Determination of Two Wound Healing Components in Streptocaulon juventas (Lour.) Merr.: Periplogenin and Digitoxigenin.

Streptocaulon juventas (Lour.) Merr. (SJ) is a herbal medicine can promote wound healing. Cardiac glycosides, especially periplogenin, digitoxigenin, and their glycosides were the main constituents of SJ. We aim to establish a method for the simultaneous determination of periplogenin and digitoxigenin in SJ and evaluate the wound healing activities of these two components. UPLC-QqQ-MS/MS was used for the determination of periplogenin and digitoxigenin. Meanwhile, rats were subjected to full-thickness skin resection on the back to investigate the wound healing effects of periplogenin and digitoxigenin. The content of periplogenin and digitoxigenin in 13 batches of SJ extracts ranged from 43.26 to 97.15 µg/g and 18.04 to 55.55 µg/g, respectively. Periplogenin and digitoxigenin significantly increased the rate of wound healing in rats, increased the content of hydroxyproline in wound tissue, and improved the pathological state of wound skin tissue.

Combination of Coptis chinensis polysaccharides and berberine ameliorates ulcerative colitis by regulating gut microbiota and activating AhR/IL-22 pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Coptis chinensis Franch. polysaccharide (CCP) and berberine (BBR) are the primary active components of Coptis chinensis Franch. BBR is clinically used for the treatment of intestinal infections and gastroenteritis. CCP was also reported to be effective for the treatment of ulcerative colitis (UC). However, whether CCP combined with BBR shows a synergistic effect on the treatment of UC has not been elucidated yet. AIM OF THE STUDY: This study aspired to investigate the therapeutic effect and the possible mechanisms of the combination of CCP with BBR on chronic UC. MATERIALS AND METHODS: By periodic administration of dextran sulfate sodium (DSS) to C57BL/6J mice, chronic UC model mice were induced. CCP (15 mg/kg), BBR (50 mg/kg), and CCP.BBR (a combination of 15 mg/kg CCP and 50 mg/kg BBR) were orally administered to the model mice for 10 days. Changes of body weight, disease activity index, colon length, organ index, histopathological damage, expression of cytokines, and intestinal tight junction proteins were determined to evaluate the therapeutic effects. 16S rDNA sequencing, targeted short-chain fatty acid metabolomics, qPCR, and western blotting were performed to elucidate the potential mechanism. RESULTS: Both CCP and BBR alleviated UC via improving colon pathological damage, inhibiting the inflammatory response, and regulating the expression of intestinal tight junction proteins. The combination of CCP with BBR showed a more substantial therapeutic effect via increasing the relative abundance of short-chain fatty acids (SCFAs) producing bacteria, thereby increasing the contents of SCFAs in vivo and activating AhR/IL-22 pathway. CONCLUSION: The combination of CCP and BBR showed a synergistic effect on the therapy of chronic UC and the mechanism was associated with regulating gut microbiota and activating AhR/IL-22 pathway.

Deciphering the underlying wound healing mechanisms of Streptocaulon juventas (Lour.) Merr. by integrating network pharmacology, transcriptomics, and experimental validation.

ETHNOPHARMACOLOGICAL RELEVANCE: Streptocaulon juventas (Lour.) Merr. (SJ), a traditional Chinese folk medicine, has been widely used for the treatment of dysentery and traumatic injuries since ancient times. However, the mechanisms underlying its wound healing activity remain unclear. AIM OF THE STUDY: The aim of this study was to evaluate the wound healing activity of SJ and clarify the underlying molecular mechanisms. MATERIALS AND METHODS: The wound healing activity of an ethanol extract of SJ (ESJ) was confirmed in rat full-thickness wound models. UPLC-Q-TOF-MS/MS was used to analyze the composition of ESJ. Potential molecular targets and signaling pathways involved in the wound healing activity of ESJ were predicted using network pharmacology and transcriptomic analyses. In addition, the L929 cells were used to evaluate the in vitro wound healing activity of ESJ and to verify the predicted pathways. RESULTS: In rat wound models, ESJ significantly accelerated wound healing and promoted hydroxyproline production in wounds. Network pharmacology and transcriptomic analyses results revealed that ESJ might promote wound healing by activating the AKT and MAPK pathways. In L929 cells, ESJ significantly promoted cell proliferation, migration, and expression of collagen I and α-SMA. Additionally, ESJ treatment increased the phosphorylation of AKT, mTOR, ERK, and p38 in a time- and dose-dependent manner. CONCLUSIONS: ESJ significantly promoted wound healing in vivo and in vitro. AKT-mTOR and ERK-p38 signaling pathways were involved in the wound healing activity of ESJ.

