Processed polygonum multiflorum root
Also known as: He Shou Wu, Fo-Ti, Chinese knotweed, P. multiflorum Praeparata, Polygonum multiflorum
Overview
Polygonum multiflorum root, commonly known as He Shou Wu or Fo-Ti, is a traditional Chinese medicinal herb with over a millennium of use. It is primarily valued for its purported benefits in nourishing the liver and kidneys, promoting hair growth, and exhibiting anti-aging properties. The processed root form (PMP) undergoes steaming or other treatments, which is believed to reduce its toxicity compared to the raw root. In Traditional Chinese Medicine (TCM), it is frequently employed for conditions such as dyslipidemia, neurodegenerative diseases, and sleep disorders. Despite its long historical use, recent decades have seen a rise in reported cases of liver injury associated with its consumption, leading to regulatory warnings and increased scientific scrutiny. While some research supports its efficacy in certain areas, safety concerns, particularly regarding hepatotoxicity, have prompted more rigorous investigations into its use.
Benefits
Processed Polygonum multiflorum root is traditionally used for liver and kidney nourishment, anti-aging effects, hair darkening, and lipid regulation. Clinical evidence, though limited by the scarcity of high-quality randomized controlled trials (RCTs) with large sample sizes, suggests potential benefits in managing dyslipidemia and certain neurodegenerative conditions. Most studies have been conducted in Chinese populations using TCM formulations, making it difficult to generalize findings to other demographics. The strength of evidence for these benefits is moderate, primarily derived from observational studies and reviews rather than robust clinical trials. Quantitative effect sizes are not well-established. Traditional use implies that benefits may appear after chronic administration over weeks to months.
How it works
Processed Polygonum multiflorum root contains active compounds such as stilbene glycosides (e.g., 2,3,4′,5-tetrahydroxystilbene-2-O-β-D-glucoside) and anthraquinones (e.g., emodin). The processing method significantly alters the chemical profile, reducing certain stilbene glycosides by approximately 55.8% and increasing emodin content by about 34%. These chemical changes are believed to modify both the efficacy and toxicity of the herb. Proposed biological mechanisms include antioxidant, anti-inflammatory, and lipid-lowering activities. While the exact mechanisms of its beneficial effects are still under investigation, its hepatotoxicity is thought to involve metabolic activation of toxic constituents, immune-mediated injury, and oxidative stress pathways within the liver.
Side effects
The most significant and concerning side effect associated with processed Polygonum multiflorum root is liver injury, with over 100 cases documented worldwide since 2006. While the processed form is considered less hepatotoxic than the raw root, it still carries a notable risk. Other less common side effects may include allergic reactions and gastrointestinal discomfort. Polygonum multiflorum can potentially interact with other hepatotoxic drugs or medications metabolized by liver enzymes, increasing the risk of adverse effects. It is contraindicated in individuals with pre-existing liver disease and pregnant women due to a lack of safety data. Caution is also advised for the elderly or those with compromised liver function. Regulatory agencies in the UK, Australia, and China have issued warnings regarding the hepatotoxicity risks associated with its use, emphasizing the need for careful consideration and monitoring.
Dosage
There is no standardized minimum effective dose for processed Polygonum multiflorum root established from rigorous randomized controlled trials. Traditional dosing varies widely, and the herb is typically administered in decoctions or extracts. While processing reduces toxicity, the optimal dosage to balance efficacy and safety remains unclear. In TCM practice, it is usually taken daily over extended periods, often weeks to months, to achieve desired effects. The bioavailability of its active compounds can vary significantly depending on the specific processing method and the formulation used. Due to the risk of liver injury, it is crucial to exercise caution and consider professional guidance when determining dosage, as upper limits and safety thresholds are not well-defined in modern clinical research.
FAQs
Is processed Polygonum multiflorum root safe?
While processed Polygonum multiflorum root is considered safer than the raw form, it still carries a risk of liver injury. Monitoring liver function during use is recommended due to documented cases of hepatotoxicity.
How long before benefits appear?
Traditional use suggests that benefits may appear after chronic administration over weeks to months. However, clinical evidence from high-quality studies on the time course of effects is limited.
Can it be used with other medications?
Caution is advised when using processed Polygonum multiflorum root with other medications, especially those that are hepatotoxic or metabolized by liver enzymes, due to potential interactions and increased risk of liver damage.
Does processing eliminate toxicity?
No, processing reduces but does not entirely eliminate the hepatotoxic compounds in Polygonum multiflorum. While it lowers the concentration of certain toxic stilbene glycosides, a risk of liver injury remains.
Research Sources
- https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2017.00791/full – This systematic review confirmed the hepatotoxicity risk of Polygonum multiflorum, particularly the raw root, noting that processing reduces but does not eliminate this risk. The study highlighted that mechanisms of liver injury involve metabolic and immune pathways, drawing conclusions primarily from case reports and animal studies.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC4471648/ – This review of clinical and pharmacokinetic studies indicated that processing Polygonum multiflorum reduces toxic stilbene glycosides by 55.8% and increases emodin by 34%. It suggested that processed forms exhibit lower toxicity in animal models and clinical settings, though it noted the scarcity of high-quality randomized controlled trials.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC6923272/ – This narrative review focused on liver injury associated with Polygonum multiflorum, emphasizing the increasing number of reported cases. It underscored the need for improved quality control and safety monitoring, stating that the exact mechanisms of liver injury are not fully clear and advocating for standardized clinical use.