Hyperelodiones A-C, monoterpenoid polyprenylated acylphoroglucinols from Hypericum elodeoides, induce cancer cells apoptosis by targeting RXRα

Filicinic acid based meroterpenoids from Hypericum elodeoides and their anti-Alzheimer's disease effects

(±)-Elodeoidileons A-L (1-12), 12 pairs of previously undescribed filicinic acid based meroterpenoids were isolated from Hypericum elodeoides with unique linear or angular 6/6/6 ring core. Modern spectroscopic techniques, modified Mosher's method and quantum chemical calculations were used to identify the planner structures and configurations of 1-12. Additionally, the potential biosynthetic pathways for 1-12 were anticipated. Moreover, biological activity assessments suggested that 1a, 5a, and 11b could activate Retinoid X receptor-α (RXRα) transcription and enhance the ATP-binding cassette transporter A1 (ABCA1) protein's expression. Fluorescence titration assay suggested that 1a might have a direct interaction with the RXRα-LBD protein, with an estimated Kd value of 5.85 μM. Moreover, molecular docking study confirmed the binding of 1a to RXRα and further validated by cellular thermal shift assay (CETSA). Thus, compound 1a may promote β-amyloid (Aβ) clearance by targeting RXRα and upregulating the expression of the ABCA1 protein, showing promise as anti-Alzheimer's agent.

(±)-hypermonanones A-G, seven pairs of monoterpenoid polyprenylated acylphloroglucinol enantiomers from Hypericum monanthemum

Seven pairs of undescribed monoterpenoid polyprenylated acylphloroglucinol enantiomers [(±)-hypermonanones A-G (1-7)], together with three known analogues, were identified from the whole plant of Hypericum monanthemum Hook. The structures of these compounds were determined by analyses of their UV, HRESIMS, 1D/2D NMR spectroscopic data, and NMR calculations. The absolute configurations of these compounds were assigned by ECD calculations after chiral HPLC separation. Diverse monoterpene moieties were fused at C-3/C-4 of the dearomatized acylphloroglucinol core, which led to 3,4-dihydro-2H-pyran-integrated angular or linear type 6/6/6 tricyclic skeletons in 1-7. Compounds (-)-2 and (+)-2 exhibited significant NO inhibitory activity against LPS induced RAW264.7 cells with the IC50 values of 7.07 ± 1.02 μM and 11.39 ± 0.24 μM, respectively.

Exhaled metabolic markers and relevant dysregulated pathways of lung cancer: a pilot study

INTRODUCTION

The clinical application of lung cancer detection based on breath test is still challenging due to lack of predictive molecular markers in exhaled breath. This study explored potential lung cancer biomarkers and their related pathways using a typical process for metabolomics investigation.

MATERIAL AND METHODS

Breath samples from 60 lung cancer patients and 176 healthy people were analyzed by GC-MS. The original data were GC-MS peak intensity removing background signal. Differential metabolites were selected after univariate statistical analysis and multivariate statistical analysis based on OPLS-DA and Spearman rank correlation analysis. A multivariate PLS-DA model was established based on differential metabolites for pattern recognition. Subsequently, pathway enrichment analysis was performed on differential metabolites.

RESULTS

The discriminant capability was assessed by ROC curve of whom the average AUC and average accuracy in 100-fold cross validations were 0.871 and 0.787, respectively. Eight potential biomarkers were involved in a total of 18 metabolic pathways. Among them, 11 metabolic pathways have p-value smaller than .1.

DISCUSSION

Some pathways among them are related to risk factors or therapies of lung cancer. However, more of them are dysregulated pathways of lung cancer reported in studies based on genome or transcriptome data.

CONCLUSION

We believe that it opens the possibility of using metabolomics methods to analyze data of exhaled breath and promotes involvement of knowledge dataset to cover more volatile metabolites.

