In vitro combination effects of plant-derived quercetin with synthetic bicalutamide on prostate cancer and normal cell lines: in silico comparison.

Prostate cancer is the second most frequent and the fifth greatest cause of death in men. Although diet has been connected to the prevalence of cancer in addition to other factors, the relation between cancer and prevention is weak. Treatment options are at risk due to cell resistance. To identify new combinations, we tried plant-derived quercetin with bicalutamide on cell lines. To determine the cytotoxicity and apoptotic potential of plant-derived quercetin and its combination, MTT [3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide] and dual stain assays were performed. In silico protein-ligand interaction was performed to support the in vitro findings. A thin layer, column, and high-performance chromatography were used to purify quercetin along with an authentic sample. In the cytotoxic study, quercetin was minimized by 80% similar to bicalutamide and a combination of quercetin and bicalutamide by 50% when compared to controls by 2%. Quercetin and bicalutamide showed a similar binding affinity for androgen receptors (9.7 and 9.8), hub genes (10.8 and 10.0), and a few other PCa-related genes (9.4 and 9.1). We propose to conclude that the combination of quercetin plus bicalutamide can be used for chemotherapy if additional in vivo studies are conducted. The intake of foods high in polyphenolic compounds can help to prevent prostate cancer. Examination of quercetin on several cell lines will provide a definite conclusion to combat cancers.

Amalgamation of quercetin with anastrozole and capecitabine: A novel combination to treat breast and colon cancers - An in vitro study.

Context: Globally, cancer stands as the principle cause of mortality and immediate attention on its treatment options is required. Natural compounds stay at first priority in encountering novel therapeutics without adverse effects. Aim: The aim of the study is to extract flavonol quercetin from leafy vegetables of Anethum graveolens L. and Raphanus sativus L. and find out its potential in combination with drugs used for chemotherapy to reduce the adverse effects of drugs. Settings and Design: Observational study. Materials And Methods: Column chromatography is used for quercetin extraction and anticancer activity of quercetin + anastrozole and quercetin + capecitabine were determined by (4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay (MTT), apoptosis assay, cell cycle analysis, mitochondrial membrane potential, and caspase 3 expression. Statistical Analysis Used: Cytotoxic assay results were assessed by mean, standard deviation and ANOVA; and results were compared for determining its significance. Results: The results noted that quercetin at very less concentration (16 and 31 µg/ml on Michigan Cancer Foundation-7 and 43 and 46 µg/ml on COLO 320) in combination with anastrozole and capecitabine was able to control the growth of cells, increase cell death, arrest cell cycle, and induce mitochondrial depolarization and expression of caspase 3. Conclusions: The natural compound used in the present study is effective in treating breast and colon cancer at minimal concentrations in combination with the drugs. This combinational treatment appears to be reported for the first time in the present study.

New tetrameric forms of the rotavirus NSP4 with antiparallel helices.

Rotavirus nonstructural protein 4, the first viral enterotoxin to be identified, is a multidomain, multifunctional glycoprotein. Earlier, we reported a Ca2+-bound coiled-coil tetrameric structure of the diarrhea-inducing region of NSP4 from the rotavirus strains SA11 and I321 and a Ca2+-free pentameric structure from the rotavirus strain ST3, all with a parallel arrangement of α-helices. pH was found to determine the oligomeric state: a basic pH favoured a tetramer, whereas an acidic pH favoured a pentamer. Here, we report two novel forms of the coiled-coil region of NSP4 from the bovine rotavirus strains MF66 and NCDV. These crystallized at acidic pH, forming antiparallel coiled-coil tetrameric structures without any bound Ca2+ ion. Structural and mutational studies of the coiled-coil regions of NSP4 revealed that the nature of the residue at position 131 (Tyr/His) plays an important role in the observed structural diversity.

Conformational Differences Unfold a Wide Range of Enterotoxigenic Abilities Exhibited by rNSP4 Peptides from Different Rotavirus Strains.

NSP4 has been recognized as the rotavirus-encoded enterotoxin. However, a few studies failed to support its diarrheagenic activity. As recombinant NSP4 (rNSP4) peptides of different lengths were used in the limited number of studies, a comparison of relative diarrheagenic potential of NSP4 from different strains could not be possible. To better understand the diarrheagenic potential of NSP4 from different strains, in this report we have evaluated the enterotoxigenic activity of the deletion mutant ΔN72 that lacks the N-terminal 72 residues and the biologically relevant ΔN112 peptide which when derived from SA11 rotavirus strain were previously shown to be highly diarrheagenic in newborn mice. Detailed comparative analysis of biochemical and biophysical properties and diarrheagenic activity of the recombinant ΔN72 peptides from seventeen different strains under identical conditions revealed wide differences among themselves in their resistance to trypsin cleavage, thioflavin T (ThT) binding, multimerization and conformation without any correlation with their diarrhea inducing abilities. These results support our previously proposed concept for the requirement of a unique conformation for optimal biological functions conferred by cooperation between the N- and C-terminal regions of the cytoplasmic tail.

The flexible C terminus of the rotavirus non-structural protein NSP4 is an important determinant of its biological properties.

The rotavirus non-structural protein NSP4 functions as the viral enterotoxin and intracellular receptor for the double-layered particles (DLP). The full-length protein cannot be expressed and/or purified to homogeneity from bacterial or insect cells. However, a bacterially expressed and purified mutant lacking the N-terminal 72 aa (DeltaN72) was recently obtained from strains Hg18 and SA11 exhibiting approximately 17-20-, 150-200- and 13166-15800-fold lower DD50 (50% diarrhoea-inducing dose) values in suckling mice compared with that reported for the partially pure, full-length protein, a C-terminal M175I mutant and a synthetic peptide comprising aa 114-135, respectively, suggesting the requirement for a unique conformation for optimal functions of the purified protein. The stretch of approximately 40 aa from the C terminus of the cytoplasmic tail of the endoplasmic reticulum-anchored NSP4 is highly flexible and exhibits high sequence variation compared with the other regions, the significance of which in diarrhoea induction remain unresolved. Here, it was shown that every amino acid substitution or deletion in the flexible C terminus resulted in altered conformation, multimerization, trypsin resistance and thioflavin T (ThT) binding, and affected DLP binding and the diarrhoea-inducing ability of the highly diarrhoeagenic SA11 and Hg18 DeltaN72 in suckling mice. These studies further revealed that high ThT fluorescence correlated with efficient diarrhoea induction, suggesting the importance of an optimal ThT-recognizable conformation in diarrhoea induction by purified NSP4. These results based on biological properties provide a possible conformational basis for understanding the influence of primary sequence variations on diarrhoea induction in newborn mice by purified NSP4s that cannot be explained by extensive sequence analyses.