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A new flexible germacranolide (1, lobatolide H) was isolated from the aerial parts of Neurolaena lobata. The structure elucidation was performed by classical NMR experiments and DFT NMR calculations. Altogether, 80 theoretical level combinations with existing 13C NMR scaling factors were tested, and the best performing ones were applied on 1. 1H and 13C NMR scaling factors were also developed for two combinations utilizing known exomethylene containing derivatives, and the results were complemented by homonuclear coupling constant (JHH) and TDDFT-ECD calculations to elucidate the stereochemistry of 1. Lobatolide H possessed remarkable antiproliferative activity against human cervical tumor cell lines with different HPV status (SiHa and C33A), induced cell cycle disturbance and exhibited a substantial antimigratory effect in SiHa cells.

Current plant-derived anticancer therapeutics aim to reach higher effectiveness, to potentiate chemosensitivity and minimize the toxic side effects compared to conventional chemotherapy. Cotinus coggygria Scop. is a herb with high pharmacological potential, widely applied in traditional phytotherapy. Our previous study revealed that leaf aqueous ethanolic extract from C. coggygria exerts in vitro anticancer activity on human breast, ovarian and cervical cancer cell lines. The objective of the present research was to investigate possible molecular mechanisms and targets of the antitumor activity of the extract in breast cancer MCF7 cells through analysis of cell cycle and apoptosis, clonogenic ability assessment, evaluation of the extract genotoxic capacity, characterization of cells thermodynamic properties, and analysis on the expression of genes involved in cellular epigenetic processes. The obtained results indicated that in MCF7 cells C. coggygria extract causes S phase cell cycle arrest and triggers apoptosis, reduces colony formation, induces DNA damage, affects cellular thermodynamic parameters, and tends to inhibit the relative expression of DNMT1, DNMT3a, MBD3, and p300. Further studies on the targeted molecules and the extract anti-breast cancer potential on animal experimental model system, need to be performed in the future.

Cotinus coggygria Scop. leaf aqueous ethanolic extract was examined for its in vitro antiproliferative and antioxidant activity. Antiproliferative effect was assessed on four human gynecological cancer cell lines: breast (MCF7, T47D), cervical (HeLa) and ovarian (A2780) and compared to the cell growth inhibitory effect on non-cancerous breast epithelial cell line MCF10A using MTT cell proliferation assay. Radical scavenging assay with DPPH was applied to evaluate antioxidant potential of the extract. The obtained results showed that the herb inhibited cell growth of all of the tested cancer cell lines and the highest was the cytostatic effect on A2780 cells with a half maximal inhibitory concentration (IC50) value of 30.8 μg/ml. For the other cell lines the IC50 values were in the range of 55-122.7 μg/ml. Additionally, the extract exerted considerably weaker reduction in cell proliferation of the non-cancerous cell line MCF10A compared to cancer cells, which indicates for antiproliferative selectivity. C. coggygria extract showed high free radical scavenging activity with an IC50 value of 11.2 μg/ml. The obtained data provide evidence for pharmacological potential of the tested extract and future more detailed studies concerning the molecular mechanisms of the anticancer effect of the herb are needed.

