Potential activity of fevicordin-A from Phaleria macrocarpa (Scheff) Boerl. seeds as estrogen receptor antagonist based on cytotoxicity and molecular modelling studies

Anti-cancer bioprospecting on medicinal plants from Indonesia: A review

The Indonesian archipelago is home to the second largest biodiversity in the world and is inhabited by more than 300 ethnic groups with a total population of more than 270 million. The indigenous population still rely on traditional medicine practices, especially the use of plant-based remedies. Although modern science-based exploration on Indonesian medicinal plants started with the European settlement in the archipelago in the 16th century, it was not until the 1970's that the phytochemistry of Indonesian medicinal plants was recognized for its potency. The need for new cancer cures to increase the quality of human life has led to the bioprospecting of medicinal plants including those of Indonesian origin. Despite published reports on the anticancer potency of Indonesian medicinal plants, to date there has been no comprehensive review on this topic. In this manuscript, we review the phytochemical and pharmacological studies on medicinal plants from Indonesia related to cancer therapy. Established databases (GARUDA, SciFinder, and PubMed) were used to collate data from 1990 to 2022, resulting in the description of 134 medicinal plants and their phytochemical and pharmacological properties including examples containing potent agents against breast, leukaemia, cervix, lung, and colon cancer cell lines based on in vitro bioassays and in vivo evaluation. These findings provide valuable insights into the bioprospecting of Indonesian medicinal plant providing directions for future studies, including the development of new therapeutics, both as botanicals or by using conventional dosage.

Molecular Docking Study of Isoxazole Indole Derivatives (B2A2 Series) as Promising Selective Estrogen Receptor Modulators & Anticancer Drugs

A series of 7 compounds with isoxazole - indole - γ-resorcylic acid scaffold, segregated into B2 & A2 series, wherein, B2 comprises Compounds: 13, 14, 15 & 16 and A2 comprises Compounds: 10, 11 & 12, on the basis of the variable substituents at the indole, resorcinol and isoxazole end of the scaffold as in Figure: 1, were designed and docked with human estrogen receptor: 1ERRα. The Binding affinity (BA) and the interacting amino acids compared with reference selective estrogen receptor modulators (SERM's) such as Raloxifene, Estradiol, Bazedoxifene, Bisphenol, Genistein, Daidzein, Ormiloxifene, Tamoxifen, 6-hydroxy-naphthalen-2yl-benzo(D)-isoxazol-6-ol(1) using PyRx software and their ADME properties predicted with SWISS ADME online tool. Significant similarities and minor differences in the binding pattern between the key interacting aminoacids such as Arg 394, Glu 353, Asp 351, Leu 346, Leu 525, Trp 383, Phe 404, Ala 350, Leu 387, Met 421 responsible for ER agonist/antagonist affinity found in the binding cavity of a 1 Errα -Bazedoxifene/1 Errα -raloxifene/1 Errα -estradiol docked complex AND 1 Errα -isoxazole-indole- resorcinol docked complex indicate their promising potential to serve as potent ER agonists in bone or ER antagonists against breast cancer and other cancer diseases. The Compounds with highest BA is of the order: BA (A1series)>B1series>/<BA(A2 series)>/=BA (B2 series) exceptions: compounds: 4, 5 of B1 series & compound:13 of B2 series with identical and least BA values.BA(6)=BA(8)>BA(7)>BA(2)>BA(9)=BA(1)>BA(12)>BA(10)=BA(15)=BA(11)=BA(3)>BA(14)=BA(16)>BA(4)=BA(5)=BA(13).

Insilico Docking Study of Isoxazole Indole Linked Resorcinol Derivatives as Promising Selective Estrogen Receptor Modulators & Anticancer Drugs

