do duodeno e do jejuno, que podem ter sido provocados por alguma injúria no intestino e não por efeito direto do óleo de buriti. Nas demais variáveis, não houve diferença entre os tratamentos, e conclui-se que o óleo de buriti não causou prejuízo ao desempenho, ao rendimento e à morfometria intestinal de frangos de corte no período de 14 a 28 dias de idade.

Prevalence of antimicrobial-resistant Enterococcus faecium in commercial cattle: a systematic review and meta-analysis / Prevalência de Enterococcus faecium resistente a antimicrobianos na bovinocultura comercial: uma revisão sistemática e meta-análise

The use of antimicrobials in animals is broader compared to humans, which can influence the increase in microbial resistance. This study was a systematic review which determined the prevalence of resistant Enterococcus faecium in commercial cattle. Eighteen studies were included, mainly carried out in European countries (n=9) and in the production (n= 11) and retail (n= 7) environments. The main material used in the detection of the microorganism was milk. The mean prevalence of resistant E. faecium in cattle was 4.3% (95% CI = 2.8-5.0%), but the prevalence in Asia was higher [25.4% (95% CI = 20.5-30.6%)]. There was a higher prevalence in samples from retail (13.7%; 95% CI=11.5-16.1%) and collected mainly from equipment surfaces (12.5%; 95% CI= 5.5-26.1%) than in the others tested samples. Antibiotics frequently tested were vancomycin, tetracycline, ciprofloxacin, and erythromycin, with resistance percentages of 50%, 59%, 79%, and 94%, respectively. These results reinforce the need to plan interventions to reduce antimicrobials in food-producing animals.

O uso de antimicrobianos em animais é mais frequente quando comparado aos humanos, e isso pode influenciar no desenvolvimento da resistência microbiana. O presente estudo teve como objetivo realizar uma revisão sistemática cujo desfecho de interesse foi a prevalência de E. faecium resistente a antimicrobianos na bovinocultura comercial. Foram incluídos 18 estudos, realizados principalmente em países europeus (n=9), em ambientes de produção (n=11) e destinados ao varejo (n=7). O principal material utilizado na detecção do microrganismo foi o leite. A prevalência de E. faecium resistente em bovinos foi de 4,3% (IC 95% -2,8-5,0%), mas a prevalência na Ásia foi maior [25,4% (IC 95%=20,5-30,6%)]. Houve maior prevalência em amostras do varejo (13,7%; IC 95%=11,5-16,1%) e coletadas principalmente de superfícies de equipamentos (12,5%; IC 95%-5,5-26,1%). Os antibióticos frequentemente testados foram vancomicina, tetraciclina, ciprofloxacino, e eritromicina, com percentuais de resistência de 50%, 59%, 79%, e 94%, respectivamente. Estes resultados reforçam a necessidade de intervenções planejadas para reduzir a utilização de antimicrobianos nos animais criados para produção de alimentos.

Leptin decreases apoptosis and promotes the activation of primordial follicles through the phosphatidylinositol-3-kinase/protein kinase B pathway in cultured ovine ovarian tissue.

This study evaluated the effects of leptin on primordial follicle survival and activation after in vitro culture of ovine ovarian tissue and if leptin acts through the phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt) pathway. Ovarian fragments were fixed for histology (fresh control) or cultured for 7 days in control medium (α-MEM+) alone or supplemented with leptin (1, 5, 10, 25 or 50 ng/ml). Follicle morphology, activation and apoptosis were analyzed. Next, the fragments were cultured in the medium that showed the best results in the absence or the presence of the PI3K inhibitor (LY294002), and immunohistostaining of p-Akt protein was assessed. After culture, the percentage of normal follicles decreased (P < 0.05) in all treatments compared with the fresh control. Moreover, control medium and 1 ng/ml leptin had similar (P > 0.05) percentages of normal follicles, which were significantly higher than those in other treatments. However, culture with 1 ng/ml leptin maintained apoptosis similarly (P > 0.05) to that of the fresh control and lower (P < 0.05) than that in α-MEM+. Leptin did not influence follicle activation (P > 0.05) compared with the control medium (α-MEM+). Culture in 1 ng/ml leptin with LY294002 decreased the normal follicles and increased apoptosis, inhibited follicle activation (P < 0.05), and reduced p-Akt immunostaining, compared with the medium containing 1 ng/ml leptin without PI3K inhibitor. In conclusion, leptin at 1 ng/ml reduces apoptosis and promotes the activation of primordial follicles compared with the fresh control after in vitro culture of ovine ovarian tissue possibly through the PI3K/Akt pathway.

Effect of pre-exercise carbohydrate availability on fat oxidation and energy expenditure after a high-intensity exercise.

The aim of this study was to test the hypothesis that reduced pre-exercise carbohydrate (CHO) availability potentiates fat oxidation after an exhaustive high-intensity exercise bout. Eight physically active men underwent a high-intensity exercise (∼95% V̇O2max) until exhaustion under low or high pre-exercise CHO availability. The protocol to manipulate pre-exercise CHO availability consisted of a 90-min cycling bout at ∼70% V̇O2max + 6 × 1-min at 125% V̇O2max with 1-min rest, followed by 48 h under a low- (10% CHO, low-CHO availability) or high-CHO diet (80% CHO, high-CHO availability). Time to exhaustion was shorter and energy expenditure (EE) lower during the high-intensity exercise in low- compared to high-CHO availability (8.6±0.8 and 11.4±1.6 min, and 499±209 and 677±343 kJ, respectively, P<0.05). Post-exercise EE was similar between low- and high-CHO availability (425±147 and 348±54 kJ, respectively, P>0.05), but post-exercise fat oxidation was significantly higher (P<0.05) in low- (7,830±1,864 mg) than in high-CHO availability (6,264±1,763 mg). The total EE (i.e., exercise EE plus post-exercise EE) was similar between low- and high-CHO availability (924±264 and 1,026±340 kJ, respectively, P>0.05). These results suggest that a single bout of high-intensity exercise performed under low-CHO availability increased post-exercise fat oxidation, and even with shorter exercise duration, both post-exercise EE and total EE were not impaired.