海菜花结合酚的组成、抗氧化活性及其对DNA损伤的保护作用

采用福林-酚法、亚硝酸钠-氯化铝法分别测定海菜花花、茎、叶中结合酚总酚及黄酮含量,采用高效液相色谱(HPLC)分析结合酚的组成,并研究其抗氧化活性及其对过氧自由基(ROO·)介导的DNA损伤保护作用.结果表明,海菜花结合酚总酚含量为209.72～366.35 mg GAE/g提取物(Extract),黄酮含量为156....

Composition,Antioxidant Activity and DNA Damage Protective Effect of Bound Phenolics from Ottelia acuminata

Folin-Ciocalteu method and sodium nitrite-aluminum chloride method were used to determine total phenolic content and flavonoid content of bound phenolics from the inflorescences, peduncles and leaves of Ottelia acuminata (O. acuminata), respectively. The composition of bound phenolics was analyzed by high performance liquid chromatography (HPLC). The antioxidant activity and protective effect against ROO· mediated DNA damage were also investigated. The results showed that total phenolic content of O. acuminata was in the range of 209.72~366.35 mg GAE/g Extract while total flavonoid content was in the range of 156.69~466.08 mg CAE/g Extract. Five phenolics, namely, caffeic acid, quercetin-3-O-glucoside, luteolin, chlorogenic acid and ferulic acid were identified in bound phenolics of O. acuminata. Trolox equivalent antioxidant activity (TEAC), 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) radical scavenging ability, iron ion reduction antioxidant ability (FRAP) and hydroxyl radical (·OH) scavenging rate IC₅₀ value of different plant parts were in the range of 1.19~1.25 μmol TE/g Extract, 0.74~0.94 mmol/g Extract, 3.61~4.75 mmol Fe2+/g Extract, 0.34~1.26 mg/mL, respectively, among which the leaves displayed the strongest antioxidant activity. In the concentration range of 12.5~500 mg/mL, the percentage of double helix DNA in bound phenolics of inflorescences, peduncles and leaves ranged from 22.74% to 50.07%, 18.25% to 53.28% and 25.93% to 53.60%, respectively, among which the leaves showed the strongest DNA damage protective effect, followed by the peduncles. The results showed that O. acuminata was rich in bound phenolics which possessed strong antioxidant activity and DNA damage protective effect.