Dong quai has a long history of use in both Traditional Chinese Medicine and Native American medicine, and it continues to he used for female conditions to balance the effects of menopause (hot flashes and night sweats) and PMS (cramping). The active components in dong quai are thought to be the coumarins, ferulic acid, and ligustilide. The coumarins are known to increase blood flow, and ferulic acid and ligustilide are known to have muscle-relaxing effects. Although there have been no known estrogenic compounds found in dong quai, it has been confirmed to have both esirogenic and antiestrogenic activity in vitro (Amato et al., 2002). Dong quai is sometimes used in "bust-enhancing" herbal products, but no clinical studies have been conducted on it for this purpose (Fugh-Berman, 2003). Dong quai has been shown to possess nonspecific immunomodulatory activity in vitro (Wilasrusmee et al., 2002a, 2002b).
Dong quai was included in a phytoestrogen combination that a clinical study found to be beneficial in treating migraines associated with the menstrual cycle, but how much dong quai contributed to its efficacy is unknown (Burke et al., 2002). After only one negative clinical study, dong quai was abandoned from clinical practice by many in the United States; however, considering its long history of use and reported success in alternative medicine settings, ilseems dong quai deserves more clinical research and more credit.
Hirata et al. (1997) examined the use of dong quai in postmenopausal women in a double-blind, randomized, placebo-control led clinical trial. Outcome parameters measured its effects on endometrial thickness (by ultrasonography), cellular maturation of vaginal cells, the Kupperman index (for determining menopausal symptoms), and frequenq' of hot flashes. Seventy-one women were included in the study and given either dong quai or a placebo for 24 weeks. No statistically significant differences were found between the treatment and placebo groups for any of the parameters measured. The authors concluded that dong quai does not produce estrogen-like responses in postmenopausal women for the parameters measured.
Generally, dong quai is administered in the dosage range of 250-1,000 mg/day (taken in divided doses) for the relief of menopausal or menstrual symptoms. There is no consensus on the standardization of dong quai because activity has been found in different fractions of the plant extracts. Dong quai is considered quite safe, but there is some concern of its potential to increase photosensitivity because of the coumanns it.
No clinical support on the single phytotherapeutic preparation is available.
Generally, damiana is recommended in the dosages of 400-800 mg 3 times daily if used singly. Not much is known about the long-term safety of damiana, but it has been noted to cause a euphoric and mild laxative effect at high dosages. Another concern is a potential drug interaction with aspirin because of dong quai's aniiplatelel activity (Abebe, 2002, 2003).
Evening primrose oil is made from the seeds of the herb Qtmothera biennis, which grows wild in arid environments like sand dunes. True to its name, the bright yellow evening primrose flowers open in the evening and fade in bright sunlight. First documented medicinally in England, evening primrose oil is most commonly used for relieving premenstrual syndrome, fibrocystic breasts, and menopausal symptoms such as hot flashes.