The spice ajwain (also known as ajowan, Trachyspermum ammi and Carum copticum ) has a long history of use in Indian cooking. In addition, it is said to have medicinal effects. Test tube studies have provided support for some its traditional uses. Based on these findings, a preliminary human trial has been performed, with promising results.

This trial enrolled people with asthma. Researchers compared two different doses of ajwain against the outdated asthma drug theophylline, as well as against placebo. Participants were given initial pulmonary function tests, and then given either theophylline, one of the two doses of ajwain, or placebo. Repeat pulmonary function tests were done at stated intervals for the next three hours. The results from this preliminary trial suggest that ajwain was less effective than theophylline, but more effective than placebo.

Ajwain is thought to act by dilating the bronchial tubes in the lungs. This is no longer the primary approach used for treating any, but the mildest, asthma. Nonetheless, the herb could be a source of a novel way to accomplish this. However, considerably more study is necessary before ajwain could be considered an effective (or safe) treatment for asthma.