- Ammi, Ammi daucoides, Ammi visnaga, Bischofskrautfruchte, bishop’s weed, bishop’s weed fruit, daucus visagna, false Queen Anne’s lace, fruits de khella, germakellin, honeyplant, khellin, picktooth, Spanish toothpick, toothpick plant, visnaga, visnagae, Visnagafruchte, visnagin.
- Khella (Ammi visnaga) was originally cultivated by the ancient Egyptians who used it to treat many ailments, including urinary tract diseases. It was also used in the Middle Ages as a diuretic.
- The whole fruit has traditionally been used to treat respiratory system diseases such as asthma, bronchitis, emphysema and whooping cough, as well as cardiovascular disorders, premenstrual syndrome (PMS), liver and gall bladder disorders and to stimulate diuresis (increase in urine production). Its purported effect is related to its antispasmodic action on smaller bronchial muscles, coronary arteries and urinary tract tubules. Ammi visnaga may vasodilate the coronary arteries, which increases the blood supply to the myocaridium, and as a result, can be used to treat mild forms of angina (chest pain). It is also used to treat problems associated with spasms and constriction of the gallbladder and bile duct and facilitates the discharge of kidney stones and gallstones.
- The clinical and therapeutic effectiveness of khellin, a constituent of khella, with respect to coronary, respiratory and urologic indications, has been demonstrated in experiments. Current khella indications include mild angina (chest pain) complaints, postoperative treatment of urinary calculus (kidney stones) and supportive treatment of mild forms of obstructive pulmonary diseases.
- Few clinical trials have investigated khella (the whole herb vs. its constituent khellin). However, based on traditional use, more studies of khella for the treatment of psoriasis (chronic skin disease) or lipid panel may be warranted.
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Preliminary evidence suggests that khellin, taken by mouth, may be an effective therapy for psoriasis. However, additional study is needed to confirm these results.
Several studies have investigated the use of khellin for the treatment of vitiligo. However, the evidence of the efficacy of khellin is conflicting. Further research is warranted in order to draw a firm conclusion.
*Key to grades:
The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.
Adults (over 18 years old)
- There is no proven safe or effective dose for khella. For vitiligo (loss of skin pigment), weekly applications of a 2% solution of khellin in acetone and propylene glycol (90 and 10%, respectively) with exposure to 90 minutes of sunlight for a period of four months has been studied. Traditionally, 30-60 drops of khella have been taken three to five times daily. An infusion of 1 teaspoon of crushed seeds per cup of water, infused for 25 minutes; or 1:3 dry liquid extract: 20-60 drops 1-4 times daily in a little water has also been used.
Children (under 18 years old)
- There is no proven safe or effective dose for khella in children.
The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
- Avoid in individuals with a known allergy or hypersensitivity to khella (Ammi visnaga). Long-term use of the monosubstance khellin in large dosages may occasionally result in allergic manifestations.
Side Effects and Warnings
- It has been proposed that the observed side effects are of no practical relevance in the therapeutic use of Ammi visnaga extracts, as khella is thought to be clinically effective at moderate doses. However, there is a lack of clinical trials to support this claim. Use khella cautiously in asthmatics or after myocardial infarction (heart attack) because khella may act unreliably.
- Reported adverse effects include chest pain, skin rashes, hives, itchy or swollen skin, breathing problems, and tightness of the throat. Elevated liver enzymes or permanent jaundice (yellow skin color) may occur with the use of khella. When taken in high doses, khella may cause liver damage. Khella may also increase photosensitivity or increase the risk of skin cancer; avoid prolonged exposure to sunlight.
- Long-term use of the monosubstance khellin in high doses may occasionally result in nausea, constipation, loss of appetite, dizziness, headaches or sleep disturbances.
Pregnancy and Breastfeeding
- Avoid if pregnant or breastfeeding as the active constituent in khella has uterine stimulant activity.
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
Interactions with Drugs
- Khella may decrease the toxicity of the cardiac glycoside digoxin due to the coronary vasodilator and antiarrhythmic effects of khella.
Interactions with Herbs and Dietary Supplements
- Khella may have beneficial effects when combined with other respiratory antispasmodics, such as skunk cabbage, lobelia, thyme.
- Khella may decrease the toxicity of the cardiac glycoside digoxin in some herbs, due to the coronary vasodilator and antiarrhythmic effects of khella.
Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.
- This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration ().
- Abdel-Fattah A, Aboul-Enein MN, Wassel G, et al. Preliminary report on the therapeutic effect of khellin in psoriasis. Dermatologica 1983;167(2):109-110.
- Abdel-Fattah A, Aboul-Enein MN, Wassel GM, et al. An approach to the treatment of vitiligo by khellin. Dermatologica 1982;165(2):136-140.
- Blumenthal M, Goldberg A, Brinckmann J, et al. Herbal Medicine, Expanded Commission E Monographs. Boston, MA: Integrative Medicine Communications, 1998.
- Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. ed. Eclectic Medical Publications: Sandy, OR, 1998.
- Chrysanthis K. [Infusion of khella seeds in the treatment of bronchial asthma.]. Cyprus Med J 1950;3(4):333-335.
- de Leeuw J, van der BN, Maierhofer G, et al. A case study to evaluate the treatment of vitiligo with khellin encapsulated in L-phenylalanin stabilized phosphatidylcholine liposomes in combination with ultraviolet light therapy. Eur J Dermatol 2003;13(5):474-477.
- Franchi GG, Bovalini L, Martelli P, et al. High performance liquid chromatography analysis of the furanochromones khellin and visnagin in various organs of Ammi visnaga (L.) Lam. at different developmental stages. J Ethnopharmacol 1985;14(2-3):203-212.
- Hudson J, Towers GHN. Phytomedicines as antivirals. Drugs Fut 1999;24(3):295-320.
- Martelli P, Bovalini L, Ferri S, et al. Rapid separation and quantitative determination of khellin and visnagin in Ammi visnaga (L.) Lam. fruits by high-performance liquid chromatography. J Chromatogr 1984;301(1):297-302.
- Morliere P, Honigsmann H, Averbeck D, et al. Phototherapeutic, photobiologic, and photosensitizing properties of khellin. J Invest Dermatol 1988;90(5):720-724.
- Orecchia G, Perfetti L. Photochemotherapy with topical khellin and sunlight in vitiligo. Dermatology 1992;184(2):120-123.
- Stevens TJ, Jones BW, Vidmar TJ, et al. Hypocholesterolemic effect of khellin and khelloside in female cynomolgus monkeys. Arzneimittelforschung 1985;35(8):1257-1260.
- Stevens TJ, Phillips WA, Day CE. Comparative effects of khellin and timefurone on serum parameters in normal male cynomolgus monkeys. J Med Primatol 1985;14(5):255-262.
- Uhlenbroock K, Mulli K. [Khellin, a contribution to pharmacology of the constituents of Ammi visnaga. 3.]. Arzneimittelforschung 1953;3(5):219-223.
- Valkova S, Trashlieva M, Christova P. Treatment of vitiligo with local khellin and UVA: comparison with systemic PUVA. Clin Exp Dermatol 2004;29(2):180-184.
Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to . Selected references are listed below.