Linden trees, commonly planted along city sidewalks for ornamental effect, feature heart-shaped leaves and fragrant white flowers. Extracts from the flowers -- and occasionally the bark -- are used in herbal medicines. Linden is a trusted remedy in Europe, where German Commission E, a government herbal regulatory agency, approves its use in cold remedies, cough syrups and sedative drugs. Although clinical studies are lacking, animal research supports therapeutic effects from linden extracts, including anxiety-reducing, antibacterial and anti-inflammatory properties. Consult your doctor before using linden extracts.
The linden -- botanically known as Tilia cordata and Tilia platyphyllos and commonly called the basswood tree and the lime tree -- is a deciduous tree native to Europe, but presently found in Northern temperate regions, including the United States. Although lindens are called lime trees, they bear no relation to the lime-producing tropical tree Citrus aurantifolia. Extracts from linden flowers have been used in European folk medicine to induce sweating with colds and influenza, as well as to treat nervous tension, anxiety, insomnia, high blood pressure, arteriosclerosis, migraines and digestive upsets. The bark has been used to treat liver and gallbladder disorders. Present-day herbalists might advise linden for the relief of fever, to treat colds and influenza, relieve headaches and enhance the immune system.
Constituents and Effects
Linden flowers contain tannins, volatile oil and mucilage, a gummy substance with documented soothing and protective effects. Also present are the flavonoids quercetin, rutin and kaempferol, as well as caffeic acid, eugenol -- also found in clove oil -- limonene, and the amino acids alanine, cysteine and phenylalanine.
Drugs.com -- which provides peer-reviewed medical information to consumers -- credits linden with the ability to relieve nasal congestion, soothe sore throats and inhibit coughs. The website adds that linden has sedative properties and anxiety-reducing effects in animal studies, which might account for its ability to relieve sinus and migraine headaches. Linden's quercetin and kaempferol content give it its ability to promote sweating, as well as antispasmodic properties. Linden also has anti-inflammatory qualities, along with antibacterial activity against H. pylori, a gastrointestinal pathogen. UMMC attributes antioxidant properties to linden's flavonoids.
In a study published in 2001 in "Pharmacopsychiatry'," researchers tested the anxiety-reducing effects of linden extracts on mice, and found that the extracts significantly lowered anxiety, as demonstrated by the rodents' performance and behavior on an elevated plus maze and horizontal-wire tests. Mice given linden extracts showed fewer signs of anxiety, manifested by increased immobility time and diminution of rearing and other parameters. Researchers concluded that linden extracts had a clear sedative effect.
Usage and Considerations
To make a soothing, pleasantly-flavored linden tea, pour 8 oz. of boiling water over 1 to 2 tsp. of dried linden flowers, then steep, covered, for 20 minutes. Strain and cool. UMMC advises a dosage of three cups a day, adding that linden might also be taken in a liquid flower extract in dosages of 2 to 4 ml a day. Linden has few side effects, but contact dermatitis and allergic reactions have been reported. Drugs.com reports that rare episodes of cardiac damage have been associated with linden tea, and advises that patients with a history of heart disease avoid linden. To avoid possible contamination with pesticides, buy linden extracts only from reputable health food stores. Consult your doctor before using linden extracts. Don't use linden if you are pregnant or breast feeding.