Scientists are studying the use of cockroaches in making drugs - and for a possible Aids cure, Xinhua reported yesterday. Professor Li Shunan, head of the Medicinal Faculty of Yunnan Dali Medical Academy, told the agency that after years of research he had extracted 'three useful organic substances' from cockroaches. Xinhua said experiments conducted by the Kunming Animals Research Institute under the Chinese Academy of Sciences showed that one of the three organic substances taken from cockroaches was effective in resisting HIV. Fen Kunlong, a researcher who oversaw the experiments, said the organic substance was about 10 per cent as effective as the drugs currently used in the United States in treating Aids patients. Mr Fen claimed that there were no side effects from the substance but more clinical studies were needed. Xinhua quoted Professor Li as saying his research was inspired by local traditions in Yunnan province, where people of the Bai minority had been using the insects to cure skin diseases. He first managed to extract organic substances from cockroaches 14 years ago and developed a drug to heal skin wounds.