Preparation of cellulose microfibrils from Gelidium amansii relieving ocular endoplasmic reticulum stress and inflammatory responses in human retinal pigmented epithelial cells.

This study investigated the physicochemical properties of cellulose microfibrils (CMFs) derived from Gelidium amansii (GA) and their potential functionality in preventing retinal pathologies. GA was subjected to microwave-assisted extraction, microfibrillation, centrifugation, and autoclave sterilization, yielding G, GM, GC, and GS, respectively. Each processing steps induced distinct microstructural modifications affecting the final functional properties of the CMFs. To explore their protective effects against anti-endoplasmic reticulum (ER) stress and anti-inflammatory effects, ARPE-19 cells were pretreated with these processed CMFs before exposure to either thapsigargin or lipopolysaccharide. Among the variants, GS most effectively alleviated ocular ER stress by suppressing unfolded protein responses, reducing vascular endothelial growth factor gene and protein expressions, and lowering intracellular calcium levels. Moreover, GS significantly mitigated ocular inflammatory responses by inhibiting the translocation of nuclear factor-kappa B (NF-κB) into the nucleus; consequently preserving tight-junction integrity and downregulating inflammatory cytokine gene expressions. These findings highlight the potential of GS as a protective agent against retinal stress and inflammation.