Description
Medicinal Parts
The medicinal part is the root of the plant (the dried roots and rhizomes).
Flower and Fruit
The calyx is 4 to 5 mm in the flower, 5 to 6 mm in the fruit and eglandular. The corolla is blue and glabrous outside. The funnel is as long as or slightly longer than the calyx. The limb is 6 to 7 mm in diameter. There are 5 stamens, and the anthers are fused with the corolla tube. The nutlets are 2 mm in diameter, irregularly reticulate and tuberculate.
Leaves, Stem, and Root
Alkanet is a short-bristled, perennial half-rosette shrub. The stems are 10 to 20 cm, procumbent or ascending and glandular. The basal leaves are 6 to 15 cm by 0.7 to 1.5 cm, linear-lanceolate; the lower ones are cauline, oblong-linear and cordate at base. The bracts are slightly longer than calyx and oblong-lanceolate. The neck of the root is covered with the remains of leaves and the stems. The root is spindle-shaped, curved, up to 25 cm long and 1.5 cm thick, with purplish root bark.
Habitat
The plant is indigenous to southeastern Europe and some parts of Turkey and Hungary. It is cultivated in other parts of Europe, Britain, and northern Africa.
Production
Alkanna rhizomes are the dried roots and rhizomes of Alkanna tinctoria Tausch.
Other Names
Anchusa, Dyer's Bugloss, Spanish Bugloss, Alkanet Root, Alkanna
Actions & Pharmacology
Compounds
Naphthazarine derivatives: including the ester of the (-)-alkannin (stained red)
Pyrrolizidine alkaloids
Tannins
Effects
Antimicrobial action: In the agar diffusion test, Alkanet root extracts and Alkannin esters impaired the growth of Staphylococcus aureus and Staphylococcus epidermidis, however Alkannin worked only against Candida albicans.
Healing action for wounds: In a double-blind study, 72 patients suffering from ulcers of the leg (Ulcus cruris) caused by varicose veins, were treated with Histoplastin Red® over a period of 3 years. After 5 to 6 weeks of daily administration, 80% of the patients' ulcers had healed or were considerably reduced in size.
The results are difficult to assess, as details concerning the patients, the treatment pattern, and control groups are unavailable.
Indications & Usage
Unproven Uses
Used by the ancient Greeks to heal wounds; also for skin diseases and diarrhea.
Precautions & Adverse Reactions
Hepatotoxicity and carcinogenicity are expected due to the pyrrolizidine alkaloids with 1,2-unsaturated necic parent substances in its makeup. Alkanna should not be taken internally for this reason and is recommended for external use only. Not to be used during pregnancy or nursing.
Dosage
Mode of Administration
Seldom used as a drug. Internal administration is not recommended, due to the drugs toxic characteristics and its uncertain efficacy. Alkannin and extracts of the root are used externally in pharmacy.
Preparations
Extractum alcannae: almost black, green glistening mass (no extraction information).
Histoplastin Red® Ointment: The ointment, approved in Greece, contains 76.5 gm loosely defined ethereal oily Alkanet root extract with lipophil ointment base (beeswax, mastic rubber and olive oil q.s. ad 100 gm).
Daily Dosage
Maximum 0.1 mcg pyrrolizidine alkaloids with 1.2 unsaturated necin framework and their N-oxides.
