Protective Effect of Probiotics against Pseudomonas aeruginosa Infection of Human Corneal Epithelial Cells.

Probiotic therapy needs consideration as an alternative strategy to prevent and possibly treat corneal infection. This study aimed to assess the preventive effect of Lactobacillus reuteri and Bifidobacterium longum subsp. infantis on reducing the infection of human corneal epithelial (HCE) cells caused by Pseudomonas aeruginosa. The probiotics' preventive effect against infection was evaluated in cell monolayers pretreated with each probiotic 1 h and 24 h prior to P. aeruginosa challenge followed by 1 h and 24 h of growth in combination. Cell adhesion, cytotoxicity, anti-inflammatory, and antinitrosative activities were evaluated. L. reuteri and B. longum adhered to HCE cells, preserved occludin tight junctions' integrity, and increased mucin production on a SkinEthicTM HCE model. Pretreatment with L. reuteri or B. longum significantly protected HCE cells from infection at 24 h, increasing cell viability at 110% (110.51 ± 5.15; p ≤ 0.05) and 137% (137.55 ± 11.97; p ≤ 0.05), respectively. Each probiotic showed anti-inflammatory and antinitrosative activities, reducing TNF-α level (p ≤ 0.001) and NOx amount (p ≤ 0.001) and reestablishing IL-10 level (p ≤ 0.001). In conclusion, this study demonstrated that L. reuteri and B. longum exert protective effects in the context of corneal infection caused by P. aeruginosa by restoring cell viability and modulating inflammatory cytokine release.

Studies on the Accumulation of Secondary Metabolites and Evaluation of Biological Activity of In Vitro Cultures of Ruta montana L. in Temporary Immersion Bioreactors.

The present work focuses on in vitro cultures of Ruta montana L. in temporary immersion PlantformTM bioreactors. The main aim of the study was to evaluate the effects of cultivation time (5 and 6 weeks) and different concentrations (0.1-1.0 mg/L) of plant growth and development regulators (NAA and BAP) on the increase in biomass and the accumulation of secondary metabolites. Consequently, the antioxidant, antibacterial, and antibiofilm potentials of methanol extracts obtained from the in vitro-cultured biomass of R. montana were evaluated. High-performance liquid chromatography analysis was performed to characterize furanocoumarins, furoquinoline alkaloids, phenolic acids, and catechins. The major secondary metabolites in R. montana cultures were coumarins (maximum total content of 1824.3 mg/100 g DM), and the dominant compounds among them were xanthotoxin and bergapten. The maximum content of alkaloids was 561.7 mg/100 g DM. Concerning the antioxidant activity, the extract obtained from the biomass grown on the 0.1/0.1 LS medium variant, with an IC50 0.90 ± 0.03 mg/mL, showed the best chelating ability among the extracts, while the 0.1/0.1 and 0.5/1.0 LS media variants showed the best antibacterial (MIC range 125-500 µg/mL) and antibiofilm activity against resistant Staphylococcus aureus strains.