CLINICAL SIGNIFICANCE

Although a series of related research reported diagnostic models with highly sensitive and specific prediction, the clinical application of lung cancer detection based on breath test is still challenging due to disease heterogeneity and lack of predictive molecular markers in exhaled breath. This study may promote the clinical application of this technique which is suitable for large-scale screening thanks to its low-cost and non-invasiveness. As a result, the mortality of lung cancer may be decreased in future.Key messagesIn the present study, 11 pathways involving 8 potential biomarkers were discovered to be dysregulated pathways of lung cancer.We found that it is possible to apply metabolomics methods in analysis of data from breath test, which is meaningful to discover convinced volatile markers with definite pathological and histological significance.

Hypericum Genus as a Natural Source for Biologically Active Compounds

Hypericum L. genus plants are distributed worldwide, with numerous species identified throughout all continents, except Antarctica. These plant species are currently used in various systems of traditional medicine to treat mild depression, wounds and burns, diarrhea, pain, fevers, and their secondary metabolites previously shown, and the in vitro and/or in vivo cytotoxic, antimicrobial, anti-inflammatory, antioxidant, antihyperglycemic, and hepatoprotective activities, as well as the acetylcholinesterase and monoamine oxidase inhibitory activities. We conducted a systematic bibliographic search according to the Cochrane Collaboration guidelines to answer the question: "What is known about plants of Hypericum genus as a source of natural products with potential clinical biological activity?" We documented 414 different natural products with confirmed in vitro/in vivo biological activities, and 58 different Hypericum plant species as sources for these natural products. Phloroglucinols, acylphloroglucinols, xanthones, and benzophenones were the main chemical classes identified. The selective cytotoxicity against tumor cells, cell protection, anti-inflammatory, antimicrobial, antidepressant, anti-Alzheimer's, and adipogenesis-inhibition biological activities are described. Acylphloroglucinols were the most frequent compounds with anticancer and cell-protection mechanisms. To date, no work has been published with a full descriptive list directly relating secondary metabolites to their species of origin, plant parts used, extraction methodologies, mechanisms of action, and biological activities.

Seco-polyprenylated acylphloroglucinols from Hypericum elodeoides induced cell cycle arrest and apoptosis in MCF-7 cells via oxidative DNA damage

Four undescribed seco-polyprenylated acylphloroglucinols (seco-PAPs), elodeoidesones A-D (1-4), were characterized from Hypericum elodeoides. Compound 1 represents the 1,6-seco-PAPs with fascinating 5/5 fused ring, while 2-4 possess a 1,2-seco-PAPs skeleton with a five-membered lactone core. Their structures including absolute configurations were established by spectroscopic analyses and quantum chemical computations. A possible biosynthetic pathway of 1-4 from normal PAPs was proposed. All the isolates were investigated for their cytotoxicity against tumor cells. Notably, 1 inhibited the proliferation of MCF-7 cells with the IC₅₀ value of 7.34 μM. Mechanism investigation indicated that 1 induced MCF-7 cells apoptosis by blocking cell cycle at S phase via inducing oxidative DNA damage.

Discovery of dearomatized isoprenylated acylphloroglucinols with colon tumor suppressive activities in mice via inhibiting NFκB-FAT1-PDCD4 signaling activation

Dearomatized isoprenylated acylphloroglucinols (DIAPs) are specific natural products mainly distributed in the plants of genus Hypericum. In this study, guided by HPLC-UV screening, 46 DIAPs (approximately 70% of all DIAPs) including 20 new ones and an unprecedented architecture, were discovered from the roots of Hypericum henryi, which were elucidated by comprehensive spectroscopic, X-ray crystallography, and ECD methods. Compounds 1-7, 39, and 41-42 exhibited remarkable cytotoxicities (IC₅₀ = 0.84-5.63 μM) in human colon cancer HCT116 cells, in which 2 and 6 possessed selective cytotoxicities towards colon cancer cells. The preliminary structure-activity relationships of these tested compounds were discussed. In addition, mechanistic investigations demonstrated that 2 and 6 could significantly suppress the expressions of NFκB, FAT1, and promoted novel tumor suppressor gene PDCD4 in HCT116 cells. Furthermore, in HCT116 colon xenograft-bearing mouse model, treatments with 2 and 6 reduced the growth of xenograft tumors in dose-dependent manner. Expressions of FAT1 in tumors were also decreased in mice treated with 2 and 6, suggesting their anti-tumor effects were via FAT1 signaling pathway. In conclusion, this is the first report on the mechanistic and in vivo studies of DIAP, indicating that these metabolites can be considered as a new type of anti-colon cancer lead agents for further drug development.

