Stereospecific pharmacokinetic characterization of liquiritigenin in the rat

Chemical analysis of the Chinese herbal medicine licorice (Gan-Cao): An update review

ETHNOPHARMACOLOGICAL RELEVANCE

Licorice, called Gan-Cao in China, is one of the most popular traditional herbal medicines. It is derived from the dried roots and rhizomes of Glycyrrhiza uralensis, G. glabra, and G. inflata. Licorice is recorded in the pharmacopoeias of China, Japan, US, and Europe.

AIM

This review updates research progress of licorice from the perspectives of chemical analysis, quality evaluation, drug metabolism, and pharmacokinetic studies from 2009 to April 2022.

MATERIALS AND METHODS

Both English and Chinese literatures were collected from databases including PubMed, Elsevier, Web of Science, and CNKI (Chinese). Licorice, extraction, structural characterization/identification, quality control, metabolism, and pharmacokinetics were used as keywords.

RESULTS

Newly developed analytical methods, including LC/UV, 2DLC, LC/MS, GC/MS, and mass spectrometry imaging (MSI) for chemical analysis of licorice were summarized.

CONCLUSION

This review provides a comprehensive summary on chemical analysis of licorice.

The fate of flavonoids after oral administration: a comprehensive overview of its bioavailability

Despite advancements in synthetic chemistry, nature remains the primary source of drug discovery, and this never-ending task of finding novel and active drug molecules will continue. Flavonoids have been shown to possess highly significant therapeutic activities such as anti-inflammatory, anti-oxidant, anti-viral, anti-diabetic, anti-cancer, anti-aging, neuroprotective, and cardioprotective, etc., However, it has been found that orally administered flavonoids have a critical absorption disorder and, therefore, have low bioavailability and show fluctuating pharmacokinetic and pharmacodynamic responses. A detailed investigation is required to assess and analyze the variation in the bioavailability of flavonoids due to interactions with the intestinal barrier. This review will emphasize on the bioavailability and the pharmacological applications of flavonoids, key factors affecting their bioavailability, and strategies for enhancing bioavailability, which may lead to deeper understanding of the extent of flavonoids as a treatment and/or prevention for different diseases in clinics.

Characterization of the global metabolic profile of liquiritin in rat plasma, urine, bile and feces based on UHPLC-FT-ICR MS

Liquiritin is a major flavonoid in Radix Glycyrrhizae and it has been reported to possess various pharmacological activities. In the present work, a strategy based on an ultra high performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry (UHPLC-FT-ICR MS) method was proposed to systematically characterize the in vivo metabolites of liquiritin for the first time. After oral administration of liquiritin to rats in a single dose of 120 mg kg⁻¹, the rat plasma, urine, feces and bile samples were collected and used to discover metabolites. As a result, besides the parent drug, a total of 76 metabolites (6 phase I and 70 phase II metabolites) of liquiritin were detected and tentatively identified. It was indicated that the metabolic pathways of liquiritin in rats included oxidation, reduction, deglycosylation, isomerization, methylation, glucuronidation and sulfation. In summary, the results could provide valuable information regarding the metabolism of liquiritin in rats, which could contribute to a better understanding of its action mechanism.

Liquiritin is a major flavonoid in Radix Glycyrrhizae and it has been reported to possess various pharmacological activities.