Quantitative analysis of Glycyrrhizic acid from a polyherbal preparation using liquid chromatographic technique

Stability Indicating Method Development and Validation of Glycyrrhizin Using RP-HPLC-DAD: Application to Glycyrrhiza glabra Extract

Glycyrrhiza glabra is commonly known as licorice. Licorice is the major source of glycyrrhizin. There is no reported stability indicating method for glycyrrhizin in the literature so far. Therefore, it was proposed to develop a stability indicating method and validate the method for glycyrrhizin and its application in G. glabra root extract. Method validation parameters were performed as per the International Council for Harmonization guidelines. The chromatographic separation was achieved on a Zorbax Extended C-18 (250 × 4.6 mm, 5 μm) column. The separation achieved using the mobile phase consisted of 0.1% formic acid in water and acetonitrile in gradient elution. The flow rate was kept at 1 mL/min, and ultraviolet-visible spectroscopy detection was at 250 nm. The average retention time of glycyrrhizin was found to be 7.30 min. Stress degradation studies were performed and confirmed that only acidic degradation has shown a degradation profile of glycyrrhizin up to 40%. The percentage of glycyrrhizin was found to be 0.40% in the G. glabra extract. This may be further explored for commercial applications.

Implementation of Quality by Design Approaches for Development and Validation of Reverse-Phase High-Performance Liquid Chromatography Assay Method for Determination of Glycyrrhizin in Nanoformulation

Glycyrrhizin (GL) is the principal constituent of Glycyrrhiza glabra, having antiallergic, anticancer, anti-inflammatory, and antimicrobial action. The reverse-phase high-performance liquid chromatography (RP-HPLC) analytical method was used to quantitatively estimate GL in a nanoformulation and validated as per International Conference on Harmonization Q2 (R1) standards. A stationary phase of the C18-HL reversed-phase column and a mobile phase of acetonitrile and water were used for effective elution. The chromatographic conditions of RP-HPLC were optimized utilizing a quality-by-design approach to accomplish the required chromatographic separation of GL from its nanoformulation with minimal experimental runs. Optimized RP-HPLC conditions for the assay method consist of acetonitrile (41%) and water, pH 1.8, balanced with phosphoric acid (0.1%) as a mobile phase with a flow rate of 1 mL/min. The retention time was found at 7.25 min, and method validation confirmed its sensitivity, preciseness, accuracy, and robustness.

Feasibility study of novel nanoparticles derived from Glycyrrhizae radix as vaccine adjuvant for cancer immunotherapy

Aims: The feasibility of using nanoparticles derived from Glycyrrhizae radix extract (Glycyrrhiza NPs) as a vaccine adjuvant for cancer immunotherapy was evaluated. Methods: C57BL/6J mice were immunized with ovalbumin (OVA) and Glycyrrhiza NPs. After immunization, splenocytes were incubated with the H-2K^b epitope peptide of OVA (SL8) and the production of IFN-γ was evaluated. Moreover, an OVA-expressing lymphoma cell line (E.G7-OVA cells) was inoculated into mice after immunization to evaluate the antitumor effect. Results: The immunization of OVA with Glycyrrhiza NPs induced IFN-γ production and completely rejected E.G7-OVA cells. Conclusion: Glycyrrhiza NPs could prime antigen-specific CD8⁺ T-cells resulting in antitumor effects. Therefore, Glycyrrhiza NPs can be an effective vaccine adjuvant for cancer immunotherapy.

Efficacy of a standardized herbal formulation from Glycyrrhiza glabra L. as an adjuvant treatment in hospitalized patients with COVID-19: A Randomized Controlled trial

Introduction

As no specific pharmacological intervention has been known for COVID-19, medicinal plants may be a suitable candidate for management of this disease. The aim of this study was to investigate the efficacy of a herbal syrup from licorice as an adjuvant treatment in hospitalized patients with COVID-19.

Materials and methods

213 hospitalized patients diagnosed with COVID-19 were assigned to receive either standardized licorice syrup as an adjuvant treatment plus standard care [Syrup Group (SYRUP), N = 91], or standard care alone [Standard Group (STANDARD), N = 104], for 7 days. The primary endpoint was duration of hospitalization in survivors. The secondary endpoints included 25% increase in oxygen saturation, C-reactive protein (CRP) difference and lymphocyte difference from baseline, number of death and number of patients transferred to ICU.

Results

Mean duration of admission was 5.24 days in SYRUP and 7.14 days in STANDARD (p < 0.001). Oxygen saturation increased in 86 of 91 patients (94.5%) in the licorice group, compared to 83 of 104 patients (79.8%) in the control group (p = 0.002). There was no significant difference between the two groups in the number of patients died during hospitalization (p = 0.837). Five patients in SYRUP and 16 patients in STANDARD were transferred to ICU (p < 0.026). Mean reduction in CRP (p < 0.001) and mean increase in the number of lymphocytes (p = 0.008) in SYRUP were significantly higher than STANDARD.

Discussion

Licorice syrup as an adjuvant treatment demonstrated promising results on duration of hospital admission, O2 saturation as well as inflammatory markers in COVID-19 patients; however, further clinical studies with larger sample size are suggested to achieve more conclusive results.