Vicious vine. leafy, flowering vines called Aristolochia are used in a supplement herbal that can cause cancer.
Carsten Niehaus / Creative Commons
SHANGHAI, CHINA -Many people are turning to herbal supplements to improve their health. In China, the belief in traditional medicine is so strong that peddle pharmacies unprocessed herbs alongside modern pharmaceuticals. But an ingredient found in some supplements may also be cancerous than smoking, two new studies found.
The ingredient in question is aristolochic acid, a compound found in leafy, flowering vines called Aristolochia or Aristolochia. For centuries, Aristolochia was used in traditional medicine in China (and ancient Greece before that) to treat arthritis and ease childbirth, among other conditions. (The flower is shaped uterus). Today aristolochic acid pronounced "a laugh-to-LOW-stroke" is found in supplements for weight loss, menstrual symptoms, and rheumatism. It is widely used in Asia, where it is added to medicinal wine , ointments, and pills. one study found that between 1997 and 03, a third of Taiwanese have been prescribed Aristolochia supplements by a Chinese medicine practitioner.
Warnings on grass first emerged in the early 190s, when a scandal involving dozens of women in Belgium who had inadvertently taken for weight loss surfaced. as stated in the Lancet in 1993, several patients developed severe kidney failure.
Soon after, scientists discovered a link in the region's rural Danube River between kidney damage and wheat that had been contaminated with Aristolochia when the seeds of both plants mixed during harvest. in 01, the Food and Drug Administration issued an advisory note of consumers about the diet supplements and other products containing aristolochic acid, calling for its use to be interrupted. In 03, many countries, including Taiwan had banned the substance. The International Agency for Research on Cancer has classified based compounds derived from Aristolochia plants as a group 1 carcinogen, meaning there is sufficient evidence that it causes cancer in humans, not only animals.
But these supplements are available from Chinese traditional practitioners and the Internet, says Bin Tean Teh, a cancer researcher at the Singapore National Cancer Centre and National University of Singapore (NUS) and corresponding author on one of the new papers appearing in this week science Translational Medicine. and although some studies have shown a link between Aristolochia and is greater urinary tract cancer or kidney disease, they had only traced the mechanism provided that mutations in a gene P53 , a gene commonly associated with cancer. "I thought there should be more than that," said Teh, who has long been struck by the fact that Taiwan, with high use of supplements containing Aristolochia, also has the highest incidence of upper known cancer pathways urinary worldwide.
For a broader picture, Teh and his colleagues sequenced the tissues from nine Taiwanese patients with upper urinary tract cancer who took Aristolochia. From previous research, scientists know that carcinogens such as cigarette smoke leave DNA on the genome of a person, as characteristic alterations in the letters that make up DNA sometimes considered 'mistakes' spelling". Because cancer of the upper urinary tract occurs in the kidney, the researchers used the latest methods of gene sequencing to examine cancerous kidney tissue side by side with non-tumor tissue nearby. In malignant tissues, they found up to 1500 genes with higher-mutations than what has been found to be lung cancer in smokers or skin cancer in patients with high exposure to ultraviolet radiation. "People have always thought it was a gene" affected by Aristolochia, said Teh. "We found that it was thousands."
Meanwhile, a scientific team that was looking to sequences from a patient with liver cancer noticed a strikingly similar genetic fingerprint. Using the same procedure, the group found that Aristolochia may be responsible as well as the cancer the first time that the grass has been associated with liver cancer.
The study is the final nail in the coffin for Aristolochia, says Steven Rozen, genetics researcher cancer Graduate Medical School Duke-NUS in Singapore and Duke University Medical Center in Durham, North Carolina, and an author on the paper. "This is a pretty clear story," he said. "These plants are very dangerous."
The second paper, by another group of authors in the United States and Taiwan, arrived at similar results. After tissues from 19 Taiwanese patients with upper urinary tract cancer sequencing, the researchers found that a group of patients with cancer of the upper urinary tract, but no use of Aristolochia background check n has not shown the same pattern of mutations.
The work raises new possibilities for diagnosis, said Marc Ladanyi, a cancer researcher at Memorial Sloan Kettering Center in New York City-cancer. One day, the first clue that a patient has ingested Aristolochia might come not from the clinical history of the person, but powerful genetic fingerprint of the plant, he said. If found in patients living in areas not widely known to have a Aristolochia exposure, such a mark could be a sign that public health campaigns are needed.
0 Komentar