Anti-necroptosis and anti-ferroptosis compounds from the Deep-Sea-Derived fungus Aspergillus sp. MCCC 3A00392.

Eight undescribed (1-8) and 46 known compounds (9-54) were isolated from the deep-sea-derived Aspergillus sp. MCCC 3A00392. Compounds 1-3 were three novel oxoindolo diterpenoids, 4-6 were three bisabolane sesquiterpenoids, while 7 and 8 were two monocyclic cyclopropanes. Their structures were established by exhaustive analyses of the HRESIMS, NMR, and theoretical calculations of the NMR data and ECD spectra. Compounds 10, 33, 38, and 39 were able to inhibit tumor necrosis factor (TNF)-induced necroptosis in murine L929 cell lines. Functional experiments verified that compounds 10 and 39 inhibited necroptosis by downregulating the phosphorylation of RIPK3 and MLKL. Moreover, compound 39 also reduced the phosphorylation of RIPK1. Compounds 10, 33, and 34 displayed potent inhibitory activities against RSL-3 induced ferroptosis with the EC50 value of 3.0 µM, 0.4 µM, and 0.1 µM, respectively. Compound 10 inhibited ferroptosis by the downregulation of HMOX1, while compounds 33 and 34 inhibited ferroptosis through regulation of NRF2/SLC7A11/GCLM axis. However, these compounds only showed weak effect in either the necroptosis or ferroptosis relative mouse disease models. Further studies of pharmacokinetics and pharmacodynamics might improve their in vivo bioactivities.

Chemical Constituents of the Deep-sea Gammarid Shrimp-Derived Fungus Penicillium citrinum XIA-16.

One new alkaloid, (S)-2-acetamido-4-(2-(methylamino)phenyl)-4-oxobutanoic acid (1), was isolated from the deep-sea-derived Penicillium citrinum XIA-16, together with 25 known compounds including ten polyketones (2-11), eight alkaloids (12-19), six steroids (20-25), and a fatty acid (26). Their planar and relative structures were determined by an analysis of 1D and 2D nuclear magnetic resonance (NMR) as well as high resolution electrospray ionization mass spectroscopy (HR-ESI-MS) data. The absolute configuration of 1 was determined by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. Penicitrinol B (6) significantly inhibited RSL3-induced ferroptosis (EC50 =2.0 µM) by reducing lipid peroxidation and heme oxygenase 1 (HMOX1) expression. Under the concentration of 10 µM, penicitrinol A (7) was able to inhibit cuproptosis with the cell viabilities of 68.2 % compared to the negative control (copper and elesclomol) with the cell viabilities of 14.8 %.

Chemical constituents and biological activities of Artemisia argyi H.Lév. & vaniot.

Artemisia argyi is a widely distributed and inexpensive plant resource, and study on its chemical compositions and biological activities will provide an important basis for its food applications and pharmaceutical developments. In this study, fourteen known guaiane-type sesquiterpenes (1-14), four known eudesmane-type sesquiterpenes (15-18), two known germacranolide-type sesquiterpenes (19, 20), and eight other types of terpenoids (20-28) were isolated from the leaves of A. argyi by polyamide and ODS CC and HPLC. The structures of all compounds are determined by 1 D NMR (1H-NMR、13C-NMR) and literature comparison. Among them, compounds 1 and 8 were isolated from Chinese folk medicine A. argyi for the first time. Besides, the LPS-induced RAW264.7 cell model has been evaluated the anti-inflammatory activities in vitro by the Griess reagent. The results indicated that the guaianolide sesquiterpenoids obtained from A. argyi have an excellent ability to inhibit NO production, especially Argyin A, a guaianolide sesquiterpenoid with isovaleryloxy substitution.

Secondary Metabolites from the Fresh Leaves of Pinus yunnanensis Franch.

Fifteen metabolites, including two flavonols (1-2), three lignans (3-5), and ten diterpenoids (6-15), were isolated from the leaves of Pinus yunnanensis. Among them, flavanonol (1) were identified as undescribed flavonol derivative with natural rarely B-ring fission lactone. Massive spectroscopic methods, the DP4+ probabilities and CD/ECD calculations were applied to establish the structure of component 1. Among these compounds, taxifolin (2) showed potent cytotoxicity, having IC50 values from 21.33 to 45.48 µg/mL, it also showed broad antibacterial activity against human pathogens with MIC values from 32 to 64 µg/mL.

