VCOM Louisiana Research Day Program Book 2024

Biomedical Research: Section 2

Robert Paul, OMS-II; Sarah Voth, PhD; Hassan Ebrahim, PhD; Stephanie Torres, OMS-IV, Md. Towhidul Islam Tarun, BPharm, Nehal Ahmed, MSci, Khalid A El Sayed, PhD; K. Adam Morrow, PhD VCOM-Louisiana Campus; University of Louisiana Monroe College of Pharmacy 20 OLIVE OIL PHENOLICS FOR THE CONTROL OF NOSOCOMIAL PNEUMONIA

Background: Pseudomonas aeruginosa is a formidable pulmonary pathogen in healthcare settings, exhibiting high resistance and virulence profiles, via producing protein factors that evade the immune system and enable colonization. Its lectins, pili, and flagella enhance adhesion and dissemination, while injected toxins and biofilm formation promote disease progression. Nosocomial infections with P. aeruginosa strain healthcare systems, prolong hospital stays, and elevate morbidity in challenging cases. Discovering effective interventions to control nosocomial Pseudomonas infections is of high therapeutic priority. Objective: In this study, we sought to determine the potential of diverse olive phenolics for protection against P. aeruginosa-induced damage in pulmonary microvascular endothelial cells. Methods: We used the MTT assay to assess the effect of diverse extra-virgin olive oil-derived active phenolics, namely the secoiridoids (-)-oleocanthal (OLC), (-)-hydroxyoleocanthal (HydroxyOLC), and (-)-oleuropein (OLE), along with the lignan (+)-acetoxy-pinoresinol (AcP) on the viability of rat pulmonary microvascular endothelial cells (PMVECs) at a dose range of 1-150 μM. Using 1 μM and 5 μM doses, we

sought to assess olive phenolics effectiveness on both primary infection with P. aeruginosa and on exposure to experimentally derived cytotoxic material in PMVECs. PMVECs were pre-treated with OLC, HydroxyOC, OLE, and AcP for 2 hours in a dose range from 1 – 5 µM prior to Pseudomonas aeruginosa infection. Images were captured at 6 hours post-infection, at which point supernatant was collected, filter sterilized, boiled, cold-shocked, and transferred to naïve cell monolayers to investigate the effects of this cytotoxic material derived from infected cells. Images were captured at 24 and 48 h post-transfer, and a Resazurin assay was performed at 48 h post-transfer. During the experiment, bacterial suspensions were collected at 0 h and 6h for plating assays to determine potential bactericidal activity of each compound. In silico docking study used ExoY crystal structure PDB 5XNW. Results: Determined IC50 values of OLC, HydroxyOLC, OLE, and AcP against PMVECs were 110.3, 120.0, 41.6, and 59.0 μM, respectively. We visualized significant protection to the cellular monolayers during primary infection and in supernatant transfer using a pretreatment strategy with olive phenolics in a dose-dependent manner. OLC and HydroxyOLC did not impair bacterial growth unlike AcP and

OLE, which exhibited potential novel bactericidal activity against P. aeruginosa. These results were consistent with in-silico study that suggested the preferred potential of AcP and OLE to bind at the P. aeruginosa endotoxin ExoY. Conclusions: Our study highlights the potential of olive phenolics to control and protect against nosocomial Pseudomonas infections. Further mechanistic elucidation through in-depth in vitro investigations is warranted for a comprehensive validation.

33 2024 Via Research Recognition Day