Besides conducting the world's largest Aids vaccine trial, the Public Health Ministry was also doing tests on two other major topics: the potential of four Thai herbs as new medicines and stem-cell research to curb certain illnesses, Permanent Secretary for Public Health Dr Prat Boonyawongvirot said.

The study in Prachin Buri on the ability of Derris scandens Benth (known in Thai as Thaowanpriang) to cure lower back pain had yielded a result beyond expectations and was considered as good as imported medicines when compared over a seven-day period, Prat said.

Another study on mulberry to cure non-hereditary diabetes, a type that affects as many as two million Thais, yielded very good initial results with no side-effects, he said. The mulberry leaves were also found to help lower cholesterol and triglyceride levels, so another study would soon be done on high cholesterol patients.

Two other studies being conducted in Chiang Rai should be completed within a month. They are a study into the safety of Hyptis suaveolens Poit to cure flu and Aids, and another Aids cure, the herb Jiaogolan.

The National Research Council was now scrutinising a proposal for medical teams from the ministry and Mahidol University to conduct joint research on stem cells to repair corneas, to treat patients with myocardial infarction as well as curing Parkinson's Disease, Prat said.

The Medical Science Department would also build a stem-cell lab soon, he said.