[Adverse effects of licorice consumed as food: An update]. / Toxicités de l'exposition alimentaire à la réglisse : mise au point.

The word "licorice" refers to the plant, its root, and its aromatic extract. From a commercial point of view, Glycyrrhiza glabra is the most important species with a wide range of uses (herbal medicine, tobacco industry, cosmetics, food and pharmaceutical). Glycyrrhizin is one of the main constituents of licorice. Glycyrrhizin is hydrolyzed in the intestinal lumen by bacterial ß-glucuronidases to 3ß-monoglucuronyl-18ß-glycyrrhetinic acid (3MGA) and 18ß-glycyrrhetinic acid (GA), which are metabolized in the liver. Plasma clearance is slow due to enterohepatic cycling. 3MGA and GA can bind to mineralocorticoid receptors with very low affinity, and 3MGA induces apparent mineralocorticoid excess syndrome through dose-dependent inhibition of 11ß-hydroxysteroid dehydrogenase type 2 in renal tissue. The cases of apparent mineralocorticoid excess syndrome reported in the literature are numerous and sometimes severe, even fatal, most often in cases of chronic high dose consumption. Glycyrrhizin poisonings are characterized by hypertension, fluid retention, and hypokalemia with metabolic alkalosis and increased kaliuresis. Toxicity depends on the dose, the type of product consumed, the mode of consumption (acute or chronic) and a very large inter-individual variability. The diagnosis of glycyrrhizin-induced apparent mineralocorticoid excess syndrome is based on the history, clinical examination, and biochemical analysis. Management is primarily based on symptomatic care and stopping licorice consumption.

Effects of mesotherapy introduction of compound glycyrrhizin injection on the treatment of moderate to severe acne.

BACKGROUND: Compound glycyrrhizin has achieved outstanding results in the treatment of various skin diseases. However, the use of mesotherapy to inject compound glycyrrhizin into the skin to treat acne is still understudied. AIMS: This paper aims to explore the effects of mesotherapy introduction of compound glycyrrhizin injection on the acne. MATERIALS & METHODS: A total of 108 patients were included in this study and divided into the control group (n = 54) and the observation group (n = 54). The control group was treated with topical clindamycin gel, while the study group was treated with topical clindamycin gel + mesotherapy and compound glycyrrhizin injection. Skin transepidermal water loss (TEWL), cuticle water content, acne severity, adverse reactions, and inflammatory reactions were documented before and after treatment in the two groups. RESULTS: The usage of mesotherapy to inject compound glycyrrhizin into the skin of acne patients more effectively treat acne than traditional clindamycin gel. The mesotherapy compound glycyrrhizin can more effectively protect the skin barrier of patients and reduce the loss of skin moisture. Compared with the traditional clindamycin gel, the combination of mesotherapy and compound glycyrrhizin more effectively inhibit the inflammatory reaction in acne patients and reduce skin damage in acne patients. DISCUSSION/CONCLUSION: Mesoderm introduction of compound glycyrrhizin injection has better effects on the treatment of moderate to severe acne than clindamycin gel.

Efficacy and Safety of Glycyrrhizic Acid in Treatment of Autoimmune Hepatitis.

To compare the long-term efficacy and safety of glycyrrhizic acid preparation and hormone treatment in patients with autoimmune hepatitis, we enrolled 377 patients in a study that lasted from January 2009 to January 2020. After performing propensity score matching, we included 58 patients in the hormone group and 58 in the glycyrrhizic acid preparation group in statistical analysis. We then compared the ratio of sustained biochemical responses at 48 weeks after treatment. Adverse events, including some incidence of decompensated liver cirrhosis and liver cancer, were evaluated. The results showed that a total of 61.8% of treated patients achieved complete biochemical remission. The cumulative biochemical remission rate in the hormone group and glycyrrhizic acid preparation group showed no significant difference (62.3% vs. 60.7%, [Formula: see text], [Formula: see text]). At the end of follow-up, the total bile acid in the hormone group was significantly higher than that in the glycyrrhizic acid preparation group (8.9[Formula: see text][Formula: see text]mol/L vs. 5.6[Formula: see text][Formula: see text]mol/L, [Formula: see text], [Formula: see text]). The incidence of adverse reactions in the hormone group was significantly higher than that in the glycyrrhizic acid preparation group (31.03% vs. 15.52%, [Formula: see text], [Formula: see text]). In conclusion, compared with the hormone treatment, glycyrrhizic acid preparation might be a safe and effective treatment for autoimmune hepatitis.

