WSPFE reduces choroidal neovascularization and inflammation

Abstract

Purpose : Angiogenesis and inflammation play an important role in metabolic and age-related diseases, such as age-related macular degeneration (AMD). Neovascular AMD (nAMD) due to choroidal neovascularization (CNV) still represents the leading cause of vision loss in the developed countries despite intravitreal anti-VEGF therapy. To improve quality of life and vision an oral compound that prevents or improves the course of the disease would be a game changer. The fruit of the oil palm (Elaeis guineensis) is rich in phytonutrients. Here, we examined the role of phenolics-enriched water-soluble palm fruit extract (WSPFE), produced from palm oil processing, in angiogenesis and inflammation.

Methods : WSPFE was administered in liquid form in drinking water as parts per million (ppm) gallic acid equivalent (GAE). C57BL/6J mice underwent laser photocoagulation (532-nm laser, 100mW, 50 μm, 100ms) to induce CNV. On day 3 after injury, 10μm frozen sections of the posterior eye segment were stained with F4/80, CD11b, CD45, CD68 and CD163. Lesion volume was quantified with confocal microscopy on day 14. Uveitis was induced by injecting 100 μg of lipopolysaccharide (LPS; Salmonella typhimurium) diluted in 0.1 ml sterile saline into one hind footpad of mice. Perfusion with rhodamine-labeled concavalin A stained the vasculature. Abdominal aortas of apoE-/- mice were excised and stained with Oil-Red-O. Photomicrographs were obtained across the length of the entire aortic whole mount. Cell culture experiments and FACS were performed with Human Umbilical Vein Endothelial Cells (HUVEC), and RAW264.7 mouse macrophage cell lines, respectively.

Results : Oral WSPFE significantly decreased CNV volume and macrophages infiltration in a mouse model of CNV, in addition VEGF-A in cultured endothelium was substantially reduced. WSPFE reduced M2-like macrophages, known to foster angiogenesis. In an established model of acute inflammation, the endotoxin-induced uveitis (EIU) oral WSPFE treatment reduced leukocyte accumulation in retinal vessels and in a chronic model of arterial inflammation in apoE-/- mice, the size of atheorosclerotic plaques was significantly less.

Conclusions : These results indicate oral supplementation of WSPFE reduces inflammation and angiogenesis. WSPFE is an accessible and affordable nutritional supplement and could provide a non-invasive alternative or addition in prevention and treatment of inflammatory and angiogenic diseases, such as AMD.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.