Angelica sinensis is one of the most widely used herbs in traditional Chinese medicine formula for blood tonification such as danggui buxue tang, which is related to the treatment of circulatory system. Traditional usage of Angelica sinensis is water boiling. As polysaccharide is one of the main component in water extract, the pro-angiogenic effect of polysaccharide from Angelica sinensis was investigated in this study. Blood vessels loss of Tg(fli-1a:EGFP)y1 zebrafish embryos are induced by 500 ng/ml VEGFR tyrosine kinase inhibitor II (VRI) for 3 h at 21 hour post-fertilization (hpf). VRI was then replaced with different concentrations (10, 30, 100, 300 μg/ml) of Angelica Sinensis polysaccharide and acidic polysaccharide solution. The morphological changes of embryos were observed through fluorescence microscope at 48hpf. The number of intersegmental vessels (ISV) in each embryo was quantified. Two polysaccharide fractions isolated from Angelica sinensis by ultrafiltration, “molecular weight < 20 kDa & diameter < 0.1 μm” and “molecular weight 50-200 kDa”, restored VRI-induced blood vessel loss in zebrafish significantly. Polysaccharide of Angelica sinensis has pro-angiogenesis effect in zebrafish model with deficiency of blood vessel. The active ingredient existed in the fractions “molecular weight < 200 kDa & diameter < 0.1 μm” and “molecular weight 50 - 200 kDa”. Keywords: Angelica sinensis，polysaccharide，VRI，zebrafish，angiogenesis

當歸為常用傳統中藥，具有補血活血，調經止痛之功效。因其功效顯著而被 廣泛使用，在傳統中藥應用上常以複方形式與其他中藥混合，如加入黃耆的當歸 補血湯。由於主治功能與血液循環系統有著密切關係，而當歸的傳統服用形式以 水煮為主，因此假設當歸水提物中具有促血管新生的活性成份。多醣為當歸水提 物的主要成份之一，為進一步研究當歸中促血管新生的有效成份，本實驗以當歸 多醣及酸性多醣為研究對象，並比較不同分子量範圍的當歸多醣在斑馬魚血管缺 失模型的促血管新生活性。 利用 500 ng/ml 血管內皮生長因子受體酪氨酸激酶抑制劑（VRI）處理轉基 因斑馬魚 Tg(fli1a:EGFP) 3 h 抑制血管生長，隨後替換成不同分子大小的當歸多 醣及酸性多醣（10-300 μg/ml）處理斑馬魚 24 h，觀察斑馬魚節間血管（ISV）的 生長情況。 VRI 預處理 3h 使斑馬魚節間血管減少；將 VRI 清洗去除，替換成當歸多醣 及當歸酸性多醣處理 24 h，斑馬魚節間血管結構有不同程度的恢復。其中分子量 為 200 kDa 至直徑為 0.1 μm 及分子量為 50 - 200 kDa 兩個片段的當歸多醣實驗組， 在濃度為 10 及 30 μg/ml 時，ISV 結構較完整。 實驗結果表明，當歸多醣中分子量為 200 kDa 至直徑為 0.1 μm 及分子量為 50 - 200 kDa 兩個片段，對 VRI 誘導的斑馬魚血管缺失模型有明顯促血管新生活 性。結果對於進一步從當歸中提取有效活性成份開發促血管新生藥物具有意義。