Canterbury sponge extract may be anticarcinogen

Press, 15 July 1987, Page 3

Canterbury sponge extract may be anticarcinogen

A 12-year search by a University of Canterbury team has uncovered two substances with strong potential as antiviral or anticancer agents. The team, headed by Dr Murray Munro and Dr John Blunt, has taken out patents on the compounds, and an associated company in the United States hopes to start clinical trials on one of them within a year. The two compounds have been extracted from a species of sea-squirt found off Kaikoura, and a species of sponge found off Otago.

The discoveries were "the first tangible reward” of their investigations, said Dr Munro, although usable drugs were still several years away, and the programme could yet fail. For more than a decade, the Canterbury team has been painstakingly collecting samples of marine invertebrates — simple life forms without spinal cords — from New Zealand waters. Chemicals are extracted from them and tested for antiviral and antitumour properties. About 3000 species have

now been tested, and the search is being extended to cover southern hemisphere oceans from the Antarctic to the equator. A team recently returned from Western Samoa with another 250 species. Dr Munro said that the project gained momentum about four years ago with the participation of the American firm, SeaPharm, and funding from the American National Cancer Institute. Previously, the Canterbury team had to send samples to the United States for antiviral trials, but now does its own.

Dr Blunt said that they decided to look for such chemicals in marine invertebrates, partly because they had become accessible through new diving techniques and partly because there were indications that they would be a relatively rich source. Development of the two compounds is continuing, with work both in New Zealand and in the United States on “analogues” —• subtely changed versions which could prove even more effective — and on totally synthetic versions which could prove more

commercially viable. At present, only about 50 milligrams of the chemical extracted from the Otago sponge exists, equivalent to only a few grains of sugar, said Dr Munro. The sponge was abundant, however, and enough had now been harvested to increase the world supply a thousandfold to 50 grammes. Dr Munro said that they were cautious not to make unjustified claims for the compound, but it warranted the term “a potential anticancer agent.”