Cervical cancer is the fourth most frequently diagnosed tumor and the fourth leading cause of cancer death in females worldwide. Cervical cancer is predominantly related with human papilloma virus (HPV) infection, with the most oncogenic types being HPV-18 and -16. Our previous studies demonstrated that some d-secoestrone derivatives exert pronounced antiproliferative activity. The aim of the current investigation was to characterize the mechanism of action of d-secoestrone-triazole (D-SET) on three cervical cancer cell lines with different pathological backgrounds. The growth-inhibitory effects of D-SET were determined by a standard MTT assay. We have found that D-SET exerts a pronounced growth-inhibitory effect on HPV 18-positive HeLa and HPV-negative C-33 A cells, but it has no substantial inhibitory activity on HPV 16-positive SiHa or on intact fibroblast MRC-5 cell lines. After 24h incubation, cells showed the morphological and biochemical signs of apoptosis determined by fluorescent double staining, flow cytometry and caspase-3 activity assay. Besides the elevation of the ratio of cells in the subG1 phase, flow cytometric analysis revealed a cell cycle arrest at G2/M in both HeLa and C-33 A cell lines. To distinguish the G2/M cell population immunocytochemical flow cytometric analysis was performed on HeLa cells. The results show that D-SET significantly increases the ratio of phosphorylated histone H3, indicating cell accumulation in the M phase. Additionally, D-SET significantly increased the maximum rate of microtube formation measured by an in vitro tubulin polymerization assay. Besides its direct antiproliferative activity, the antimigratory property of D-SET has been investigated. Our results demonstrate that D-SET significantly inhibits the migration and invasion of HeLa cells after 24h incubation. These results suggests that D-SET is a potent antiproliferative agent against HPV 16+ and HPV-negative cervical cancer cell lines, with an efficacious motility-inhibiting activity against HPV 16+ cells. Accordingly D-SET can be regarded as a potential drug candidate with a promising new mechanism of action among the antiproliferative steroids, potentially allowing for the design of novel anticancer agents.

Mycochemical examination of a methanol extract of Scleroderma bovista Fr. (Agaricomycetes) led to the isolation of 7 compounds, which were, to our knowledge, identified for the first time in this species. The chemical structures of these compounds were determined through extensive spectroscopic methods (nuclear magnetic resonance and mass spectrometry). The fungal metabolites were identified as steroids based on ergostane (compounds 1-4) and lanostane (compounds 6 and 7) skeletons, whereas compound 5 was a ceramide derivative. We evaluated the antiproliferative activity of compounds 4-7 against human cancer cell lines (HeLa, A2780, MDA-MB-231, and MCF-7) using the MTT assay. The lanostane-type derivatives (compounds 6 and 7) and ergosterol peroxide 3-glucoside (compound 4) exerted significant antiproliferative property on 1 or more human cancer cell lines.

2-Methoxyestradiol (ME), one of the most widely investigated A-ring-modified metabolites of estrone, exerts significant anticancer activity on numerous cancer cell lines. Its pharmacological actions, including cell cycle arrest, microtubule disruption and pro-apoptotic activity, have already been described in detail. The currently tested D-ring-modified analogue of estrone, D-homoestrone, selectively inhibits cervical cancer cell proliferation and induces a G2/M phase cell cycle blockade, resulting in the development of apoptosis. The question arose of whether the difference in the chemical structures of these analogues can influence the mechanism of anticancer action. The aim of the present study was therefore to elucidate the molecular contributors of intracellular processes induced by D-homoestrone in HeLa cells. Apoptosis triggered by D-homoestrone develops through activation of the intrinsic pathway, as demonstrated by determination of the activities of caspase-8 and -9. It was revealed that D-homoestrone-treated HeLa cells are not able to enter mitosis because the cyclin-dependent kinase 1-cyclin B complex loses its activity, resulting in the decreased inactivation of stathmin and a concomitant disturbance of microtubule formation. However, unlike 2-ME, D-homoestrone does not exert a direct effect on tubulin polymerization. These results led to the conclusion that the D-homoestrone-triggered intracellular processes resulting in a cell cycle arrest and apoptosis in HeLa cells differ from those in the case of 2-ME. This may be regarded as an alternative mechanism of action among steroidal anticancer compounds.

