The effect of Coix lachrymal L. seed extract on the expression of inflammation and fibrogenesis genes in human retinal pigment epithelial cells

Abstract

Proliferative vitreoretinopathy (PVR) is a vision-threatening condition associated with retinal-detachment (RD), primarily caused by fibrocellular scar membrane formation. This study investigates the therapeutic potential of adlay seed extract fractions in mitigating PVR-associated pathways, focusing on oxidative stress, proliferation, inflammation, and fibrogenesis in retinal pigment epithelial (RPE) cells. Adlay seed extract fractions (methanolic: MeOH and residual: Res) were obtained through solvent extraction and characterized for carbohydrate, protein, flavonoid content, and antioxidant activity. RPE cells were cultured, and their viability in response to adlay fractions was assessed using the MTT assay. Gene expression analysis of IL-1β, IL-6, LIF, TGF-β, Snail and α-SMA genes was conducted via real-time PCR after treatment with adlay fractions. The Res fraction exhibited higher levels of protein, carbohydrate, flavonoids, and phenols compared to the MeOH fraction, along with significantly enhanced antioxidant activity. Both fractions showed inhibitory effects on RPE cell viability, with the Res fraction demonstrating a more pronounced impact. Gene expression analysis revealed a significant decrease in IL-6 and TGF-β expression with the MeOH fraction treatment, while the Res fraction led to decreased expression of IL-6, LIF, TGF-β, Snail and α-SMA, indicating a more comprehensive modulation of PVR-associated pathways. This study highlights the potential therapeutic benefits of adlay seed extract fractions in mitigating PVR-associated pathways in RPE cells. The Res fraction, particularly rich in bioactive compounds and exhibiting potent antioxidant activity, shows promise in attenuating oxidative stress, proliferation, inflammation, and fibrogenesis, critical processes in PVR development. These findings underscore the potential of adlay seed extracts as a novel therapeutic strategy for PVR warranting further investigation and clinical validation.