Botanical Drugs in Traditional Chinese Medicine With Wound Healing Properties.

Chronic and unhealed wound is a serious public problem, which brings severe economic burdens and psychological pressure to patients. Various botanical drugs in traditional Chinese medicine have been used for the treatment of wounds since ancient time. Nowadays, multiple wound healing therapeutics derived from botanical drugs are commercially available worldwide. An increasing number of investigations have been conducted to elucidate the wound healing activities and the potential mechanisms of botanical drugs in recent years. The aim of this review is to summarize the botanical drugs in traditional Chinese medicine with wound healing properties and the underlying mechanisms of them, which can contribute to the research of wound healing and drug development. Taken together, five botanical drugs that have been developed into commercially available products, and 24 botanical drugs with excellent wound healing activities and several multiherbal preparations are reviewed in this article.

Pharmacokinetics of Five Alkaloids and their Metabolites in Normal and Diabetic Rats after Oral Administration of Rhizoma coptidis.

Rhizoma coptidis has been clinically used for a long time for the treatment of various diseases in China, such as hypertension, diabetes, and inflammation. Previous studies have shown that alkaloid components of Rhizoma coptidis extract could be extensively metabolized and the metabolites were also considered to be the therapeutic material basis. However, until now, pharmacokinetic studies of the in vivo metabolites have not been revealed yet. The aim of the present study was to characterize the pharmacokinetics and excretions of five main alkaloids (berberine, jatrorrhizine, palmatine, epiberberine, and coptisine) and their seven metabolites (berberrubine, demethyleneberberine, jatrorrhizine-3-O-ß-D-glucuronide, thalifendine-10-O-ß-D-glucuronide, berberrubine-9-O-ß-D-glucuronide, demethyleneberberine-2-O-sulfate, and demethyleneberberine-2-O-ß-D-glucuronide) in rats after oral administration of Rhizoma coptidis extract. Meanwhile, comparative pharmacokinetics and excretions of these analytes in diabetic model rats were also investigated, since Rhizoma coptidis is widely used for the treatment of diabetes. Our results showed that the in vivo existing forms of alkaloid components were phase II metabolites, highlighting the glucuronidation metabolic pathway. In diabetic model rats, the utilization of Rhizoma coptidis alkaloids was significantly increased and the biotransformation of berberine into berberrubine was significantly inhibited.

Drug-drug interactions induced by Linderane based on mechanism-based inactivation of CYP2C9 and the molecular mechanisms.

Linderane (LDR) is a main furan-containing sesquiterpenoid of the common herbal medicine Lindera aggregata (Sims) Kosterm. Our early study indicated that LDR led to mechanism-based inactivation (MBI) of CYP2C9 in vitro, implying possible drug-drug interactions (DDIs) in clinic. In the present study, influence of LDR on the pharmacokinetics of the corresponding hydroxylated metabolites of CYP2C9 substrates in rats was investigated. Pharmacokinetic studies revealed that pretreatment with LDR at 20 mg/kg for 15 days inhibited the metabolism of both tolbutamide and warfarin catalyzed by CYP2C9. As for 4-hydroxytolbutamide, the Cmax was decreased, the t1/2z was prolonged, and the Vz/F was increased, all with significant difference. As for 7-hydroxywarfarin, the AUC0-t/AUC0-∞ and CLz/F were significantly decreased and increased, respectively. Furthermore, the underlying molecular mechanisms based on MBI of CYP2C9 by LDR were revealed. Two reactive metabolites of LDR, furanoepoxide and γ-ketoenal intermediates were identified in CYP2C9 recombinant enzyme incubation systems. Correspondingly, covalent modifications of lysine and cysteine residues of CYP2C9 protein were discovered in the CYP2C9 incubation system treated with LDR. The formation of protein adducts exhibited obvious time- and dose-dependence, which is consistent with the trend of enzyme inhibition caused by LDR in vitro. In addition to the apoprotein of CYP2C9, the heme content was significantly reduced after co-incubation with LDR. These data revealed that modification of both apoprotein and heme of CYP2C9 by reactive metabolites of LDR led to MBI of CYP2C9, therefore resulting in the inhibition of biotransformation of CYP2C9 substrates to their corresponding metabolites in vivo.