Exploration for the real causative agents of licorice-induced pseudoaldosteronism.

I investigated the causative agents of licorice-induced pseudoaldosteronism, which is a frequent side effect of Japanese traditional Kampo medicines. Glycyrrhizin (GL), the main ingredient of licorice, is absorbed after being metabolized to glycyrrhetinic acid (GA) by intestinal bacteria, and then metabolized in liver to 3-monoglucuronyl-glycyrrhetinic acid (3MGA). In normal condition, 3MGA is excreted into bile via a multidrug resistance-related protein (Mrp) 2, therefore, 3MGA does not appear in blood circulation. However, under the dysfunction of Mrp2, 3MGA appears in the blood circulation and is excreted into the urine by not glomerular filtration but tubular secretion via organic anion transporter (OAT) 1 and 3. At this time, 3MGA inhibits type 2 11ß-hydroxysteroid dehydrogenase (11ßHSD2) in tubular cells to cause pseudoaldosteronism. Since GA is not the substrates of these transporters, GA cannot inhibit 11ßHSD2 in tubular cells. Therefore, it was considered that 3MGA was the causative agents of licorice-induced pseudoaldosteronism. After that, I isolated and identified three other GL metabolites, 22α-hydroxy-18ß-glycyrrhetyl-3-O-sulfate-30-glucuronide (1), 22α-hydroxy-18ß-glycyrrhetyl-3-O-sulfate (2), and 18ß-glycyrrhetyl-3-O-sulfate (3) from the urine of Mrp2-deficient rats orally treated with GA, and found that their blood and urinary concentrations were much higher than 3MGA and that their pharmacokinetic behaviors were similar to 3MGA. 3MGA was not detected in the blood of patients with pseudoaldosteronism who developed rhabdomyolysis due to licorice, and compound 3 was detected at a high concentration. In addition, a multicenter retrospective study was conducted using the serum and urine of 97 patients who took Kampo medicines containing licorice. Of a total of 97 patients, 67 detected GA in the serum (median 122 nM, 5 nM-1.8 µM) and 68 detected compound 3 (median 239 nM, 2 nM-4.2 µM), and there were no cases of detection of GL, 3MGA, compounds 1, and 2. High blood concentrations of compound 3 were associated with low plasma renin activity, plasma aldosterone levels, and serum potassium levels. It is highly probable that compound 3 is the true causative agent of pseudoaldosteronism.

Compound glycyrrhizin combined with antihistamines for chronic urticaria: A protocol for systematic review and meta analysis.

BACKGROUND: To investigate the efficacy and safety of compound glycyrrhizin (CG) combined with antihistamines in the treatment of chronic urticaria (CU). METHODS: We will use computers to search all databases including Medline, Embase, Pubmed, Web of Science and Cochrane Central Register of Controlled Trials and China's 4 databases: China National Knowledge Infrastructure Database, China Biomedical Literature Database, China Science Journal Database, and Wanfang Database. Find data from creation date to July 2020. In addition, we will manually search the list of medical journals as a supplement. The scope of the search included randomized controlled clinical studies related to CG combined with antihistamines for CU. The primary outcome is the disease activity control. Secondary outcomes include response rate, adverse events, and recurrence rates. The Cochrane RevMan V5.3 Deviation Assessment Tool will be used to assess bias assessment risk, data integration risk, meta-analysis risk, and subgroup analysis risk (if conditions are met). The average difference, standard mean difference, and binary data will be used to represent continuous results. RESULTS: This study will comprehensively review the existing evidence on CG combined with antihistamines for CU. CONCLUSION: This systematic review will provide a basis for judging the effectiveness and safety of CG combined with antihistamines in the treatment of CU. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42020156153.

