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

Randomized double-blind personalized N-of-1 clinical trial to test the safety and potential efficacy of TJ-68 for treating muscle cramps in amyotrophic lateral sclerosis (ALS): study protocol for a TJ-68 trial

INTRODUCTION/AIMS

Muscle cramps are a common and often disabling symptom in amyotrophic lateral sclerosis (ALS), a devastating and incurable neurodegenerative disorder. To date, there are no medications specifically approved for the treatment of muscle cramps. Ameliorating muscle cramps in ALS may improve and sustain quality of life. A widely prescribed traditional Japanese (Kampo) medicine against muscle cramps, shakuyakukanzoto (TJ-68), has been studied in advanced liver disease, spinal stenosis, kidney failure, and diabetic neuropathy. The Japanese ALS Management Guideline mentions TJ-68 for difficult muscle cramps in ALS. Therefore, the rationale of our trial is to investigate the safety and effectiveness of TJ-68 in treating painful and disabling muscle cramps in people with ALS outside of Japan. Accordingly, we are conducting a randomized clinical trial to test the safety and efficacy of TJ-68 in participants with ALS reporting frequent muscle cramps using an innovative, personalized N-of-1 design. If successful, TJ-68 may be used for muscle cramps in a broader population of people with ALS.

METHODS

This is a two-site, double-blind, randomized personalized N-of-1 early clinical trial with TJ-68. At least 22 participants with ALS and daily muscle cramps will receive drug or placebo for 2 weeks (one treatment period) followed by a 1-week washout in a four-period cross-over design. While the primary objective is to evaluate the safety of TJ-68, the study has 85% power to detect a one-point shift on the Visual Analog Scale for Muscle Cramps Affecting Overall Daily Activity of the Columbia Muscle Cramp Scale (MCS). Secondary outcomes include the full MCS score, a Cramp Diary, Clinical Global Impression of Changes, Goal Attainment Scale, quality of life scale and ALS functional rating scale-revised (ALSFRS-R).

DISCUSSION

The study is underway. A personalized N-of-1 trial design is an efficient approach to testing medications that alleviate muscle cramps in rare disorders. If TJ-68 proves safe and efficacious then it may be used to treat cramps in ALS, and help to improve and sustain quality of life.

TRIAL REGISTRATION

This clinical trial has been registered with ClinicalTrials.gov (NCT04998305), 8/9/2021.

Natural Products as a Potential Source of Promising Therapeutics for COVID-19 and Viral Diseases

Background

A global pandemic has recently been observed due to the new coronavirus disease, caused by SARS-CoV-2. Since there are currently no antiviral medicines to combat the highly contagious and lethal COVID-19 infection, identifying natural sources that can either be viricidal or boost the immune system and aid in the fight against the disease can be an essential therapeutic support.

Methods

This review was conducted based on published papers related to the herbal therapy of COVID-19 by search on databases including PubMed and Scopus with herbal, COVID-19, SARS-CoV-2, and therapy keywords.

Results

To combat this condition, people may benefit from the therapeutic properties of medicinal plants, such as increasing their immune system or providing an antiviral impact. As a result, SARS-CoV-2 infection death rates can be reduced. Various traditional medicinal plants and their bioactive components, such as COVID-19, are summarized in this article to assist in gathering and debating techniques for combating microbial diseases in general and boosting our immune system in particular.

Conclusion

The immune system benefits from natural products and many of these play a role in activating antibody creation, maturation of immune cells, and stimulation of innate and adaptive immune responses. The lack of particular antivirals for SARS-CoV-2 means that apitherapy might be a viable option for reducing the hazards associated with COVID-19 in the absence of specific antivirals.

Characteristics of psychiatric patients with hypokalemia after yokukansan administration: A retrospective study

Aim

Yokukansan is a Japanese herbal medicine used in psychiatry to treat behavioral and psychological symptoms of dementia and other psychiatric symptoms. However, the glycyrrhizic acid included in this medicine can cause pseudoaldosteronism and hypokalemia. We aimed to identify the risk factors for hypokalemia due to yokukansan.

