Purification, Molecular Docking and Cytotoxicity Evaluation of Bioactive Pentacyclic Polyhydroxylated Triterpenoids from Salvia urmiensis.

Triterpenoids, as one of the largest classes of naturally occurring secondary metabolites in higher plants, are of interest due to their high structural diversity and wide range of biological activities. In addition to several promising pharmacological activities such as antimicrobial, antiviral, antioxidant, anti-inflammatory and hepatoprotective effects, a large number of triterpenoids have revealed high potential for cancer therapy through their strong cytotoxicity on cancer cell lines and, also, low toxicity in normal cells. So, this study was aimed at discovering novel and potentially bioactive triterpenoids from the Salvia urmiensis species. For this, an ethyl acetate fraction of the acetone extract of the aerial parts of the plant was chromatographed to yield five novel polyhydroxylated triterpenoids (1: -5: ). Their structure was elucidated by extensive spectroscopic methods including 1D (1H, 13C, DEPT-Q) and 2D NMR (COSY, HSQC, HMBC, NOESY) experiments, as well as HRESIMS analysis. Cytotoxic activity of the purified compounds was also investigated by MTT assay against the MCF-7 cancer cell line. Furthermore, a molecular docking analysis was applied to evaluate the inhibition potential of the ligands against the nuclear factor kappa B (NF-κB) protein, which promotes tumor metastasis or affects gene expression in cancer disease. The 1ß,11ß,22α-trihydroxy-olean-12-ene-3-one (compound 4: ) indicated the best activity in both in vitro and in silico assays, with an IC50 value of 32 µM and a docking score value of - 3.976 kcal/mol, respectively.

Influence of Slco2b1-knockout and SLCO2B1-humanization on coproporphyrin I and III levels in rats.

BACKGROUND AND PURPOSE: Coproporphyrin (CP) I and III are byproducts of haem synthesis currently investigated as biomarkers for drug-drug interactions involving hepatic organic anion transporting polypeptide (OATP) 1B transporters. Another hepatically expressed OATP-member is OATP2B1. The aim of this study was to test the impact of OATP2B1, which specifically transports CPIII, on CP serum levels, applying novel rat models. EXPERIMENTAL APPROACH: CPIII transport kinetics and the interplay between OATP2B1 and multidrug resistance-associated proteins (MRPs) were determined in vitro using the vTF7 expression system. Novel rSlco2b1-/- and SLCO2B1+/+ rat models were characterized for physiological parameters and for CP serum levels. Hepatic and renal expression of transporters involved in CP disposition were determined by real-time qPCR, Western blot analysis, and immunohistochemistry. KEY RESULTS: In vitro experiments revealed differences in transport kinetics comparing human and rat OATP2B1 and showed a consistent, species-specific interplay with hMRP3/rMRP3. Deletion of rOATP2B1 was associated with a trend towards lower CPI serum levels compared with wildtype rats, while CPIII remained unchanged. Comparing SLCO2B1+/+ with knockout rats revealed an effect of sex: only in females the genetic modification influenced CP serum levels. Analysis of hepatic and renal transporters revealed marginal, but in part, statistically significant differences in rMRP2 abundance, which may contribute to the observed changes in CP serum levels. CONCLUSION AND IMPLICATIONS: Our findings support that factors other than OATP1B transporters are of relevance for basal CP levels. Only in female rats, humanization of SLCO2B1 affects basal CPI and CPIII serum levels, despite isomer selectivity of OATP2B1.

The influence of OATP2B1 and atorvastatin on coproporphyrin isomers in rats.

Coproporphyrin I (CPI) and III (CPIII) are discussed as biomarkers for organic anion transporting polypeptides (OATPs). We report on CPI and CPIII levels in wildtype, rSlco2b1-knockout, and SLCO2B1-humanized rats at baseline and after administration of atorvastatin, an inhibitor of the CPIII-specific rOATP2B1/hOATP2B1 and the CPI/CPIII-transporting rOATP1B2. OATP-inhibition by atorvastatin leads to significantly increased CPI and CPIII serum levels. However, basal CP serum levels in rSlco2b1-knockout animals were significantly lower (CPI), or unaffected (CPIII). In the presence of atorvastatin, this genotype effect was abolished. In conclusion, our results indicate an unexpected impact of OATP2B1 on CP serum levels in rats.

Alkaloids in commercial preparations of California poppy - Quantification, intestinal permeability and microbiota interactions.