A series of 9 compounds with isoxazole-indole-γ-resorcylic acid scaffold, segregated into B1 & A1 series, wherein, B1 comprises compounds:1,3,4,5, & 9 and A1comprises compounds: 2,6,7, & 8 , on the basis of variable substituents at the indole , resorcinol and isoxazole end of the scaffold as in Fig. 1, were designed and docked with human estrogen receptor:1ERRα. The binding affinity (BA) and the interacting amino acids compared with reference selective estrogen receptor modulators (SERMs) such as Raloxifene, Estradiol, Bazedoxifene, Bisphenol, Genistein, Daidzein, Ormiloxifene,Tamoxifen,6-hydroxy-naphthalen-2yl-benzo(D)-isoxazol-6-ol(1)(WAY-397) using PyRx software and their ADME properties predicted with SWISS ADME online tool. Significant similarities and minor differences in the binding pattern between the key interacting aminoacids such as Arg 394,Glu 353, Asp 351, Leu 346, Leu 525, Trp 383,Phe 404 ,Ala 350, Leu 387, Met 421 responsible for ER agonist/antagonist activity found in the binding cavity of a 1 Errα -Bazedoxifene/1 Errα -raloxifene/1 Errα -estradiol docked complex AND 1 Errα -isoxazole-indole- resorcinol docked complex indicate their promising potential to serve as potent ER agonists in bone or ER antagonists against breast cancer and other cancer diseases. The Compounds with Highest BA is of the order: BA (A1series)>B1 series & BA(6)=BA(8)>BA(7)>BA(2)>BA(9)=BA(1)>BA(3)>BA(4)=BA(5).

Human Estrogen Receptor Alpha Antagonists, Part 3: 3-D Pharmacophore and 3-D QSAR Guided Brefeldin A Hit-to-Lead Optimization toward New Breast Cancer Suppressants

The estrogen receptor α (ERα) is an important biological target mediating 17β-estradiol driven breast cancer (BC) development. Aiming to develop innovative drugs against BC, either wild-type or mutated ligand-ERα complexes were used as source data to build structure-based 3-D pharmacophore and 3-D QSAR models, afterward used as tools for the virtual screening of National Cancer Institute datasets and hit-to-lead optimization. The procedure identified Brefeldin A (BFA) as hit, then structurally optimized toward twelve new derivatives whose anticancer activity was confirmed both in vitro and in vivo. Compounds as SERMs showed picomolar to low nanomolar potencies against ERα and were then investigated as antiproliferative agents against BC cell lines, as stimulators of p53 expression, as well as BC cell cycle arrest agents. Most active leads were finally profiled upon administration to female Wistar rats with pre-induced BC, after which 3DPQ-12, 3DPQ-3, 3DPQ-9, 3DPQ-4, 3DPQ-2, and 3DPQ-1 represent potential candidates for BC therapy.

Synthesis, Anticancer Activity, Structure-Activity Relationship, and Molecular Modeling Studies of α-Mangostin Derivatives as hERα Inhibitor

α-Mangostin is one of the secondary metabolites in mangosteen pericarp, which has been reported to have anti-breast cancer activity. In our previous study, three α-mangostin derivatives were computationally designed as hERα antagonists. In this present study, the designed compounds were synthesized undergoing a benzoylation reaction between α-mangostin with three benzoyl chloride derivatives to produce three derivatives, namely, AMB-1, AMB-2, and AMB-10. The synthesized compounds were then evaluated for their antiproliferative activity against the MCF-7 breast cancer cell model with hERα as the protein target. The in vitro assay shows moderate activity (57-126 μM) for all derivatives. The dynamic behaviors of all ligands, including α-mangostin and 4-hydroxytamoxifen (4-OHT), were studied with 100 ns of MD simulation. The structure-activity relationship shows that although it does not entirely concord with the expected design, it can explain the trend of α-mangostin and its derivatives antiproliferative activities against MCF-7, which associates with hERα antagonism.

α-Mangostin and its derivatives against estrogen receptor alpha

Estrogen receptor alpha (ERα) acts as the transcription factor and the main therapeutic target against breast cancer. One of the compounds that has been shown to act as an ERα is α-mangostin. However, it still has weaknesses due to its low solubility and low potent activity. In this study, α-mangostin was modified by substituting -OH group at C6 using benzoyl derivatives through a step by step in silico study, namely pharmacokinetic prediction (https://preadmet.bmdrc.kr/adme/), pharmacophore modeling (LigandScout 4.1), molecular docking simulation (AutoDock 4.2), molecular dynamics simulation (AMBER 16) and a binding free energy analysis using MM-PBSA method. From the computational studies, three compounds which are derived from α-mangostin (AMB-1 (-9.84 kcal/mol), AMB-2 (-6.80 kcal/mol) and AMB-10 (-12.42 kcal/mol)) have lower binding free energy than α-mangostin (-1.77 kcal/mol), as evidenced by the binding free energy calculation using the MM-PBSA method. They can then be predicted to have potent activities as ERα antagonists.Communicated by Ramaswamy H. Sarma.

