Rue(Tena Adam),a pale green plant with strong aroma has historically been associated with magic, mysticism, and witchcraft. Since ancient times, tena Adam has had many uses, both in food preparation and medicine, as well as in witchcraft.
During the European Middle Ages, people hung rue on their doors and windows as a protection against evil spirits. They rubbed their floors with it to kill fleas and to protect against plagues and pestilence. Christians sprinkled church entrances with the herb before performing mass and during exorcisms. Rue was considered sacred and the precious herb was planted around temples and churchyards. People carried bundles of rue twigs with them as they went about to ward off spells by witches. In courts and law offices, rue was strewn as a protection against diseases that might be carried by criminals. Even today there are people who believe that a rue plant in their garden can be protective of their home and bring harmony, prosperity and happiness. Although rue is still used in many cultures as a flavoring agent, most people in the West are afraid to consume it. While the volatile oils extracted from rue are concentrated and can be poisonous if taken in large doses, some people believe that the rue leaves and berries are also poisonous. Ethiopians have used rue berries in powdered berbere blend, in mitten shiro, and the leaves or berries in clarified butter for centuries. Rue berries are also often added to coffee and tea drinks. In all these situations, the dried and ground rue berries or leaves impart pungency and a pleasant aroma and flavor. The fresh leaves are sometimes added to boiling water or milk and given to children who have pain in their stomach and poor bowel movements.
Medicinally, tena Adam is used as an antidote (corrective measure) against poisons, pestilences, and afflictions. The oil extract of tena Adam is used to counter the deadly effect of poisonous snakebites (like that of cobra and king cobra). The venom produced by these snakes’ attacks is called neurotoxin because it affects the nervous system of the victim, causing them to suffocate and die. The venom released by vipers—such as copperheads, cottonmouths and most rattlesnakes— on the other hand, damages the blood vessels, causing the blood to become very thin and the victim eventually bleeds to death. This venom is called hemotoxic. Rue has no effect on hemotoxic venom. To continue with rue’s “anti-” effects, the herb is also known to be anti-arthritic,anti-rheumatic, anti-epileptic and anti-hysteric, to name but just a few. Rue’s essential oils function as an anesthetic to all the affected bodily parts. These oils are also effective anti-bacterial and anti-fungal agents. Therefore these substances can help prevent infections both internally—like the colon, intestines and urinary tract, and externally—those that appear on the skin, such as ringworm, athlete’s foot, and dermatitis. Furthermore, these oils have antiviral, anti-inflammatory, and antioxidant properties. In small amounts, these compounds can alleviate headaches. The main active ingredient responsible for all these activities is called rutin, found as 7% to 8% in dried leaves. It’s this compound that is the cause of the strong aroma and bitter taste when eaten in larger quantities. In small amounts, both the smell and taste are rather pleasant. Tena Adam is also an excellent insect repellant; it discourages the presence of beetles and slugs and other vermin. Other uses include treatment in intestinal worms, mouth cancer, hepatitis, hemorrhage and fever. It’s similarly used to treat arthritis, dislocations, swellings, sprains, tumors, warts, and aches associated with the ears, teeth and head. In foods and beverages, rue and its oil are used as flavoring agents. In manufacturing, rue oil is used as fragrance in soaps and cosmetics. The literature also warns that tena Adam (or rue), particularly the oil, can be poisonous when taken in excess and pregnant women should never take tena Adam because it might cause uterine contractions, leading to abortion.
Reference: Ethiopian Foods and Drinks by Getty Ambau