Virtual screening of active compounds from jasminum lanceolarium and potential targets against primary dysmenorrhea based on network pharmacology.

In present study, multi-target and multi-pathway mechanisms of Jasminum lanceolarium Roxb (JL) on primary dysmenorrhea (PDM) treatment were predicted by the approach of network pharmacology and molecular docking, leading to the obtaining of 22 predicted targets for 69 compounds in JL. The Compound-Target analysis displayed intimate association among targets and compounds. Meanwhile, the Compound-Target-Target revealed PTGS2, OPRD1 and NOS3 were the key targets with intensive interaction. The Compound-Target-Pathway network indicated these pathways were closely related to hormone regulation, central analgesia, spasmolysis and inflammation. The anti-inflammation pathways might be the key mechanism of JL for the treatment of PDM based on KEGG pathway enrichment analysis and pharmacological experiment, and 10-hydroxyoleoside dimethyl ester might be a promising leading compound due to its good molecular docking scores and previous experimental evaluation.

Rare benzonaphthoxanthenones from Chinese folk herbal medicine Polytrichum commune and their anti-neuroinflammatory activities in vitro.

Two new (1-2) as well as five known (3-7) compounds were isolated from Polytrichum commune, a folk herbal medicine in China, and three of them (2, 4, 5) belong to benzonaphthoxanthenones that are rarely found in nature. Their structures were elucidated by the approach to 1D and 2D NMR spectra. The absolute configuration of 2 was assigned by comparing its experimental and calculated ECD data. 1-5 were investigated for their anti-neuroinflammatory activity against LPS-induced BV-2 cells. 1 and 3 exhibited well protective effect at a concentration of 2.5 µmol/mL. Molecular docking studies were adopted to further investigate the possible mechanism, whose results suggested that 1 might exert anti-neuroinflammatory effect by inhibiting activity of p38α, JNK2 and TAK1 to reduce the liberation of pro-inflammatory cytokines.

Polyhydroxyl guaianolide terpenoids as potential NF-кB inhibitors induced cytotoxicity in human gastric adenocarcinoma cell line.

Six new guaiane-type sesquiterpenes (1-6), and one monoterpenoid (7) along with five known analogues (8-12), were isolated from the leaves of Artemisia argyi Lévl et Vant. The new compounds were characterized by the basic analysis of the spectroscopic data (HRMS, 1D and 2D NMR), and the absolute configurations were determined by both calculated electronic circular dichroism and DP4 calculations. The inhibitory effects of 1-12 against human gastric adenocarcinoma (AGS) cells were investigated in vitro, among which 1-3 and 8 showed remarkable cytotoxic activity with IC50 values in the range of 6.69-10.25 µM. The results suggested that the variation in the inhibitory activities of the compounds are the result of different substitutions on C-8. In order to rationalize the binding interactions of active compounds with the active site of NF-кB, in silico study was conducted and the results were in complete agreement with the experimental data for cytotoxicity evaluation.

Isoquinolines from national herb Corydalis tomentella and neuroprotective effect against lipopolysaccharide-induced BV2 microglia cells.

Five new isoquinolines (1-5) were isolated from national herb Corydalis tomentella. Their structures were elucidated by extensive analysis of the 1D and 2D NMR spectra and from the HRESIMS. Absolute configurations of 1-3 were determined by comparing their experimental and computed ECD data. Since plants from Corydalis have been reported to protect against Alzheimer's disease, all compounds were evaluated for their neuroprotective effect against lipopolysaccharide-induced BV2 microglia cells. Compound 2 and 3 showed well anti-neuroinflammatory activity at low concentration (25 µM).

Revealing synergistic mechanism of multiple components in Stauntonia brachyanthera Hand.-Mazz. for gout by virtual screening and system pharmacological approach.

