St. Johns Wort

4 in 10 St. Johns wort supplements are adulterated

Labs propose proper test methods to identify fake herb

In a test of 37 commercial supplement samples, a consortium of testing laboratories discovered that 38 percent of them were adulterated as fake product.

The lab group also offered ways to detect what is seen as economically motivated adulteration—a not-uncommon practice with well-selling ingredients.

 “It’s common knowledge that when an herbal product is a strong seller, there will be unscrupulous vendors who try to find ways around established testing methods,” said Sidney Sudberg, Alkemist Labs founder and chief science officer, who was one of six researchers on the study, published in Journal of AOAC International. “Collaboration between industry experts to strengthen analytical methods is the best way to combat this practice, and for people like us, it’s incredibly satisfying.”

Although fallen from its superstar status in the late 1990s, St. John’s wort is still a big seller for its utility in combating mild to moderate depression.

The goal of the study was to investigate St. John’s wort ingredients and products suspected to be adulterated first using preliminary high performance thin-layer chromatography (HPTLC) tests. Commercial samples were analyzed following the USP monograph methodology, with additional visualization under white light.

The inauthentic products presented with either an admixture of synthetic dyes combined with an uncharacteristic flavonoid pattern (about 22 percent) or exhibited an uncharacteristic flavonoid pattern only (about 16 percent). None of the raw herb samples were adulterated with dyes—this was found only with extracts and finished products. The researchers developed a new reversed-phase HPTLC method to identify the cheats. In the study, the proposed enhanced authentication procedures are accompanied with a decision flowchart to systematically rule out adulteration of St. John’s wort.

“I think this work is an excellent example illustrating the great potential of HPTLC, unlocked by standardized methodology, suitable equipment and validated methods provided by CAMAG, when it comes to analysis of highly complex and naturally variable samples such as botanicals,” said Débora Frommenwiler, a researcher with CAMAG, a manufacturer of HPTLC equipment.

It’s important to note that there is no one-size-fits-all botanical authentication test. A combination of methodologies and strong quality and traceability management systems are the only way to guarantee authenticity. For more on this important issue, see this infographic on the keys to proper botanical authentication.

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