秦岭特色药王茶的营养组成、抗氧化活性及其对DNA损伤的作用

目的:揭示秦岭特色药食同源植物药王茶的营养保健功效与活性物质基础，为药王茶资源的开发利用提供参考。方法:采用高效液相色谱法、等离子体发射光谱法等分析药王茶的化学组成，测定其营养素和活性成分的种类与水平，采用自由基清除实验等评价其抗氧化活性，采用琼脂糖凝胶电泳技术研究其抗DNA损伤作用。结果:药王茶含有槲皮苷、槲皮素和没食子酸，提取物中含量依次为0.17%±0.00%、0.29%±0.01%和0.28%±0.01%。必需氨基酸含量为65.65±1.97 mg/g。锰、硒、镁的含量分别为1.19±0.04、0.43±0.02、2.80±0.05 mg/kg，砷、镉、汞、铅等重金属均未超过国家限量标准。清除DPPH、ABTS自由基的EC₅₀值分别为0.0704、0.3810 mg/mL，具有较高的还原力。对DNA损伤的保护作用具有明显的剂量依赖性，在药王茶提取物浓度达到1×10?2 mg/mL时抗DNA损伤作用强于抗坏血酸。结论:药王茶含有多种生物活性物质，重金属含量符合标准，具有一定的体外抗氧化能力和抗DNA损伤作用。

Nutritional Composition,Antioxidant Capacity and Protective Activity against DNA Damage of Yaowang Tea (Potentilla glabra var. mandshurica) Endemic to Qinling Mountain

Objective: In order to provide evidence to scientific exploitation of Yaowang tea endemic to Qinling mountain, nutritional value, health benefits and their material basis of Yaowang tea were investigated. Methods: Chemical composition as well as nutrients and bioactive constituents profile of Yaowang tea was analyzed by high performance liquid chromatography and plasma emission spectroscopy, etc. Antioxidant activity was determined by free radical scavenging experiment, and protective effect on DNA damage was studied by agarose gel eletrophoresis. Results: Quercitrin, quercetin and gallic acid were determined in Yaowang tea, and their contents were 0.17%±0.00%, 0.29%±0.01% and 0.28%±0.01%, respectively. Content of essential amino acids was 65.65±1.97 mg/g. Contents of manganese, selenium and magnesium were 1.19±0.04, 0.43±0.02 and 2.80±0.05 mg/kg, respectively, while heavy metals (e.g., arsenic, cadmium, mercury, lead) did not exceed the national permissible limit. Yaowang tea extract exhibited the ability to scavenge DPPH and ABTS radicals with EC₅₀ values of 0.0704 and 0.3810 mg/mL, respectively. Protective activity of Yaowang tea extract against DNA damage was in dose-dependent manner. Protective effect of 1×10?2 mg/mL Yaowang tea extract against DNA damage was higher than that of ascorbic acid. Conclusion: Yaowang tea contains several bioactive constituents, and it is safe in respect to heavy metals. Yaowang tea possesses in vitro antioxidant activity and protective effect against DNA damage.