Bishop's Weed

Scientific Name(s): Trachyspermum ammi L. Sprague.
Common Name(s): Ajava seeds, Ajowan caraway, Ajowan seed, Ajowanj, Ajwain, Bishop's weed, Carum, Omum., Yavani

Medically reviewed by Drugs.com. Last updated on Dec 30, 2021.

Clinical Overview

Use

High quality clinical trials are very limited. The medical literature documents numerous pharmacological activities including analgesia (neuropathic), antifungal, antimicrobial, hypolipidemic, antihypertensive, antilithiasis, abortifacient, antitussive, nematicidal, anthelmintic, and antifilarial.

Dosing

Bishop's weed is commercially available as a single entity or herbal blend in numerous dosage forms including capsules, liquids, powders, and cream. Internet sources list the product as being primarily marketed as "ajwain" and as an overall panacea. One herbal blend prescribes 1 or 2 capsules (200 mg/capsule) with a full glass of water for GI discomfort. The prescription drug methoxsalen, as documented by various Internet resources, was developed from bishop's weed (Ammi majus Linn) and is used to treat several skin conditions. Use of a 10% topical cream twice daily has been supported by a clinical trial in adults with neuropathic pain.

Contraindications

Hypersensitivity to any of the components of bishop's weed. Avoid use during pregnancy and lactation due to documented adverse effects.

Pregnancy/Lactation

Avoid use. Documented adverse effects. Bishop's weed was listed as 1 of 14 indigenous medicinal plants used for abortion in some districts of India in 1987, and it may also cause congenital defects. The same review article also documents a risk of human fetotoxicity as observed in rat teratogenicity studies.

Interactions

Data are lacking concerning specific drug interactions. Potentiation of the effects of antibiotics and antiplatelet medications could be theorized.

Adverse Reactions

Caution may be warranted in patients taking nonsteroidal anti-inflammatory drugs (NSAIDs) or antiplatelet medications due to platelet aggregation inhibition by bishop's weed.

Toxicology

Bishop's weed is toxic in high doses and can result in fatal poisoning. Avoid use during pregnancy due to documented adverse effects.

Scientific Family

• Apiaceae (carrot)

Botany

Bishop's weed is a smooth, or slightly hairy, branched annual growing 60 to 90 cm tall. The stem is striated, containing up to 16 small, white flowers, and the leaves are pinnately divided with a terminal and 7 pairs of adjacent leaflets. The grayish-brown, ovoid, aromatic fruit is 2 mm long and 1.7 mm wide. The fruit is harvested from February to March and is separated when dried. The plant is indigenous to India, Iran, Egypt, Afghanistan, and Ethiopia. It is widely grown in arid and semiarid areas, particularly where the soil contains high levels of salt.1, 2, 3 The scientific name is synonymous with Carum copticum (L.) Benth., Ammi copticum L. and Hook. f. and Trachyspermum copticum (L.) Link.1

History

Bishop's weed has been used for curing numerous diseases in humans and animals,2 and it is used in Ayurvedic and Unani medical systems.4, 5, 6, 7 Ayurvedic use of bishop's weed includes treatment of atrophy, cachexia, spasms, and rheumatism. Patients diagnosed with fever and lung ailments, including bronchitis, the common cold, cough, consumption, and emphysema have also benefited from treatment with bishop's weed. To treat a...