Antioxidant activity and cell toxicity of pressurised liquid extracts from 20 selected plant species in Jeju, Korea

Twenty plant species were selected from Jeju, Korea, and extracts made using a pressurised liquid extraction system. Integral antioxidative capacity (IAC), inhibitory activity of nitric oxide (NO) production, and cell toxicity were evaluated to identify new dietary antioxidants of natural origin with a low degree of cell toxicity. Geranium thunbergii and Pyrrosia lingua showed high IAC values of water-soluble substances (9.76 and 9.48 mmol ascorbic acid equivalents/g), with high IAC values of lipid-soluble substances of 5.20 and 1.97 mmol trolox equivalents/g, respectively. Prunus padus and Rhus javanica did not show any cytotoxicity on RAW 264.7 macrophages or HS-68 normal skin fibroblast cells and showed inhibitory activity of NO production (IC50 = 327 and 337 μg/ml) with LPS-induced RAW 264.7 macrophages. Malus sieboldii did not exhibit cytotoxicity with either cell type and showed high inhibitory activity of NO production (IC50 = 219 μg/ml) and high IAC values of water-soluble substances (4.93 mmol ascorbic acid equivalents/g).