不同采收期虫草参多酚对羟基自由基介导的DNA氧化损伤保护作用的研究

采用Folin-酚法测定两个采收地（S1和S2）三个采收期（T1、T2和T3）虫草参游离酚和结合酚提取物的多酚含量。采用HPLC法检测多酚提取物中没食子酸、绿原酸、咖啡酸和迷迭香酸的含量。同时，评价了虫草参多酚提取物对羟基自由基（·OH）介导的DNA氧化损伤的保护作用。结果显示，虫草参游离酚和结合酚提取物的多酚含量范围分别为86.53~181.40和89.70~193.58 μg GAE/mg；咖啡酸在结合酚中含量较高，且S2采收地高于S1；而迷迭香酸在游离酚中含量较高，且在T1和T3采收期，S2采收地的高于S1，相反在T2采收期，S2采收地的低于S1；虫草参游离酚（25~300 μg/mL）和结合酚（3.125~50 μg/mL）提取物对DNA氧化损伤保护作用的双螺旋百分比范围分别为1.81%~55.04%和1.67%~70.83%。相较于游离酚，结合酚提取物表现出更好的保护效果。

Hydroxy Radical Mediated DNA Oxidative Damage Protective Effect of Polyphenols from Lycopus lucidus Turcz. at Different Harvest Times

The phenolic content of free and bound phenolic extracts from Lycopus lucidus Turcz. harvested from two sites (S1 and S2) at three different times (T1, T2 and T3) was determined by Folin-Ciocalteu method. The content of gallic acid, chlorogenic acid, caffeic acid and rosmarinic acid in the phenolic extracts was detected by HPLC. Meanwhile, the protective effect of polyphenolic extracts on ·OH mediated DNA oxidative damage was evaluated. The results revealed that the phenolic contents of free and bound phenolic extracts were in the range of 86.53~181.40 and 89.70~193.58 μg GAE/mg, respectively. Higher amount of caffeic acid was found in the bound phenolic extract and the content of S2 L. lucidus Turcz. was higher than that of S1. Where as higher amount of rosmarinic acid was observed in the free phenolic extract. Furthermore, the rosmarinic acid content in S2 L. lucidus Turcz. was higher than that of S1 at T1 and T3. On the contrary, lower rosmarinic acid content was detected in S2 L. lucidus Turcz. at T2. The contents of caffeic acid and rosmarinic acid varied greatly with the harvest sites. The percentage of DNA double helices of free (25~300 μg/mL) and bound phenolic extracts (3.125~50 μg/mL) were in the range of 1.81%~55.04% and 1.67%~70.83%, respectively. The DNA damage protective effect of bound phenolics was higher than that of free phenolics.