Sulfite as the substrate of C-sulfonate metabolism of α, ß-unsaturated carbonyl containing andrographolide: analysis of sulfite in rats' intestinal tract and the reaction kinetics of andrographolide with sulfite.

One-sixth of the currently known natural products contain α, ß-unsaturated carbonyl groups. Our previous studies reported a rare C-sulfonate metabolic pathway. Sulfonate groups were linked to the ß-carbon of α, ß-unsaturated carbonyl-based natural compounds through this pathway. However, the mechanism of this type of metabolism is still not fully understood, especially whether it is formed through enzyme-mediated biotransformation or direct sulfite addition. In this work, the enzyme-mediated and non-enzymatic pathways were studied. First, the sulfite content in rat intestine was determined by LC-MS/MS. The results showed that the amount of sulfite in rat intestinal contents was from 41.5 to 383 µg·g-1, whereas the amount of sulfite in rat feed was lower than the lower limit of quantitation (20 µg·g-1). Second, the reaction kinetics of sulfite-andrographolide reactions in phosphate buffer solutions (pH 6-8) was studied. The half-lives of andrographolide ranged from minutes to hours. This was suggested that the C-sulfonate reaction of andrographolide was very fast. Third, the C-sulfonate metabolites of andrographolide were both detected when andrographolide and L-cysteine-S-conjugate andrographolide were incubated with the rat small intestine contents or sulfite, indicating that the sulfite amount in rat intestine contents was high enough to react with andrographolide, which assisted a significant portion of andrographolide metabolism. Finally, the comparison of andrographolide metabolite profiles among liver homogenate (with NADPH), liver S9 (with NADPH), small intestine contents homogenate (with no NADPH), and sulfite solution incubations showed that the C-sulfonate metabolites were predominantly generated in the intestinal tract by non-enzymatic pathway. In summary, sulfite can serve as a substrate for C-sulfonate metabolism, and these results identified non-enzymatically nucleophilic addition as the potential mechanism for C-sulfonate metabolism of compounds containing α, ß-unsaturated carbonyl moiety.

Corrigendum to "Metabolic profiling of icaritin in rats using UHPLC-Q/TOF-MS" [Chinese Herbal Medicines 11 (2019) 185-191].

[This corrects the article DOI: 10.1016/j.chmed.2019.03.008.].

Traditional application and modern pharmacological research of Artemisia annua L.

As a Traditional Chinese Medicine, Artemisia annua L. (A. annua) has been used for the treatment of various diseases since ancient times, including intermittent fevers due to malaria, bone steaming and heat/fever arising from exhaustion, tuberculosis, lice, wounds, scabies, dysentery et al. With the discovery of artemisinin and its excellent anti-malarial activity, A. annua has received great attention. Recently, A. annua has been revealed to show inhibitory effects against parasites (e.g. Plasmodium, Toxoplasma gondii, Leishmania, Acanthamoeba, Schistosoma), viruses (e.g. hepatitis A virus, herpes simplex viruses 1 and 2, human immunodeficiency virus), fungi (Candida, Malassezia, Saccharomyces spp.) and bacteria (Enterococcus, Streptococcus, Staphylococcus, Bacillus, Listeria, Haemophilus, Escherichia, Pseudomonas, Klebsiella, Acinetobacter, Salmonella, Yersinia spp.). A. annua has also been reported to possess anti-inflammatory and anti-cancer actions and been employed for the treatment of osteoarthritis, leukemia, colon cancer, renal cell carcinoma, breast cancer, non-small cell lung cancer, prostate cancre and hepatoma. Besides, the immunoregulation, anti-adipogenic, anti-ulcerogenic, anti-asthmatic, anti-nociceptive and anti-osteoporotic activities of A. annua were also evaluated. Along these lines, this review summarizes the traditional application and modern pharmacological research of A. annua, providing novel insights of A. annua in the treatment of various diseases.

Systematic screening and characterization of absorbed constituents and in vivo metabolites in rats after oral administration of Rhizoma coptidis using UPLC-Q-TOF/MS.

