Crocin is a unique water-soluble carotenoid found in crocus and gardenia flowers. Crocin has been shown to have a variety of pharmacological activities, such as antioxidant, anti-cancer, memory improvement, antidepressant, anti-ischemia, blood pressure lowering and aphrodisiac, gene protection and detoxification activities. Due to their amphiphilicity, crocin molecules form concentration-dependent self-associates (micelles) in a water solution. In the present study, using various NMR techniques (T2 relaxation and selective gradient NOESY), we have demonstrated that crocin forms mixed micelles with water-soluble drug delivery system glycyrrhizin and linoleic acid molecules. Note, that the spin-spin T2 relaxation time and NOESY spectroscopy are very sensitive to intermolecular interactions and molecular diffusion mobility. The second purpose of this work was the elucidation of the interaction of crocin with a model lipid membrane using NMR techniques and a molecular dynamics simulation and its effects on lipid oxidation. It was shown that the crocin molecule is located near the surface of the lipid bilayer and effectively protects lipids from oxidation by peroxyl radicals. The role of glycyrrhizin and vitamin C in metal-induced lipid oxidation was also elucidated. The results of this study may be useful for expanding the field of application of crocin in medicine and in the food industry.

Glycyrrhizin (GA) and its derivative Enoxolone (18β), isolated from the Glycyrrhiza glabra plant, are two potential molecules for treating viral diseases. Both demonstrate to regulate immune system with antiviral and anti-inflammatory activities, with the latter mainly due to modulation of inflammatory cytokines. The aim of this clinical trial was to evaluate the safety and efficacy of a nebulized GA/18β drug for treating COVID-19 patients.
An open label, randomized, placebo-controlled clinical trial was conducted in Mexico City from January-August 2022 (Registration No. PROTAP-CLI-00). Clinical and biochemical parameters were recorded. Blood samples from patients were regularly collected to evaluate interleukins IL-4, IL-2, IL-1b, TNF-α, IL-17A, IL-6, IL-10,IFN-γ, IL-12, IL-8 and TGF-β1, as well as IgM and IgG against SARS-CoV-2. Two doses of the drug were used - 30/2 mg (dose A) and 90/4 mg (dose B).
Both GA/18β doses modulated inflammatory response by reducing mainly IL-17A expression, which in turn kept IL-1β, IL-6, IL-8 and TNF-α interleukins unchanged, indicating significant modulation of key interleukin levels to prevent exacerbation of the immune response in COVID-19 patients. Early on, dose A increased IgM, while dose B induced expression of the antiviral IFN-γ. No severe side effects were seen with either dose, indicating nebulized GA/18β is a safe treatment that could be used for COVID-19 and potentially other viral infections involving inflammatory response.

Licorice extract (glycyrrhizin), a potent antiviral, anti-inflammatory, and antioxidant remedy, is a potential therapeutic option for COVID-19. We evaluated the efficacy and safety of licorice in patients with moderate COVID-19. In this study, 60 patients with confirmed COVID-19 were randomly assigned in a 1:1 ratio to receive licorice (at a dose of 760 mg three times a day for seven days) or control groups. The primary outcomes were SPO2, body temperature, and respiratory rate (RR) after the end of the intervention. The findings indicated that SPO2, body temperature, and RR had no significant difference between the groups at the end of the intervention. However, CRP and ALT improved in the licorice group toward the baseline. The number of patients with worse prognoses, LOS, mortality, and the incidence of adverse events were not different between the groups at the end of the study. Licorice had no beneficial effect on the clinical symptoms of COVID-19. Moreover, this intervention demonstrated a safe profile of adverse events. The confirmation of the results of this preparatory trial requires more detailed multiple-center trials with a larger sample size.

