Polygala Tenuifolia: Is Your Herbal Supplement Safe?

study PMID: 29620485

Quick Summary: A recent study found that some herbal supplements, including Polygala tenuifolia, can be contaminated with potentially harmful fungi and toxins. This means you could be exposed to substances that might make you sick.

What The Research Found

Researchers tested several root herbs sold in Chinese markets and found that almost all of them were contaminated with fungi. Some of these fungi can produce dangerous toxins called aflatoxins (AFs) and ochratoxin A (OTA). The study showed that a significant number of samples contained these toxins, with some exceeding safe limits, especially for aflatoxins.

Study Details

Who was studied: 48 samples of various root herbs, including Polygala tenuifolia, used in traditional medicine and supplements. These samples were purchased from markets in China, Korea, and Japan.

How long: The study was a snapshot in time, looking at the contamination levels of the herbs at the time of testing.

What they took: The researchers analyzed the herbs for the presence of fungi and two specific toxins: aflatoxins and ochratoxin A. They did not study how people used the herbs.

What This Means For You

Potential Health Risks: Consuming contaminated herbs could expose you to toxins that can be harmful to your health. Aflatoxins, in particular, are known to be dangerous.

Choose Wisely: When buying herbal supplements like Polygala tenuifolia, look for products from reputable companies that test for contaminants.

Ask Questions: Don't hesitate to ask your supplier about their quality control measures and testing procedures.

Be Aware: Be aware of the potential risks associated with herbal supplements and make informed choices.

Study Limitations

Limited Scope: The study only looked for two types of toxins, so other harmful substances might be present.

Where the Herbs Came From: The study primarily focused on herbs from Chinese markets, so the results might not apply to products from other regions.

Small Sample: The researchers tested a limited number of fungal isolates for toxin production, which may not fully represent the contamination risks.

No Dosage Information: The study didn't look at how much of the herbs people were taking or how it affected them.

Key Findings

All 48 root herb samples (100%) tested were contaminated with fungi, yielding 1,844 isolates across 25 genera. Aspergillus (10% of isolates) and Penicillium (25%) were the most prevalent toxigenic genera. Among 33 isolates tested for mycotoxin production:
- Aflatoxins (AFs): 5/13 Aspergillus flavus and 1/1 Aspergillus parasiticus isolates produced AFs.
- Ochratoxin A (OTA): No OTA production detected in Aspergillus niger or Penicillium polonicum isolates.
AF contamination was found in 37.50% (18/48) of samples (6 herbs), with 14.58% (7/48) exceeding permissible limits (≥5 μg/kg for aflatoxin B₁). OTA contaminated 16.67% (8/48) of samples (4 herbs), though none surpassed regulatory thresholds.

Study Design

This cross-sectional study analyzed 48 commercial root herb samples (including Polygala tenuifolia) from Chinese markets, alongside imports from Korea and Japan. Fungi were identified via morphological analysis and MultiGeneBlast targeting β-tubulin/calmodulin genes. Mycotoxin production by isolates was assessed in vitro, while AF/OTA levels in samples were quantified using ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

Dosage & Administration

This study did not evaluate dosage or administration of Polygala tenuifolia or other herbs. It focused on contamination levels rather than therapeutic use.

Results & Efficacy

Fungal prevalence: 100% contamination (48/48 samples), with Penicillium being the most common toxigenic genus.
AF contamination: 37.50% of samples (18/48) contained detectable AFs; 7 samples (14.58%) exceeded China’s aflatoxin B₁ limit (5 μg/kg).
OTA contamination: 16.67% of samples (8/48) contained OTA, but levels remained below regulatory limits.
Toxigenic isolates: 6/14 Aspergillus isolates (42.9%) produced AFs, while OTA-producing species were not detected.
No statistical significance (p-values) was reported, as the study aimed to describe contamination prevalence rather than test hypotheses.

Limitations

Sampling bias: Fungal isolates tested for toxigenicity (n=33) were arbitrarily selected, potentially underrepresenting true contamination risks.
Limited scope: Only AFs and OTA were analyzed; other mycotoxins (e.g., fumonisins) were not assessed.
Geographic restriction: Most samples originated from China, limiting generalizability to other regions.
Cross-sectional design: No causal links established between fungal species and mycotoxin production in situ.
Small isolate subset: Toxigenicity testing focused on 33 isolates (from 25 genera), possibly missing key AF/OTA producers.

Clinical Relevance

Root herbs like Polygala tenuifolia, used in traditional medicine and supplements, carry a significant risk of fungal and aflatoxin contamination. Consumers may unknowingly ingest mycotoxins exceeding safety limits, particularly in ginseng, polygala, and licorice products. Regulatory agencies should prioritize monitoring AFs in root herbs, while manufacturers must implement stricter drying/storage protocols to mitigate fungal growth. Users are advised to source herbs from suppliers with rigorous quality control to reduce exposure risks. This study underscores the need for standardized safety measures in herbal product supply chains.