Herb lovers in North America tend to think of lemon balm (Melissa officinalis) as the source of pleasant-tasting, citrus-scented leaves that can be brewed into a delicious tea. In Germany, however, lemon balm is more often considered a medicinal herb. The German government allows the sale of preparations of lemon balm to treat insomnia caused by nervous conditions and functional gastrointestinal symptoms, and several studies have shown lemon balm to be effective against the herpes simplex virus (the causative agent of cold sores and genital herpes). Hot-water extracts of lemon balm have shown strong antiviral activity in egg- and cell-culture systems, and this has been attributed to tannin and polyphenols other than caffeic acid.
Extracts were also assessed in a clinical study involving 115 patients with herpes, 45 males and 70 females. Patients applied a cream containing 1 percent dried lemon balm extract as needed five times daily for as long as two weeks, or until their lesions had healed completely. Symptoms were documented at the beginning of treatment and on the fourth, sixth, and eighth days of treatment. Healing was deemed complete in 96 percent of the patients by the eighth day of the treatment. Healing usually takes ten to fourteen days with no treatment.
The promising results of this study led to a further clinical trial in which two dermatological centers carried out a randomized, placebo-controlled double-blind study on the effect of a cream containing 1 percent dried extract of lemon balm leaves. Case reports of 116 patients were evaluated. Both physicians and patients judged the lemon balm cream superior overall to the placebo. The lemon balm cream was significantly more effective than the placebo in the initial stage of treatment and in reducing swelling on the second day. To be effective, treatment must be started in the earliest stages of the infection. Accelerated healing was most pronounced in the first two days of treatment.(1)
Four clinical trials reported since 1987 have concluded that St.-John’s-wort (Hypericum perforatum), a European native plant that is a ubiquitous weed throughout the United States, may be useful in treating mild forms of depression. In one of these trials, a psychiatrist, an internist, and a general practitioner conducted a randomized, placebo-controlled double-blind study on 105 patients diagnosed with mild to moderate depression or temporary depressive moods. Patients were given the equivalent of 300 mg of St.-John’s-wort extract or a placebo daily for four weeks. Of those taking the extract, 67 percent responded to the treatment whereas only 28 percent patients in the placebo group responded. Patients who took the extract felt significantly less sad, hopeless, helpless, or useless, were less fearful, and slept better. No significant side effects were observed.(2)
Red or Oregon alder (Alnus rubra, formerly A. oregona) is a shrub or tree to 25 feet tall found on stream banks and in marshes in western North America from Alaska to California. A 1990 publication on the ethnobotany of the Thompson Indian group of British Columbia reported that the group has used the bark of red alder to treat infections(3). Researchers at the University of British Columbia subsequently tested a methanol extract of red alder bark against seven bacteria strains. Although the antimicrobial activity that they found was considerably weaker than that of commercial antibiotics such as gentamicin and methicillin, the study nonetheless provides a rational scientific basis for the use of the bark by Native Americans to treat infections.(4)
Kudzu (Pueraria lobata), a member of the pea family that is a rampant weed in the southern United States, is indigenous to eastern Asia, where it has many culinary uses. In traditional Chinese medicine, kudzu flower and root preparations have also been used to sober up a drunk. A study conducted in the United States showed that both daidzin and daidzein (two isoflavones that are the primary biologically active components in kudzu) in daily doses of 150 mg/kg suppressed the free choice of ethanol by Syrian golden hamsters. The authors concluded that kudzu root extracts, as well as daidzin and daidzein, may offer therapeutic choices in the treatment of alcohol abuse.(5)
(1) Wöbling, R. H., and K. Leonhardt. Phytomedicine 1994, 1(1):25–31.
(2) Harrer, G., and H. Sommer. Phytomedicine 1994, 1(1):3–8.
(3) Turner, N., L. Thompson, M. Thompson, and A. York. Thompson Ethnobotany, Royal British Columbia Museum, Memoir No. 3. Victoria, British Columbia: Royal British Columbia Museum, 1990.
(4) Saxena, G., S. Farmer, R.E.W. Hancock, and G.H.N. Towers. Int. J. Pharmacog. 1995, 33(1):33–36.
(5) Keung, W. M., and B. L. Vallee. Proc. Natl. Acad. Sci. 1993, 90:10008–10012.