The present study aimed at the phytochemical and pharmacological investigation of Sideritis montana L. (Lamiaceae). Two new abietane diterpenes [sideritins A (1) and B (2)] were isolated from the methanol extract of the plant. Six known compounds [pomiferin E (3), 9α,13α-epi-dioxyabiet-8(14)-en-18-ol (4), paulownin (5), 6-methoxysakuranetin (6), 3-oxo-α-ionol (7) and 4-allyl-2,6-dimethoxyphenol glucoside (8)] were also obtained from the plant. The structures were determined by means of HREIMS and NMR experiments. The antiproliferative effect of the isolated compounds was investigated on human cancer cell lines (HeLa, SiHa and C33A) at 10 and 30 μM concentrations, using the MTT assay. The results demonstrated that pomiferin E (3) and 6-methoxysakuranetin (6) displayed considerable activity [inhibition (%) ± SEM: 46.93 ± 2.35 on HeLa (pomiferin E), and 51.52 ± 2.45 on C33A (6-methoxysakuranetin)] at 30 μM concentration.

The syntheses of C-13 epimeric 3-[(1-benzyl-1,2,3-triazol-4-yl)methoxy]-d-secoestrones are reported. Triazoles were prepared from 3-(prop-2-inyloxy)-d-secoalcohols and p-substituted benzyl azides via Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC). The antiproliferative activities of the products and their precursors were determined in vitro against a panel of human adherent cervical (HeLa, SiHa and C33A), breast (MCF-7, MDA-MB-231, MDA-MB-361 and T47D) and ovarian (A2780) cell lines by means of MTT assays. The orientation of the angular methyl group and the substitution pattern of the benzyl group of the azide greatly influenced the cell growth-inhibitory potential of the compounds. The 13β derivatives generally proved to be more potent than their 13α counterparts. Introduction of a benzyltriazolylmethyl group onto the 3-OH position seemed to be advantageous. One 13α compound containing an unsubstituted benzyltriazolyl function displayed outstanding antiproliferative activities against three cell lines.

Thanks to its biologically active constituents, Ruta graveolens L. (Rutaceae) is a widely used medicinal plant. In our study, six furanoacridone alkaloids isolated from Ruta graveolens were investigated for their antiproliferative and pro-apoptotic effects on human breast cancer cell lines (MCF-7, MDA-MB-361, MDA-MB-231 and T47D).The cell lines were pretreated with alkaloid components (rutacridone, isogravacridone chlorine (IGC), gravacridonediol monomethyl ether, gravacridonediol, gravacridonetriol, a 1:1 mixture of gravacridonetriol and - diol monoglucosides) and their antiproliferative effects were determined by the MTT assay.IGC had the most marked effect on cell proliferation of MDA-MB-231 (half maximal inhibitory concentration (IC50)=2.27 μM). Cell-cycle analysis was applied to quantify the effect of IGC on subpopulations of MDA-MB-231 and MCF-7 cells. It caused a cell-cycle disturbance by decreasing the G2/M and G0/G1 and increasing the S phase and the appearance of the subdiploid (sub-G1) population. Hoechst 33258-propidium iodide staining was used to evaluate the morphological changes in IGC-pretreated MDA-MB-231 and MCF-7 cells, revealing the appearance of apoptotic features. IGC was found to cause a modest activation of caspase-3 and -9, but not caspase-8, indicating the activation of an intrinsic apoptotic pathway in MDA-MB-231 cells.These in vitro findings indicate that furanoacridones are suitable candidates for anticancer drug development.

In the present work, aqueous and organic extracts of 16 Basidiomycetes mushrooms and 1 Ascomycetes mushroom were investigated in vitro for their antiproliferative activity against HeLa (cervix epithelial adenocarcinoma), A431 (skin epidermoid carcinoma), A2780 (ovarian carcinoma), and MCF7 (breast epithelial adenocarcinoma) cells, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. A total of 68 n-hexane, chloroform, 50% methanol, and water extracts of selected species were screened for their potential cell growth inhibitory activity. Our experiments revealed that 7 of 17 species demonstrated notable antiproliferative activity (at least 50% inhibition of cell proliferation) against one or more cell lines. Kuehneromyces mutabilis, Lactarius quietus, and Lentinellus cochleatus, which exerted the highest activity on cancer cells, are considered valuable species in the perspective of further mycochemical studies.

