A psoriasis treatment composition derived from the plant Asphodelus Microcarpus includes 3-methylanthralin, chrysophanol, aloe-emodin, aloe-emodin monoacetate, and/or derivatives thereof. The composition is prepared by extracting a liquid from the Asphodelus Microcarpus root and mixing the liquid with acetic acid. A method of treatment includes applying the composition to an affected area of skin at a frequency sufficient to effect an alleviation of symptoms, typically once per day for 14-56 days.