A local scientist, intent on finding a cure for cancer, believes he’s on the brink of a breakthrough as he and his counterparts in Germany have been able to produce the anti-cancer compound, dibenzyl trisulphide (DTS), from guinea hen weed (petivera alliacea), which grows wild across Jamaica.

According to zoologist Dr Lawrence Williams, a research consultant with the Scientific Research Council, he is now ready to take his research to the next level – the use of the compound on mice induced with cancer and an investigation into the side effects, including DTS’s impact on the kidneys and the liver. The work is to cost an estimated US$150,000.

And while human testing may be between three and five years away, Dr Williams said he was confident that he would have no problems getting volunteers.

In the last few months, he said, he has been receiving inquiries from people who have heard of the healing properties of the guinea hen weed and who have indicated an interest in participating in any clinical trial that may be set up.

At least five of them have been taking the DTS compound, which Williams said was also synthetically produced by the German firm Aldrich Chemical. The reports filtering in from those people, he added, have been positive.

There is one man with skin cancer, he said, who has been using the plant leaves to make tea and the extract as a salve for his lesions with encouraging results.

“The lesions are gone and he is feeling much better,” an enthusiastic and smiling Williams said of the man, who could not be reached for comment on Friday.

The DTS compound, produced through three years of work at the University of Hohenheim in Germany, has, when applied to cancer cells in vitro (outside a living organism), been found effective in the cure of various types of cancer. Among them:

. brain (neuro blastoma),

. bladder (primary bladder carcinoma),

. breast (mammary carcinoma),

. fibrous (sarcoma),

. skin (melanoma), and

. small cell lung cancer.

“Despite the fact that people are using it, we still need to do the toxicological work on the pure compound to validate safety,” said Dr Williams. “Also, in terms of patenting the data, we would need to have that data too.

Dr Williams’s counterparts in Germany are professors Harold Rosner and Wolfgang Kraus. They intend, Williams said, to create DTS tablets for the human testing phase of the research.

“It is a promising project,” said Williams. “I am very positive about the work and I think also that one day it will come off as a curative agent for cancer. It may be that we should look at the effects of DTS in combination with radiation therapy and see if they can enhance each other.”

Williams’s positive outlook is based in large part, he said, on the fact that the compound was drawn from a plant and that there was need for a cancer drug with limited side effects, if any.

“Cancer is one of the most challenging diseases to mankind, and anything that can work against cancer with minimum side effects is worth the while developing,” he said. “Most of the drugs they use to treat cancer now have too many side effects. We are hoping that because the compound is natural, it will have less side effects. That is one of the beliefs.”

Cancer is among the leading causes of death in Jamaica and the Caribbean. According to data received from the Cancer Registry at the University of the West Indies, in 1999 there were 2,697 cancer deaths in Jamaica, representing 17.7 per cent of deaths in that year. Of that number, 1,466 were males and 1,231 were females.

Dr Williams told the Sunday Observer that his preliminary work has shown that the DTS compound does not affect healthy cells, which, he said, is a bonus.

“The anti-cancer action of dibenzyl trisulphide is linked to the molecule ability to disrupt the skeletal framework of cells, of which there are two – actin and microtubules,” he explained. “Microtubles is the one responsible for cell division and that is the one that the dibenzyl trisulphide acts on. So we have found that with a normal cell, the dibenzyl trisulphide has no effect on it.”

This is not the case with chemotherapy, for example, which does affect healthy cells that multiply quickly because the treatment is designed to kill faster growing cancer cells. Among those healthy cells likely to be affected are blood cells forming in the bone marrow and cells in the digestive tract, reproductive system, and hair follicles. Chemotherapy may also damage cells of the heart, kidney and lungs.

Williams’ revelation of his work comes on the heels of an announcement by the pharmaceutical giant, GlaxoSmithKline, of their intention to introduce to the local market next year a vaccine to prevent cervical cancer.

The vaccine, called Cervarix, was developed over the last five to 10 years at a cost of approximately £1.8-billion and has been proven to prevent the strains of the human papilloma virus (HPV), which is known to cause cervical cancer.

The vaccine is to be administered to people before they become sexually active.

The Manchester-based Northern Caribbean University is also enaged in cancer research, focussing on sorrel and garlic and their effects on cancer cells, as well as on over-the-counter substances that contain dismuth and their effects on cancer cells.

Dr Devon Gardener, a professor of physical chemistry at the institution, said last October that should funding become available, the expectation was that the scientists would make significant progress in a few years.

Last week, Dr Williams said he was not worried about the possibility of his research being stolen, as he has published works on his progress to date, even as he moves to secure a patent internationally for the biological activity of the DTS compound. Among the journals in which his works have been published are Phytotherapy Research Journal in England, the Biochemica et Biophysica Acta (BBA) Journal and the Jamaica Journal of Science and Technology.

“The Germans and myself are trying to get a patent for the biological activity,” Williams said. “The papers that have been published are copyright to the journals and as leading researcher I can write to the journal to get the patent for the biological activity.”

williamsp@jamaicacobserver.com