Khella

Khella, also known as Ammi visnaga, toothpick plant, or bishop's weed, is a herbaceous plant from the umbellifer family (Apiaceae). Originally native to the Mediterranean region and North Africa, it now also grows in other parts of Europe, Asia, and North America. The plant is particularly striking for its delicate white umbel flowers and fine, feathery leaves. As early as antiquity, Ammi visnaga was used medicinally – both in the time of the pharaohs and in traditional Arabic medicine.

In naturopathy, it is said to act primarily on the respiratory tract, the cardiovascular system, and smooth muscle. In addition, khella is credited with antispasmodic, vasodilating, and antioxidant properties. This could make it an interesting candidate for a variety of functional complaints in the future.

What are the benefits of khella?

In addition to its many areas of use in traditional medicine, Ammi Visnaga is also repeatedly examined more closely by science. Studies suggest various benefits associated with khella and the various active compounds it contains. As is so often the case, however, the results of these studies should be viewed critically, as the findings are not readily transferable. Here are some of the scientific findings:

  • Relaxation of smooth muscle: The active compounds it contains can relieve muscle spasms – for example in the digestive tract, the gallbladder, or in bronchial asthma (1,2,3).
  • Vasodilation: Khellin, a main constituent, has a vasodilating effect – meaning it can contribute to widening the coronary vessels, and it is traditionally used for angina pectoris (1,2,4).
  • Kidney health: In some cultures, the herb is used as a remedy for kidney stones, as it relaxes the urinary tract and relieves cramps (1,5).
  • Anti-inflammatory effect: Investigations link the plant to anti-inflammatory effects, which are presumably related to the visnagin it contains (1,6).
  • Use against vitiligo: Active compounds of the plant have proven effective in both oral and topical photochemotherapy for the treatment of vitiligo (1,7).
  • Antibacterial effect: Several studies have reported on the antimicrobial effects of the various extracts of Ammi visnaga (1,8,9)

How does khella work?

The plant's effects can be attributed primarily to the furanochromones and flavonoids it contains, first and foremost khellin and visnagin. These furanochromones have a relaxing effect on smooth muscle and act as vasodilators and bronchodilators (1). In addition, flavonoids also contribute to the overall effect (1).

Side Effects and Risks

Despite the potential benefits demonstrated in studies, khella should be used with care:

  • Photosensitivity: The furocoumarins it contains can make the skin sensitive to light – especially with external use or at high doses.
  • Interactions: Khellin can influence the effects of certain medications (e.g., calcium channel blockers or blood thinners).
  • Do not use during pregnancy or breastfeeding, as sufficient safety data are not available
  • Allergic reactions: As with many umbellifers, intolerances can occur.

Conclusion

Khella is an ancient medicinal plant that has been used in many ways in traditional medicine, particularly for functional complaints affecting the heart, breathing, and urinary tract. Its relaxing effect on smooth muscle, documented in studies, could make it a versatile remedy in phytotherapy. Due to potential side effects, however, it should be used under expert supervision. Moreover, more research is needed before definitive statements about its effects can be made.

Sources:

  1. Khalil, N., Bishr, M., Desouky, S., & Salama, O. (2020). Ammi Visnaga L., a Potential Medicinal Plant: A Review. Molecules, 25(2), 301. https://doi.org/10.3390/molecules25020301
  2. Rauwald, H.W.; Brehm, O.; Odenthal, K.P. The involvement of a Ca2+ channel blocking mode of action in the pharmacology of Ammi visnaga fruits. Planta Med. 1994, 60, 101–105.
  3. Al-Snafi, A.E. A Review of Medicinal Plants with Broncho-Dilatory Effect-Part 1. Sch. Acad. J. Pharm. 2016, 5, 297–304.
  4. Campos-Toimil, M.; Orallo, F.; Santana, L.; Uriarte, E. Synthesis and Vasorelaxant Activity of New Coumarin and Furocoumarin Derivatives. Bioorg. Med. Chem. Lett. 2002, 12, 783–786.
  5. Abdel–Aal, E.A.; Yassin, A.M.K.; El-Shahat, M.F. Inhibition of nucleation and crystallisation of kidney stone (calcium oxalate monohydrate) using Ammi visnaga (Khella) plant extract. Int. J. Nano Biomaterial. 2016, 6, 110–126.
  6. Lee, J.; Jung, J.; Park, S.; Sim, Y.; Kim, S.; Ha, T.; Suh, H. Anti-inflammatory effect of visnagin in lipopolysaccharide-stimulated BV-2 microglial cells. Arch. Pharma. Res. 2010, 33, 1843–1850.
  7. De Leeuw, J.; Assen, Y.J.; van der Beek, N.; Bjerring, P.; Martino Neumann, H.A. Treatment of vitiligo with khellin liposomes, ultraviolet light and blister roof transplantation. J. Eur. Acad. Dermatol. Venereol. 2011, 25, 74–81.
  8. Ghareeb, A.M.; Zedan, T.H.; Gharb, L.A. Antibacterial and antifungal activities of Ammi visnaga extracts against pathogenic microorganisms. Iraqi J. Sci. 2011, 52, 30–36.