Free radical and reactive oxygen species scavenging activities of the extracts from seahorse, Hippocampus kuda Bleeler

Abstract: Seahorse, Hippocampus kuda (SH) a marine teleost fish, is well known not only for its special medicinal composition and used as one of the most famous and expensive materials of traditional Chinese medicine. It was extracted with water (SHW), methanol (SHM), and ethanol (SHE), respectively and evaluated by various antioxidant assays. The including reducing power, total antioxidant, DPPH radical scavenging, hydroxyl radical scavenging, superoxide anion radical scavenging, alkyl radical scavenging, and protective effect on DNA damage caused by hydroxyl radicals generated. Further, the ROS level was detected using a fluorescence probe, 2′,7′-dichlorofluorescin diacetate (DCFH-DA), which could be converted to highly fluorescent dichlorofluorescein (DCF) with the presence of intracellular ROS on mouse macrophages, RAW264.7 cell and inhibited myeloperoxidase (MPO) activity in human myeloid, HL60 cells, respectively. Those various antioxidant activities were compared to standard antioxidants such as α-tocopherol. Among SHM exhibited the highest antioxidant activity in linoleic acid system, effective reducing power, DPPH radical scavenging, hydroxyl radical scavenging, superoxide radical scavenging, alkyl radical scavenging, inhibitory intracellular ROS, and inhibited MPO activity. Furthermore, MTT assay showed no cytotoxicity on mouse macrophages cell (RAW264.7) and human cell lines (MRC-5, HL60, U937). This antioxidant property depends on concentration and increasing with increased amount of extracts. The results obtained in the present study indicated that the see horse (Hippocampus kuda Bleeker) is a potential source of natural antioxidant.