Stauntonia brachyanthera Hand.-Mazz. (SB), reported as a traditional Chinese medicine, displays a wide spectrum of interesting bioactivities, such as anti-inflammatory and analgesia. It is noteworthy that anti-gout effects of the components in SB have been reported. Hence, this study contributes to the prediction of promising active compounds and mechanisms for the treatment of gout. The active compounds with better oral bioavailability, and drug-likeness of SB were selected for further investigation by the approach of network pharmacology, molecular docking, gene ontology (GO) analysis, and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis, respectively. A total of 34 predicted targets and 98 compounds in SB were obtained. Sorted by structure types of compounds, phenylethanoid glycosides exhibited the best anti-gout activity, followed by phenolics and flavonoids. What's more, it was shown in the network analysis that Serine/threonine-protein kinase mTOR (mTOR), Mitogen-activated protein kinase 12 (MAPK12), tumor necrosis factor (TNF-α), Integrin alpha-4 (ITGA4) and Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit gamma (PIK3CG) were the key targets with intensely interaction, which should be attached more attention for further study. The functional enrichment analysis indicated that SB probably produced the anti-gout effects by synergistically regulating many biological pathways, such as MAPK signaling pathway, PI3K-Akt signaling pathway, Toll-like receptor signaling pathway and NOD-like receptor signaling pathway, etc. In addition, C61, C67, C68 and C81 might be promising leading compounds with good molecular docking score. As a consequence, the active constituents and mechanisms based on data analysis were holistically illuminated, which was of vital importance to the development of new drugs for gout.

Systems Pharmacological Approach to Investigate the Mechanism of Ohwia caudata for Application to Alzheimer's Disease.

Ohwia caudata (OC)-a traditional Chinese medicine (TCM)-has been reported to have large numbers of flavonoids, alkaloids, and triterpenoids. The previous studies on OC for treating Alzheimer's disease (AD) only focused on single targets and its mechanisms, while no report had shown about the synergistic mechanism of the constituents from OC related to their potential treatment on dementia in any database. This study aimed to predict the bioactive targets constituents and find potential compounds from OC with better oral bioavailability and blood-brain barrier permeability against AD, by using a system network level-based in silico approach. The results revealed that two new flavonoids, and another 26 compounds isolated from OC in our lab, were highly connected to AD-related signaling pathways and biological processes, which were confirmed by compound-target network, Gene Ontology (GO) analysis, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, respectively. Predicted by the virtual screening and various network pharmacology methods, we found the multiple mechanisms of OC, which are effective for alleviating AD symptoms through multiple targets in a synergetic way.

Virtual screening of active compounds from Artemisia argyi and potential targets against gastric ulcer based on Network pharmacology.

Artemisia argyi (AA) is one of the renowned herbs in China often used in the treatment of gastric ulcer (GU). Aiming to predict the active compounds and systematically investigate the mechanisms of Artemisia argyi for GU treatment, the approach of network pharmacology, molecular docking, gene ontology (GO) analysis, and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis were adopted, respectively, in present study. A total of 13 predicted targets of the 103 compounds in Artemisia argyi were obtained. Sorted by pathogenic mechanisms of targets and structure types of compounds, it was revealed that flavonoids and sesquiterpenes had better performance than monoterpenes. The network analysis showed that Phospholipase a2 (PA21B), Sulfotransferase family cytosolic 2b member 1 (ST2B1), Nitric-oxide synthase, endothelial (NOS3), Gastrin (GAST), neutrophil collagenase (MMP-8), Leukotriene A-4 hydrolase (LKHA4), Urease maturation factor HypB (HYPB), and Periplasmic serine endoprotease DegP (HtrA) were the key targets with intensely interaction. The functional enrichment analysis indicated that AA probably produced the gastric mucosa protection effects by synergistically regulating many biological pathways, such as NF-κB signaling pathway, HIF-1 signaling pathway, TNF signaling pathway, VEGF signaling pathway, and Toll-like receptor signaling pathway, etc. In addition, C73 and C15 might be promising leading compounds with good molecular docking score. As a consequence, this study holistically illuminates the active constituents and mechanisms based on data analysis, which contributes to searching for leading compounds and the development of new drugs for gastric ulcer.

UPLC-QTOF/MSE and Bioassay Are Available Approaches for Identifying Quality Fluctuation of Xueshuantong Lyophilized Powder in Clinic.