Rhizoma coptidis has been used for a long time in China owing to its anti-bacterial, anti-diabetes, anti-hyperlipidemia and anti-obesity activities. However, the in vivo biotransformation of Rhizoma coptidis is still unclear to date. In this study, a three-step strategy using UPLC-Q-TOF/MS was applied to clarify the in vivo absorbed constituents and metabolites in rats after oral administration of Rhizoma coptidis. First, alkaloids in Rhizoma coptidis extract were identified. Second, six abundant alkaloids (berberine, palmatine, coptisine, epiberberine, jatrorrhizine, and columbamine) were selected as representative prototypes and the metabolic fates of them in rats were investigated to obtain a database of Rhizoma coptidis-derived metabolites. Finally, the metabolic profiles of Rhizoma coptidis were fully elucidated based on the above-mentioned results. In summary, 29 alkaloids were identified in Rhizoma coptidis, and a database of Rhizoma coptidis-derived metabolites was obtained with 144 characterized metabolites. A total of 89 xenobiotics including 12 absorbed constituents and 77 metabolites were identified in dosed rat biosamples. Major metabolic pathways of Rhizoma coptidis were hydroxylation, reduction, methylation, demethylation, demethylenation, desaturation, glucuronidation and sulfation. This is the first systematic study on the in vivo absorbed constituents and metabolic profiling of Rhizoma coptidis and will be beneficial for its further studies.

Curcumin metabolites contribute to the effect of curcumin on ameliorating insulin sensitivity in high-glucose-induced insulin-resistant HepG2 cells.

ETHNOPHARMACOLOGICAL EVIDENCE: Curcumin (CUR) is the active ingredient of Traditional Chinese Medicine turmeric (Curcuma longa L.), which has been used for treatment of diabetes in Ayurveda and China. CUR exerts potent anti-insulin-resistant effects in various cell lines. However, previous studies indicated CUR was metabolized extensively in vivo and massively degraded in a medium alkaline buffer solution. The real active component of the anti-insulin-resistant activity of CUR in vitro is not clear. AIM OF THE STUDY: Our study identified the functional contribution of the metabolites of CUR and the related molecular mechanism in improving insulin sensitivity. MATERIALS AND METHODS: HPLC and UPLC-QQQ-MS analyses were used to investigate the stability and metabolism of CUR in HepG2 cells. The effect of the metabolic products of CUR on insulin sensitivity was evaluated in high glucose (HG)-induced insulin-resistant HepG2 cells. A network pharmacology approach was used to examine the potential targets of the metabolites, and Western blotting was performed to verify changes in the targets. RESULTS: CUR was unstable in the cell culture medium, but the prototypes, metabolites and degradation products of CUR coexisted in the HepG2 cell culture experiment. The insulin sensitivity assay demonstrated that CUR and its metabolites enhanced insulin sensitivity in HG-induced insulin-resistant HepG2 cells, but the total degradation products of CUR may not play the major role. Similar to CUR, hexahydrocurcumin (HHC) and octahydrocurcumin (OHC) improved insulin sensitivity by strengthening the PI3K-AKT-GSK3B signal and suppressing the phosphorylation of ERK/JNK in HG-induced insulin-resistant HepG2 cells. CONCLUSIONS: Metabolites of CUR played a critical role in counteracting insulin resistance in HG-induced HepG2 cells. CUR exerted anti-insulin resistance effect in HepG2 cells in a multi-component, multi-target, and multi-pathway manner.

Simultaneous determination of five isoflavones in rat plasma by LC-MS/MS: Comparative pharmacokinetic characteristics of Puerariae lobatae radix in normal and type 2 diabetic rats.

A rapid and sensitive liquid chromatography with tandem mass spectrometry method was developed and validated for simultaneous determination of puerarin, daidzin, daidzein, 3'-hydroxy puerarin, and genistein in rat plasma after oral administration of Puerariae lobatae radix extract. The method of protein precipitation with acetonitrile was used for sample preparation. Chromatographic separation was achieved on a C18 column with the mobile phases of acetonitrile/water containing 0.1% formic acid. The analytes were detected by mass spectrometer with an electrospray ionization source operating in the negative ion mode. The linearity, precision, accuracy, dilution reliability, recovery, matrix effects, and stability of the method were within acceptable ranges. The developed method was successfully used to compare the pharmacokinetic characteristics of five analytes in normal and type 2 diabetics rats after oral administration of Puerariae lobatae radix extract. Several pharmacokinetic alterations were observed and this might be caused by the pathological state of type 2 diabetes.