A Review of the Pharmacological Efficacy and Safety of Licorice Root from Corroborative Clinical Trial Findings.

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 11ß-hydroxysteroid dehydrogenase (11ß-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 11ß-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.

18ß-glycyrrhetyl-3-O-sulfate would be a causative agent of licorice-induced pseudoaldosteronism.

Licorice-induced pseudoaldosteronism is a common adverse effect in traditional Japanese Kampo medicine, and 3-monoglucuronyl glycyrrhetinic acid (3MGA) was considered as a causative agent of it. Previously, we found 22α-hydroxy-18ß-glycyrrhetyl-3-O-sulfate-30-glucuronide (1), one of the metabolites of glycyrrhizin (GL) in the urine of Eisai hyperbilirubinuria rats (EHBRs) treated with glycyrrhetinic acid (GA), and suggested that it is also a possible causative agent of pseudoaldosteronism. The discovery of 1 also suggested that there might be other metabolites of GA as causal candidates. In this study, we found 22α-hydroxy-18ß-glycyrrhetyl-3-O-sulfate (2) and 18ß-glycyrrhetyl-3-O-sulfate (3) in EHBRs' urine. 2 and 3 more strongly inhibited rat type 2 11ß-hydroxysteroid dehydrogenase than 1 did in vitro. When EHBRs were orally treated with GA, GA and 1-3 in plasma and 1-3 in urine were detected; the levels of 3MGA were quite low. 2 and 3 were shown to be the substrates of organic anion transporter (OAT) 1 and OAT3. In the plasma of a patient suffering from pseudoaldosteronism with rhabdomyolysis due to licorice, we found 8.6 µM of 3, 1.3 µM of GA, and 87 nM of 2, but 1, GL, and 3MGA were not detected. These findings suggest that 18ß-glycyrrhetyl-3-O-sulfate (3) is an alternative causative agent of pseudoaldosteronism, rather than 3MGA and 1.

Potassium chloride mixture may maintain hypokalaemia and hypertension.

Hypokalaemia can be treated with potassium chloride mixture. Some mixtures contain liquorice extract (glycyrrhizin) as a supplement to improve taste. Glycyrrhizin can cause pseudohyperaldosteronism and thereby result in hypertension and hypokalaemia. We here present a case where treatment with potassium chloride mixture causes hypertension and hypokalaemia in a 50-year-old woman. After unravelling differential diagnosis, the potassium chloride mixture was stopped. After the discontinuation, the patient's blood pressure was well managed and the potassium levels normalised.

[Scientific Evaluation of Crude Drugs and Kampo Medicines Using the Eastern Blotting Method and Its Application to Biological Metabolic Studies].

　The scientific evaluation of crude drugs and kampo medicines (KMs) was demonstrated using the eastern blotting method with monoclonal antibodies (MAbs) against bioactive natural compounds. Scutellariae radix is one of the most important crude drugs used in KMs. Part of its pharmaceutical properties is due to the flavone glycoside baicalin (BI). A quantitative analysis method based on eastern blotting was developed for BI using an anti-BI MAb. A rapid, simple, sensitive, specific analytical system was subsequently established for BI with the eastern blotting technique using dot-blot and chemiluminescent methods. This system was useful as a high-throughput analytical method for the determination of BI in KMs as well as HPLC and enzyme-linked immunosorbent assay systems. Furthermore, an eastern blotting method was applied to the biological metabolic study of glycyrrhizic acid (GL), the major active constituent of licorice, for investigation of metabolites of GL such as 3-monoglucuronyl-glycyrrhetinic acid (3MGA) because licorice causes pseudoaldosteronism as a side effect. This approach may make it possible to determine the pathogenic agents of licorice-induced pseudoaldosteronism.