To understand that 18β-Glycyrrhetic acid 3-O-mono-β-D-glucuronide (GAMG) showed better pharmacological activity and drug-like properties than 18β-Glycyrrhizin (GL); a rapid and sensitive HPLC-MS/MS method was established for the simultaneous determination of GAMG and its metabolite 18β-Glycyrrhetinic acid (GA) in rat plasma and tissues after oral administration of GAMG or GL. This analytical method was validated by linearity, LLOQ, specificity, recovery rate, matrix effect, etc. After oral administration, GAMG exhibited excellent Cmax (2377.57 ng/mL), Tmax (5 min) and AUC0-T (6625.54 mg/L*h), which was much higher than the Cmax (346.03 ng/mL), Tmax (2.00 h) and AUC0-T (459.32 mg/L*h) of GL. Moreover, GAMG had wider and higher tissue distribution in the kidney, spleen, live, lung, brain, etc. These results indicated that oral GAMG can be rapidly and efficiently absorbed and be widely distributed in tissues to exert stronger and multiple pharmacological activities. This provided a physiological basis for guiding the pharmacodynamic study and clinical applications of GAMG.

Recent evidence points to a potential therapeutic role for glycyrrhizin(GR) and boswellic acids (BA) in the treatment of COVID-19 but conclusive evidence is lacking. Our aim is to investigate the efficacy of GR + BA versus placebo for the treatment of hospitalized patients with moderate SARS-CoV-2 or COVID-19 variants infection. The current study is a randomized, double-blind, placebo-controlled, single-center trial. Patients with SARS-CoV-2 or COVID-19 variants diagnosed by PCR test who were admitted to Sohag University hospital were eligible if they were at least 18 years of age and had moderate symptoms. Patients were randomly assigned to receive oral GR capsule (60 mg) and BA (200 mg) twice daily for 14 days or a matching placebo. All patients also received treatment with the institutional protocol for COVID-19. The primary outcome was mortality and time to recovery. Secondary outcome was clinical status score, 14 days after receiving study drugs. Adverse events from use of study drugs have been evaluated for up to 14 days. The trial is registered at ClinicalTrials.gov (Identifier NCT04487964). During the 6-month enrollment period (June-November, 2021) only 50 patients (54% women; median age 60 years, IQR 54-65) met eligibility and were randomly assigned. Evaluation of the primary outcome at 14 days showed that there were five deaths in the placebo group and no deaths in the GR + BA group. With regard to recovery time, it was significantly shorter (p = 0.0001) in the group receiving GR + BA capsule compared to the placebo group (median 7.0; IQR 6.0-8.0 days vs. median 12.5; IQR 12-20 days). Clinical status on the ordinal score scale as a secondary outcome showed a significant difference between the GR + BA group (median (IQR) score, 2 [2-3]) and placebo groups (mean (IQR) score, 3 [3-5.5]). There was a significant decrease in CRB (p = 0.000041) in GR + BA compared with the placebo group. In conclusion, this safe, inexpensive, antiviral, immunomodulating and anti-inflammatory combination may be considered for use in mild to moderate infections of SARS-CoV-2 or COVID-19 variants. The study is limited by the small sample size; therefore, larger randomized trials are required.

High Mobility Group Box 1 protein (HMGB1) is an abundant protein with multiple functions in cells, acting as a DNA chaperone and damage-associated molecular pattern molecule. It represents an attractive target for the treatment of inflammatory diseases and cancers. The plant natural product glycyrrhizin (GLR) is a well-characterized ligand of HMGB1 and a drug used to treat diverse liver and skin diseases. The drug is known to bind to each of the two adjacent HMG boxes of the non-glycosylated protein. In cells, HMGB1 is N-glycosylated at three asparagine residues located in boxes A and B, and these N-glycans are essential for the nucleocytoplasmic transport of the protein. But the impact of the N-glycans on drug binding is unknown. Here we have investigated the effect of the N-glycosylation of HMGB1 on its interaction with GLR using molecular modelling, after incorporation of three N-glycans on a Human HMGB1 structure (PDB code 2YRQ). Sialylated bi-antennary N-glycans were introduced on the protein and exposed in a folded or an extended conformation for the drug binding study. The docking of the drug was performed using both 18α- and 18β-epimers of GLR and the conformations and potential energy of interaction (ΔE) of the different drug-protein complexes were compared. The N-glycans do not shield the drug binding sites on boxes A and B but can modulate the drug-protein interaction, via both direct and indirect effects. The calculations indicate that binding of 18α/β-GLR to the HMG box is generally reduced when the protein is N-glycosylated vs. the non-glycosylated protein. In particular, the N-glycans in an extended configuration significantly weaken the binding of GLR to box-B. The effects of the N-glycans are mostly indirect, but in one case a direct contact with the drug, via a carbohydrate-carbohydrate interaction, was observed with 18β-GLR bound to Box-B of glycosylated HMGB1. For the first time, it is shown (at least in silico) that N-glycosylation, one of the many post-translational modifications of HMGB1, can affect drug binding.