California poppy products are commonly used for the treatment of nervousness, anxiety and sleeping disorders. Pharmacologically relevant constituents include the main alkaloids californidine, escholtzine and protopine. However, only limited information is available about the alkaloid content in commercial preparations and their intestinal absorption. Moreover, a possible metabolization of these alkaloids by the gut microbiota, and their impact on microbial activity and viability have not been investigated. Californidine, escholtzine and protopine were quantified by UHPLC-MS/MS in eight commercial California poppy products. The intestinal permeability of alkaloids was studied in Caco-2 cell as a model for absorption in the small intestine. The gut microbial biotransformation was explored in artificial gut microbiota from the in vitro PolyFermS model. In addition, the impact of these alkaloids and a California poppy extract on the microbial production of short-chain fatty acids (SCFAs) and the viability of microbiota was investigated. Contents of californidine, escholtzine and protopine in California poppy products were in the ranges of 0.13-2.55, 0.05-0.63 and 0.008-0.200 mg/g, respectively. In the Caco-2 cell model, californidine was low-to-moderately permeable while escholtzine and protopine were highly permeable. An active transport process was potentially involved in the transfer of the three alkaloids. The three compounds were not metabolized by the artificial gut microbiota over 24 h. Neither the California poppy extract nor the alkaloids markedly impacted microbial SCFA production and bacterial viability.

Qualitative and Quantitative Secondary Metabolite Profiles in a Large Set of Sumatra Benzoin Samples.

Sumatra benzoin, a resin produced by Styrax benzoin and Styrax paralleloneurum, is used as an aromatic agent and may have the potential to be developed as a new agricultural fungicide. In this context, we performed a comprehensive metabolite profiling of a commercial grade A resin by high-performance liquid chromatography coupled with photodiode array detection, evaporative light scattering detection, and mass spectrometry (HPLC-PDA-ELSD-MS) analysis in combination with 1H NMR. Thirteen compounds including a new cinnamic acid ester containing two p-coumaroyl residues were identified after preparative isolation. These compounds accounted for an estimated 90% of the crude resin according to 1H NMR analysis. The two major constituents, p-coumaryl cinnamate (5) and sumaresinolic acid (11), were quantified by HPLC analysis. In a next step, the chemical profiles and the content in p-coumaryl cinnamate were compared in a large set of resin samples of different quality grades that were obtained from various commercial suppliers in Sumatra. The qualitative profiles of the samples were very similar, but significant quantitative differences were observed between different quality grades and origins of the samples for the relative contents.

Assay for evaluation of proarrhythmic effects of herbal products: Case study with 12 Evodia preparations.

Guidelines for preclinical drug development reduce the occurrence of arrhythmia-related side effects. Besides ample evidence for the presence of arrhythmogenic substances in plants, there is no consensus on a research strategy for the evaluation of proarrhythmic effects of herbal products. Here, we propose a cardiac safety assay for the detection of proarrhythmic effects of plant extracts based on the experimental approaches described in the Comprehensive In vitro Proarrhythmia Assay (CiPA). Microelectrode array studies (MEAs) and voltage sensing optical technique on human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were combined with ionic current measurements in mammalian cell lines, In-silico simulations of cardiac action potentials (APs) and statistic regression analysis. Proarrhythmic effects of 12 Evodia preparations, containing different amounts of the hERG inhibitors dehydroevodiamine (DHE) and hortiamine were analysed. Extracts produced different prolongation of the AP, occurrence of early after depolarisations and triangulation of the AP in hiPSC-CMs depending on the contents of the hERG inhibitors. DHE and hortiamine dose-dependently prolonged the field potential duration in hiPSC-CMs studied with MEAs. In-silico simulations of ventricular AP support a scenario where proarrhythmic effects of Evodia extracts are predominantly caused by the content of the selective hERG inhibitors. Statistic regression analysis revealed a high torsadogenic risk for both compounds that was comparable to drugs assigned to the high-risk category in a CiPA study.

Transplacental passage of hyperforin, hypericin, and valerenic acid.