The association between consistent licorice ingestion, hypertension and hypokalaemia: a systematic review and meta-analysis.

There have been numerous case reports of severe adverse events including deaths following chronic licorice ingestion. The aim of the present study was to evaluate the effect of chronic ingestion of licorice on blood pressure, plasma potassium, plasma renin activity and plasma aldosterone. A search of MEDLINE, PubMed, EMBASE, CENTRAL, DARE, CINAHL and Current Contents Connect was performed from inception through to 26 April 2017. Trials that included a treatment group ingesting a product containing at least 100 mg of glycyrrhizic acid daily were selected. Pooled mean changes from baseline with 95% confidence intervals were calculated for diastolic blood pressure, systolic blood pressure, plasma potassium, plasma renin activity and plasma aldosterone using a random effects model. An assessment of dose-response was also undertaken. A total of 18 studies (n=337) were included in the meta-analysis. There was a statistically significant increase in mean systolic blood pressure (5.45 mm Hg, 95% CI 3.51-7.39) and diastolic blood pressure (3.19 mm Hg, 95% CI 0.10-6.29) after chronic ingestion of a product containing glycyrrhizic acid. Plasma potassium (-0.33 mmol l-1, 95% CI -0.42 to 0.23), plasma renin activity (-0.82 ngml-1 per hour, 95% CI -1.27 to -0.37) and plasma aldosterone (-173.24 pmol l-1, 95% CI -231.65 to -114.83) were all significantly decreased. A significant correlation was noted between daily dose of glycyrrhizic acid and systolic blood pressure (r2=0.55) and diastolic blood pressure (r2=0.65), but not for the other outcome measures. Hence, chronic licorice ingestion is associated with an increase in blood pressure and a drop in plasma potassium, even at modest doses. This is of particular relevance for individuals with existing cardiovascular disease.

Compound glycyrrhizin plus conventional therapy for psoriasis vulgaris: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Psoriasis vulgaris is a chronic skin condition affecting patients' quality of life. Long-term use of conventional therapy increases risk of unwanted side effects. Compound glycyrrhizin in conjunction with conventional therapy has been used in clinical practice, but the evidence for such practice has not been evaluated systematically. OBJECTIVE: This review aims to evaluate the efficacy and safety of compound glycyrrhizin in combination with conventional therapy for psoriasis vulgaris. METHODS: PubMed, Excerpta Medica dataBASE (Embase), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Central Register of Controlled Trials, Allied and Complementary Medicine Database (AMED), CiNii, Chinese Biomedical Literature, China National Knowledge Infrastructure, Chinese Scientific Journals Full Text Database and Wanfang Data were searched from their respective inceptions to July 2015. Randomized controlled trials comparing compound glycyrrhizin plus conventional therapy to conventional therapy alone for psoriasis vulgaris were included. Data analysis was performed using Review Manager 5.3. RESULTS: Eleven randomized controlled trials were included in this review. Meta-analysis of the 11 randomized controlled trials indicated that the addition of compound glycyrrhizin increased the number of patients achieving Psoriasis Area and Severity Index (PASI) 60 (RR: 1.30 [1.21, 1.40], I2 = 6%), when compared with conventional therapy alone. Comparable numbers of patients experienced adverse events in the two groups. CONCLUSIONS: Compound glycyrrhizin in conjunction with conventional therapy enhances clinical response, and compound glycyrrhizin as add-on therapy does not appear to pose any additional risk in the treatment of psoriasis vulgaris. However, the findings should be interpreted with caution of methodological flaws in the included studies. PROSPERO registration number: CRD42015027763.

Hypertension induced by liquorice tea.

