Garlic to kill cancer cells

Chennai, Nov 17: Researchers at the Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, and IIT, Madras have developed a compound from garlic that acts in synergy with known anti-cancer agents to kill cancer cells.

The compound, diallyl trisulfide (DATS) kills cancer cells when used in combination with agents like taxol and tumour necrosis factor. DATS acts with lower than usual doses of taxol, providing a double benefit as taxol is toxic, Prof D Karunagaran of the Departmentof Biotechnology, IIT, said.

He told UNI that though the idea was not new, its application to this set of compounds was new. They had also shown the mechanism, whereby DATS inhibited NF kappa B, which was a transcription factor known to promote survival of cancer cells.

The work began in 1998 and culminated in the application for a patent in India. The grant of patent is being awaited.

He said Garlic (Allium sativum), a member of the Allium family, is one of the earliest documented plants for its manifold uses.

Authoritative texts of ancient times endorsed its use not only in the medicine chest but also for religious purposes.

The knowledge of its beneficial effects spanned all major ancient civilizations. Egyptians, Greeks, Chinese and Indians used garlic for centuries for treating various ailments like heart disease, arthritis, pulmonary complaints, abdominal growths (particularly uterine), diarrhoea and worm infestation.

In 1958, its anti-tumor properties were clearly documented.

Prof Karunagaran said extensive research on garlic had shown its major biological effects could be attributed to the numerous chemical compounds present in it. It is rich in organosulphur compounds, having over 33 of them. Many of them inhibited proliferation of cancer cells and some induced apoptosis (cell death) in tumor cells of different tissue origin.

Allicin was one such organosulphur compound produced in freshly crushed garlic and was responsible for its characteristic odour. It was biologically very active but highly unstable. Allicin decomposed into diallyl disulfide (DADS), diallyl trisulfide (DATS), ajoene, S-allyl mercapto cysteine, S-allyl cysteine and vinyl dithiines.

Compared to DADS, DATS exhibited a potent anti-proliferative activity in colon cancer and lung cancer cells. So they focussed research on developing a composition, which comprised a garlic organosulphur compound together with an anti-neoplastic agent for treatment of tumors. This was the composition for which a patent had been applied for.

Taxol was a chemotherapeutic agent effective in many types of cancer, particularly abdominal cancers.

The proportion of the garlic organosulphur compound and the anti-neoplastic agent could vary. They could either be combined in a single composition or co-administered to the patient.

Prof Karunagaran, a winner of the C R Krishnamurthi lecture Award for 2003 by the Society for Biological Scientists, India, was a post-doctoral fellow at the Weizmann Institute of Science, Israel and a Project Investigator at the M D Anderson Cancer Centre, Houston, US. He had shifted to Chennai recently.

UNI