Polygonum multiflorum, commonly known as He Shou Wu in China and Fo-Ti in Western markets, is a plant used in Traditional Chinese Medicine (TCM). This herbaceous perennial vine is native to central and southern China, where its tuberous root has been utilized for centuries. The name He Shou Wu translates to “Mr. He’s black hair,” stemming from a legend about an elderly man who restored his youthful vitality and dark hair after consuming the herb. It is also known as tuber fleeceflower and Chinese knotweed.
Traditional and Modern Applications
Historically, Polygonum multiflorum has held a significant place in TCM, with its earliest recorded use dating back to the Song Dynasty (973-974 A.D.). Practitioners traditionally used it to nourish the liver and kidneys. It was also applied to supplement essence and blood, strengthen bones and tendons, and address conditions like dizziness, tinnitus, and constipation.
The herb gained renown for its anti-aging properties, particularly restoring black hair color and combating hair loss. Modern dietary supplements frequently incorporate Polygonum multiflorum for hair health, aiming to reduce premature graying and stimulate hair growth. It is also promoted for general vitality and anti-aging effects in contemporary wellness products.
Potential Health Risks and Side Effects
Despite its traditional uses, Polygonum multiflorum is associated with health risks, with herb-induced liver injury (hepatotoxicity) being the primary concern. Reports of liver damage have emerged globally. This injury can range from mild to severe, and in rare instances, has led to liver failure and even death.
Symptoms of liver injury manifest about one month after beginning consumption and may include jaundice (yellowing of the skin or eyes), dark or tawny urine, fatigue, loss of appetite, nausea, vomiting, and abdominal pain. While most affected individuals recover after discontinuing the herb and receiving medical care, some cases of chronic liver disease have been observed. The risk may increase with long-term use or higher doses, though individual sensitivities also play a role.
Other potential side effects include gastrointestinal upset, such as diarrhea and nausea. These digestive reactions are more common when the raw, unprocessed root is consumed. The herb may also interact with certain medications like warfarin, potentially increasing the risk of bleeding, or digoxin, by decreasing potassium levels. Individuals with pre-existing liver conditions, as well as pregnant or breastfeeding women, are advised to avoid this herb due to its potential to mimic estrogen in the body.
The Role of Preparation
The properties and traditional uses of Polygonum multiflorum differ significantly between its raw and processed forms. The raw root, often referred to as “sheng shouwu,” is traditionally employed for purposes like detoxification, clearing carbuncles, and as a laxative. This raw form is considered to carry a higher risk of toxicity, especially gastrointestinal upset, due to its natural compounds.
In contrast, the processed form, known as “zhi heshouwu,” is used for its tonic and anti-aging properties. The traditional curing method involves slicing the roots and simmering or steaming them in a black bean liquid. This process can extend for several hours or even days until the liquid is absorbed or evaporated, after which the roots are dried.
This preparation is believed to reduce the herb’s toxicity and enhance its therapeutic effects, such as nourishing the liver and kidneys, enriching blood, and supporting hair darkening. Scientific analysis indicates that processing alters the chemical composition of the herb, notably decreasing the content of certain stilbene glucosides, such as TSG, by 55.8% to over 90%. These changes in compound profiles are thought to contribute to the reduction in toxicity observed with the processed herb.
Scientific Basis of Action
The biological effects attributed to Polygonum multiflorum are linked to its diverse chemical compounds, primarily stilbenes and anthraquinones. Other compounds, including flavonoids and phospholipids, are also present. These constituents are believed to mediate both the traditional applications and the reported adverse effects of the herb.
Tetrahydroxystilbene glucoside (TSG) is a prominent stilbene compound found in the plant. Preliminary research, largely from cell and animal studies, suggests that TSG exhibits antioxidant and anti-inflammatory properties. These effects are thought to contribute to its potential for anti-aging, neuroprotection, and promoting hair growth.
Conversely, anthraquinones, such as emodin, rhein, and chrysophanol, are also present in Polygonum multiflorum. These compounds are associated with the herb’s traditional laxative action, particularly in its raw form. Anthraquinones are also implicated in the liver toxicity observed with the herb, with studies identifying rhein as a potential hepatotoxicant. Traditional processing aims to modify the balance of these compounds, including altering anthraquinones.