A feasible procedure to detect widespread wrong labeling of Ashwagandha root extracts in dietary supplements

Abstract

Aim: Ashwagandha is a widely recognized medicinal plant in Ayurveda, a traditional Indian system of medicine. These extracts, which are concentrated forms of the root, contain specified withanolides (WLs) at a 5% median concentration on their packaging. Given the visual similarity between the capsule contents of these dietary supplements and authentic pulverized Ashwagandha root, there is a growing suspicion that these so-called extracts may be merely pulverized roots. To address these concerns, a procedure for evaluating Ashwagandha root extracts is presented that offers simplicity, cost-effectiveness, and the ability to provide a valid estimation. Methods: The procedure incorporates microscopic investigations to facilitate the identification of plant fragments, which should be absent in properly prepared extracts. High-performance liquid chromatography (HPLC) with ultraviolet detection is employed to check whether the supplements are more than 10-fold concentrated compared to the powdered root, as claimed on the product labels. Results: In the analyzed Ashwagandha root extracts, plant fragments and starch granules were detected, which could be attributed to the root in terms of size and shape. HPLC analysis of both root extracts and roots revealed nearly identical chromatograms with respect to peak patterns and signal intensity. Quantitative analysis indicated a WL content of approximately 0.15% in all tested Ashwagandha root extracts, considerably lower than the claimed 5% median content but consistent with published data for Ashwagandha root. Conclusions: Notably, none of the 10 dietary supplements labeled as Ashwagandha root extracts fulfilled the manufacturers’ claims. These findings emphasize the need for practical and simple evaluation procedures, such as those proposed in this study. Such methods enable the evaluation of Ashwagandha root extracts without requiring the complex coupling of HPLC to mass spectrometry, making them accessible and feasible.

Keywords

Ashwagandha root extract / dietary supplement / HPLC-UV / microscopy / wrong labeling / withanolides

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