LC/MS analysis of Viscum cruciatum Sieber ex Boiss. extract with anti-proliferative activity against MCF-7 cell line via G0/G1 cell cycle arrest: An in-silico and in-vitro study.

ETHNOPHARMACOLOGICAL RELEVANCE: Viscum cruciatum Sieb is a well-known medicinal plant in Jordan containing various secondary metabolites. It has traditionally been used to treat many ailments, most notably cancer. However, there is a significant gap between scientific research and its value in traditional medicine. AIM OF THE WORK: To evaluate the antiproliferative activity of different V. cruciatum extracts against MCF-7 breast cancer cell lines and recognize the affected cell cycle phase. Besides, identifying the bioactive components present in the active extract using LC/MS technique. Also, to determine the possible mechanism of action by in silico and in-vitro study. MATERIALS AND METHODS: V. cruciatum was extracted using solvents with increasing polarity. The antiproliferative effects of the extracts against MCF-7 cell lines were evaluated using SRB assay. Further, flow cytometry was used to identify the inhibited phase of the cell cycle, while LC/MS-MS technique was used to analyze the chemical composition of the most active extract. After that, the putative mechanism of action was investigated through in-silico docking, molecular dynamic simulation for compounds with the highest docking scores, and Western blot analysis of cyclin-dependent kinases (CDK2/4/6). RESULTS: The chloroform/methanol 90/10 (ChMe) extract showed the most potent antiproliferative effect against MCF-7 cells (IC50 = 23.8 µg/mL), and cell cycle arrest at the G0/G1phase. Furthermore, LC-MS/MS analysis revealed the presence of several polyphenolics belonging to the flavonoids and phenolic acids classes. Additionally, quercetin-4'-glucoside, 3, 5, 7-trihydroxy-4'-methoxy flavone, and hesperetin-7-O-neohesperidoside demonstrated the highest docking binding scores and stable complexes against CDK2 and CDK4/6. Moreover, RMSD (root-mean-square deviation), RMSF (root-mean-square fluctuation), Rg (radius of gyration), and energy analysis during molecular dynamic simulation indicated the stable binding of the studied complexes. These results were supported by Western blot analysis, which revealed the downregulation of CDK2, CDK4, and CDK6 protein expression in MCF-7 cell lines. CONCLUSION: These findings emphasized the potential breast anticancer activity of the V. cruciatum ChMe extract by arresting the G0/G1 phase of the cell cycle, which could be related to its flavonoid content. Moreover, the results provided experimental support for the traditional anticancer activity of V. cruciatum, and its ChMe extract might be a source of chemoprotective or chemotherapeutic isolates.

Design and Synthesis of 4-O-Podophyllotoxin Sulfamate Derivatives as Potential Cytotoxic Agents.

4-O-Podophyllotoxin sulfamate derivatives were prepared using the natural lignan podophyllotoxin. The prepared compounds were afforded by reacting O-sulfonyl chloride podophyllotoxin with ammonia or aminoaryl/heteroaryl motif. Biological evaluation was performed in human breast cancer (MCF7), ovarian cancer (A2780), colon adenocarcinoma (HT29), and normal lung fibroblast (MRC5) cell lines. Compound 3 exhibited potent inhibitory activity and good selectivity margin. Compounds 2, 3, and 7 exerted apoptotic effect in MCF7 cells in a dose-dependent manner. The cytotoxicity of the verified compounds was inferior to that of podophyllotoxin.

Proapoptotic Activity of Achillea membranacea Essential Oil and Its Major Constituent 1,8-Cineole against A2780 Ovarian Cancer Cells.