13α-Estrone derivatives containing various substituents on C-3 and C-17 were synthesized, and evaluated by means of MTT assays for in vitro antiproliferative activity against a panel of human adherent cancer cell lines (HeLa, MCF-7, A2780 and A431). Compounds with N-benzyltriazolylmethoxy moieties on C-3 proved to be more potent than their 3-hydroxy or 3-ether counterparts. Some triazoles exerted substantial cytostatic effects against particular tumor cell lines, with submicromolar IC50 values.

Novel 16-hydroxymethyl-19-nortestosterone diastereomers were prepared by Birch reduction from the corresponding 3-methoxy-16-hydroxymethylestra-1,3,5(10)-trien-17-ol isomers with known configurations. The synthesized compounds are 16α- and 16β-hydroxymethyl-substituted 19-nortestosterone and their 17α-epimers. To prepare 17α-19-nortestosterone, the Mitsunobu inversion reaction of 19-nortestosterone with different alkyl and aryl carboxylic acids was chosen. Deacylation of the new compounds by the Zemplen method yielded the required 17α-19-nortestosterone. The antiproliferative activities of the structurally related compounds were determined in vitro through microculture tetrazolium assays on a panel of human adherent cervical (HeLa, SiHa and C33A), breast (MCF-7, MDA-MB-231, MDA-MB-361 and T47D) and ovarian (A2780) cell lines. The 17α epimer of 19-nortestosterone demonstrated considerable activity, selectively for HeLa cells, with a calculated IC50 of 0.65 μM. The reference compound, cisplatin, displayed an order of magnitude higher IC50 (12.4 μM). The cancer selectivity of 17α-19-nortestosterone was tested by MTT assay performed with noncancerous human fibroblast cell line MRC-5. The results indicated that 17α-19-nortestosterone selectively disturbs the viability of HeLa cells without greatly affecting other cancer cell types and intact fibroblasts.

The possibility of the therapeutic use of estrogens emerged following the recognition that certain estradiol analogs, and particularly metabolites ( e.g. the A-ring metabolite 2-hydroxyestrone, etc .) inhibit the differentiation of diverse tumor cell lines. Until recently, despite the investigation of numerous synthetic d -ring-substituted estrone derivatives, no analysis had been published on the effects of d -ring expansion of estrone on its tumor-suppressing activity. The aim of the present study was to characterize the antiproliferative effects of normal and 13- epi - d -homoestrone and their 3-methyl ethers (1–4) on human reproductive cancer cell lines. The antitumor activities of the two epimer pairs on HeLa, MCF-7 and Ishikawa cells were determined. Normal d -homoestrone exerted the greatest cytostatic effect on HeLa cells (IC 50 = 5.5 μM) and was subjected to further investigations to elucidate its mechanism of action on apoptosis induction. Morphological changes detected by Hoechst 33258–propidium iodide double staining, the cell cycle arrest at phase G2/M and the subsequent increase in the proportion of the subG1 fraction determined by flow cytometric analysis and the significant increase in the activity of caspase-3 confirmed the induction of apoptosis in HeLa cells treated with d -homoestrone. d -Homoestrone was also tested on a non-cancerous human lung fibroblast cell line (MRC-5) to determine its selective toxicity. The concentration in which it inhibited cell proliferation by 50% was at least six times higher for the fibroblast cells than for cervical cancer cells. No significant in vivo estrogenic activity was observed as concerns the uterus weight of gonadectomized rats after a 7-day treatment with normal d -homoestrone. These results led to the conclusion that normal d -homoestrone is a novel antitumor compound with a similar activity on HeLa cells as that of the reference agent cisplatin, but its selectivity toward non-cancerous cells is significantly higher than that of cisplatin. It may be considered to be a basic lead molecule for the preclinical development of potential anticancer agents.