A 45-year-old woman presented to her general practitioner with a 4-month history of hot flushes, sweating and headaches. On examination, she was found to be hypertensive, and blood tests revealed mild hypokalaemia. While awaiting the results of further investigation into the cause of her elevated blood pressure, the patient conducted her own research and identified liquorice tea as the potential cause of her symptoms. The patient had been drinking up to six cups of liquorice tea per day as a substitute for caffeinated tea and fruit-based infusions. The patient immediately stopped consuming the drink and within 2 weeks her symptoms, hypertension and hypokalaemia had entirely resolved.

Antiviral effects of the constituents derived from Chinese herb medicines on infectious bursal disease virus.

CONTEXT: The prevalence of infectious bursal disease has brought about enormous financial losses to the world poultry industry. Chinese herb medicines can provide valuable materials for discovery and development of new drugs. OBJECTIVE: To screen constituents derived from Chinese herb medicines for their antiviral activity against infectious bursal disease virus (IBDV) in vitro. MATERIALS AND METHODS: Twenty constituents derived from Chinese herb medicines and B87 strain of IBDV were used. The 50% cytotoxic concentration (CC50) and 50% effective concentration (EC50) were determined by visualization of cytopathologic effect (CPE) and 3-(4,5-dimethyithiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) test on chicken embryo fibroblast. Selectivity index (SI) and inhibition ratio (%I) were calculated from the data obtained from the MTT test. RESULTS: Antiviral assays showed dipotassium glycyrrhizinate and ligustrazine hydrochloride among the 20 constituents tested exhibited significant inhibitory activity against IBDV in a dose-dependent manner. EC50 of dipotassium glycyrrhizinate and ligustrazine hydrochloride were 663.2 ± 268.4 and 92.52 ± 21.13 µg/mL, and SI were >4.52 and >21.62, respectively. The time-of-addition and virucidal assay indicated that anti-IBDV activity of the two constituents could be due to their inhibiting virus replication and/or inactivating virus directly. The inhibition of virus attachment was not observed in the adsorption inhibition assay. Dipotassium glycyrrhizinate and ligustrazine hydrochloride exhibited more than 70% and 80% inhibition of IBDV, respectively, at the maximum safe concentration. DISCUSSION AND CONCLUSION: We believe that dipotassium glycyrrhizinate and ligustrazine hydrochloride can be used to develop a new anti-IBDV compound, and it is worth applying the constituents in clinical practice.

A randomized controlled trial comparing total glucosides of paeony capsule and compound glycyrrhizin tablet for alopecia areata.

OBJECTIVE: To observe the efficacy and safety of total glucosides of paeony capsule (TGPC) in patients with mild and moderate alopecia areata. METHODS: A total of 86 outpatients were randomly allocated into two groups of TGPC (treatment, 44 cases) and compound glycyrrhizin tablet (control, 42 cases). The treatment group was given oral TGPC, three times daily and 600 mg per time; the control group was given oral compound glycyrrhizin tablets, three times daily and 50 mg per time. In addition, both groups were given 10 mg of vitamin B(2) and tapped the bold patches with massage. The treatment course was three months for both groups. Peripheral blood T-cell subsets (CD3(+)CD4(+), CD3(+)CD8(+), Th, Ts, Th/Ts) of 10 patients randomly selected from each group respectively were tested before and after three months of treatment. The effectiveness and adverse reaction of all cases were observed each month. The safety was evaluated according to the incidence rate of adverse reaction. RESULTS: In the treatment group, the cured and markedly effective rate was 36.36% (16/44), 50.00% (22/44) and 68.18% (30/44) at the end of first, second and third month of treatment, respectively, and the incidence rate of adverse reaction was 13.64% (6/44). In the control group, the cured and markedly effective rate was 38.10% (16/42), 57.14% (24/42) and 71.43% (30/42), respectively, and the incidence rate of adverse reaction was 16.67% (7/42). The cured and markedly effective rate and the incidence rate of adverse reaction were similar in both groups (P>0.05). TGPC and compound glycyrrhizin tablet can inhibit CD3(+)CD4(+) and CD3(+)CD8(+), and decrease the ratio of Th/Ts (P<0.05). CONCLUSION: TGPC is effective and safe in the treatment of alopecia areata.

