金錢薄荷、化石草及紅藤仔草（金劍草）等三種植物，為臺灣民間市售常見青草茶（藥）之組成原料，本研究主要目的是評估其抗氧化活性，探討方法應用DPPH（1,1-二苯基苦基苯肼1, 1-diphenyl-2-picryhydrazyl）清除自由基活性、還原力測試、Trolox 等價抗氧化能力（Troloxequivalent antioxidant capacities, TEAC）分析、測定總多酚含量及類黃酮含量等方式。結果顯示，紅藤仔草在DPPH 清除自由基活性（439.9 ± 0.3 μg of Vit E equivalents / gextract）、還原力測試（249.4 ± 0.7 μg of GSH equivalents / g extract）及維生素E 水溶性類似物（326.5 ± 2.0 μg Trolox equivalents / g extract）等價抗氧化能力（Trolox TEAC）分析中，皆具有較強的抗氧化活性，而化石草次之，金錢薄荷最低。測定總多酚類含量分析中，金錢薄荷顯示較高的酚含量（78.3 ± 0.1 μg gallic acid equivalents / g extract），紅藤仔草次之，化石草最低。測定類黃酮含量分析中，紅藤仔草顯示較高的含量（41.3 ± 1.1 μg rutin equivalents/ g extract），化石草次之，金錢薄荷最低。綜上，得知茜草科紅藤仔草為本研究中抗氧化活性較為顯著之植物，因此，未來將繼續追蹤探討其有效之抗氧化活性成分，以進一步開發本產藥用植物之應用價值。

Three species in the Labiatae family, Glechoma hederaceae L. Grandis (A. Gray) Kude,Orthosiphon aristatus (Blume) Miq and Rubia akane, are commonly used for herbal tea in Taiwan.This study aimed to investigate the antioxidant activities of the three plants by DPPH (1,1-diphenyl-2-picryhydrazyl) radical-scavenging activity, reducing power assay (RP), trolox equivalent antioxidant capacity (TEAC), determination of total phenolic content (TPC) and determination of total flavonoid content (TFC)
The results showed that in DPPH, RP and TEAC assays, R. akane had the best antioxidant activities (439.9 ± 0.3 μg of Vit E equivalent / g extract, 249.4 ± 0.7 μg of GSH equivalent / g extract, 326.5 ± 2.0 μg Trolox equivalent / g extract) followed by O. aristatus and G. hederaceae in descending order. In the TPC assay, G. hederaceae had the highest content of phenolic compounds (78.3 ± 0.1 μg gallic acid equivalent / g extract) followed by R. akane and O. aristatus. In TFC assay, R. akane had the highest content of phenolic compounds (41.3 ± 1.1 μg rutin equivalents / g extract), followed by O. aristatus and G. hederaceae. This study will continue to search for the antioxidant active components and further develop on the uses of plants which are native to Taiwan.