本研究針對市售水丁香藥材和實地採集水丁香屬(柳葉菜科)植物，進行評估。首先鑑定植物學名以確定植物基源，植物材料以甲醇水溶液加熱迴流抽取，粗抽取物注射於pentobarbital麻醉狀態下之正常血壓或自發性高血壓的大白鼠，觀察頸動脈壓之變化。
研究結果發現四種水丁香屬植物並無降血壓效果，反而是兩種代用藥材－田香草(玄參科)和三肉草(三白草科)－具有顯著降血壓效果。對於田香草之分配萃取分劃，降血壓試驗顯示正丁醇層具有最大生物活性，目前正在進行本植物成分研究之中。 A Taiwan Folk-medicine named "Shui-Ding-Xiang", Genus Ludwigia, is currently used in the treatment of hypertension. The origin of these medicinal plants was identined in this study. The hypertensive effects of the crude extracts were examined on normotensive and spontaneous hypertensive rats under anesthetization. The active principles were traced by the hypotensive tests.
In this preliminary study, it was found that the most commonly employed plants, Ludwigia hyssopifolia and Ludwigia octovalvis, were practically ineffective on hypertension. In contrast, the Substituted plants for Shui-Ding-Xiang, Limnophila rugosa and Saunsrus chinensis, exhibited hypotensive effects regularly. Thus, the possible hypotensive effects of Shui-Ding-Xiang may attribute to the involvement of these two substitutive plants.
