Horseradish Wins Herb of the Year Despite Volatile Chemistry

What do historians, horticulturalists, foodies, and chemists have in common? Horseradish, Herb of the Year 2011!1  Horseradish, or Armoracia rusticana, is best known as a spicy condiment for meat and seafood dishes, but its chemical properties extend beyond the kitchen to the laboratory and doctor's office. Egyptians and Greeks used horseradish over 3,000 years ago as a cure-all. Today, this bitter herb continues to have significant historical and cultural importance in the Jewish Passover Seders.

The pungency and heat of horseradish is caused by the presence of allyl isothiocyanate2 (CAS Registry Number (RN): 57-06-7). Allyl isothiocyanate (AITC) provides a defense mechanism for plants to ward off fungi and animals. When horseradish is bitten, ground, or grated, released myrosinase enzyme cleaves glucose (CAS RN: 50-99-7) from the glucosinolate synigrin (CAS RN: 534-69-0) in a hydrolysis reaction to produce AITC. It is the AITC which repels animals, irritates the eyes, and burns the skin.

When ingested or inhaled, AITC creates a burning sensation distinct from taste (gustation) and smell (olfaction). Instead, this burning sensation is somatosensory and results from free nerve endings (nociceptors) in the nasal mucosa and olfactory epithelium.3

The nociceptor sensory neurons detect stimuli such as AITC, capsaicin (CAS RN: 404-86-4) from chili peppers, and delta-9-tetrahydrocannabinol (CAS RN: 1972-08-3) or THC.4 Neuron activation by AITC transmits 'pain' signals to the spinal cord and releases peptides that cause inflammation and tenderness on contact.

Medicinal benefits attributed to horseradish include aphrodisiac, anti-rheumatic, anti-asthmatic, antioxidant, and anti-cancer agent. AITC protects against cancer by regulating inflammation and improving the detoxification of carcinogens.5 Industry relies on the antibacterial and antifungal properties of AITC in food packaging and feeds, cosmetics, and industrial materials.

Other inventive uses for AITC include:

Enjoy the many uses of horseradish for National Herb Week, May 1-7, 2011, or throughout the year!

Use SciFinder® and STN® to explore the many uses of horsereadish to be found in the CAS databases.

Contributed by
Kathryn J. Meloche, Ph.D.
CAS Product Marketing Communications



  1. The International Herb Association Herb of the Year. (accessed April 13, 2011).
  2. Depree, J. A.; Howard, T. M.; Savage, G. P. Flavor and Pharmaceutical Properties of the Volatile Sulfur Compounds of Wasabi. Food Res. Int. 1998, 31, 329-337. SciFinder users link here.
  3. Lang, J. Clinical Anatomy of the Nose, Nasal Cavity and Paranasal Sinuses. Thieme: Stuttgart, Germany, 1989; translated by P. M. Stell.
  4. Jordt, S.; Bautista, D. M.; Chuang, H.; McKemy, D. D.; Zygmunt, P. M.; Hoegestaett, E. D.; Meng, I. D.; Julius. D. Mustard Oils and Cannabinoids Excite Sensory Nerve Fibers Through the TRP Channel ANKTM1. Nature 2004, 427, 260-265. DOI: 10.1038/nature02282. SciFinder users link here.
  5. Conaway, C. C.; Yang, Y.; Chung, F. Isothiocyanates as Cancer Chemopreventive Agents: Their Biological Activities and Metabolism in Rodents and Humans. Curr. Drug Metab. 2002, 3, 233-255. DOI: 10.2174/1389200023337496. SciFinder users link here.
                              Back to Science Connections Home                  Next >> 

    For More Chemical and Trend Insights:

     Media Contact

     Name: Rhonda Ross
     Phone: 614-447-3624