Khellin (Khe)

Khellin has been used as an herbal folk medicine, with use in the Mediterranean dating back to Ancient Egypt, to treat a variety of maladies including: renal colic, kidney stones, coronary disease, bronchial asthma, vitiligo, and psoriasis. It is a major constituent of the plant Ammi visnaga, also known as Bishop's Weed. Once purified, khellin exists as colorless, odorless, bitter-tasting needle-shaped crystals and is classified as a gamma-pyrone, a furanochromone derivative. In the early 20th century, researchers searched for khellin analogs with lower toxicity and better efficacy. A number of drugs were discovered through this research, such as amiodarone and cromolyn sodium, which are used in current medical practice. Khellin has been used to relieve the pain associated with angina pectoris by acting as a selective coronary vasodilator.