While investigating a combination of herbs used by the Caboclos people of Amazonia to treat convulsions, researchers at the Ethnopharmacology Laboratory at the Universidade Federal do Rio Grande do Sul in Porto Alegre, Brazil, found that linalool, a strong-smelling constituent of the essential oils of lemongrass, lemon verbena, lemon balm, lavender, rosemary, basil, thyme, coriander seed, and many other aromatic herbs, had a significant sedative effect on laboratory mice. (Most previous studies of linalool have focused on antimicrobial activity or its use as a fragrance in the cosmetic industry.) Their studies lend support for the use of linalool-containing plants as sedatives in folk medicine. The researchers observed that in aromatic baths, linalool would be significantly absorbed through inhalation.(1)
Echinacoside is one of a group of compounds called caffeoyl derivatives, which are found in some echinacea products. Although a study thirty years ago showed echinacoside to have insignificant biological activity, recent laboratory studies in Milan, Italy, revealed that this and related compounds may have a role in protecting the skin from ultraviolet radiation.
When human skin is exposed to ultraviolet rays, free-radical oxygen compounds, which can produce a cascade of harmful reactions, are produced. Collagen, one of the main proteins in the skin, is extremely sensitive to ultraviolet light. Degradation of collagen by aging or ultraviolet exposure results in wrinkling of the skin. The researchers found that all of the caffeoyl derivatives, and especially echinacoside, scavenged free radicals, thus inhibiting collagen degradation and consequent wrinkle formation. Their conclusion that echinacea extracts are effective for both the prevention and treatment of skin damage caused by ultraviolet radiation could lead to the use of echinacea in cosmetics.(2)
Spanish Moss and Diabetes
As a natural product, Spanish moss (Tillandsia usneoides) is more likely to be found in a florist’s shop than an herb shop. However, use of a tea made from Spanish moss by residents of southern Louisiana to treat symptoms of diabetes mellitus sparked a recent study by the pharmacy schools at Purdue University and Northeast Louisiana University. The researchers isolated and identified four compounds from a water extract of the plant, one of which significantly lowered blood sugar in laboratory mice. They recommended further investigation of this compound as a potential treatment for diabetes.(3)
In the Papaw Patch
While the fruits of the papaw (Asimina triloba), a small tree native to the eastern United States, are edible, the bark and the seeds contain toxic compounds, some of which are of increasing interest as potential cancer drugs. In 1986, researchers first isolated the compound asimicin, which showed promising antitumor activity. Since then, various research groups have isolated a number of related compounds. Recently, researchers in the College of Pharmacy, Taegu Hyosung Catholic University in Korea, in collaboration with scientists at Purdue University, isolated three related compounds from alcohol extracts of the seeds; all inhibited the growth of tumors in six human solid-tumor cell lines.(4)
(1) Elisabetsky, E., et al. Fitoterapia 1995, 61(5):407–414.
(2) Faciano, R. M., et al. Planta Medica 1995, 61:510–514.
(3) Witherup, K.M., et al. Journal of Natural Products 1995, 58(8):1285–1290.
(4) Woo, M. H., et al. Journal of Natural Products 1995, 58(10):1533–1542