A COMPREHENSIVE ANALYTICAL APPROACH FOR QUALITY EVALUATION OF FLAVONOID-RICH EXTRACT OF Glycyrrhiza glabra (GutGard®)

Quality evaluation of botanical preparations is still evolving globally due to the complex, variable, and unknown phytochemical compositions of herbs. Accordingly, the quality of commercially available products needs to be better defined and controlled to ensure consistent health benefits and safety for consumers. This study aims to develop a comprehensive analytical methodology involving both phytochemical and biological evaluations towards achieving a meaningful quality control of commercial batches of a flavonoid-rich extract (GutGard®) derived from Glycyrrhiza glabra. Nine different commercial batches of the extract were analyzed to establish the chromatographic fingerprint of flavonoids as well as biological consistency using in-vitro assays for evaluating antioxidant and anti-inflammatory activity. A total of 53 peaks were assigned using MS/MS as the “common peaks” and nine peaks as “characteristic peaks” in the fingerprint of all the nine batch samples. Quantitative determination of the latter was achieved with a validated HPLC method. The finding revealed that all the examined samples were enriched with flavonoids, although with varied contents. The biological assays complemented the phytochemical analysis by way of providing a range of IC50 values that represent the overall chemistry of the extract including both the known and unknown constituents.