Medicinal Herb: Rue (Ruta graveolens)

Introduction:

Rue is an aromatic perennial plant native to southern Europe and northern Africa and commonly cultivated in Europe and the U.S., sometimes escaping to grow wild locally. The branched, pale green, glabrous stem bears alternate, pinnately compound, somewhat fleshy leaves with oblong to spatulate leaflets. Small yellow or yellow-green flowers appear from June to August.

The stem is woody in the lower part, the leaves are alternate, bluish-green, bi- or tripinnate, emit a powerful, disagreeable odour and have an exceedingly bitter, acrid and nauseating taste.

The greenish-yellow flowers are in terminal panicles, blossoming from June to September. In England R. graveolens is one of our oldest garden plants, cultivated for its use medicinally, having, together with other herbs, been introduced by the Romans, but it is not found in a wild state except rarely on the hills of Lancashire and Yorkshire. This wild form is even more vehement in smell than the garden Rue. The whole plant has a disagreeable and powerful odour. The first flower that opens has usually ten stamens, the others eight only.

Active Compounds:

Volatile oil, 2-undecanone (50-90%), 2-haptanol, 2-nonanol, 2-nonanone, limonene, pinene, anisic acid, phenol, guiacol and others.
Flavonoids such as quercitin and rutin
Coumarins: bergapten, daphnoretin, isoimperatorin, naphthoherniarin, psoralen, pangelin, rutamarin, rutarin, scopoletin and umbelliferone
Alkaloids: arborinine, g-fagarine, graveoline, graveolinine, kokusaginine, rutacridine.
Lignans, in the root; savinin and helioxanthin.

Scientific Evidence:

Antibacterial/Antifungal activity

More than 15 compounds in rue have been identified as having in vitro antibacterial and antifungal activity. The acridone alkaloids are the most potent antimicrobial compounds; the coumarins inhibit growth only at high doses. The essential oil and flavonoids tested did not show activity. One report suggests that extracts of R. graveolens demonstrated inhibitory effects against gram positive organisms such as Staphylococcus aureus, Streptococcus pyogenes, Listeria monocytogenes, and Bacillus subtilis.

Other researchers have found that a number of components of rue interfere directly with DNA replication, thereby preventing the propagation of some viruses.

The leaf of R. graveolents is said to alleviate cancer of the mouth, as well as tumors and warts. In Chinese medicine, rue is used as a vermifuge and for insect bites.

Experimentation in H. pylori-infected gastric epithelial cells with 24 medicinal plants indigenous to Pakistan was conducted to evaluate their effect on secretion of interleukin (IL)-8 and generation of reactive oxygen species (ROS) in order to assess anti-inflammatory and cytoprotective effects. Although no significant direct cytotoxic effects on the gastric cells or bactericidal effects on H. pylori were found, leaf extract of rue was observed to have moderate and strong inhibitory activity on IL-8 at 50 and 100 mcg/mL, respectively, in H. pylori-infected gastric cells[1]. 

Traditional Applications in Herbal Medicine:

Abortificient, anthelmintic, antiseptic, antispasmodic, carminative, emmenagogue, irritant, stimulant, stomachic