Chemical composition, lipid peroxidation, and fatty acid profile in meat of broilers fed with glycerol monolaurate additive.

The objective of this study was to evaluate the chemical composition and fatty acid profile of broilers fed diets containing glycerol monolaurate (GML) in place of antimicrobials. Groups: T0 group used as control; T100, T200, and T300 groups received diets supplemented with 100, 200, and 300 mg/kg of GML, respectively. The feed mixture used in the poultry feed during the four phases of the production cycle (days 1 to 7; 8 to 21; 22 to 35; and 36 to 42 of birds age) showed similar levels of protein, lipid and ash, as well as fatty acid profiles. Samples of frozen breasts from chickens slaughtered at 42 days of age were used for chemical gross composition and fatty acid analysis. We observed lower lipid levels in the meat of broilers in the T200 and T300 groups than in the T0 group. Lower lipid peroxidation occurred in the meat of animals that consumed GML in respect to control. Total saturated fatty acid percentage was lower, while total polyunsaturated fatty acid percentage was higher in the meat of broilers fed GML than in the control group. We conclude that the increase in GML concentrations alters the lipid profile of broiler meat.

Involvement of xanthine oxidase inhibition with the antioxidant property of nanoencapsulated Melaleuca alternifolia essential oil in fish experimentally infected with Pseudomonas aeruginosa.

Nanoencapsulated Melaleuca alternifolia essential oil (tea tree oil, TTO) is a natural alternative treatment, with 100% therapeutic efficacy in fish experimentally infected with Pseudomonas aeruginosa, and has also potent protective effects linked with antioxidant properties. However, the pathways responsible for the antioxidant capacity remain unknown. Thus, this study evaluated whether the inhibition of seric xanthine oxidase (XO) activity can be considered a pathway involved in the antioxidant capacity of nanoencapsulated TTO in fish experimentally infected with P. aeruginosa. Seric samples from fish infected with P. aeruginosa showed increased XO activity, as well as increased uric acid and reactive oxygen species (ROS) levels. In contrast, the prophylactic treatment with nanoencapsulated TTO prevented these infection-induced alterations. Based on the evidence obtained, the upregulation of seric XO activity induced pro-oxidative effects in the serum of fish experimentally infected with P. aeruginosa, due to excessive formation of uric acid, which stimulates the release of ROS. This treatment was able to prevent the upregulated seric XO activity and, consequently, the excessive formation of uric acid and ROS. In summary, inhibition of seric XO activity can be considered a pathway involved in the antioxidant capacity of nanoencapsulated TTO in fish experimentally infected with P. aeruginosa.

Melaleuca alternifolia nanoparticles against Candida species biofilms.

Candida infection is an important cause of morbidity and mortality on immunosuppressed patients. This growing trend has been associated with resistance to the antimicrobial therapy and the ability of microorganism to form biofilms. TTO oil is used as antimicrobial which shows antibiofilm activity against Candida species. However, it presents problems due to its poor solubility and high volatility. The present study aimed to evaluate in vitro antibiofilm activity of TTO nanoparticles against many Candida species. It was performed the characterization of the oil and nanoparticles. The levels of exopolysaccharides, proteins, and the biomass of biofilms were measured. The chromatographic profile demonstrated that the TTO oil is in accordance with ISO 4730 with major constituents of 41.9% Terpinen-4-ol, 20.1% of γ-Terpinene, 9,8% of α-Terpinene, and 6,0% of 1,8-Cineole. The TTO nanoparticles showed pH of 6.3, mean diameter of 158.2 ± 2 nm, polydispersion index of 0.213 ± 0.017, and zeta potential of -8.69 ± 0.80 mV. The addition of TTO and its nanoparticles represented a significant reduction of biofilm formed by all Candida species, as well as a reduction of proteins and exopolysaccharides levels. It was possible to visualize the reduction of biofilm in presence of TTO nanoparticles by Calcofluor White method.

In vitro repellent effect of tea tree (Melaleuca alternifolia) and andiroba (Carapa guianensis) oils on Haemotobia irritans and Chrysomya megacephala flies.

This study aimed to evaluate the repellent effect of tea tree (Melaleuca alternifolia) and andiroba (Carapa guianensis) essential oils on two species of flies (Haemotobia irritans and Chrysomya megacephala). For the in vitro studies, free-living adult flies were captured and reared in the laboratory. To verify the repellency effect, an apparatus was constructed where H. irritans and C. megacephala were exposed to andiroba and tea tree oils (5.0%), as well as to a known repellent (citronella, 5.0%) to validate the test. The study demonstrated that all three oils used showed in vitro repellent effect against both species of flies. It is possible to conclude that the essential oils (tea tree and andiroba) have repellent effect on these species of flies used in this study.