The Department of Health reminds that importation and sale of Chinese herb Aristolochia Linn and its products are prohibited from this month due to their harmful effects. Chinese medicine traders must recall the herb and proprietary medicines containing it or Aristolochic Acid.

Deputy Director of Health Dr Leung Ting-hung said for Asarum Linn, only the root of Herba Asari can be used.

"However, it should be used under the advice of Chinese medicine practitioners. Those proprietary Chinese medicines which consist of Herba Asari must submit proof they do not contain Aristolochic Acid before the proprietary Chinese medicine is accepted for registration," he said.

Prolonged and excessive use of herbs containing Aristolochic Acid is associated with kidney failure and cancer of the urinary tract.

Tests conducted

The department, in collaboration with the Government Laboratory and Baptist University, has conducted chemical analysis using Aristolochic Acid as the testing marker on some herbs and proprietary Chinese medicines.

It was found that Caulis Aristolochiae Manshuriensis contains the highest amount of Aristolochic Acid, followed by Radix Aristolochiae, Fructus Aristolochiae, Herba Aristolochiae Mollissimae, and Radix Aristolochiae Fangchi. Herba Asari has the least amount of Aristolochic Acid.

On the amount of Aristolochic Acid in Herba Asari, the aerial part contains much higher content than the root. The amount of Aristolochic Acid through water extraction is lower than through organic solvent extraction. The Aristolochic Acid level becomes undetectable after decoction of Herba Asari root in combination with other herbs in formulation.

The Chinese Medicines Board of the Chinese Medicine Council has reassessed the related regulatory measures and decided Aristolochia Linn will be prohibited from June 1. Herba Asari, however, can be used under these appropriate circumstances:

* under the prescription and advice of Chinese medicine practitioners;

* the species used must be specified in the Chinese Medicine Ordinance;

* the medicinal part is restricted to the root only;

* the dosage should not exceed the limit of 1-3 grams as specified in Chinese Pharmacopoeia (2000 edition);

* the time of decoction should no less than an hour;

* medicine traders should only import roots belonging to the species as specified in Chinese Medicine Ordinance from herb processing factories; and,

* it should only be taken in decoction, and not grinded into powder for oral consumption.

The board has also decided to prohibit the use of Aristolochia Linn in the manufacture of proprietary Chinese medicines. But for proprietary Chinese medicines with Asarum Linn herbs, the quality requirement is that Aristolochic Acid must not be detected.

Suspension lifted

The temporary suspension of the use of Herba Solani Lyrati since March 13 will be lifted. Dr Leung said: "The department considered that the confusion in the market has been rectified, thus deciding to reinstate the supply of Herba Solani with effect from June 14."

Dr Leung said the board will issue the Guideline on Safe Use of Herba Asari to all Chinese medicine practitioners. It will also issue the Guideline on Handling Herbs & Their Products Containing Aristolochic Acid to all Chinese medicines traders.

The department will organise briefing sessions to introduce the content of the above guidelines to the traders and practitioners in due course.

Enquiries can be made at 2209 9409 and 2209 9405 during office hours.