Abstract
The polyphenol compound ellagic acid (EA) extracted from pomegranate has potential bioactivity against different types of chronic diseases. Skin aging is a long-term physiological process caused by many environmental factors, the most important of which is exposure to sun ultraviolet (UV) radiation. UV-induced chronic photodamage of the skin results in extrinsic aging. This study aimed to evaluate the photoprotective effects of EA on the human fibroblast skin cell line HFB4 and investigate its capacity to protect collagen from UV-induced deterioration. EA was encapsulated into chitosan-coated niosomes to reduce the skin aging effect of UV radiation in vitro. The tested formulations (niosomes loaded with EA and chitosan-coated niosomes loaded with EA) were characterized using transmission electron microscopy, dynamic light scattering, and scanning electron microscopy. Furthermore, the in vitro release of EA was determined. The HFB4 cell line samples were split into five groups: control, UV, UV-EA, UV-NIO-EA, and UV-CS-NIO-EA. UV irradiation was applied to the cell line groups via a UV-emitting lamp for 1 h, and then cell viability was measured for each group. The expression of genes implicated in skin aging (Co1A1, TERT, Timp3, and MMP3) was also assessed to quantify the impact of the loaded EA. The findings showed that EA-loaded chitosan-coated niosomes improved cell survival, upregulated Col1A1, TERT, and Timp3 genes, and downregulated MMP3. Thus, nanoparticles encapsulating EA are potent antioxidants that can preserve collagen levels and slow down the aging process in human skin.