A misconception that popular herbal medicines are safe simply because they have been used for thousands of years could be putting the heath of users at risk, Australian researchers said on Monday.

Researchers from the University of Adelaide said some popular herbal medicines, which have been used for generations, actually contain toxic materials from plants and animals, but are still taken because it's assumed they're beneficial.

Lead author of the study, Prof. Roger Byard from the University of Adelaide, said recent developments in linking medical conditions with some herbal treatments has uncovered new risks involved in taking traditional medicines.

"Toxic side effects of herbal medicines used in traditional societies have typically not been reported, and this is often cited in favor of their safety," Byard said in a statement released on Monday.

"However, the lack of systematic observation has meant that even serious adverse reactions, such as the kidney failure and liver damage caused by some plant species, have gone unrecognized until recently."

Co-author, Dr. Ian Musgrave from the University's Discipline of Pharmacology, said many patients don't bother to check the ingredients of some herbal medicines, because it's assumed that thousands of years of use points to everything being safe.

"Most of the time patients don't recognize herbal products as a medicine, so it doesn't come to mind when asked what medicines they are taking," Musgrave said.

He said some herbal medicines slip through the cracks of Australian regulations because they are not technically medicines under Australian law.

"A significant number of traditional herbal medicines do not comply with Australian regulations. In some cases ingredients are either not listed or their concentrations are recorded inaccurately on websites or labels," he said.

"In other cases a botanical species may be replaced with another if it is difficult to source or too expensive. The replacement species may be potentially toxic."

Byard said to avoid any potential issues or complications in the future, national body the Therapeutic Goods Administration (TGA), should "require manufacturers to have samples independently tested before placing them on the market".

source: Xinhua