A lot of health conscious people would most likely prefer herbal medicine over pharmaceutical ones when it comes to treating illnesses. And while a lot of studies showed its effectiveness, a new one shows its dark side. A traditional Chinese medicine that was used to treat a lot of conditions may cause liver cancer mutations in Asia.
Aristolochia is a large plant genus with over 500 species that is the type genus of the family Aristolochiaceae. Its members are commonly known as birthwort, pipevine or Dutchman's pipe. Around 100 species of Aristolochia are commonly used in herbal medicines. “They have very beautiful, trumpet-shaped flowers,” says Steven Rozen, author of the study and from Duke-NUS Medical School in Singapore.
Extracts from the flowers, root or stem of Aristolochia have long been used as herbal medicine. However, there have been reports of women trying a weight loss drug containing Aristolochia extracts who happened to develop kidney failure. Since then, Aristolochia extracts are linked to a type of kidney disease affecting people in Balkan territories called Balkan nephropathy.
Aristolochic acid, a compound that is found in the plant, can cause gene mutations via attacking a component of DNA, adenine. "It attacks any part of the genome with equal opportunity,” says Rozen. And when the researchers saw the same mutation found in liver cancer, they speculated that plants containing aristolochic acid would increase the risk of developing the disease.
The researchers studied 98 liver tumor samples from two hospitals in Taiwan. 78 percent of the cases showed that there is evidence of exposure to aristolochic acid. “This indicates strongly that aristolochic acid was one of the causes of these cancers,” says Rozen. The researchers also found such gene mutations in many cases from Japan, Korea and China. North America and the UK have around 5-10 percent of liver cancers linking to adenosine mutations. But aristolochic acid isn’t the only cause of mutations and it’s uncertain how many of these cases were caused by the herbal medicine.
Aristolochia extracts are banned in some countries but some are widely available and that even the banned ones can be bought online says Rozen. “It’s quite difficult to regulate. We need to warn people of the dangers of aristocholic acid.”
Oops, herb gone wrong?
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