Xueshuantong Lyophilized Powder (XST), consisting of a series of saponins extracted from Panax notoginseng, is widely applied to treat acute cerebral infarction, stroke, and coronary heart disease in China. However, most adverse drug reactions (ADR) in clinic are caused by quality problems of XST. In this study, six batches of certainly abnormal, four batches of possibly abnormal XST, and eight batches of normal XST were obtained from the clinical practice. Their quality fluctuations were identified by ultra-performance liquid chromatography coupled with an electrospray ionization quadrupole time-of-flight mass spectrometry operating in MSE mode (UPLC-QTOF/MSE) and bioassays including antithrombin and proplasmin assay. Fourteen potential components responsible for clinical ADR were identified by UPLC-QTOF/MSE, especially ginsenoside Rg1, Rg3, Rb1 and notoginsenoside R1. In addition, 83.3% (5/6) and 50.0% (3/6) certainly abnormal samples could be identified by UPLC-QTOF/MSE and bioassay, respectively. Interestingly, further integration of the two methods could entirely identify all the certainly abnormal samples and inferred that all the possibly abnormal samples were closely related to their quality fluctuation. It indicates that it is advisable to combine UPLC-QTOF/MSE and bioassay for identifying quality fluctuation of XST, and thus reduce its ADR in clinic.

A green and facile preparation approach, licochalcone A capped on hollow gold nanoparticles, for improving the solubility and dissolution of anticancer natural product.

This study described a valuable drug delivery system for poorly water-soluble anticancer naturalproduct, licochalcone A, isolated from Glycyrrhiza inflata, loaded on hollow gold nanoparticles by green method to improve solubility and dissolution and maintain its natural pharmacological property. Briefly, the formation of hollow gold nanoparticles involves three steps: preparing of silica nanospheres by Stober method, forming of a thick gold shell around the silica templates and etching of silica particles by HF solution. Hollow gold nanoparticles (HGNPs) and drug loaded hollow gold nanoparticles (L-HGNPs) displayed spherical structure and approximately 200nm in size observed by SEM, XRD, EDS and DSC analysis showed that HGNPs were gold hollow structure and crystalline form. The solubility in aqueous solution of licochalcone A was increased obviously to 488.9 µg/ml, compared with free drugs of 136.1 µg/ml. Another interesting finding is that near-infrared (NIR) irradiation increased the speed of solubility of licochalcone A in aqueous solutions, rather than quantity. In short, the method of nano-delivery system combined with poorly water-soluble drug to improve its solubility and dissolution is worth applying to other natural products in order to increase their opportunities in clinical applications.

The total triterpenoid saponins of Xanthoceras sorbifolia improve learning and memory impairments through against oxidative stress and synaptic damage.

BACKGROUND: X. sorbifolia is a widely cultivated ecologicalcrop in the north of China which is used to produce biodiesel fuel. It also possesses special medicinal value and has attracted keen interests of researchers to explore its bioactivity. PURPOSE: To extract the total triterpenoid saponins from the husk of X. sorbifolia (TSX) and investigate its effects on Alzheimer's disease (AD). STUDY DESIGN: TSX was prepared via modern extraction techniques. Its effects on two AD animal models, as well as the preliminary mechanism were investigated comprehensively. METHODS: The behavioral experiments including Y maze test, Morris water maze test and passive avoidance test were performed to observe the learning and memory abilities of the animals. ELISA assays, transmission electron microscope observation and Western blotting were employed in mechanism study. RESULTS: TSX, the main composition of X. sorbifolia, accounted for 88.77% in the plant material. It could significantly increase the spontaneous alternation in Y maze test (F (6, 65)=3.209, P<0.01), prolong the swimming time in the fourth quadrant in probe test of Morris water maze test (F (6, 71)=4.019, P<0.01), and increase the escape latency in passive avoidance test (F (6, 65)=3.684, P<0.01) in AD model animals. The preliminary mechanism research revealed that TSX could significantly increase the contents of hippocampal Ach and ChAT, and enhance activity of ChAT in hippocampus of quinolinic acid injected rats (F (5, 61)=3.915, P 0.01; F (5, 61)=3.623, P<0.01, F (5, 61)=4.344, P<0.01, respectively). It could also increase the activities of T-AOC and T-SOD, and decrease the content of MDA in hippocampus of Aß1-42 injected mice (F (5, 30)=5.193, P<0.01, F (5, 30)=2.865, P<0.05, F (5, 30)=4.735, P<0.01, respectively). Moreover, it significantly increased the expressions of SYP, PSD-95 and GAP-43 in hippocampus (F (4, 27)=3.495, P<0.05; F (4, 27)=2.965, P<0.05; F (4, 27)=4.365, P<0.01, respectively), and improved the synaptic ultra-structure damage in model rats. CONCLUSION: TSX could significantly improve the impairments of learning and memory. The preliminary mechanism might associate with its protection effects against oxidative stress damage, cholinergic system deficiency and synaptic damage. TSX are perfectly suitable for AD patients as medicine or functional food, which would be a new candidate to treat AD.

