Effects of oleanolic acid on acute liver injury triggered by lipopolysaccharide in broiler chickens.

1. Infectious injury caused by lipopolysaccharide (LPS), a metabolite of gram-negative bacteria, can induce stress responses in animals and is a significant cause of morbidity and mortality in young birds. The purpose of this study was to investigate the effects of dietary supplementation with oleanolic acid (OA) on acute liver injury in broiler chickens challenged with LPS.2. In total, 120 broiler chickens were randomly divided into six groups and fed a basal diet containing 0, 50, 100, or 200 mg/kg OA or 100 mg/kg aureomycin. On d 15, broiler chickens were injected with either LPS or an equivalent volume of normal saline. Six hours after LPS injection, two broiler chicks were randomly selected for sampling in each replicate.3. The results indicated that dietary aureomycin was ineffective in alleviating LSP-associated liver injury, but protected broiler chickens from LPS-induced liver damage. This promoted a significant reduction in the levels of malondialdehyde and an increase in the levels of superoxide dismutase in liver. In addition, OA was found to cause significant reductions in the relative expression of IL-1ß, IL-6, and TNF-α in broiler liver tissues, whereas the relative expression of IL-10 was significantly increased.4. In conclusion, oleanolic acid can alleviate oxidative stress and injury in the livers of broiler chickens induced by lipopolysaccharide. Consequently, oleanolic acid has potential utility as a novel anti-inflammatory and antioxidant feed additive.

Antibiotic Chlortetracycline Causes Transgenerational Immunosuppression via NF-κB.

The extensive and increasing global use of antibiotics results in the ubiquitous presence of antibiotics in the environment, which has made them "pseudo persistent organic contaminants." Despite numerous studies showing wide adverse effects of antibiotics on organisms, the chronic environmental risk of their exposure is unknown, and the molecular and cellular mechanisms of antibiotic toxicity remain unclear. Here, we systematically quantified transgenerational immune disturbances after chronic parental exposure to environmental levels of a common antibiotic, chlortetracycline (CTC), using zebrafish as a model. CTC strongly reduced the antibacterial activities of fish offspring by transgenerational immunosuppression. Both innate and adaptive immunities of the offspring were suppressed, showing significant perturbation of macrophages and neutrophils, expression of immune-related genes, and other immune functions. Moreover, these CTC-induced immune effects were either prevented or alleviated by the supplementation with PDTC, an antagonist of nuclear factor-κB (NF-κB), uncovering a seminal role of NF-κB in CTC immunotoxicity. Our results provide the evidence in fish that CTC at environmentally relevant concentrations can be transmitted over multiple generations and weaken the immune defense of offspring, raising concerns on the population hazards and ecological risk of antibiotics in the natural environment.

In vitro capacitation and acrosome reaction in sperm of the phyllostomid bat Artibeus jamaicensis.

Sperm capacitation occurs during the passage of sperm through the female reproductive tract. Once the sperm binds to the pellucid zone, the acrosome reaction to enable penetration of the oocyte is completed. In this study, sperm of Artibeus jamaicensis bat was used to evaluate both capacitation status and the acrosome reaction under in vitro conditions, incubating sperm at 32 and 37°C with and without progesterone. Sperm was incubated at different times to assess sperm cells' functionality in terms of capacitation and acrosome reaction, using the chlortetracycline staining, lectin fluoresceinisocyanate conjugate-Pisum sativum agglutinin (FITC-PSA), and transmission electron microscopy. Sperm cells that presented uniform fluorescence throughout the head and mid-piece were classified as non-capacitated. Subsequently, sperm cells, which were observed with fluorescence only in the anterior portion of the head and mid-piece, were classified as capacitated. Sperm cells with no fluorescence in the head, but fluorescence in the mid-piece, were categorized as sperm cells that have carried out the acrosome reaction. During the acrosome reaction, sperm cells showed changes in their morphology, so it was not possible to distinguish the plasma and acrosomal membranes. Around the entire head, it was not possible to distinguish the fusion points between these membranes that made it possible for the acrosomal reaction to take place and thus to release the enzymes necessary to penetrate the pellucid zone. In conclusion, under appropriate in vitro conditions and by supplementing the culture medium with progesterone, A. jamaicensis bat sperm cells are able to be capacitated in a period from 6 to 8 h and to carry out the acrosome reaction.

Chronic exposure to the mycotoxin T-2 promotes oral absorption of chlortetracycline in pigs.

The aim of this study was to investigate whether T-2 toxin, a potent Fusarium mycotoxin, affects the oral absorption of the antibiotic chlortetracycline in pigs. Animals were allocated to blank feed without T-2 toxin (controls), feed containing 111 µg T-2/kg feed, T-2-contaminated feed supplemented with a yeast-derived feed additive, or blank feed supplemented solely with the feed additive, respectively. After 21 days, an intragastric bolus of chlortetracycline was given to assess potential alterations in the pharmacokinetics of this commonly used antibiotic. A significantly higher area under the plasma concentration-time curve and maximal plasma concentration of chlortetracycline was observed after intake of T-2-contaminated feed compared with control. Thus, exposure to T-2-contaminated feed can influence the oral bioavailability of chlortetracycline. This effect could have consequences for the withdrawal time of the drug and the occurrence of undesirable residues in edible tissues.