Fisetin Protects DNA Against Oxidative Damage and Its Possible Mechanism

Purpose: The paper tries to assess the protective effect of fisetin against •OH-induced DNA damage, then to investigate the possible mechanism. Methods: The protective effect was evaluated based on the content of malondialdehyde (MDA). The possible mechanism was analyzed using various antioxidant methods in vitro, including •OH scavenging (deoxyribose degradation), •O 2 - scavenging (pyrogallol autoxidation), DPPH• scavenging, ABTS• + scavenging, and Cu 2+ -reducing power assays. Results: Fisetin increased dose-dependently its protective percentages against •OH-induced DNA damage (IC 50 value =1535.00±29.60 µM). It also increased its radical-scavenging percentages in a dose-dependent manner in various antioxidants assays. Its IC 50 values in •OH scavenging, •O2 - scavenging, DPPH• scavenging, ABTS• + scavenging, and Cu 2+ -reducing power assays, were 47.41±4.50 µM, 34.05±0.87 µM, 9.69±0.53 µM, 2.43±0.14 µM, and 1.49±0.16 µM, respectively. Conclusion: Fisetin can effectively protect DNA against •OH-induced oxidative damage possibly via reactive oxygen species (ROS) scavenging approach, which is assumed to be hydrogen atom (H•) and/or single electron (e) donation (HAT/SET) pathways. In the HAT pathway, the 3’,4’-dihydroxyl moiety in B ring of fisetin is thought to play an important role, because it can be ultimately oxidized to a stable ortho-benzoquinone form.