Methods

A retrospective cohort study was conducted on patients previously treated with yokukansan. The risk factors were determined by comparing the hypokalemia group with the non-hypokalemia group for each parameter.

Results

This study included 304 patients who received yokukansan treatment between April 2009 and March 2019. We found that 17.4% (n = 53) of the patients experienced yokukansan-induced hypokalemia. Risk factors detected as significantly different between patients with and without yokukansan-associated hypokalemia were low serum potassium concentration before yokukansan administration, dose 7.5 g /day or more, and dementia. Hypokalemia occurred earlier in patients with low albumin, low potassium, and dementia.

Conclusion

It is necessary to pay attention to hypokalemia onset when administering yokukansan at 7.5 g or more to patients with low potassium levels and dementia. Our findings suggest that potassium levels must be checked early after yokukansan administration, especially in patients with low albumin, low potassium, and dementia.

Analysis of the network pharmacology and the structure-activity relationship of glycyrrhizic acid and glycyrrhetinic acid

Licorice, a herbal product derived from the root of Glycyrrhiza species, has been used as a sweetening agent and traditional herbal medicine for hundreds of years. Glycyrrhizic acid (GL) and glycyrrhetinic acid (GA) are the most important active ingredients in licorice. Both GL and GA have pharmacological effects against tumors, inflammation, viral infection, liver diseases, neurological diseases, and metabolic diseases. However, they also exhibit differences. KEGG analysis indicated that licorice is involved in neuroactive ligand‒receptor interactions, while 18β-GA is mostly involved in arrhythmogenic right ventricular cardiomyopathy. In this article, we comprehensively review the therapeutic potential of GL and GA by focusing on their pharmacological effects and working mechanisms. We systemically examine the structure-activity relationship of GL, GA and their isomers. Based on the various pharmacological activities of GL, GA and their isomers, we propose further development of structural derivatives of GA after chemical structure modification, with less cytotoxicity but higher targeting specificity. More research is needed on the clinical applications of licorice and its active ingredients.

Multi-compound and drug-combination pharmacokinetic research on Chinese herbal medicines

Traditional medicine has provided a basis for health care and disease treatment to Chinese people for millennia, and herbal medicines are regulated as drug products in China. Chinese herbal medicines have two features. They normally possess very complex chemical composition. This makes the identification of the constituents that are together responsible for the therapeutic action of an herbal medicine challenging, because how to select compounds from an herbal medicine for pharmacodynamic study has been a big hurdle in such identification efforts. To this end, a multi-compound pharmacokinetic approach was established to identify potentially important compounds (bioavailable at the action loci with significant exposure levels after dosing an herbal medicine) and to characterize their pharmacokinetics and disposition. Another feature of Chinese herbal medicines is their typical use as or in combination therapies. Coadministration of complex natural products and conventional synthetic drugs is prevalent worldwide, even though it remains very controversial. Natural product–drug interactions have raised wide concerns about reduced drug efficacy or safety. However, growing evidence shows that incorporating Chinese herbal medicines into synthetic drug-based therapies delivers benefits in the treatment of many multifactorial diseases. To address this issue, a drug-combination pharmacokinetic approach was established to assess drug–drug interaction potential of herbal medicines and degree of pharmacokinetic compatibility for multi-herb combination and herbal medicine–synthetic drug combination therapies. In this review we describe the methodology, techniques, requirements, and applications of multi-compound and drug-combination pharmacokinetic research on Chinese herbal medicines and to discuss further development for these two types of pharmacokinetic research.