Safe medications for mild mental diseases in pregnancy are needed. Phytomedicines from St. John's wort and valerian are valid candidates, but safety data in pregnancy are lacking. The transplacental transport of hyperforin and hypericin (from St. John's wort), and valerenic acid (from valerian) was evaluated using the ex vivo cotyledon perfusion model (4 h perfusions, term placentae) and, in part, the in vitro Transwell assay with BeWo b30 cells. Antipyrine was used for comparison in both models. U(H)PLC-MS/MS bioanalytical methods were developed to quantify the compounds. Perfusion data obtained with term placentae showed that only minor amounts of hyperforin passed into the fetal circuit, while hypericin did not cross the placental barrier and valerenic acid equilibrated between the maternal and fetal compartments. None of the investigated compounds affected metabolic, functional, and histopathological parameters of the placenta during the perfusion experiments. Data from the Transwell model suggested that valerenic acid does not cross the placental cell layer. Taken together, our data suggest that throughout the pregnancy the potential fetal exposure to hypericin and hyperforin - but not to valerenic acid - is likely to be minimal.

Intestinal permeability and gut microbiota interactions of pharmacologically active compounds in valerian and St. John's wort.

Phytomedicines such as valerian and St. John's wort are widely used for the treatment of sleeping disorders, anxiety and mild depression. They are perceived as safe alternatives to synthetic drugs, but limited information is available on the intestinal absorption and interaction with human intestinal microbiota of pharmacologically relevant constituents valerenic acid in valerian, and hyperforin and hypericin in St. John's wort. The intestinal permeability of these compounds and the antidepressant and anxiolytic drugs citalopram and diazepam was investigated in the Caco-2 cell model with bidirectional transport experiments. In addition, interaction of compounds and herbal extracts with intestinal microbiota was evaluated in artificial human gut microbiota. Microbiota-mediated metabolisation of compounds was assessed, and bacterial viability and short-chain fatty acids (SCFA) production were measured in the presence of compounds or herbal extracts. Valerenic acid and hyperforin were highly permeable in Caco-2 cell monolayers. Hypericin showed low-to-moderate permeability. An active transport process was potentially involved in the transfer of valerenic acid. Hyperforin and hypericin were mainly transported through passive transcellular diffusion. All compounds were not metabolized over 24 h in the artificial gut microbiota. Microbial SCFA production and bacterial viability was not substantially impaired nor promoted by exposure to the compounds or herbal extracts.

A neolignan from Connarus tuberosus as an allosteric GABAA receptor modulator at the neurosteroid binding site.

In a screening of a small library of extracts from plants of the Amazonian and Cerrado biomes, a hexane extract of Connarus tuberosus roots was found to significantly potentiate the GABA induced fluorescence in a fluorescence (FLIPR) assay in CHO cells stably expressing the α1ß2γ2 subtype of human GABAA receptors. With the aid of HPLC-based activity profiling the activity was linked to the neolignan connarin. In CHO cells the activity of connarin was not abolished by increasing concentrations of flumazenil, while the effect of diazepam was increased by increasing concentrations of connarin. The effect of connarin was abolished by pregnenolone sulfate (PREGS) in a concentration-dependent manner, and the effect of allopregnanolone was further increased by increasing concentrations of connarin. In a two-microelectrode voltage clamp assay with Xenopus laevis oocytes transiently expressing GABAA receptors composed of human α1ß2γ2S and α1ß2 subunits connarin potentiated the GABA-induced currents, with EC50 values of 1.2 ± 0.3 µM (α1ß2γ2S) and 1.3 ± 0.4 µM (α1ß2), and with a maximum enhancement of currents Emax of 1959 ± 70% (α1ß2γ2S) and 185 ± 48% (α1ß2). The activation induced by connarin was abolished by increasing concentrations of PREGS.

Corrigendum: Bryophyllum pinnatum compounds inhibit oxytocin-induced signaling pathways in human myometrial cells.

[This corrects the article DOI: 10.3389/fphar.2021.632986.].

Aryltetralin lignans from Hyptis brachiata inhibiting T lymphocyte proliferation.

Increased activation and proliferation of T lymphocytes plays an essential role in the development of chronic inflammation and autoimmune diseases. Currently used immunosuppressive drugs often do not provide long-lasting relief of symptoms and show a gradual loss of efficacy over time, and are accompanied by various side effects. Therefore, novel immunosuppressive lead substances are needed. For this purpose, an in-house library consisting of 600 extracts of plants from Panama was screened for inhibition of human T lymphocyte proliferation. As one of the hits, an ethyl acetate extract from the aerial parts of Hyptis brachiata (Lamiaceae) exhibited strong inhibitory effects. Subsequent investigation resulted in the isolation of seven aryltetralin lignans, five arylnaphthalene lignans, two flavonoids, three triterpenes, and cinnamyl cinnamate. Aryltetralin lignans inhibited T lymphocyte proliferation in a concentration-dependent manner without induction of apoptosis. No relevant inhibition was observed for the arylnaphthalene lignans, flavonoids, and triterpenes. Additional cell cycle arrest investigations revealed that isolated aryltetralin lignans potently inhibited cell division in G2/M phase similarly to podophyllotoxin. Multifluorescence panel analyses of the extract also showed weak suppressive effects on the production of IL-2 and TNF-α. Therefore, preparations made out of H. brachiata could be further explored as an interesting herbal alternative in the treatment of autoimmune diseases.

