Antioxidative and Anti-photooxidative Potential of Interruptins from the Edible Fern Cyclosorus terminans in Human Skin Cells

Background: Human skin is exposed daily to oxidative stress factors such as UV light, chemical pollutants, and invading organisms. Reactive oxygen species (ROS) are intermediate molecules that cause cellular oxidative stress. In order to survive in an oxygen-rich environment, all aerobic organisms, including mammals, have evolved enzymatic and non-enzymatic defence systems. The interruptins from an edible fern Cyclosorus terminans possess antioxidative properties and can scavenge intracellular ROS in adipose-derived stem cells. Objectives: This study aimed to evaluate the antioxidative efficacy of interruptins A, B, and C in cultured human dermal fibroblasts (HDFs) and epidermal keratinocytes (HEKs). Moreover, the anti-photooxidative activity of interruptins in ultraviolet (UV)-exposed skin cells was investigated. Methods: The intracellular ROS scavenging capacity of interruptins in skin cells was measured by flow cytometry. Their induction effects on gene expression of the endogenous antioxidant enzymes was monitored using real-time polymerase chain reaction. Results: Interruptins A and B, but not interruptin C, were highly effective in ROS scavenging, particularly in HDFs. Interruptins A and B upregulated gene expression of superoxide dismutase (SOD)1, SOD2, catalase (CAT), and glutathione peroxidase (GPx) in HEKs, but they only induced SOD1, SOD2, and GPx gene expression in HDFs. Additionally, interruptins A and B efficiently suppressed UVA- and UVB-induced ROS generation in both HEKs and HDFs. Conclusion: The results suggest that these naturally occurring interruptins A and B are potent natural antioxidants and therefore may have the potential in the future of inclusion in antiaging cosmeceutical products.