n, sohr-]
| a toxic substance, C1 1H6O3, found in certain plants, including parsnips, used to increase the response to ultraviolet light in the treatment of severe cases of acne and psoriasis. |
psoralen pso·ra·len (sôr'ə-lən)
n.
Any of a group of chemical compounds found naturally in certain plants that are used in the treatment of psoriasis and vitiligo.