khellin

Khellin is a **naturally occurring furanochromone** compound primarily isolated from the seeds of *Ammi visnaga* (Khella). It has a long history of use in herbal and folk medicine across the Mediterranean and Middle East, most notably as a smooth muscle relaxant and vasodilator. Pharmacologically, khellin acts as a **vasodilator** and **bronchodilator**: it relaxes coronary vessels, dilates peripheral vasculature, and opens airways by relaxing bronchial smooth muscle. It also shows antispasmodic effects, facilitating passage of kidney stones and relieving renal colic. Khellin’s **antispasmodic and vasodilatory** actions are primarily attributed to inhibition of calcium influx in vascular smooth muscle. Topically and orally, khellin is used as an **adjunct to phototherapy** in vitiligo and psoriasis, due to its ability to sensitize the skin to ultraviolet light exposure. Some of its derivatives have served as templates for modern drugs such as cromolyn (asthma therapy) and amiodarone (antiarrhythmic). Additional effects include mild antimicrobial action and possible modest effects on lipid metabolism. However, oral use is limited by possible hepatotoxicity and phototoxic reactions.

Other names

Ammi visnaga constituentfuranochromonetoothpickweed constituent