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

Impact of dietary supplementation with Cinnamomum cassia essential oil on silver catfish (Rhamdia quelen): Toxicological effects and muscle antioxidant and fatty acid profiles

The aim of this study was to determine the biological effects of dietary supplementation with 0.05% and 0.1% cinnamon essential oil extracted from Cinnamomum cassia on silver catfish (Rhamdia quelen). The final body weight, weight gain, and specific growth rate were significantly higher in fish supplemented with 0.05% cinnamon essential oil than in the control(untreated) group. Muscle reactive oxygen species and lipid peroxidation levels were significantly lower in fish supplemented with 0.05% cinnamon essential oil but higher at the 0.1% concentration. Muscle antioxidant capacity against peroxyl radicals (ACAP) and superoxide dismutase activity were significantly higher in fish supplemented with 0.05% cinnamon essential oil, while ACAP levels were lower in fish supplemented with 0.1%. The total saturated fatty acid content was significantly higher in the muscle of supplemented fish than in controls, while the total monounsaturated fatty acid content was significantly higher only in fish fed 0.1% cinnamon essential oil. Finally, the total content of polyunsaturated fatty acids was significantly lower in fish fed 0.1% essential oil. Thus, data demonstrated that 0.05% C. cassia essential oil improves fish health by improving performance and muscle oxidant/antioxidant status. Higher doses of cinnamon essential oil produced oxidative stress in muscle, suggesting toxicity at the 0.1% level. Although this cinnamon essential oil diet exerted positive health effects, this diet impaired the muscle fatty acid profile, suggesting adverse impacts on human health.

Essential Oil and Hydrophilic Antibiotic Co-Encapsulation in Multiple Lipid Nanoparticles: Proof of Concept and In Vitro Activity against Pseudomonas aeruginosa

In the worldwide context of an impending emergence of multidrug-resistant bacteria, this research combined the advantages of multiple lipid nanoparticles (MLNs) and the promising therapeutic use of essential oils (EOs) as a strategy to fight the antibiotic resistance of three Pseudomonas aeruginosa strains with different cefepime (FEP) resistance profiles. MLNs were prepared by ultrasonication using glyceryl trioleate (GTO) and glyceryl tristearate (GTS) as a liquid and a solid lipid, respectively. Rosemary EO (REO) was selected as the model EO. REO/FEP-loaded MLNs were characterized by their small size (~110 nm), important encapsulation efficiency, and high physical stability over time (60 days). An assessment of the antimicrobial activity was performed using antimicrobial susceptibility testing assays against selected P. aeruginosa strains. The assays showed a considerable increase in the antibacterial property of REO-loaded MLNs compared with the effect of crude EO, especially against P. aeruginosa ATCC 9027, in which the minimum inhibitory concentration (MIC) value decreased from 80 to 0.6 mg/mL upon encapsulation. Furthermore, the incorporation of FEP in MLNs stabilized the drug without affecting its antipseudomonal activity. Thus, the ability to co-encapsulate an essential oil and a hydrophilic antibiotic into MLN has been successfully proved, opening new possibilities for the treatment of serious antimicrobial infections.

Therapeutic Potential of Melaleuca alternifolia Essential Oil in New Drug Delivery Systems

Medicinal plants produce secondary metabolites with special biological activities, which may be used as new therapeutic alternatives. For instance, tea tree essential oil (TTO) was shown to exert antimicrobial, antifungal, anthelmintic, antiviral, anti-tumor and anti-inflammatory activities. Due to their thermal instability, active principles can be easily degraded by physicochemical processes; therefore, they must be protected to increase their time of action and improve their controlled release. The aim of this review is to discuss formulations incorporating encapsulated TTO as the active ingredient. Micro and nanoencapsulated systems proved to be more thermostable than TTO and to exert better antimicrobial, antifungal, antiparasitic and larvicidal effects. Nanoencapsulation also reduced oil toxicity. Emulsified and hybrid systems developed by various methods showed improved repellent, antibacterial, antifungal and anti-inflammatory activities, thereby proving promising for the pharmaceutical industry. Liposomal formulations produced by hydration of lipid films exhibited constant rate of terpinen-4-ol release. In addition, their incorporation into biomaterials, such as sponges, nanofibers and films, showed great potential for treating infections. Mainly due to the advantages of their incorporation into new drug delivery systems over conventional formulations, there is an interest in the development of systems containing TTO as a pharmaceutical ingredient of plant origin.

Effects of glycinin and β-conglycinin on growth performance and intestinal health in juvenile Chinese mitten crabs (Eriocheir sinensis)

This study investigates the effects of two soybean antigens (glycinin and β-conglycinin) as an antinutritional substance in the diet on the growth, digestive ability, intestinal health and microbiota of juvenile Chinese mitten crabs (Eriocheir sinensis). The isonitrogenous and isolipidic diets contained two soybean antigens at two levels each (70 and 140 g/kg β-conglycinin, 80 and 160 g/kg glycinin) and a control diet without β-conglycinin or glycinin supplementation, and were used respectively to feed juvenile E. sinensis for seven weeks. Dietary inclusion of either glycinin or β-conglycinin significantly reduced crab survival and weight gain. The crabs fed diets containing soybean antigens had higher malondialdehyde concentrations and lower catalase activities in the intestine than those in the control. The activities of trypsin and amylase in the intestine were suppressed by dietary β-conglycinin and glycinin. Dietary glycinin or β-conglycinin impaired the immunity and morphological structure of intestine, especially the peritrophic membrane. The mRNA expression of constitutive and inducible immune responsive genes (lipopolysaccharide-induced TNF-α factor and interleukin-2 enhancer-binding factor 2) increased while the mRNA expression of the main genes related to the structural integrity peritrophic membrane (peritrophin-like gene and peritrophic 2) significantly decreased in the groups with soybean antigen addition. Soybean antigen could also change the intestinal microbial community. The abundance of pathogenic bacteria (Ochrobactrum, Burkholderia and Pseudomonas) increased significantly in both soybean antigen groups. Although pathogenic bacteria Vibrio were up-regulated in the glycinin group, the abundance of Dysgonomonas that degraded lignocellulose and ameliorated the gut environment decreased in the glycinin group. This study indicates that existence of soybean antigens (glycinin or β-conglycinin) could induce gut inflammation, reshape the community of gut microbiota, and cause digestive dysfunction, ultimately leading to impaired growth in crabs.