Since ancient times, licorice, the root of Glycyrrhiza glabra, has been known to have a wide spectrum of therapeutic effects. Glycyrrhizin is cleaved to glycyrrhizic acid, which is subsequently converted to glycyrrhetic acid by human intestinal microflora. Glycyrrhetic acid is a potent inhibitor of 11β-hydroxysteroid dehydrogenase (11β-HSD) and performs a range of corticosteroid-like activities. The pharmacologic effects of licorice contribute to its anti-inflammatory, antioxidative, anti-allergenic, and antimicrobial properties. Licorice has been used to treat liver disease, gastrointestinal disorders, oral disease, and various skin disorders and has been used in gum, candy, herbs, alcoholic beverages, and food supplements. Licorice and its extracts, especially glycyrrhizin, can be taken orally, through the skin (in the form of gels and oils), and intravenously. Licorice demonstrates mineralocorticoid-like activity not only by inhibiting 11β-HSD2, but also by binding to a mineralocorticoid receptor, leading to potentially adverse risks of mineralocorticoid-like overactivity. Chronic use of licorice can lead to hypokalemia and hypertension, and some people are more sensitive to licorice exposure. Based on clinical trials, this review summarizes the positive effects of licorice and other reported side effects.

Liquorice [main ingredient, glycyrrhizin (GL)] is widely used as a food sweetener and herbal medicine. Occasionally, liquorice consumption causes pseudoaldosteronism as a side effect which causes oedema, hypokalaemia, and hypertension due to hyperactivity of mineral corticoid receptor. We aimed to detect GL metabolites in human blood and urine samples and to determine the pathological relationship between GL metabolites and pseudoaldosteronism. For this multi-centre, retrospective, cross-sectional study, we recruited patients who had visited Center for Kampo Medicine in Keio University Hospital, Department of Japanese Oriental (Kampo) Medicine in Chiba University Hospital, Clinic of Japanese Oriental (Kampo) Medicine in Kanazawa University Hospital, and Department of Oriental Medicine in Kameda Medical Center from November 2011 to July 2018. We collected laboratory data including concentration of serum potassium, plasma activity of renin and aldosterone, and residual blood and/or urine samples of participants who had experienced symptoms/signs of pseudoaldosteronism in the form of increase in blood pressure and occurrence or aggregation of oedema while taking liquorice-containing herbal preparations, and measured GL metabolites using a highly selective liquid chromatography tandem mass spectrometer system. We registered 97 participants (mean age 60 ± 15 years; male:female 14:83). 18β-glycyrrhetinic acid (GA) was detected in 67 serum samples (median 122 nM, range 5 nM-1.8 µM) and 18β-glycyrrhetyl-3-O-sulfate (compound 3) in 68 samples (median 239 nM, range 2 nM-4.2 µM). 3-Monoglucuronyl 18β-glycyrrhetinic acid, 22α-hydroxy-18β-glycyrrhetyl-3-O-sulfate-30-glucuronide, 22α-hydroxy-18β-glycyrrhetyl-3-O-sulfate, and GL itself were not or rarely detected. We could not find any correlation between blood pressure or peripheral oedema and serum concentration of GL metabolites. Sulfotransferase 2A1 catalysed the metabolic reaction of GA to compound 3, a major GL metabolite in human blood. High serum concentration of compound 3 was related to lower renin, aldosterone, and potassium levels, suggesting a pathological relationship between compound 3 and liquorice-induced pseudoaldosteronism. This is the first study to identify the association between a novel metabolite, compound 3, and the incidence of pseudoaldosteronism, highlighting it as a promising biomarker.

