About Herbs

Dong quai is an herb used in traditional Chinese medicine to treat menstrual and menopausal symptoms and to 'tonify' blood. Root extracts of dong quai were shown to stop growth of cancer cells in laboratory studies but human data is lacking. A few studies have been done to test effectiveness of dong quai for menopausal symptoms but results are inconclusive. Dong quai has weak estrogen like effects and it was shown to increase growth of breast cancer cells in laboratory experiments. It may also contain compounds that can cause cancer in high doses. So caution is advised before use.

Dong quai is an herb used in traditional Chinese medicine for thousands of years. It is often combined with other herbs to 'tonify' blood. It is also used as a dietary supplement and promoted as a 'woman's herb' to treat menstrual and menopausal symptoms. Data regarding efficacy of dong quai for menopausal symptoms are inconclusive ^{(1) (2) (3) (4) (5) (6)}. Extracts of dong quai demonstrated antitumor ^{(7) (8) (9) (10)} and anti-tuberculosis (TB) ⁽¹¹⁾ activities in vitro. In animal studies, the polysaccharides extracted from dong quai root showed protective effects against cyclophosphamide-induced toxicity ⁽¹²⁾, doxorubicin-induced cardiotoxicity ⁽¹³⁾, and radiation-induced pneumonitis ⁽¹⁴⁾. But these effects have not been evaluated in humans. Dong quai exhibited weak estrogenic activity in vitro ⁽¹⁵⁾ and was found to stimulate proliferation of MCF-7 cells ^{(16) (17)}. Therefore, until definitive efficacy and safety data are available, patients with hormonal-sensitive cancers should use this herb with caution. Reported adverse events include bloating, loss of appetite ⁽¹⁸⁾, diarrhea, photosensitivity ⁽¹⁹⁾, and gynecomastia ⁽²⁰⁾. Due to the coumarin content, the activity of anticoagulants may be potentiated ⁽²¹⁾. Psoralens and safrole, the active constituents, are thought to be carcinogenic in high doses ⁽¹⁹⁾.

Water extract from dong quai was shown to have a weak estrogen-agonist activity and can stimulate proliferation of both estrogen receptor-positive and negative breast cancer cells ⁽¹⁷⁾. It exerts a protective effect in mice with radiation-induced pneumonitis by down regulating proinflammatory cytokines such as TNF-alpha and TGF-beta1 ⁽¹⁴⁾. Subcutaneous injection of dong quai extract also protected mice against cyclophosphamide-induced cytotoxicity by promoting recovery from leukopenia ⁽¹²⁾. The antitumor effects of dong quai may be due to its inhibitory effects on invasion and metastatic of carcinoma cells ⁽⁹⁾ and by suppression of tumor growth ^{(7) (8) (10)} which may be mediated by Nur77-dependent apoptosis ^{(23) (24)}. A component isolated from dong quai promotes wound healing and bone regeneration by inducing osteoblast proliferation hyaluronic acid deposition ⁽²⁵⁾. Furthermore, dong quai extracts promote angiogenesis by inducing proliferation and migration of endothelial cells in part by upregulating VEGF expression ⁽²⁶⁾.

Psoralens can cause photosensitization, and safrole is carcinogenic ⁽¹⁹⁾.
Pregnant and breastfeeding women should avoid Dong quai ⁽²⁷⁾.

Reported: Reported adverse events include bloating, loss of apetite ⁽¹⁸⁾, diarrhea, photosensitivity ⁽¹⁹⁾, and gynecomastia ⁽²⁰⁾.