Impact of Gut Microbiota on the Pharmacokinetics of Glycyrrhizic Acid in Yokukansan, a Kampo Medicine

Individual differences in gut microbiota can affect the pharmacokinetics of drugs. Yokukansan is a traditional Japanese kampo medicine used to treat peripheral symptoms of dementia and delirium. A study examining the pharmacokinetics of the components of yokukansan reported large individual differences in the pharmacokinetics of glycyrrhizic acid (GL). It is known that GL is metabolized by intestinal bacteria to glycyrrhetinic acid (GA), which is absorbed in the gastrointestinal tract. Thus, the gut microbiota may affect GL pharmacokinetics. We aimed to clarify the relationship between the gut microbiota composition and pharmacokinetics of GL in yokukansan. Mice were orally administered yokukansan, following the administration of various antibiotics, and the plasma concentration of GA and composition of gut microbiota were measured. The GA plasma concentration was low in mice treated with amoxicillin and vancomycin. The composition of gut microbiota revealed a different pattern from that of the control group. Mice with low plasma levels of GA had lower levels of the phylum Bacteroides and Firmicutes. Additionally, bacteria, such as those belonging to the genera Parabaceroides, Bacteroides, Ruminococcus and an unknown genus in families Lachnospiraceae and Ruminococcaceae, exerted positive correlations between the gene copies and plasma GA levels. These bacteria may contribute to the absorption of GA in the gastrointestinal tract, and multiple bacteria may be involved in GL pharmacokinetics. The pharmacokinetics of GL may be predicted by evaluating the composition of gut bacteria, rather than by evaluating the amount of a single bacterium.

Role of the microbiota in hypertension and antihypertensive drug metabolism

Recent evidence suggests that the gut microbiota plays an important role in the development and pathogenesis of hypertension. Dysbiosis, an imbalance in the composition and function of the gut microbiota, was shown to be associated with hypertension in both animal models and humans. In this review, we provide insights into host-microbiota interactions and summarize the evidence supporting the importance of the microbiota in blood pressure (BP) regulation. Metabolites produced by the gut microbiota, especially short-chain fatty acids (SCFAs), modulate BP and vascular responses. Harmful gut-derived metabolites, such as trimethylamine N-oxide and several uremic toxins, exert proatherosclerotic, prothrombotic, and proinflammatory effects. High-salt intake alters the composition of the microbiota, and this microbial alteration contributes to the pathogenesis of salt-sensitive hypertension. In addition, the microbiota may impact the metabolism of drugs and steroid hormones in the host. The drug-metabolizing activities of the microbiota affect the pharmacokinetic parameters of antihypertensive drugs and contribute to the pathogenesis of licorice-induced pseudohyperaldosteronism. Furthermore, the oral microbiota plays a role in BP regulation by producing nitric oxide, which lowers BP via its vasodilatory effects. Thus, antihypertensive intervention strategies targeting the microbiota, such as the use of prebiotics, probiotics, and postbiotics (e.g., SCFAs), are considered new therapeutic options for the treatment of hypertension.

Synthesis and anti-inflammatory activities of glycyrrhetinic acid derivatives containing disulfide bond

A series of glycyrrhetinic acid (GA, aglycone of glycyrrhizic acid) derivatives containing disulfide bond were synthesized and their anti-inflammatory and anti-fibrosis activities were evaluated in vivo and in vitro. Among them, compound 7 displayed the highest toxicity to all the tested cell lines including macrophages. Compounds 3 and 4 showed higher activities than GA in the cell and animal model. In the anti-inflammatory tests, compounds 3 and 4 down-regulated the expressions of several inflammatory factors, such as HMGB1, TLR4, IL-1β, TNF-α and TGF-β1 in LPS-treated RAW264.7 cells in a dose-dependent manner. Compounds 3 and 4 at 30 µM respectively reduced the levels of HMGB1 in the LPS group to 42.7% and 38.2%. In addition, the level of TLR4 decreased to close to that of control group when treated by compound 4 at the concentration of 30 µM. In the process of anti-fibrosis tests using TGF-β1-induced A549 cell line as the model, compounds 3 and 4 also decreased the expression levels of Col1 and α-SMA in a dose-dependent manner. Compound 3 and 4 at 30 µM respectively reduced the expression of α-SMA level by 2.2-fold and 2.6-fold compared to the TGF-β1-treated control group. Moreover, they influenced the ROS level and mitochondrial membrane potential (MMP) in A549 cells. In the paraquat-induced pulmonary fibrosis mice model, the symptoms of inflammation and fibrosis of mice were alleviated after administration of compound 3 or 4. The above results suggest that compounds 3 and 4 may be promising candidates for inflammation and lung fibrosis treatment.