Anti-gout nor-oleanane triterpenoids from the leaves of Stauntonia brachyanthera.

With the aim of finding more potential anti-gout compounds from natural resources, a phytochemical study on the leaves of Stauntonia brachyanthera was carried out, which led to the isolation of 11 nor-oleanane triterpenoids, including 4 new ones. Their structures were determined by the comprehensive 1D, 2D NMR, HRMS, and HPLC analysis after acid hydrolysis. Brachyantheraoside B4 (3) and 3-O-α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranosyl-30-norolean-12,20(29)-dien-28-oic acid (8) exhibited significant inhibitory activities on xanthine oxidase with IC50 values of 0.20 and 18.5µM, respectively. Brachyantheraoside C2 (2) also showed moderate effects on XO. A primary structure-activity relationship was also summarized, which revealed the anti-gout abilities of three nor-oleanane triterpenoids and their potential possibilities as the candidate compounds for the treatment of gout. The discovery of nor-oleanane triterpenoids also widens people's idea for the study of anti-gout agents and promotes the comprehensive development of S. brachyanthera.

The inhibitory effects of nor-oleanane triterpenoid saponins from Stauntonia brachyanthera towards UDP-glucuronosyltransferases.

The inhibition of UDP-glucuronosyltransferases (UGTs) by herbal components might be an important reason for clinical herb-drug interaction (HDI). The inhibitory effects on UGTs via nor-oleanane triterpenoid saponins, which were the bioactive ingredients from Stauntonia brachyanthera, a traditional Chinese folk medicines with highly biological values, were evaluated comprehensively with recombinant UGT isoforms as enzyme source and a nonspecific substrate 4-methylumbelliferone (4-MU) as substrate. The results showed that there are seven compounds, 2, 3, 4, 8, 9, 13 and 14, respectively, exhibited potential inhibitions towards UGT1A1, UGT1A3 and UGT1A10 among all 23 compounds isolated from the plants. The IC50 values were 17.1µM, 13.5µM, 9.5µM, 15.7µM, 16.3µM, 1.1µM, and 0.3µM, respectively. Data fitting using Dixon and Lineweaver-Burk plots demonstrated that the inhibition of UGT1A10, UGT1A1 and UGT1A3 was best fit to noncompetitive type and competitive, respectively. The inhibition kinetic parameter (Ki) was calculated to be 39µM, 17µM, 3.3µM, 10µM, 9.3µM, 0.19µM, and 0.016µM, respectively. All these experimental data suggested that HDI might occur when compounds containing herbs were co-administered with drugs which mainly undergo UGTs-mediated metabolism.

Xanthoceraside hollow gold nanoparticles, green pharmaceutics preparation for poorly water-soluble natural anti-AD medicine.

In order to increase the solubility of poorly water-soluble natural product, xanthoceraside, an effective anti-AD compound from Xanthoceras sorbifolia Bunge, and maintain its natural property, the xanthoceraside hollow gold nanoparticles were successively prepared by green ultrasonic method with silica spheres as templates and HF solution as selective etching solvent. Hollow gold nanoparticles and drug-loaded hollow gold nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The solubilities of xanthoceraside loaded on hollow gold nanoparticles were increased obviously from 3.0µg/ml and 2.5µg/ml to 12.7µg/ml and 10.7µg/ml at 25°C and 37°C, respectively. The results of XRD and DSC indicated that the reason for this increase was mainly due to the amorphous state of xanthoceraside loaded on the hollow gold nanoparticles. In summary, the method of loading xanthoceraside onto hollow gold nanoparticles was a green and useful strategy to improve the solubility and dissolution of poorly water-soluble natural products and worth to applying to other natural products.

ent-Abietane-type diterpenoids from the roots of Euphorbia ebracteolata with their inhibitory activities on LPS-induced NO production in RAW 264.7 macrophages.

