Protective Effects of Resveratrol Against Airway Hyperreactivity, Oxidative Stress, and Lung Inflammation in a Rat Pup Model of Bronchopulmonary Dysplasia.

Oxygen therapy provides an important treatment for preterm and low-birth-weight neonates, however, it has been shown that prolonged exposure to high levels of oxygen (hyperoxia) is one of the factors contributing to the development of bronchopulmonary dysplasia (BPD) by inducing lung injury and airway hyperreactivity. There is no effective therapy against the adverse effects of hyperoxia. Therefore, this study was undertaken to test the hypothesis that natural phytoalexin resveratrol will overcome hyperoxia-induced airway hyperreactivity, oxidative stress, and lung inflammation. Newborn rats were exposed to hyperoxia (fraction of inspired oxygen - FiO2>95 % O2) or ambient air (AA) for seven days. Resveratrol was supplemented either in vivo (30 mg·kg-1·day-1) by intraperitoneal administration or in vitro to the tracheal preparations in an organ bath (100 mikroM). Contractile and relaxant responses were studied in tracheal smooth muscle (TSM) using the in vitro organ bath system. To explain the involvement of nitric oxide in the mechanisms of the protective effect of resveratrol against hyperoxia, a nitric oxide synthase inhibitor - Nomega-nitro-L-arginine methyl ester (L-NAME), was administered in some sets of experiments. The superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and the tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) levels in the lungs were determined. Resveratrol significantly reduced contraction and restored the impaired relaxation of hyperoxia-exposed TSM (p<0.001). L-NAME reduced the inhibitory effect of resveratrol on TSM contractility, as well as its promotion relaxant effect (p<0.01). Resveratrol preserved the SOD and GPx activities and decreased the expression of TNF-alpha and IL-1beta in hyperoxic animals. The findings of this study demonstrate the protective effect of resveratrol against hyperoxia-induced airway hyperreactivity and lung damage and suggest that resveratrol might serve as a therapy to prevent the adverse effects of neonatal hyperoxia. Keywords: Bronchopulmonary dysplasia, Hyperoxia, Airway hyperreactivity, Resveratrol, Pro-inflammatory cytokines.

Nanoencapsulation of Origanum vulgare essential oil into liposomes with anticancer potential.

Origanum vulgare L. essential oil possesses a wide spectrum of biological activities. Nanoencapsulation of O. vulgare essential oil into liposomes seems to be a promising strategy to maintain and improve these biological properties. This research was carried out to develop a suitable liposomal formulation for the effective encapsulation of O. vulgare essential oil in order to improve the antioxidant and cytotoxic activities. The characterization of liposomal nanocarriers was conducted in terms of size, zeta potential, and encapsulation efficiency. An MTT assay was used to assess the cytotoxic activity of the prepared and characterized O. vulgare essential oil liposomes in MCF-7 cancer cell lines. Antioxidant activity was determined by assessing DPPH scavenging activity. O. vulgare essential oil exerted cytotoxic activity with an IC50 of 50 µg/ml. The essential oil of O. vulgare was effectively encapsulated in liposomes, with no significant change observed among the formulations. The antioxidant activity was significantly enhanced after encapsulating the essential oil in liposomes. Origanum vulgare essential-oil-loaded Phospholipon 90H liposomes demonstrated considerably increased cytotoxic activity against MCF-7 cells, whereas Lipoid S100 liposomes showed no significant differences from the non-encapsulated essential oil. Phospholipon 85G liposomes had the least cytotoxic impact. As a result, liposomes containing O. vulgare essential oil may be promising nanocarriers for the development of anticancer agents.

Prebiotics as excipients for enhancement of stability and functionality of Bifidobacterium longum ssp. infantis with potential application as symbiotics in food and pharmaceuticals.

Objective: Formulations containing probiotics are promoted due to health benefits. During lyophilization and subsequent storage in the gastrointestinal tract, bacteria are exposed to stress conditions that can lead to impairment and loss of viability. Methods: The suitability of various excipients for enhancing the stability and functionality of Bifidobacterium longum subsp. infantis during storage as freeze-dried powder and through exposure to acid and bile was investigated. Cells were lyophilized in the presence of sucrose, trehalose, lactose, cellobiose and fructooligosaccharide (FOS) and stored at 4 °C or 25 °C. The effect of diverse protectants on the persistence after exposure to acid and bile environment was examined through determination of the colony forming units, the ß-glucosidase and ß-galactosidase activity and the membrane integrity changes. Results: Cells freeze-dried in the presence of cryoprotectants had comparable survivability during storage at 4 °C whereas the survival rate at 25 °C of cells protected by cellobiose and FOS was higher than for those protected with sucrose and trehalose. Furthermore, the respective excipients used as cryoprotectants enhanced the stability of cells exposed to simulated gastric and small intestinal medium. Stabilization may be achieved through different mechanism of action such as protecting the membrane integrity and as metabolizable substrates. Overall, prebiotic and thus metabolizable protectants including cellobiose and FOS were superior to other protectants used. Conclusion: In symbiotic formulas with B. infantis, these sugars might serve as prebiotics and stabilizers of this probiotic strain during lyophilization, storage and in gastrointestinal conditions simultaneously, potentially increasing its health-promoting effects.