Angelica sinensis

Alternative Medicine Review,  Dec, 2004  

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Description

Angelica sinensis (commonly known as dong quai) is a fragrant, perennial herb found in mainland China, Japan, and Korea. Other common names for dong quai include Chinese Angelica, dang gui (Chinese), toki (Japanese), tanggwi (Ko rean), and kinesisk kvan (Danish). A member of the Umbelliferae family, Angelica produces white flowers that bloom in umbrella-like clusters in June-July. A typical plant grows to a height of approximately six feet (two meters). The dried root is valued for its therapeutic properties. Its flavor is a distinct blend of bitter, sweet, and pungent, and its overall effect is warming in nature. Chinese herbalists have used Angelica for thousands of years to strengthen heart, lung, and liver meridians, as well as lubricate the bowel. It is considered a blood tonic, and has been used by generations of women for health concerns such as menstrual pain and regulating the menstrual cycle.

Active Constituents

Dong quai root contains 0.4-0.7 percent volatile oil, the key components of which are nbutylidenephthalide, ligustilide, n-butylphthalide, ferulic acid, nicotinic acid, and succinic acid. (1-3) Significant amounts of vitamin A and carotenoids (0.675%), vitamin B12 (0.25-0.40 mcg/100g), vitamin E, ascorbic acid, folinic acid, biotin, various phytosterols (e.g., beta-sitosterol), calcium, magnesium, and other essential macrominerals are also found in dong quai root. (1,3,4) Other constituents include n-valerophenoneO-carboxylic acid, delta-2,4-dihydrophthalic anhydride, uracil, adenine, carvacrol, safrole, isosafrole, sesquiterpenes, beta-cadinene, n-dodecanol, n-tetradecanol, palmitic acid, angelic acid, myristic acid, sucrose (40%), and a polysaccharide with a molecular weight of approximately 3,000. (1,4)

Natural coumarin derivatives have been attributed to dong quai, but reports differ regarding which ones are truly present. The coumarin derivatives include angelol, angelicone, bergapten, oxypeucedanin, osthole, psoralen, and 7-desmethylsuberosin. (1-3,5,6)

Mechanisms of Action

Due to its varied constituents, several pharmacological actions may be attributed to dong quai. Such characteristics include anticoagulation (7) and antiplatelet activity, (l,2) as well as hematopoiesis, (4) immune support, (8, 9) and uterine tonicity. (1,2,4,10)

Anticoagulant Activity

Coumarins and coumarin derivatives, natural anticoagulants in Angelica spp., have been associated with both the bioactivity and toxicity of the plants; however, A. sinensis contains a lower coumarin content compared to other closely related species. (7)

Antiplatelet Action

Ferulic acid, one of the constituents of dong quai, can inhibit the polymerization of platelets in blood circulation. It retards platelet release of 5-hydroxytryptamine (5-HT) and adenosine diphosphate (ADP). (1) Both ferulic acid and an aqueous extract of dong quai were found to inhibit platelet aggregation and serotonin release. (2)

Immune Support and Hematopoiesis

Lymphocyte proliferation assays indicate dong quai consistently exerts an immunostimulatory effect. (8,9) A high molecular weight polysaccharide found in dong quai has demonstrated immunostimulating activity and a blood tonifying effect by inducing hematopoiesis in the bone marrow. This is accomplished, in part, by either direct or indirect stimulation of macrophages, fibroblasts, erythrocytes, granulocytes, and lymphocytes, and can induce an increased secretion of human growth factors from muscle tissue. (4)

Hematopoiesis is further supported by the presence of significant amounts of vitamin B 12, folinic acid, and biotin in dong quai. (4)

Antifibrotic Action

A mixture of dong quai and Astragalus demonstrated antifibrotic activity in a recent animal study. Rat models with chronic puromycininduced nephrosis were treated with either a dong quai and Astragalus mixture (3 mL/day) or enalapril (10 mg/kg). The normal control group received saline, and another group received puromycin but no treatment. (11) After 12 weeks the untreated rats showed marked renal fibrosis. However, dong quai and Astragalus significantly retarded the progression of renal fibrosis and deterioration of renal histological damage, with effects comparable to enalapril. (11)

Antispasmodic Activity

Ligustilide, butylidenephthalide, and hutylphthalide were found to have antispasmodic activity against rat uterine contractions and in other smooth muscle systems. The components were characterized as non-specific antispasmodics with a mechanism different from papaverine. (7,12)

Clinical Indications Cardiovascular Disease

Dong quai has demonstrated quinidinelike activity on the heart. (2) It can prolong the refractory period, lower blood pressure, and correct experimental atrial fibrillation induced by atropine, pituitrin, strophanthin, acetylcholine, or electrical stimulation. (10) Dong quai can dilate the coronary vessels, increase coronary flow, and reduce respiratory rate. An animal study using a water-based extract of dong quai demonstrated a marked protective effect against myocardial dysfunction and myocardial injury induced by ischemia. (4)