Immunological Separation of Bioactive Natural Compounds from Crude Drug Extract and Its Application for Cell-Based Studies

In this study, we present a review on a useful approach, namely, immunoaffinity column coupled with monoclonal antibodies (MAbs), to separate natural compounds and its application for cell-based studies. The immunoaffinity column aids in separating the specific target compound from the crude extract. The column capacity was stable even after more than 10 purification cycles of use under the same conditions. After applying the crude extract to the column, the column was washed with washing buffer and eluted with elution buffer. The elution fraction contained the target compound bound to MAb, whereas the washing fraction was the crude extract, which contained all compounds except a group of target compounds; therefore, the washing fraction was referred to as a knockout (KO) crude extract. Cell-based studies using the KO extract revealed the actual effects of the natural compounds in the crude extract. One-step separation of natural compounds using the immunoaffinity column coupled with MAbs may help in determining the potential functions of natural compounds in crude extracts.

Pharmacokinetics-based identification of pseudoaldosterogenic compounds originating from Glycyrrhiza uralensis roots (Gancao) after dosing LianhuaQingwen capsule

LianhuaQingwen capsule, prepared from an herbal combination, is officially recommended as treatment for COVID-19 in China. Of the serial pharmacokinetic investigations we designed to facilitate identifying LianhuaQingwen compounds that are likely to be therapeutically important, the current investigation focused on the component Glycyrrhiza uralensis roots (Gancao). Besides its function in COVID-19 treatment, Gancao is able to induce pseudoaldosteronism by inhibiting renal 11β-HSD2. Systemic and colon-luminal exposure to Gancao compounds were characterized in volunteers receiving LianhuaQingwen and by in vitro metabolism studies. Access of Gancao compounds to 11β-HSD2 was characterized using human/rat, in vitro transport, and plasma protein binding studies, while 11β-HSD2 inhibition was assessed using human kidney microsomes. LianhuaQingwen contained a total of 41 Gancao constituents (0.01-8.56 μmol/day). Although glycyrrhizin (1), licorice saponin G2 (2), and liquiritin/liquiritin apioside (21/22) were the major Gancao constituents in LianhuaQingwen, their poor intestinal absorption and access to colonic microbiota resulted in significant levels of their respective deglycosylated metabolites glycyrrhetic acid (8), 24-hydroxyglycyrrhetic acid (M2D; a new Gancao metabolite), and liquiritigenin (27) in human plasma and feces after dosing. These circulating metabolites were glucuronized/sulfated in the liver and then excreted into bile. Hepatic oxidation of 8 also yielded M2D. Circulating 8 and M2D, having good membrane permeability, could access (via passive tubular reabsorption) and inhibit renal 11β-HSD2. Collectively, 1 and 2 were metabolically activated to the pseudoaldosterogenic compounds 8 and M2D. This investigation, together with such investigations of other components, has implications for precisely defining therapeutic benefit of LianhuaQingwen and conditions for its safe use.

