(T1330-01-06) Hidden Dangers: The Serious Risk of Adulterated Herbal Supplements to Patient Health

Purpose: Patients often take herbal supplements to manage diabetes. This study aims to analyze whether the patient-supplied herbal supplements were adulterated with active hypoglycemic compounds.

Methods: Herbal supplement pills were powdered using a mortar and pestle. The powdered samples were extracted with methanol and then water. Analytical methods on Ultra-Performance Liquid Chromatography (UPLC)-ESI mass spectrometry were developed using acetonitrile and water supplemented with 0.01% formic acid. Standard diabetes pharmacological moieties were used as positive control, and a blank acetonitrile/water mixture was used as negative control. The concentrations of drugs were established using calibration curves generated under identical analytical conditions. Each sample is analyzed in triplicate to establish the standard deviation from the mean concentrations.

Results: Three different groups (green, pink, and brown) of pills were sampled for their consistency in weight. Green, pink, and brown tablets weighed significantly differently, showing a standard deviation within group of 25.6 %, 8.5 %, and 7.4 %, respectively. To our surprise, UPLC-MS analysis revealed that a green pill contained a mixture of metformin (290 ± 113.8 mg) and glibenclamide (0.33 ± 0.07 mg). Similarly, a pink tablet contained 165±69.0 mg of metformin and 0.29±0.09 mg of glibenclamide. Although the extract generated from the brown tablets revealed the presence of a mixture of many compounds, a typical hallmark of crude herbal products, the presence of metformin and glibenclamide was not detected. Although one of the peaks in the chromatogram showed a match with the molecular weight of another common diabetes drug, saxagliptin, its presence was ruled out using the standard compound.

Conclusion: We identified commonly used drugs, metformin and glibenclamide, in the herbal supplements, revealing the adulteration in the products. Therapeutically significant concentration of these drugs found in the pills and pill-to-pill variations highlights the safety risk patients face. The risk can be further exacerbated when such herbal supplements are combined with standard diabetes therapy.

Acknowledgements: This research was supported in part by the National Science Foundation-HBCU EiR award 2302454.


UPLC chromatogram of extracts generated from herbal supplement tablets. Standard metformin and glibenclamide were used as references.