Antidiabetic effects of P. macrocarpa ethanolic fruit extract in streptozotocin-induced diabetic rats

Background

The fruits of P. macrocarpa have long been used as a traditional Malay medicinal herb for hundreds of years. Intraperitoneal (i.p.) injection of streptozotocin (STZ) (65 mg/kg) was used to induce diabetes in rats confirmed by an oral glucose tolerance test (OGTT). The ethanol extract of P. macrocarpa (EEPM) fruits at 100 and 200 mg/kg were given orally for 35 days, glibenclamide. In total, 0.5 mg/kg served as a positive control.

Results

The present toxicity study suggests that the EEPM fruits are non-toxic. In an OGTT, the EEPM at 50, 100, and 200 mg/kg and glibenclamide (0.5 mg/kg) reduced the blood glucose level (hyperglycemia due to glucose load 2 g/kg p.o.) significantly after 2 h of oral administration, when compared to the diabetic control. Repeated oral administration of EEPM daily for up to 35 days exhibited significant antidiabetic activity in STZ-induced diabetic rats compared to the diabetic control. At the end of 35 days of treatment, the 200 mg/kg (EEPM) dose was found to be more effective than the 100 and 50 mg/kg (EEPM) doses and blood glucose levels decreased from 392.66 ± 3.20 to 174.33 ± 4.32 mg/dl (p ˂ 0.01). In contrast, on day 35, the blood glucose levels of the normal control, drug control, and diabetic control were 132.16 ± 5.79, 134.33 ± 7.18 (p ˂ 0.01), and 514.83 ± 7.96 respectively. From histology analysis, the pancreases of the diabetic control were granulated and dilated islet cells, whereas in the drug control they appeared granulated, without dilation and important hyper plasticity of islets. The treatment groups (EEPM 100 and 200 mg/kg) also showed granulated pancreatic islets and prominent hyper plasticity islets. Light micrographs in various regions of rat kidney tissue from the treatment groups showed absence of matrix expansion and glomerular basement membrane thickening, suggesting it became normal histoarchitecture of the renal. Biochemical aspects in treating animals’ all serum analytic parameters were almost similar to the drug control group with the exception of the 50 mg/kg treatment group.

Conclusion

In this way, it may also serve as a good alternative in the present armamentarium of antidiabetic drugs.

1,2,4-Oxadiazole-5-ones as analogues of tamoxifen: synthesis and biological evaluation

A series of 2,3,4-triaryl-substituted 1,2,4-oxadiazole-5-ones have been prepared as fixed-ring analogues of tamoxifen (TAM), a drug inhibitor of Estradiol Receptor (ER) used in breast cancer therapy, by an efficient synthetic protocol based on a 1,3-dipolar cycloaddition of nitrones to isocyanates. Some of the newly synthesized compounds (14d-f, 14h and 14k) show a significant cytotoxic effect in a human breast cancer cell line (MCF-7) possessing IC50 values between 15.63 and 31.82 μM. In addition, compounds 14d-f, 14h and 14k are able to increase the p53 expression levels, activating also the apoptotic pathway. Molecular modeling studies of novel compounds performed on the crystal structure of ER reveal the presence of strong hydrophobic interactions with the aromatic rings of the ligands similar to TAM. These data suggest that 1,2,4-oxadiazole-5-ones can be considered analogues of TAM, and that their anticancer activity might be partially due to ER inhibition.

Cytotoxicity Of Chalcone Of Eugenia aquea Burm F. Leaves Against T47D Breast Cancer Cell Lines And Its Prediction As An Estrogen Receptor Antagonist Based On Pharmacophore-Molecular Dynamics Simulation

Background

The 2ʹ,4ʹ-dihydroxy-6-methoxy-3,5-3-dimethylchalcone (ChalcEA) isolated from Eugenia aquea Burm f. leaves has potential anticancer activity against human breast-adenocarcinoma cell lines (MCF-7) with an IC₅₀ value of 250 µM. However, its apoptotic activity on the T47D breast cancer cell lines which is involving caspase-3 has not been investigated.

Materials and methods

Therefore, this study aims to evaluate the cytotoxicity of ChalcEA on the T47D cell lines using the 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium (WST) method and to predict its possible antagonistic activity on the human estrogen receptor alpha (hERα) using pharmacophore and molecular dynamics (MD) methods. The in vitro test of 10 synthesized ChalcEA derivatives was also performed as an insight into the further development of its structure as an anticancer agent.