Clinical Risk Factors of Licorice-Induced Pseudoaldosteronism Based on Glycyrrhizin-Metabolite Concentrations: A Narrative Review

Licorice, the dried root or stolon of Glycyrrhiza glabra or G. ularensis, is commonly used worldwide as a food sweetener or crude drug. Its major ingredient is glycyrrhizin. Hypokalemia or pseudoaldosteronism (PsA) is one of the most frequent side effects of licorice intake. Glycyrrhizin metabolites inhibit type 2 11β-hydroxysteroid dehydrogenase (11βHSD2), which decomposes cortisol into inactive cortisone in the distal nephron, thereby inducing mineralocorticoid receptor activity. Among the several reported glycyrrhizin-metabolites, 18β-glycyrrhetyl-3-O-sulfate is the major compound found in humans after licorice consumption, followed by glycyrrhetinic acid. These metabolites are highly bound to albumin in blood circulation and are predominantly excreted into bile via multidrug resistance-associated protein 2 (Mrp2). High dosage and long-term use of licorice are constitutional risk factors for PsA. Orally administered glycyrrhizin is effectively hydrolyzed to glycyrrhetinic acid by the intestinal bacteria in constipated patients, which enhances the bioavailability of glycyrrhizin metabolites. Under hypoalbuminemic conditions, the unbound metabolite fractions can reach 11βHSD2 at the distal nephron. Hyper direct-bilirubin could be a surrogate marker of Mrp2 dysfunction, which results in metabolite accumulation. Older age is associated with reduced 11βHSD2 function, and several concomitant medications, such as diuretics, have been reported to affect the phenotype. This review summarizes several factors related to licorice-induced PsA, including daily dosage, long-term use, constipation, hypoalbuminemia, hyper direct-bilirubin, older age, and concomitant medications.

Endometriosis Susceptibility to Dapsone-Hydroxylamine-Induced Alterations Can Be Prevented by Licorice Intake: In Vivo and In Vitro Study

Endometriosis, an estrogen-dependent chronic gynecological disease, is characterized by a systemic inflammation that affects circulating red blood cells (RBC), by reducing anti-oxidant defenses. The aim of this study was to investigate the potential beneficial effects of licorice intake to protect RBCs from dapsone hydroxylamine (DDS-NHOH), a harmful metabolite of dapsone, commonly used in the treatment of many diseases. A control group (CG, n = 12) and a patient group (PG, n = 18) were treated with licorice extract (25 mg/day), for a week. Blood samples before (T₀) and after (T₁) treatment were analyzed for: i) band 3 tyrosine phosphorylation and high molecular weight aggregates; and ii) glutathionylation and carbonic anhydrase activity, in the presence or absence of adjunctive oxidative stress induced by DDS-NHOH. Results were correlated with plasma glycyrrhetinic acid (GA) concentrations, measured by HPLC–MS. Results showed that licorice intake decreased the level of DDS-NHOH-related oxidative alterations in RBCs, and the reduction was directly correlated with plasma GA concentration. In conclusion, in PG, the inability to counteract oxidative stress is a serious concern in the evaluation of therapeutic approaches. GA, by protecting RBC from oxidative assault, as in dapsone therapy, might be considered as a new potential tool for preventing further switching into severe endometriosis.

Risk Factors for Pseudoaldosteronism with Yokukansan Use: Analysis Using the Japanese Adverse Drug Report (JADER) Database

Yokukansan is a Kampo formula that is commonly used by the elderly because it is expected to improve peripheral symptoms of dementia and delirium. However, side effects from its use are frequently reported in the elderly. In particular, pseudoaldosteronism caused by the licorice contained in yokukansan leads to hypertension, hypokalemia, and muscle weakness, which may result in death. This study aimed to identify the risk factors of pseudoaldosteronism with yokukansan use. Using cases reported in the Japanese Adverse Drug Report (JADER) database, the reporting odds ratio (ROR) was calculated and compared to assess the risk of pseudoaldosteronism for each licorice-containing Kampo formula. We also analyzed the risk factors for pseudoaldosteronism in patients taking yokukansan. Yokukansan (ROR 2.4, 95% confidence interval (CI) 1.9-2.8; p < 0.001) had a higher risk of pseudoaldosteronism than that of other licorice-containing Kampo formulas. Furthermore, the results of a logistic regression analysis in patients taking yokukansan showed that the licorice dose (OR 1.5, 95% CI 1.2-2.0; p < 0.01), older age (<70 years, OR 5.9, 95% CI 1.8-20; p < 0.01), dementia (OR 2.8, 95% CI 1.6-4.9; p < 0.001), low body weight (<50 kg, OR 2.2, 95% CI 1.1-3.5; p = 0.034) were risk factors for pseudoaldosteronism, Although not significant, treatment with loop diuretics (OR 1.8, 95% CI 0.98-3.5; p = 0.059) tended to increase the risk of pseudoaldosteronism. In summary, patients must understand the risk factors when considering taking yokukansan and reduce the licorice dose they consume.