UNASSIGNED: Dry eye disease (DED) is characterized by a loss of homeostasis of the tear film. It goes along with ocular symptoms, in which ocular surface inflammation and damage play etiological roles. High-mobility group box 1 protein (HMGB1) is a pro-inflammatory protein found in the tear fluid during conjunctivitis, blepharitis and DED. Glycyrrhizin binds to HMGB1, inhibiting cytokine activities, thus potentially improving DED.
UNASSIGNED: To assess the efficacy and tolerance of glycyrrhizin in moderate DED.
UNASSIGNED: Multicenter, open-label, prospective, nonrandomized clinical pilot study of glycyrrhizin 2.5% eye drops twice daily over 28 days in adult patients with moderate DED using standard evaluation parameters.
UNASSIGNED: The overall mean age of the 37 patients included was 59.6±19.0 years, 70.3% of the patients were female and 77.0% of the patients had an Oxford score of II. After 28 days, 60.8% of the patients had an Oxford score of 0 or I; a significant mean improvement in the score of 0.97±0.86 (P<0.001) from 2.20±0.44 at day 1 to 1.23±0.88 at day 28 was observed. Tear break-up time and Schirmer scores had significantly improved while the number of patient-reported symptoms had significantly decreased (all P≤0.010). A large majority of patients still had a few spots on their naso-bulbar conjunctiva (86.1%), temporal-bulbar conjunctiva (81.4%) and cornea (84.7%). The investigators considered that DED had improved in 71.6% of the patients. Patients appreciated the eye drops for their efficacy and good tolerance profile, leading to a decreased use of artificial tears. No changes in intraocular pressure and visual acuity were observed; glycyrrhizin 2.5% eye drops were safe, with only one patient reporting a moderate, transient treatment-related contact allergy leading to the withdrawal of the patient. Overall, two patients reported three adverse events, two (moderate contact allergy in both eyes) were related to the eye drops and experienced by the same patient; treatment was stopped; the third event was not treatment-related.
UNASSIGNED: In this pilot study, glycyrrhizin 2.5% eye drops were well tolerated and provide a good clinical benefit to patients with moderate DED after 28 days of continued daily use.

Glycyrrhizin is used to treat chronic hepatitis, but it also plays an important role in pseudoaldosteronism. Multidrug resistance-associated protein 2 is important for glycyrrhizin excretion. Dysfunction of this transporter increases the serum levels of direct bilirubin, glycyrrhizin and its metabolites. Hence, elevated direct-bilirubin levels could predict the risk of pseudoaldosteronism. This study aimed to evaluate the relationship between elevated direct-bilirubin levels and hypokalaemia, which is the most sensitive marker of pseudoaldosteronism. This retrospective cohort study was conducted in a Japanese university hospital. The occurrence of hypokalaemia is defined as a serum potassium level of ≤3.5 mEq/L after the administration of a glycyrrhizin-containing medication, and a further decline of ≥0.5 mEq/L or an increase of ≥0.5 mEq/L after discontinuing the glycyrrhizin-containing medication was examined in patients with chronic hepatitis between January 2009 and December 2015. This analysis involved 1392 patients, including 596 women. Hepatitis C virus infections were the most common cause of chronic hepatitis in this study. Seventy-nine patients received glycyrrhizin (exposed group; mean age: 60.5 ± 14.2) and 1313 did not receive glycyrrhizin (control group; mean age: 58.3 ± 15.8 years). Synergistic effects of glycyrrhizin-containing medications and elevated direct-bilirubin levels were associated with hypokalaemia. Elevated direct-bilirubin levels and hypoalbuminaemia were associated with hypokalaemia in the exposed group. Older age, female sex, high daily glycyrrhizin dosage, longer duration of glycyrrhizin intake, and potassium-lowering medications were not associated with hypokalaemia after the model adjustment. Elevated direct-bilirubin levels and hypoalbuminaemia may predict pseudoaldosteronism caused by glycyrrhizin.