Among the hundreds of reported Achillea species, A. membranacea (Labill.) DC. is one of the six that grow in Jordan. Many species of this genus are used in folk medicine to treat a variety of ailments and several biological and pharmacological activities have been ascribed to their essential oil (EO). For this study, the EO obtained from a specimen of A. membranacea grown in Jordan was analyzed by GC-MS. Ninety-six compounds were detected, of which oxygenated monoterpenes was the predominant class (47.9%), followed by non-terpene derivatives (27.9%), while sesquiterpenes represented 14.2% of the total composition. The most abundant compound in the EO was 1,8-cineole (21.7%). The cytotoxic activity of the EO was evaluated against three cancer cell lines (MCF7, A2780 and HT29), and one normal fibroblast cell line (MRC5) by MTT assay. Significant growth inhibition was observed in EO-exposed A2780 and HT29 cells (IC50 = 12.99 and 14.02 µg/mL, respectively), while MCF7 and MRC5 were less susceptible. The EO induced apoptosis and increased the preG1 events in A2780 cells. 1,8-Cineole, the major constituent of the EO, exhibited submicromolar cytotoxicity against A2780 cells, and was 42 times more selective against MRC5 cells. Its cytotoxicity against A2780 cells was comparable with that of doxorubicin, but 1,8-cineole was more selective for MRC5 normal cells. Interestingly, 1,8-cineole enhanced apoptosis in A2780, and caused a remarkable dose-dependent increase in preG1 events. Thus, 1,8-cineole has demonstrated promising cytotoxic and proapoptotic properties.

Asymmetric triplex metallohelices with high and selective activity against cancer cells.

Small cationic amphiphilic α-helical peptides are emerging as agents for the treatment of cancer and infection, but they are costly and display unfavourable pharmacokinetics. Helical coordination complexes may offer a three-dimensional scaffold for the synthesis of mimetic architectures. However, the high symmetry and modest functionality of current systems offer little scope to tailor the structure to interact with specific biomolecular targets, or to create libraries for phenotypic screens. Here, we report the highly stereoselective asymmetric self-assembly of very stable, functionalized metallohelices. Their anti-parallel head-to-head-to-tail 'triplex' strand arrangement creates an amphipathic functional topology akin to that of the active sub-units of, for example, host-defence peptides and p53. The metallohelices display high, structure-dependent toxicity to the human colon carcinoma cell-line HCT116 p53(++), causing dramatic changes in the cell cycle without DNA damage. They have lower toxicity to human breast adenocarcinoma cells (MDA-MB-468) and, most remarkably, they show no significant toxicity to the bacteria methicillin-resistant Staphylococcus aureus and Escherichia coli.

Synthesis and biological evaluation of colchicine B-ring analogues tethered with halogenated benzyl moieties.

Deacetylcolchicine was reacted with substituted benzyl halides to provide a library of compounds for biological analysis. Compound 7 (3,4-difluorobenzyl-N-aminocolchicine) was shown to possess cytotoxicity in cancer cell lines in the low nanomolar range. Significantly, it showed no loss of activity in the resistant A2780AD ovarian carcinoma cell line known to overexpress the ABCB1 drug transporter and was also unaffected by overexpression of class III ß-tubulin in HeLa transfected cells.

Minor structural modifications to alchemix influence mechanism of action and pharmacological activity.

Alchemix is an exemplar of a class of anthraquinone with efficacy against multidrug resistant tumours. We have explored further the mechanism of action of alchemix and investigated the effect of extending its side arm bearing the alkylating functionality with regard to DNA binding and activity against multidrug resistant cancer cells. Increasing the distance between the intercalating chromophore and the alkylating functionality of ICT2901 (propyl), ICT2902 (butyl) and ICT2903 (pentyl), led to a higher number of DNA alkylation sites, more potent topoisomerase II inhibition and generated more apoptotic and necrotic cells when analysed in p53-proficient HCT116 cells. Intriguingly, alchemix, the compound with the shortest distance between its intercalative chromophore and alkylating functionality (ethyl), did not conform to this SAR. A different toxicity pattern against DNA repair defective CHO cell lines as well as arrest of cells in G1 supports a somewhat distinct mode of action by alchemix compared with its analogues. Importantly, both alchemix and ICT2901 demonstrated greater cytotoxic activity against anthraquinone-resistant MCF-7/adr cells than wild-type MCF-7 cells. Subtle synthetic modification in this anthraquinone series has led to significant changes to the stability of DNA-compound complexes and cellular activity. Given that the failure of chemotherapy in the clinic is often associated with MDR, the results of both alchemix and ICT2901 represent important advances towards improved therapies.