Results

It is shown that ChalcEA has an IC₅₀ of 142.58 ± 4.6 µM against the hERα-overexpressed T47D breast cancer cell lines, indicating its possible mechanism of anticancer activity as an antagonist of hERα. Pharmacophore study showed that ChalcEA shares similar features with the known hERα antagonist, 4-hydroxytamoxifen (4-OHT), which has hydrogen bond donor (HBD), hydrogen bond acceptor (HBA), ring aromaticity (RA), and hydrophobicity (Hy) features. Molecular docking showed that ChalcEA formed hydrogen bonds with Glu353 and Arg394, and hydrophobic interactions in a similar manner with 4-OHT. Moreover, MD simulations showed that ChalcEA destabilized the conformation of His524, a remarkable behavior of a known hERa antagonist, including 4-OHT. Furthermore, the 10 best chalcone derivatives resulted from pharmacophore- and docking-based screening, were tested against the T47D cell lines. None of the derivatives have better activity than ChalcEA. It is suggested that the functional groups at the B-ring of ChalcEA are interesting to be further optimized in the next studies.

Conclusion

ChalcEA might act as an antagonist toward hERα, thus warranting further investigation as a potential anticancer agent.

Hormonally active phytochemicals from macroalgae: A largely untapped source of ligands to deorphanize nuclear receptors in emerging marine animal models

Hormonally active phytochemicals (HAPs) are signaling molecules produced by plants that alter hormonal signaling in animals, due to consumption or environmental exposure. To date, HAPs have been investigated mainly in terrestrial ecosystems. To gain a full understanding of the origin and evolution of plant-animal interactions, it is necessary also to study these interactions in the marine environment, where the major photosynthetic lineages are very distant from the terrestrial plants. Here we focus on chemicals from red and brown macroalgae and point out their potential role as modulators of the endocrine system of aquatic animals through nuclear hormone receptors. We show that, regarding steroids and oxylipins, there are already some candidates available for further functional investigations of ligand-receptor interactions. Furthermore, several carotenoids, produced by cyanobacteria provide candidates that could be investigated with respect to their presence in macroalgae. Finally, regarding halogenated compounds, it is not clear yet which molecules could bridge the gap to explain the transition from lipid sensing to thyroid hormone high affinity binding among nuclear receptors.

Structural insight into the antagonistic action of diarylheptanoid on human estrogen receptor alpha

Estrogen receptor α (ER α) is an important therapeutic target in the regulation of ligand dependent signaling in breast cancer. The current study investigates the anti-estrogenic potential of the Diarylheptanoid, 5-hydroxy-7-(4-hydroxy-3 methoxyphenyl)-1-phenyl-3-heptanone (DAH) in silico. Rigid Docking analysis of DAH at the ligand binding domain (LBD) of ER α showed hydrogen bond interactions with Arg394 and Glu353 at the active site, similar to the positive controls 4-Hydroxy Tamoxifen (4-OHT) and Fulvestrant (FUL). The protein and the protein-DAH complexes were further analyzed using molecular dynamics simulations for a time scale of 50 ns using GROMACS. Root mean square fluctuation (RMSF) analysis showed large fluctuations at the N-terminal region of Helices (H) 3, 9 and at the C-terminal region of H11, which could be involved in the antagonistic conformational change. Interestingly, H12 appeared to move away from the ligand binding pocket and occupy the co-activator binding groove at the LBD of ER α. Secondary structure analysis of the protein upon binding of DAH and CUR showed structural change from α-helix to Turn conformation at H4. We hypothesize that this structural change at H4, similar to the positive control, could hinder the activity of AF-2 by blocking the binding of co-activator. These conformational changes in ER α indicate an anti-estrogenic and therapeutic potential of the DAH.

Molecular Docking and 3D-Pharmacophore Modeling to Study the Interactions of Chalcone Derivatives with Estrogen Receptor Alpha