Identification of an Alternative Glycyrrhizin Metabolite Causing Liquorice-Induced Pseudohyperaldosteronism and the Development of ELISA System to Detect the Predictive Biomarker

Liquorice is usually used as crude drug in traditional Japanese Kampo medicine and traditional Chinese medicine. Liquorice-containing glycyrrhizin (GL) can cause pseudohyperaldosteronism as a side effect. Previously, we identified 18β-glycyrrhetyl-3-O-sulfate (3) as a GL metabolite in Eisai hyperbilirubinuria rats (EHBRs) with the dysfunction of multidrug resistance-related protein (Mrp2). We speculated that 3 was associated with the onset of liquorice-induced pseudohyperaldosteronism, because it was mainly detected in serum of patients with suspected to have this condition. However, it is predicted that other metabolites might exist in the urine of EHBRs orally treated with glycyrrhetinic acid (GA). We explored other metabolites in the urine of EHBRs, and investigated the pharmacokinetic profiles of the new metabolite in EHBRs and normal Sprague-Dawley rats. We further analyzed the serum concentrations of the new metabolite in the patients of pseudohyperaldosteronism. Finally, we developed the analyzing method of these metabolites as a preventive biomarker for the onset of pseudohyperaldosteronism using an enzyme-linked immunosorbent assay (ELISA). We isolated a new GL metabolite, 18β-glycyrrhetyl-3-O-sulfate-30-O-glucuronide (4). Compound 4 significantly inhibited rat type-2 11β-hydroxysteroid dehydrogenase (11β-HSD2) and was a substrate of both organic anion transporter (OAT) 1 and OAT3. Compound 4 was also detected in the serum of patients with suspected pseudohyperaldosteronism at an approximately 10-fold lower concentrations than 3, and these concentrations were positively correlated. Compound 4 showed a lower serum concentration and weaker inhibitory titer on 11β-HSD2 than 3. We developed an enzyme-linked immunosorbent assay system using an anti-18β-glycyrrhetyl-3-O-glucuronide (3MGA) monoclonal antibody to measure the serum concentration of 3 to facilitate the measurement of biomarkers to predict the onset of pseudohyperaldosteronism. Although we found 4 as the secondary candidate causative agent, 3 could be the main potent preventive biomarker of liquorice-induced pseudohyperaldosteronism. Compound 3 was detected in serum at a higher concentration than GA and 4, implying that 3 may be a pharmacologically active ingredient mediating not only the development of pseudohyperaldosteronism but anti-inflammatory effects in humans administered GL or other liquorice-containing preparations.

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 11β-hydroxysteroid dehydrogenase (11βHSD2) in tubular cells to cause pseudoaldosteronism. Since GA is not the substrates of these transporters, GA cannot inhibit 11βHSD2 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-18β-glycyrrhetyl-3-O-sulfate-30-glucuronide (1), 22α-hydroxy-18β-glycyrrhetyl-3-O-sulfate (2), and 18β-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.

Glycyrrhizin: An alternative drug for the treatment of COVID-19 infection and the associated respiratory syndrome?

