Chen Yongsheng, Wang Gaoyan, Wang Hong, Cheng Chaohua, Zang Gonggu, Guo Xinbo, Liu Rui Hai
School of Light Industry and Food Sciences, South China University of Technology, Guangzhou, Guangdong, The People's Republic of China.
Department of Food Science, Cornell University, Ithaca, New York, United States of America.
PLoS One. 2014 Sep 22;9(9):e108140. doi: 10.1371/journal.pone.0108140. eCollection 2014.
Increased consumption of vegetables or plant food has been associated with decreased risk of developing major chronic diseases, such as cancers, diabetes, cardiovascular diseases, and age-related functional decline. Ramie leaves are rich in phenolics and flavonoids, which have been suggested for human health benefits. Phenolic contents, flavonoid contents, phenolic compounds, and anti-cancer properties in six species of ramie leaves were analyzed by Folin-reagent method, sodium borohydride/chloranil-based assay (SBC), HPLC method and antiproliferation, cytoxicity, respectively. Antioxidant activities were measured through peroxyl radical scavenging capacity (PSC) method, oxygen radical absorbance capacity (ORAC) method, and cellular antioxidant activity (CAA). Research indicated that Boehmeria penduliflora contained the highest total phenolic content (2313.7±27.28 mg GAE/100 g FW), and flavonoid content (1682.4±27.70 mg CAE/100 g FW). Boehmeria tricuspis showed the highest PSC value (9574.8±117.63 µM vit. C equiv./100 g FW), while Boehmeria penduliflora indicated the highest ORAC value (330.44±16.88 µmol Trolox equiv./g FW). The antioxidant activities were correlated with phenolic contents and flavonoid contents. Boehmeria tricuspis had the highest antiproliferative capacity with the lowest EC₅₀ (4.11±0.19 mg/mL). The results for the analyzed ramie for CAA were significantly different from each other (p<0.05), Boehmeria tricuspis had the highest CAA value (133.63±7.10 µmol QE/100 g). Benzoic acid, 4-coumaric acid, caffeic acid, and ferulic acid were the dominant phenolic ingredients in the ramie leaves according to HPLC analysis. Our research is the first report to study the phytochemical profiles and antioxidant activities in different species of ramie leaves for their health benefit.
蔬菜或植物性食物摄入量的增加与患主要慢性疾病（如癌症、糖尿病、心血管疾病和与年龄相关的功能衰退）风险的降低有关。苎麻叶富含酚类和黄酮类化合物，这些物质对人体健康有益。分别采用福林试剂法、硼氢化钠/四氯苯醌法（SBC）、高效液相色谱法以及抗增殖、细胞毒性实验，对六种苎麻叶中的酚类含量、黄酮类含量、酚类化合物和抗癌特性进行了分析。通过过氧自由基清除能力（PSC）法、氧自由基吸收能力（ORAC）法和细胞抗氧化活性（CAA）来测定抗氧化活性。研究表明，垂序苎麻的总酚含量最高（2313.7±27.28毫克没食子酸当量/100克鲜重），黄酮类含量最高（1682.4±27.70毫克儿茶素当量/100克鲜重）。三叉苎麻的PSC值最高（9574.8±117.63微摩尔维生素C当量/100克鲜重），而垂序苎麻的ORAC值最高（330.44±16.88微摩尔 Trolox 当量/克鲜重）。抗氧化活性与酚类含量和黄酮类含量相关。三叉苎麻具有最高的抗增殖能力，最低半数有效浓度（EC₅₀）为（4.11±0.19毫克/毫升）。所分析苎麻的CAA结果彼此差异显著（p<0.05），三叉苎麻的CAA值最高（133.63±7.10微摩尔芦丁当量/100克）。根据高效液相色谱分析，苯甲酸、对香豆酸、咖啡酸和阿魏酸是苎麻叶中主要的酚类成分。我们的研究是首篇针对不同种类苎麻叶的植物化学特征和抗氧化活性进行有益健康研究的报告。
