Effect of palmitoylethanolamide on degeneration of a human-derived retinal pigment epithelial cell induced by all-trans retinal

Palmitoylethanolamide (PEA) for Prevention of Gastroesophageal Inflammation: Insights from In Vitro Models

Gastroesophageal reflux disease (GERD) is a digestive disorder that can lead to chronic mucosal damage, causing esophagitis, Barrett's esophagus and esophageal cancer. GERD currently affects about 13% of the world's population and represent a major public health concern due to the increasing prevalence and incidence. The aim of this study was to explore complementary strategies for GERD management based the natural compound palmitoylethanolamide (PEA), alone or associated with plant extracts with demonstrated anti-GERD activity (Zingiber officinale, Musa × paradisiaca, Opuntia ficus-indica and Olea europaea). For this purpose, two in vitro models based on the esophageal mucosa CP-B cell line were chosen. The first one was based on the exposure of esophageal cells to HCl, while the second one was based on lipopolysaccharide (LPS) treatment to cause a strong inflammatory cell response. Inflammation induced was assessed using a Luminex® assay, measuring the secretion of IL-1β, IL-6, IL-10, IL-8 and TNF-α. Results obtained demonstrate that PEA strongly decreased the inflammatory response elicited by HCl exposure. Moreover, the effect of PEA was enhanced by the presence of natural extracts of Zingiber officinale, Musa × paradisiaca, Opuntia ficus-indica and Olea europaea. PEA should be considered as an anti-GERD natural compound of interest.

Impact of umbelliprenin-containing niosome nanoparticles on VEGF-A and CTGF genes expression in retinal pigment epithelium cells

AIM

To investigate the impact of niosome nanoparticles carrying umbelliprenin (UMB), an anti-angiogenic and anti-inflammatory plant compound, on the expression of vascular endothelial growth factor (VEGF-A) and connective tissue growth factor (CTGF) genes in a human retinal pigment epithelium (RPE)-like retina-derived cell line.

METHODS

UMB-containing niosomes were created, optimized, and characterized. RPE-like cells were treated with free UMB and UMB-containing niosomes. The IC50 values of the treatments were determined using an MTT assay. Gene expression of VEGF-A and CTGF was evaluated using real-time polymerase chain reaction after RNA extraction and cDNA synthesis. Niosomes' characteristics, including drug entrapment efficiency, size, dispersion index, and zeta potential were assessed. Free UMB had an IC50 of 96.2 µg/mL, while UMB-containing niosomes had an IC50 of 25 µg/mL.

RESULTS

Treatment with UMB-containing niosomes and free UMB resulted in a significant reduction in VEGF-A expression compared to control cells (P=0.001). Additionally, UMB-containing niosomes demonstrated a significant reduction in CTGF expression compared to control cells (P=0.05). However, there was no significant reduction in the expression of both genes in cells treated with free UMB.

CONCLUSION

Both free UMB and niosome-encapsulated UMB inhibits VEGF-A and CTGF genes expression. However, the latter demonstrates significantly greater efficacy, potentially due to the lower UMB dosage and gradual delivery. These findings have implications for anti-angiogenesis therapeutic approaches targeting age-related macular degeneration.