Does Houttuynia cordata have aristolochic acid?
As early as 2000 years ago, Houttuynia cordata was used as a kind of wild vegetable as an auxiliary food in China. According to legend, during the Spring and Autumn Period, Gou Jian, the King of Yue, led everyone to choose Houttuynia cordata to eat to satisfy hunger and waste the famine. Since Wei and Jin Dynasties, the water shield has been officially used as medicine, and it has been recorded in medical classics under the name of Houttuynia cordata Thunb. In the historical changes and development, it has always played the role of both medicine and food, and played a role in health care and disease prevention and treatment for the people. With modern people advocating nature more and more and pursuing simplicity, wild or home-grown houttuynia cordata has become a "wild vegetable" with a double price on the public dining table in various places (especially in southwest China).
Houttuynia cordata Thunb , also known as dog heart grass, broken ears and so on. Is an edible plant with the functions of clearing away heat and toxic materials, diuresis and detumescence. Recently, it is said that Houttuynia cordata Thunb. Contains aristolochic acid, which may cause cancer if eaten frequently. This can make many friends worry.
Aristolochiaceae is a branch of the plant kingdom. Aristolochic acid is a chemical component and aristolochic lactam is a metabolite of aristolochic acid. Most aristolochic herbs contain aristolochic acid. At present, there are more than 60 kinds of Chinese herbal medicines such as Akebia manshuriensis and Aristolochia.
It has long been concluded that aristolochic acid is indeed toxic. China Pharmacopoeia published in 2005 no longer included Aristolochia manshuriensis, Aristolochia and other Chinese medicines containing aristolochic acid, but replaced them with other varieties. In 2008, the International Center for Research on Cancer listed it as a 1 carcinogen, and the natural mixture of aristolochic acid as a 2A carcinogen. It should be noted that Houttuynia cordata does not contain aristolochic acid. The deputy director of the Pharmacy Department of Chongqing Hospital of Traditional Chinese Medicine calmly said that Houttuynia cordata is not an aristolochic plant and does not contain aristolochic acid, but it contains aristolochic lactam, which is different.
The content of aristolochic acid ≠ aristolochic acid in Houttuynia cordata Thunb is very small. From the cytotoxicity point of view, it is aristolochic lactam -I that has certain damage and inhibition on renal epithelial cells. Aristolochia lactam -BII, AII and FII were found in the extract of Houttuynia cordata Thunb. It is not clear whether it contains class I.
Aristolochic acid can cause cancer, but there is no aristolochic acid in Houttuynia cordata, but it is not clear whether aristolochic acid -I is harmful to kidney and has inhibitory effect.
Efficacy and function of aristolochic acid
Main ingredients: Aristolochia seeds contain aristolochic acid, aristolochic acid and so on.
Efficacy and function: clearing lung and relieving cough, but the expectorant effect is not obvious.
Processing: raw or honey.
Nature and taste: bitter and cold.
Meridian tropism: entering lung and large intestine meridian.
Aristolochic acid has strong mutagenic and carcinogenic effects. The occurrence of tumor is related to the dose and duration of aristolochic acid. The effect of aristolochic acid on tumor is related to the mutation and activation of tumor-related genes caused by AL-DNA adduct, so it is called genotoxic carcinogen. The expression of P53 gene in urinary tract tumor tissue of patients with Chinese herbal medicine nephropathy increased, and p53 gene mutated. AA-ⅰ induced the mutation of ras gene (c-Ha-ras, c-N-ras, c-ki-ras) in tumor tissues of rats. Cell culture in vitro also proved that AA-I can induce p53 gene mutation in mouse embryonic fibroblast cell line carrying human p53 gene. The above gene mutation types are very consistent, mainly A-T translocation (A:T →T:A), which is called the landmark mutation of aristolochic acid poisoning, because the gene mutation of A:T →T:A is rare in urothelial carcinoma of patients with non-aristolochic acid nephropathy. The mutation of p53 gene is obviously related to the function of dA-AL adduct.
List of medicinal materials containing aristolochic acid