Cytoprotective Effects of Ethanolic Makiang Fruit (Cleistocalyx nervosum var. paniala) Extract Against Sodium Iodate-Induced Oxidative Stress in ARPE-19 Cells

Abstract

Age-related macular degeneration (AMD) is a major cause of irreversible vision loss in the elderly, with oxidative stress to retinal pigment epithelial (RPE) cells playing a key role in its pathogenesis. Natural antioxidants have the potential to protect against oxidative retinal damage. Makiang fruit, a dark purple fruit rich in anthocyanins, has been reported to possess strong antioxidant properties. However, its protective effects in ARPE-19 cells have not yet been investigated. This study investigated the antioxidant capacity and cytoprotective effects of Makiang extract against NaIO₃-induced oxidative stress in ARPE-19 cells. Makiang fruits (Cleistocalyx nervosum var. paniala) were extracted using 95% ethanol (MKE95). ARPE-19 cells were co-treated with MKE95 (2, 20, and 200 µg/mL) and NaIO₃ (1200 µg/mL) for 24 h. At 200 µg/mL, MKE95 significantly (p < 0.05) attenuated intracellular ROS production, enhanced antioxidant defenses (SOD, CAT, GPx, and GSH), and decreased caspase-9 and caspase-3 activities. These findings indicate that MKE95 exerts cytoprotective effects against oxidative stress in ARPE-19 cells. However, the findings provide only preliminary in vitro evidence. Further studies in animal and clinical models are warranted to confirm its potential to prevent or delay AMD progression.