The Possible Pre- and Post-UVA Radiation Protective Effect of Amaranth Oil on Human Skin Fibroblast Cells

BACKGROUND: The health effects of Amaranth Oil (AO) are attributed to its specific chemical composition. That makes it an outstanding natural product for the prevention and treatment of ultraviolet (UV) irradiation-related pathologies such as sunburn, photoaging, photoimmunosuppression, and photocarcinogenesis. Most of the studies are taken on animal model, and there is a lack of research on the endogenous effect of AO on fibroblast level, where UVA takes it harmful place. OBJECTIVE: The aim of this study was evaluation if AO can protect or abolish UVA exposure effect on human skin fibroblast. MATERIALS AND METHODS: The 0.1% AO, 0.25% AO, and 0.5% AO concentration and irradiation for 15 min under UVA-emitting lamp were studied in various condition. In all experiments, the mean values for six assays ± standard deviations were calculated. RESULTS: Pretreatment with various concentrations of AO was tested. The highest concentration of AO where cell survival was observed was 0.5%. Cytotoxicity assays provided evidence for pre- and post-UVA protective effect of 0.1% AO among three tested concentrations. The results also provide evidence that UVA has inhibitory effect on collagen biosynthesis in confluent skin fibroblast, but presence of 0.1% AO abolishes pre- and post-UVA effect comparing to other used AO concentration. The assessment results on DNA biosynthesis show the significant abolished post-UVA effect when 0.1% and 0.5% of AO were added. CONCLUSION: AO gives pre- and post-UVA protection in low concentration. This provides the evidence for using it not as a main protective factor against UV but as one of the combined components in cosmetic formulation. SUMMARY: The recommended Amaranth Oil (AO) concentration in cosmetic formulation is between 0.1 and 5%. Pretreatment with various concentrations of AO suggests to use the highest 0.5% concentration of AO in human skin fibroblast cultures. The 0.1% of AO in fibroblast cultures, protects and abolishes effect of ultraviolet A (UVA) exposure. UVA has inhibitory effect on collagen biosynthesis in skin fibroblast, but presence of 0.1% AO abolishes pre- and post-UVA effect. The abolished post-UVA effect occurs when 0.1% and 0.5% of AO were added on DNA biosynthesis. Abbreviations used: AO: Amaranth Oil.