By Sean Henahan, Access Excellence

SAN DIEGO, CA (10/19/96) The poisonous Jack-O'Lantern mushroom, also known as Omphalotus illudens, is not one you want to put in your Halloween soup. However, a new compound derived from the mushroom's toxin appears to have very potent and specific anticancer activity.

A substance derived from the Jack-O'Lantern mushroom, called illudin S, was shown to have potential anticancer activity 30 years ago. But the toxin was not selective in its toxicity against cancer cells as compared to normal cells and so was not developed as a cancer therapy.

Now Dr. Trevor C. McMorris and his colleagues at the University of California at San Diego (UCSD) have converted illudin S to a new compound, hydroxymethyl acylfulvene (HMAF). "It possesses remarkable anticancer activity," McMorris says, "because it has much greater selectivity and is quite effective when tested on mice implanted with human tumors."

In experiments at UCSD the McMorris group observed that "in mice bearing human metastatic lung adenocarcinoma, HMAF caused complete shrinkage of the tumors and greatly increased the life span of the animal." He also notes that "HMAF was more efficacious than many standard chemotherapeutic agents including doxorubicin, cis-platin and paclitaxel."

The UCSD results have been corroborated in other laboratories with mice bearing different solid tumors, including breast, melanoma and colon cancers. Clinical trials with the new toxin are now underway and "are progressing favorably," according to McMorris.

The research appeared in the October issue of Journal of Natural Products, a monthly journal of the American Chemical Society.