Phytochemical Comparison of Medicinal Cannabis Extracts and Study of Their CYP-Mediated Interactions with Coumarinic Oral Anticoagulants.

Introduction: Treatment with cannabis extracts for a variety of diseases has gained popularity. However, differences in herb-drug interaction potential of extracts from different plant sources are poorly understood. In this study, we provide a characterization of cannabis extracts prepared from four cannabis chemotypes and an in vitro assessment of their Cytochrome P450 (CYP)-mediated herb-drug interaction profiles. Methods: Plant extracts were either commercially obtained or prepared using ethanol as solvent, followed by overnight decarboxylation in a reflux condenser system. The extracts were characterized for their cannabinoid content using NMR and HPLC-PDA-ELSD-ESIMS. CYP inhibition studies with the cannabis extracts and pure cannabinoids (tetrahydrocannabinol [THC] and cannabidiol [CBD]) were performed using pooled, mixed gender human liver microsomes. Tolbutamide and testosterone were used as specific substrates to assess the inhibitory potential of the extracts on CYP2C9 and CYP3A4, and the coumarinic oral anticoagulants warfarin, phenprocoumon, and acenocoumarol were studied as model compounds since in vivo herb-drug interactions have previously been reported for this compound class. Results: In accordance with the plant chemotypes, two extracts were rich in THC and CBD (at different proportions); one extract contained mostly CBD and the other mostly cannabigerol (CBG). Residual amounts of the corresponding acids were found in all extracts. The extracts with a single major cannabinoid (CBD or CBG) inhibited CYP2C9- and CYP3A4-mediated metabolism stronger than the extracts containing both major cannabinoids (THC and CBD). The inhibition of CYP3A4 and CYP2C9 by the extract containing mostly CBD was comparable to their inhibition by pure CBD. In contrast, the inhibitory potency of extracts containing both THC and CBD did not correspond to the combined inhibitory potency of pure THC and CBD. Although being structural analogs, the three coumarin derivatives displayed major differences in their herb-drug interaction profiles with the cannabis extracts and the pure cannabinoids. Conclusion: Despite the fact that cannabinoids are the major components in ethanolic, decarboxylated cannabis extracts, it is difficult to foresee their herb-drug interaction profiles. Our in vitro data and the literature-based evidence on in vivo interactions indicate that cannabis extracts should be used cautiously when co-administered with drugs exhibiting a narrow therapeutic window, such as coumarinic anticoagulants, regardless of the cannabis chemotype used for extract preparation.

Polyacetylenic caffeoyl amides from Ammodaucus leucotrichus.

Six undescribed polyacetylenic caffeoyl amides, five known flavones and three known lignans were obtained from the fruits of the North African traditional medicinal plant Ammodaucus leucotrichus Coss. & Durieu (Apiaceae). Isolation was achieved by a combination of chromatographic methods, and structures were established by extensive 1D and 2D NMR spectroscopy, mass spectrometry, electronic circular dichroism, and by GC-MS analysis of sugar derivatives. Polyacetylenic caffeoyl amides are reported for the first time as specialized metabolites.

Isolation and purification of terpenoid compounds from Ferula haussknechtii and evaluation of their antibacterial effects.

The roots of F. haussknechtii are used by local people in order to treat wounds and urinary infections. Ferula species are rich in bioactive compounds with biological effects. In line with our previous studies about screening antibacterial natural products, five terpenoid derivatives were purified from Ferula haussknechtii. The separation and purification were performed by column chromatography. Their structures were determined by 1 D and 2 D NMR as hawraman 8-p-hydroxybenzoyl-tovarol (1), ferutinin (2), lancerotriol 6-(p-hydroxybenzoate) (3), chimganin (4), and chimgin (5). Then, the antibacterial effects of the purified compounds were evaluated by measuring their MIC values against Gram-positive and Gram-negative bacteria. The results showed that compound (1) had the most antibacterial effect on Bacillus cereus (MIC = 16 µg/mL). The antibacterial effects of F. haussknechtii compounds are in line with their local application and it is suggested that further studies should be conducted to determine their mechanism of action.