Ten ent-abietane diterpenoids (1-10), including four new (1-4) and six known ones (5-10) were isolated from the roots of Euphorbia ebracteolata. Their structures were determined by 1D, 2D NMR, and HRESIMS. Compounds 2, 4, and 7 exhibited significant inhibitory activities on lipopolysaccharide (LPS)-induced nitric oxide production in RAW 264.7 macrophages with IC50 values of 0.69, 1.97, and 0.88µM, respectively. A primary structure-activity relationship was also discussed.

Anti-inflammatory activity studies on the stems and roots of Jasminum lanceolarium Roxb.

Jasminum lanceolarium Roxb is an important traditional Chinese medicine. Its stems and roots have been used for the treatment of rheumatism and fever while the leaves are used as an anti-inflammatory agent to relieve pain. In order to support its traditional Chinese medicinal uses, five animal models were designed and the anti-inflammatory and analgesic properties of the 70% EtOH-H2O extracts of J. lanceolarium (EJL) were investigated. Meanwhile, biochemical parameters such as cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX) in blood serum of rats exposed to acute (carrageenan) inflammation model were evaluated. At doses of 400 mg/kg, EJL exhibited higher anti-inflammation effect than that of indomethacin and better analgesic activity than that of aspirin (P<0.001). Furthermore, eleven isolated compounds including six lignanoids (1, 2, 6, 7, 8, and 11) and five iridoids (3, 4, 5, 9, and 10) were isolated from the active extracts and showed significant anti-inflammatory activities with the IC50 values of 1.76-5.22 mg/mL, respectively, when testing their inhibitory effects on phospholipase A2 in vitro. The results demonstrated that the possible anti-inflammatory mechanisms might be attributed to inhibit the hydrolysis of membrane phospholipids, production on both COX-2 and 5-LOX, and then finally inhibit the release of prostaglandins (PGs), which suggested that EJL had a non-selective inhibitory effect on the release or actions of these mediators, and might be a dual LOX-COX inhibitor for the treatment of inflammation from the natural resource. The studies on the animals and the inflammatory mediators, along with the bioactive compounds presumed that the existences of iridoids and lignanoids could be response for their bioactivities of the whole plants.

Structure-inhibition relationship of podophyllotoxin (PT) analogues towards UDP-glucuronosyltransferase (UGT) isoforms.

UDP-glucuronosyltransferases (UGTs) are involved in the clearance of many important drugs and endogenous substances, and inhibition of UGTs' activity by herbal components might induce severe herb-drug interactions or metabolic disturbances of endogenous substances. The present study aims to determine the inhibition of UGTs' activity by podophyllotoxin derivatives, trying to indicate the potential herb-drug interaction or metabolic influence towards endogenous substances' metabolism. Recombinant UGT isoforms (except UGT1A4)-catalyzed 4-methylumbelliferone (4-MU) glucuronidation reaction and UGT1A4-catalyzed trifluoperazine (TFP) glucuronidation were employed to firstly screen the podophyllotoxin derivatives' inhibition potential. Structure-dependent inhibition behavior of podophyllotoxin derivatives towards UGT isoforms was detected. Inhibition kinetic type and parameter (Ki) were determined for the inhi- bition of podophyllotoxin towards UGT1A1, and competitive inhibition of podophyllotoxin towards UGT1A1 was observed with the inhibition kinetic parameter (Ki) to be 4.0 µM. Furthermore, podophyllotoxin was demonstrated to exert medium and weak inhibition potential towards human liver microsomes (HLMs)-catalyzed SN-38 glucuronidation and estradiol-3-glucuronidation. In conclusion, podophyllotoxin inhibited UGT1A1 activity, indicating potential herb-drug interactions between podophyllotoxin-containing herbs and drugs mainly undergoing UGT1A1-mediated metabolism.