Metabolic profiling of icariin in rat feces, urine, bile and plasma after oral administration using ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry.

Icariin, the major flavonoid constituent of the traditional Chinese medicine Epimedii Folium, is extensively researched owing to its comprehensive beneficial effects. This study aimed at identifying the in vivo metabolites and the metabolic profiling in rats after oral administration at a dose of icariin (100 mg/kg) with the aid of an ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS/MS) and metabolynx™ software. A total of 25 metabolites were detected and 4 of them were compared with standard substances. Among them, 10 metabolites were reported for the first time. The results indicated that the principal metabolism pathways of icariin in rat were hydroxylation and the conjugation with glucuronide. It also confirmed that M2, M14, M18 and M23 were the major circulating forms of icariin in rats following oral administration. Demethylation, dehydrogenation, epoxidation, reduction, oxidation were also observed and the epoxidation and reduction on the isopentenyl were regarded as new metabolic patterns of icariin. Moreover, this study could enrich the understanding of the metabolism of icariin and help to elucidate the metabolic profiling of other prenylflavonoids.

Discovery and identification of quality markers of Chinese medicine based on pharmacokinetic analysis.

BACKGROUND: Quality control of Chinese medicine (CM) is an effective measure to ensure the safety and efficacy of CM in clinical practice, which is also a key factor to restrict the modernization process of CM. Various chemical components exist in CM and the determination of several chemical components is the main approach for quality control of vast majority of CM in the present. However, many components determined lack not only specificity, but also biological activities. This is bound to greatly reduce the actual value of quality standard of CM. PURPOSE: Professor Changxiao Liu proposed the "quality marker" (Q-marker) concept to ensure the standardization and rationalization for the quality control of CM. As we all know, CMs are taken orally in most cases and could be extensively metabolized in vivo. Both prototype components and the metabolites could be the actual therapeutic material basis. Pharmacokinetic studies could benefit the elucidation of actual therapeutic material basis which is closely related to the identification of Q-markers. Therefore, a new strategy about Q-marker was proposed based on the pharmacokinetic analysis of CM, hoping to provide some ideas for the discovery and identification of Q-marker. METHODS: The relationship between pharmacokinetic studies and the identification of Q-markers was demonstrated in this review and a new strategy was proposed. Starting from the pharmacokinetic analysis, reverse tracing of the prototype active components and the potential prodrugs in CM were conducted first and the therapeutic material basis were identified as Q-markers. Then, modern analytical techniques and methods were applied to obtain comprehensive quality control for these constituents. Several CMs including gingko biloba, ginseng, Periplocae Cortex, Mori Cortex, Bupleuri Radix and Scutellariae Radix were listed as examples to clarify how the new strategy could be applied. CONCLUSION: Pharmacokinetic studies play an important role for the elucidation of therapeutic material basis of CM and the identification of Q-markers and it should be taken into account during the process of the investigation of Q-marker.

Identification of absorbed constituents and in vivo metabolites in rats after oral administration of Physalis alkekengi var. franchetii by ultra-high-pressure liquid chromatography quadrupole time-of-flight mass spectrometry.

The calyces of Physalis alkekengi var. franchetii (Chinese Lantern, JDL) are well-known as traditional Chinese medicine owing to its various therapeutic effects. However, the bioactive constituents responsible for the pharmacological effects of JDL and their metabolites in vivo are still unclear to date. In this paper, an ultra-high-pressure liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS/MS) method was established to identify absorbed constituents and in vivo metabolites in rat biological fluids after oral administration of JDL. Based on the proposed strategy, 33 compounds were observed in dosed rat biosamples. Twelve of 33 compounds were indicated as prototype components of JDL, and 21 compounds were predicted to be metabolites of JDL. Finally, the metabolic pathways were proposed, which were glucuronidation, sulfation, methylation and dehydroxylation for flavonoid constituents and sulfonation and hydroxylation for physalin consitituents. This is the first systematic study on the absorbed constituents and metabolic profiling of JDL and will provide a useful template for screening and characterizing the ingredients and metabolites of traditional Chinese medicine.

Identification of berberrubine metabolites in rats by using ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry.