Placental Passage of Protopine in an Ex Vivo Human Perfusion System.

The placental passage of protopine was investigated with a human ex vivo placental perfusion model. The model was first validated with diazepam and citalopram, 2 compounds known to cross the placental barrier, and antipyrine as a positive control. All compounds were quantified by partially validated U(H)PLC-MS/MS bioanalytical methods. Protopine was transferred from the maternal to the fetal circuit, with a steady-state reached after 90 min. The study compound did not affect placental viability or functionality, as glucose consumption, lactate production, and beta-human chorionic gonadotropin, and leptin release remained constant. Histopathological evaluation of all placental specimens showed unremarkable, age-appropriate parenchymal maturation with no pathologic findings.

Sesquiterpene Lactones with Astrodaucane Skeleton from Astrodaucus orientalis.

Four sesquiterpene lactones, astrodaucanolide A - D (1: -4: ) with unique structures, toghether with two known phenylpropanoid esters (5: and 6: ) were isolated from a flower extract of Astrodaucus orientalis. The structures were established by 1D and 2D NMR spectroscopy and high-resolution mass spectrometry (HRESIMS), and the absolute configuration of 1: -4: was determined by electronic circular dichroism (ECD). Compounds 1: -4: novel architecture represents a new class of sesquiterpenes with new skeleton. A putative biosynthetic pathway for their scaffold is proposed with a germacryl cation as the precursor. The suggested biosynthesis pathway is similar to that of eudesmane sesquiterpenes with a different direction of protonation which then leads to the new skeleton, named astrodaucane by the 1,2-methyl migration.

A Dimerosesquiterpene and Sesquiterpene Lactones from Artemisia argyi Inhibiting Oncogenic PI3K/AKT Signaling in Melanoma Cells.

A library of more than 2500 plant extracts was screened for activity on oncogenic signaling in melanoma cells. The ethyl acetate extract from the aerial parts of Artemisia argyi displayed pronounced inhibition of the PI3K/AKT pathway. Active compounds were tracked with the aid of HPLC-based activity profiling, and altogether 21 active compounds were isolated, including one novel dimerosequiterpenoid (1), one new disesquiterpenoid (2), three new guaianolides (3-5), 12 known sesquiterpenoids (6-17), and four known flavonoids (19-22). A new eudesmanolide derivative (13b) was isolated as an artifact formed by methanolysis. Compound 1 is the first adduct comprising a sesquiterpene lactone and a methyl jasmonate moiety. The absolute configurations of compounds 1 and 3-18 were established by comparison of their experimental and calculated ECD spectra. The absolute configuration for 2 was determined by X-ray diffraction analysis. Guaianolide 8 was the most potent sesquiterpene lactone, inhibiting the PI3K/AKT pathway with an IC50 value of 8.9 ± 0.9 µM.

Flavonoids from Ericameria nauseosa inhibiting PI3K/AKT pathway in human melanoma cells.

The PI3K/AKT and MAPK/ERK pathways are frequently mutated in metastatic melanoma. In a screen of over 2500 plant extracts, the dichloromethane extract of Ericameria nauseosa significantly inhibited oncogenic activity of AKT in MM121224 human melanoma cells. This extract was analyzed by analytical HPLC, and the column effluent was fractionated and tested for activity to generate the so-called HPLC-based activity profile. Compounds eluting within active time-windows of the chromatogram were subsequently isolated in a larger scale to afford 11 flavones (1-11), four flavanones (12-15), two diterpenes (16, 17), and a seco-caryophyllene (18). All isolated compounds were tested for activity, whereby only flavonoids were found active. Of these, flavones were shown to be more active than the flavanones. The most potent flavone was compound 9, that was displaying an IC50 of 14.7 ± 1.4 µM on AKT activity in MM121224 cells. The terpenoids (16-18) were found to be inactive in the assay. Both diterpenes, a grindelic acid derivative (16) and an ent-neo-clerodane (17) were identified as new natural products. Their absolute configuration was established by ECD. Compound 17 is the first description of a clerodane type diterpene in the genus Ericameria.