Safe and efficient drugs to combat the current COVID-19 pandemic are urgently needed. In this context, we have analyzed the anti-coronavirus potential of the natural product glycyrrhizic acid (GLR), a drug used to treat liver diseases (including viral hepatitis) and specific cutaneous inflammation (such as atopic dermatitis) in some countries. The properties of GLR and its primary active metabolite glycyrrhetinic acid are presented and discussed. GLR has shown activities against different viruses, including SARS-associated Human and animal coronaviruses. GLR is a non-hemolytic saponin and a potent immuno-active anti-inflammatory agent which displays both cytoplasmic and membrane effects. At the membrane level, GLR induces cholesterol-dependent disorganization of lipid rafts which are important for the entry of coronavirus into cells. At the intracellular and circulating levels, GLR can trap the high mobility group box 1 protein and thus blocks the alarmin functions of HMGB1. We used molecular docking to characterize further and discuss both the cholesterol- and HMG box-binding functions of GLR. The membrane and cytoplasmic effects of GLR, coupled with its long-established medical use as a relatively safe drug, make GLR a good candidate to be tested against the SARS-CoV-2 coronavirus, alone and in combination with other drugs. The rational supporting combinations with (hydroxy)chloroquine and tenofovir (two drugs active against SARS-CoV-2) is also discussed. Based on this analysis, we conclude that GLR should be further considered and rapidly evaluated for the treatment of patients with COVID-19.

Differential annotation of converted metabolites (DAC-Met): Exploration of Maoto (Ma-huang-tang)-derived metabolites in plasma using high-resolution mass spectrometry

INTRODUCTION

Traditional herbal medicine (THM) contains a vast number of natural compounds with varying degrees of pharmacological activity. To elucidate the mode of action, comprehensive metabolite profiling in the plasma before and after administration of THM is essential.

OBJECTIVE

The aim of this study was to explore and identify/annotate converted metabolites after administration of THM in humans.

METHODS

We performed untargeted metabolome analysis of human plasma collected before and after administration of maoto (ma-huang-tang), a traditional Japanese Kampo medicine. Maoto-derived metabolites were then selected and annotated following the DAC-Met strategy, which is an annotation method that uses mass differences of major metabolic reactions among the detected peaks and a differential network analysis.

RESULTS

About 80% of maoto-derived components were found to be converted forms. Following DAC-Met, the structures of 15 previously unidentified metabolites were determined, and five of these were later confirmed with authentic standards. Using published literature, we also reconstructed the metabolic pathway of maoto components in humans. A kinetic time-course analysis revealed their diverse kinetic profiles.

CONCLUSION

The results demonstrated that time-resolved comprehensive metabolite profiling in plasma using the DAC-Met strategy is highly useful for elucidating the complex nature of THM.

Bioactive Candy: Effects of Licorice on the Cardiovascular System

Licorice, today chiefly utilized as a flavoring additive in tea, tobacco and candy, is one of the oldest used herbs for medicinal purposes and consists of up to 300 active compounds. The main active constituent of licorice is the prodrug glycyrrhizin, which is successively converted to 3β-monoglucuronyl-18β-glycyrrhetinic acid (3MGA) and 18β-glycyrrhetinic acid (GA) in the intestines. Despite many reported health benefits, 3MGA and GA inhibit the 11-β-hydrogenase type II enzyme (11β-HSD2) oxidizing cortisol to cortisone. Through activation of mineralocorticoid receptors, high cortisol levels induce a mild form of apparent mineralocorticoid excess in the kidney and increase systemic vascular resistance. Continuous inhibition of 11β-HSD2 related to excess licorice consumption will create a state of hypernatremia, hypokalemia and increased fluid volume, which can cause serious life-threatening complications especially in patients already suffering from cardiovascular diseases. Two recent meta-analyses of 18 and 26 studies investigating the correlation between licorice intake and blood pressure revealed statistically significant increases both in systolic (5.45 mmHg) and in diastolic blood pressure (3.19/1.74 mmHg). This review summarizes and evaluates current literature about the acute and chronic effects of licorice ingestion on the cardiovascular system with special focus on blood pressure. Starting from the molecular actions of licorice (metabolites) inside the cells, it describes how licorice intake is affecting the human body and shows the boundaries between the health benefits of licorice and possible harmful effects.