Berberrubine, an isoquinoline alkaloid isolated from many medicinal plants, possesses diverse pharmacological activities, including glucose-lowering, lipid-lowering, anti-inflammatory, and anti-tumor effects. This study aimed to investigate the metabolic profile of berberrubine in vivo. Therefore, a rapid and reliable method using the ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) and metabolynx™ software with mass defect filter (MDF) technique was developed. Plasma, bile, urine and feces samples were collected from rats after oral administration of berberrubine with a dose of 30.0mg/kg and analyzed to characterize the metabolites of berberrubine in vivo for the first time. A total of 57 metabolites were identified, including 54 metabolites in urine, 39 metabolites in plasma, 28 metabolites in bile and 18 metabolites in feces. The results indicated that demethylenation, reduction, hydroxylation, demethylation, glucuronidation, and sulfation were the major metabolic pathways of berberrubine in vivo.

Metabolites identification of berberine in rats using ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry.

Berberine (BBR), the principle component for many medicinal plants such as Coptis chinensis Franch., Phellodendron chinense Schneid., and Mahonia bealei (Fort.) Carr., possesses diverse pharmacological activities, including anti-bacterial, anti-inflammatory, antitumor, hypolipidemic and antidiabetic activities. In this study, a rapid and reliable method using a five-step strategy based on the ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS), and metabolynx™ software with mass defect filter (MDF) technique was developed to investigate the metabolism of BBR. Plasma, bile, urine and feces samples were collected from rats after oral administration of BBR with a dose of 100mg/kg/day for three consecutive days and analyzed to characterize the metabolic profile of BBR. By comparing the molecular weights and MS fragmentations of the metabolites with those of the parent drug and reference standards, a total of 97 metabolites were identified, including 68 metabolites in urine, 45 metabolites in plasma, 44 metabolites in bile and 41 metabolites in feces. Demethylation, demethylenation, reduction, hydroxylation, and subsequent glucuronidation, sulfation and methylation were the major metabolic pathways of BBR in vivo.

A new phenone from the roots of Paeonia suffruticosa Andrews.

Thirteen phenones were obtained from the 70% ethanol extract of Paeonia suffruticosa Andrews. Their structures were determined on the basis of chemical methods and spectral data. Among them, compound 1 was identified as a new compound, and compounds 5 and 13 were obtained from genus Paeonia for the first time. The inhibitory effects of isolated compounds (1-12) on nitric oxide (NO) production in lipopolysaccharide-activated macrophages were evaluated, and NO production was suppressed significantly by compound 7.

Two new lignans from the aerial part of Vitex negundo.

A new phenyldihydronaphthalene-type lignan, (3R,4S)-6-hydroxy-4-(4-hydroxy- 3-methoxyphenyl)-5,7-dimethoxy-3,4-dihydro-2-naphthaldehyde-3a-O-ß-d-glucopyranoside (1), and a new phenylnaphthalene-type lignan, 6,7,4'-trihydroxy-3'-methoxy-2,3- cycloligna-1,4-dien-2a,3a-olide (2), along with 10-known lignan derivatives (3-12) were isolated from the aerial part of Vitex negundo var. heterophylla. Their structures were established by comprehensive 1D- and 2D-NMR spectroscopic analyses.

Potential drug interactions associated with glycyrrhizin and glycyrrhetinic acid.

Glycyrrhizin (GZ), the main active component of licorice, is a widely used therapeutic in the clinic. Depending on the disease, the treatment may involve a long course of high dose GZ. Another component of licorice, glycyrrhetinic acid (GA), is the main active metabolite of GZ and is thought to be responsible for the majority of the pharmacological properties of GZ. Therefore, GZ and GA are both used for therapeutic purposes. In addition, GZ and GA are also widely used to sweeten and flavor foods. Due to this widespread, multifaceted use of these substances, potential drug interactions with GZ and GA have recently gained attention. Along these lines, this review covers the known effects of GZ and GA on drug-metabolizing enzymes and efflux transporters. We conclude that both GZ and GA may have an effect on the activity of CYPs. For example, GZ may induce CYP3A activity through activation of PXR. Also, GZ and GA may affect glucuronidation in rats and humans. Furthermore, 18ß-GA is a potent inhibitor of P-gp, while GZ and GA are inhibitors of MRP1, MRP2 and BCRP. The pharmacokinetics and pharmacodynamics of many medications may be altered when used concurrently with GZ or GA, which is also covered in this review. Overall, GZ, GA or related products should be taken with caution when taken with additional medications due to the possible drug interactions.