Hyperpatulones C-G, new spirocyclic polycyclic polyprenylated acylphloroglucinols from the leaves of Hypericum patulum

Five new spirocyclic polycyclic polyprenylated acylphloroglucinols, Hyperpatulones C-G (1-5), were obtained from the leaves of Hypericum patulum. Their structures were characterized by the comprehensive analysis of their IR, NMR, CD spectra and HRESIMS data. All the new compounds were evaluated for the α-glycosidase inhibitory activities. Among them, compounds 3-5 showed α-glucosidase inhibitory activities, with IC₅₀ values of 14.06-37.69 μM.

Unprecedented Monoterpenoid Polyprenylated Acylphloroglucinols with a Rare 6/6/5/4 Tetracyclic Core, Enhanced MCF-7 Cells' Sensitivity to Camptothecin by Inhibiting the DNA Damage Response

(±)-Hypersines A-C (1-3), the three pairs of enantiomerically pure monoterpenoid polyprenylated acylphloroglucinols with an unprecedented 6/6/5/4 fused ring system, were isolated from Hypericum elodeoides. Their structures, including absolute configurations, were elucidated by comprehensive spectroscopic data, single-crystal X-ray diffraction, and quantum chemical calculations. The plausible, biosynthetic pathway of 1-3 was proposed. Moreover, the bioactivity evaluation indicated that 1a might be a novel DNA damage response inhibitor, and could enhance MCF-7 cell sensitivity to the anticancer agent, camptothecin.

Phloroglucinol-derived lipids from the leaves of Syzygium cumini and their neuroprotective activities

Based on the typical HPLC-UV-MS profiles and characteristic ¹H NMR signals, twelve new phloroglucinol-derived lipids (1-12), featuring a long linear aliphatic side chain, together with three known ones (13-15) were isolated from the ethanol extract of the leaves of Syzygium cumini. Their structures were elucidated on the basis of extensive NMR spectroscopic analyses and mass spectrometric data. Compounds 1-5 characterize an enolizable β,β'-tricarbonyl motif with a cyclohexa-3,5-dien-1-one core that is hitherto undescribed in phloroglucinol-derived lipids. Compounds 4 and 10-12 are novel phloroglucinol-derived lipids containing an uncommon methylene interrupted trans double bond in their polyunsaturated aliphatic side chains. A polyketide biogenetic pathway for those phloroglucinol-derived lipids was also proposed. In addition, the isolates were evaluated for their neuroprotective activities against oxygen-glucose deprivation and re‑oxygenation (OGD/R)-induced Neuro-2a cell injury. Notably, compounds 1, 5, and 10-12 significantly improved viability of Neuro-2a cells after OGD/R damage.

Dimeric Acylphloroglucinol Derivatives with New Skeletons from Leptospermum scoparium

Leptosparones A-F (1-6), six new dimeric acylphloroglucinol derivatives with unprecedented skeletons, were isolated from Leptospermum scoparium. Compounds 1-3 and 5-6 are phenylpropanoyl-phloroglucinol dimers, while 4 is a phenylpropanoylphloroglucinol-isovalerylphloroglucinol hybrid. Structurally, these compounds represent the first examples of dimeric phloroglucinols with unprecedented C(7')-C(8) linkage between the phloroglucinol core and the acyl side chain. Their structures were elucidated by comprehensive analyses of spectroscopic data, single crystal X-ray diffraction and chemical calculations. In addition, all compounds showed inhibitory effects against α-glucosidase with IC₅₀ values ranging from 39.5 to 186.8 μM.

