India has forced the US Patent and Trademark Office (PTO) to revoke a contentious patent it granted two years ago to researchers in the United States on the use of powdered turmeric (Curcuma longa) for wound healing.

The PTO withdrew the patent on 13 August after a year-long legal battle with India's Council of Scientific and Industrial Research (CSIR), which argued that turmeric, a native Indian plant, had been used for centuries by its people for wound healing, and so lacked the “novelty” criterion required for patenting.

The Indian agency hired a US patent lawyer and spent $15,000 to fight the case, which it supported with documents ranging from scientific publications to books on home remedies and ancient Ayurvedic texts on Indian systems of medicine.

Indian scientists claim this is the first time that a move in the United States to patent a traditional remedy from the developing world has been successfully overturned. Earlier efforts by an international coalition of environmentalists to get the US patents on products of the neem tree cancelled ended in failure (Nature 377, 95; 95; 1995).

The CSIR's director, Ragunath Mashelkar, said the success of the case had far-reaching consequences for the protection of the traditional knowledge base, “not only in India but in other Third World countries”. He said the case also highlights the importance of documenting traditional knowledge, to provide evidence of prior knowledge.

The turmeric patent was granted in 1995 to two researchers, Soman K. Das and Harihar Kohli of the University of Mississippi Medical Center. Their six patent claims covered the oral and topical use of turmeric powder to heal surgical wounds and ulcers. Das and Kohli contested CSIR's objections, but the patent office rejected all their claims.

The patenting of traditional remedies from developing countries became a global issue after patents were granted for neem. These patents were upheld because they covered novel processes for increasing the useful life of azadirachtin, neem's active ingredient.

Mashelkar says that India fought the turmeric patent not for financial reasons, but to uphold “national pride” and to dispel unfounded fears that India was incapable of protecting its traditional knowledge base.

In cooperation with other agencies, the CSIR has already launched a programme to analyse 490 medicinal plants and place the information on CD-ROM. This will be made available to European and US patent offices as a reference guide.