Tamoxifen is the most frequently used anti-estrogen adjuvant treatment for estrogen receptor-positive breast cancer. However, it is associated with an increased risk of several serious side-effects, such as uterine cancer, stroke, and pulmonary embolism. The 2',4'-dihydroxy-6-methoxy-3,5-dimethylchalcone (ChalcEA) from plant leaves of Eugenia aquea, has been found to inhibit the proliferation of MCF-7 human breast cancer cells in a dose-dependent manner, with an IC₅₀ of 74.5 μg/mL (250 μM). The aim of this work was to study the molecular interactions of new ChalcEA derivatives formed with the Estrogen Receptor α (ERα) using computer aided drug design approaches. Molecular docking using Autodock 4.2 was employed to explore the modes of binding of ChalcEA derivatives with ERα. The 3D structure-based pharmacophore model was derived using LigandScout 4.1 Advanced to investigate the important chemical interactions of the ERα-tamoxifen complex structure. The binding energy and the tamoxifen-pharmacophore fit score of the best ChalcEA derivative (HNS10) were -12.33 kcal/mol and 67.07 kcal/mol, respectively. The HNS10 interacted with Leu346, Thr347, Leu349, Ala350, Glu353, Leu387, Met388, Leu391, Arg394, Met421, and Leu525. These results suggest that the new ChalcEA derivatives could serve as the lead compound for potent ERα inhibitor in the fight against breast cancer.

Estrogenic terpenes and terpenoids: Pathways, functions and applications

Terpenes are made of the isoprene unit (C₅), and along with their derivatives, terpenoids, they are widely distributed in plants as active ingredients involved in anti-inflammation, anti-carcinogenesis and neuroprotection. Estrogenic terpenes and terpenoids are an important category of phytoestrogens and have been used as traditional medicines. The comprehensive list of estrogenic terpenes and terpenoids includes hemi-, mono-, sesqui-, di-, tri-, tetra- and polyterpenes, their derivatives, and meroterpenes, along with the signaling pathways and cellular functions on which their estrogenicity is exerted. Signaling pathways are further classified as bidirectional or unidirectional, the latter being further divided into two types depending upon the presence of both ligands, or the absence of one or both ligands. Although estrogenic activity of terpenes and terpenoids was evaluated by ligand-binding assays, yeast two-hybrid assays, reporter-gene assays, transcription assays, protein assays, cell assays and animal testing, the mechanism of estrogenic activity is still not fully understood. Applications of estrogenic terpenes and terpenoids are categorized into cancer treatment and prevention, cardioprotection, endocrine toxicity/reproductive dysfunction, food/supplement/traditional medicine, immunology/inflammation, menopausal syndromes and neuroprotection, where their benefits are discussed based on their availability, stability and variations.

Phaleria macrocarpa (Boerl.) fruit induce G0/G1 and G2/M cell cycle arrest and apoptosis through mitochondria-mediated pathway in MDA-MB-231 human breast cancer cell

ETHNOPHARMACOLOGICAL RELEVANCE

Phaleria macrocarpa (Scheff) Boerl, is a well-known folk medicinal plant in Indonesia. Traditionally, P. macrocarpa has been used to control cancer, impotency, hemorrhoids, diabetes mellitus, allergies, liver and hearth disease, kidney disorders, blood diseases, acne, stroke, migraine, and various skin diseases.

AIM OF THE STUDY

The purpose of this study was to determine the in situ cytotoxicity effect P. macrocarpa fruit ethyl acetate fraction (PMEAF) and the underlying molecular mechanism of cell death.

MATERIALS AND METHODS

MDA-MB-231 cells were incubated with PMEAF for 24h. Cell cycle and viability were examined using flow cytometry analysis. Apoptosis was determined using the Annexin V assay and also by fluorescence microscopy. Apoptosis protein profiling was detected by RayBio® Human Apoptosis Array.

RESULTS

The AO/PI staining and flow cytometric analysis of MDA-MB-231 cells treated with PMEAF were showed apoptotic cell death. The cell cycle analysis by flow cytometry analysis revealed that the accumulation of PMEAF treated MDA-MB-231 cells in G₀/G₁ and G₂/M-phase of the cell cycle. Moreover, the PMEAF exert cytotoxicity by increased the ROS production in MDA-MB-231 cells consistently stimulated the loss of mitochondrial membrane potential (∆_Ψm) and induced apoptosis cell death by activation of numerous signalling proteins. The results from apoptosis protein profiling array evidenced that PMEAF stimulated the expression of 9 pro-apoptotic proteins (Bax, Bid, caspase 3, caspase 8, cytochrome c, p21, p27, p53 and SMAC) and suppressed the 4 anti-apoptotic proteins (Bcl-2, Bcl-w, XIAP and survivin) in MDA-MB-231 cells.

CONCLUSION

The results indicated that PMEAF treatment induced apoptosis in MDA-MB-231 cells through intrinsic mitochondrial related pathway with the participation of pro and anti-apoptotic proteins, caspases, G₀/G₁ and G₂/M-phases cell cycle arrest by p53-mediated mechanism.