Elodeoidins A–H, acylphloroglucinol meroterpenoids possessing diverse rearranged skeletons from Hypericum elodeoides

Inspired by the biosynthetic fragment (9), the first example of rearranged dimethylated acylphloroglucinol and monoterpene adducts, elodeoidins A–H (1–8) representing four skeletons and two rearranged pathways were authenticated from H. elodeoides.

Cytotoxic polyprenylated phloroglucinol derivatives from Hypericum elodeoides Choisy modulating the transactivation of RXRα

Hyperelodione D (1), an undescribed polyprenylated phloroglucinol derivative possessing 6/6/5/5 fused tetracyclic core, together with hyperelodiones E-F (2-3), two unreported analogues bearing 6/5/5 fused tricyclic structure, were isolated from Hypericum elodeoides Choisy. Their planar structures were elucidated by spectroscopic analysis (HRESIMS, 1D and 2D NMR) and their absolute configurations were determined by comparison of experimental and calculated ECD data. The cytotoxicity and retinoid X receptor-α (RXRα) related activities of the isolates were evaluated and the plausible biogenetic pathways of 1-3 were proposed.

12-Deacetyl-12-epi-Scalaradial, a Scalarane Sesterterpenoid from a Marine Sponge Hippospongia sp., Induces HeLa Cells Apoptosis via MAPK/ERK Pathway and Modulates Nuclear Receptor Nur77

12-Deacetyl-12-epi-scalaradial, a scalarane sesterterpenoid from a marine sponge Hippospongia sp, has been reported to possess cytotoxic activity on HepG2, MCF-7, and HCT-116 cells. However, there is no research to indicate that 12-deacetyl-12-epi-scalaradial exhibited anticancer effect on cervical cancer HeLa cells. The aim of this study was to investigate the anticancer activity of 12-deacetyl-12-epi-scalaradial against HeLa cells and to explore the mechanism. The results from a methylthiazolyldiphenyl-tetrazolium (MTT) assay suggested that 12-deacetyl-12-epi-scalaradial suppressed the proliferation of HeLa cells and flow cytometry analysis showed 12-deacetyl-12-epi-scalaradial could induce the apoptosis of HeLa cells in dose- and time-dependent manner. Western blotting analysis demonstrated that 12-deacetyl-12-epi-scalaradial triggered apoptosis via mediating the extrinsic pathway and was found to suppress MAPK/ERK pathway which was associate with cancer cell death. Nur77, a critical number of orphan nuclear receptors, plays diverse roles in tumor development as a transcription factor and has been considered as a promising anticancer drug target. The dual-luciferase reporter assays suggested that 12-deacetyl-12-epi-scalaradial could selectively enhance the trans-activation activity of Nur77. Furthermore, Western blotting analysis and fluorescence quenching showed that 12-deacetyl-12-epi-scalaradial could induce the phosphorylation of Nur77 and interact with the ligand-binding domain (LBD) of Nur77. Our research confirmed 12-deacetyl-12-epi-scalaradial as a potential agent for cervical cancer therapy and provided a view that 12-deacetyl-12-epi-scalaradial may be a modulator of Nur77.

The Fluoro-Thiazolylhydrazone Compound TSC-3C Inhibits Triple Negative Breast Cancer (TNBC) Cell Line Activity by Promoting Apoptosis, Regulating the MAPK Pathway and Inducing Mitochondrial Dysfunction

Triple negative breast cancer (TNBC) is the most aggressive cancer in women, and despite improved treatments, it remains a major cause of morbidity and mortality. We and others have demonstrated that different hybrid compounds targeting PARP/MAPK or other pathways to inhibit cancer progression may lead to promising therapeutic results. We introduced fluorine to alter the physical properties of the compounds. TSC-3C was one of the generated compounds. Upon treatment with TSC-3C, MDA-MB-231 cell proliferation, invasion, and migration were inhibited. TSC-3C induced MDA-MB-231 cell mitochondrial dysfunction and apoptosis, which may be caused by reducing the level of phosphorylated p44/42 MAPK (ERK1/2) and increasing the level of p-JNK. The present study may help to elucidate the role of the MAPK pathway in the development of breast cancer and may promote further research on halogenated heterocyclic compounds for the treatment of breast cancer.