Is glycyrrhizin sensitivity increased in anorexia nervosa and should licorice be avoided? Case report and review of the literature.

OBJECTIVE: Hypokalemia is a potentially life-threatening electrolyte disturbance in anorexia nervosa and is most frequently caused by purging behavior. We report a case of severe hypokalemia in anorexia nervosa induced by daily ingestion of approximately 20 g of licorice. METHODS: To confirm the diagnosis of licorice-induced pseudohyperaldosteronism, a re-exposure trial was performed. RESULTS: Cessation of the licorice intake normalized plasma potassium, renin, and aldosterone levels and the urine cortisol/cortisone ratio. Re-exposure confirmed the diagnosis. The pronounced response to a relatively low daily dose of licorice suggests high glycyrrhizin sensitivity. CONCLUSION: Patients with anorexia nervosa not only have decreased food intake but also selective and sometimes bizarre eating habits that, in association with increased sensitivity to glycyrrhizin, may cause severe hypokalemia.

[Clinical characteristics of five elderly patients with severe hypokalemia induced by glycyrrhizin derivatives].

Although hypokalemia is a common clinical problem, symptoms generally do not become manifest unless the serum potassium (K) falls rapidly. We encountered five cases with symptomatic severe hypokalemia (K<2.0 mEq/L) hospitalized for the past 15 months at our hospital. We examined the clinical characteristics and treatment of these patients. All five patients were women, and their mean age was 77.8 (73-82)years. They suffered from hypertension. Mean K level at admission was 1.66 (1.4-1.9) mEq/L and HCO3(-) was 48.3 (33.6-56.1) mmol/L. Plasma aldosterone level was low and plasma rennin activity was suppressed. All patients developed progressive muscle weakness with elevated creatinine phosphokinase. Three of the patients had received Chinese medicine which contained licorice, one received glycyrrhizin and the other one had received both. We diagnosed these cases as pseudoaldosteronism induced by glycyrrhizin. With discontinuation of the drugs and intravenous as well as oral K supplementation, serum K were normalized and clinical symptoms improved within 12 days. For one patient who developed cardiac dysfunction, concentrated K solution (230 mEq/L) was infused into the central vein. These findings show that glycyrrhizin ingestion should be kept in mind as a cause of an extreme degree of an hypokalemia, especially in elderly patients.

Pseudoaldosteronism caused by combined administration of cilostazol and glycyrrhizin.

We report a case of obvious pseudoaldosteronism which occurred after the additional administration of cilostazol against arteriosclerosis obliterans (ASO) for bilateral legs in a 65 year-old man patient who had safely received glycyrrhizin for the previous ten years. Serum potassium level of the patient had been kept above 4 mEq/L until initiating cilostazol in November, 2006, then gradually decreased to 2.5 mEq/L for the following seven months. Both plasma renin activity and aldosterone were suppressed under co-administration of the angiotensin converting enzyme inhibitor, imidapril and the angiotensin II receptor blocker, olmesartan, both of which had been prescribed for longer than a year. Urinary potassium excretion was accelerated even in the critical level of hypokalemia. Because other drugs and supplements had not been changed at least for a year, pseudoaldosteronism caused by the combination of glycyrrhizin and another triggering factor, possibly cilostazol was highly suspected. By discontinuation of glycyrrhizin, potassium supplement, and the additional administration of the aldosterone blocker, spironolactone, the serum potassium level returned to the normal level two weeks later, even though cilostazol had been continued to avoid progression in his ASO. This is the first report of a case exhibiting pseudoaldosteronism induced by the interaction of glycyrrhizin with cilostazol, not by glycyrrhizin alone.