Positive Regulation of Osteoblast Proliferation and Differentiation in MC3T3- E1 Cells by 7,3',4'-Trimethoxyflavone.

OBJECTIVES: Increasing ratio of bone fragility, and susceptibility to fractures constitutes a major health problem worldwide. Therefore, we aimed to identify new compounds with a potential to increase proliferation and differentiation of osteoblasts. METHODS: Cellular and molecular assays, such as ALP activity, alizarin staining, and flow cytometry were employed to check the effect of TMF on osteogenesis. Moreover, gene expression analysis of certain important genes and transcriptional factors was also performed. RESULTS: Our findings report for the first time that 7,3',4'-trimethoxyflavone is capable of enhancing proliferation, and differentiation in osteoblast cells. Results from flow cytometry analysis also indicated that TMF increases the number of cells in S-phase. Furthermore, treatment with TMF altered the expression of osteogenic genes, OCN and Axin-2 indicating possible activation of Wnt signaling pathway. CONCLUSION: Taken together, this study identified that 7,3',4'-trimethoxyflavone has the potential to enhance osteoblast proliferation and differentiation, possibly due to the activation of Wnt/ß-catenin pathway. Thus, demonstrating TMF as naturally occurring agent to promote osteogenesis and prevention of bone fragility, and related disorders.

A transcriptional complex of FtMYB102 and FtbHLH4 coordinately regulates the accumulation of rutin in Fagopyrum tataricum.

Tartary buckwheat is rich in flavonoids, which not only play an important role in the plant-environment interaction, but are also beneficial to human health. Rutin is a therapeutic flavonol which is massively accumulated in Tartary buckwheat. It has been demonstrated that transcription factors control rutin biosynthesis. However, the transcriptional regulatory network of rutin is not fully clear. In this study, through transcriptome and target metabolomics, we validated the role of FtMYB102 and FtbHLH4 TFs at the different developmental stages of Tartary buckwheat. The elevated accumulation of rutin in the sprout appears to be closely associated with the expression of FtMYB102 and FtbHLH4. Yeast two-hybrid, transient luciferase activity and co-immunoprecipitation demonstrated that FtMYB102 and FtbHLH4 can interact and form a transcriptional complex. Moreover, yeast one-hybrid showed that both FtMYB102 and FtbHLH4 directly bind to the promoter of chalcone isomerase (CHI), and they can coordinately induce CHI expression as shown by transient luciferase activity assay. Finally, we transferred FtMYB102 and FtbHLH4 into the hairy roots of Tartary buckwheat and found that they both can promote the accumulation of rutin. Our results indicate that FtMYB102 and FtbHLH4 can form a transcriptional complex by inducing CHI expression to coordinately promote the accumulation of rutin.

A new ent-clerodane diterpene from Detarium microcarpum Guill. & Perr. and its protective potential for osteoporosis.

A new clerodane diterpene, named 6α-hydroxy-3,13E-clerodien-15-oic acid (1), together with a known clerodane diterpene (2), four known labdane diterpenes (3-6), a triterpenoid (7), a known steroid (8), and two benzenoid compounds (9 and 10) were isolated from Detarium microcarpum Guill. & Perr. The structures of all obtained compounds were determined by chemical properties and spectroscopic evidence, accompanied by comparisons with data in the literature. Electronic circular dichroism (ECD) was performed for compounds 1-4 to confirm the absolute configuration. Compounds 1-3 and 8-10 were evaluated for the protective effect on osteoblasts. Compound 1 was observed to increase the proliferation of dexamethasone (DEX)-treated MC3T3-E1 cells significantly at 1 µM, which was comparable with the positive control geniposide at 10 µM. The results were further confirmed by flow cytometry analysis. In addition, compound 1 increased the level of alkaline phosphatase (ALP) and mineralization in osteoblasts inhibited by DEX. Moreover, Compound 9 (vanillic acid) showed a pronounced inhibition (IC50 6.5 ± 0.6 µM) on reactive oxygen species (ROS) production, and 10 (4-O-methyl gallic acid) showed a good inhibition with IC50 as 103.3 ± 2.2 µM, compared with the standard drug ibuprofen (IC50 54.2 ± 9.2 µM). Besides, compounds 1-3 and 8-10 were non-cytotoxic against MCF-7, NCI-H460, Hela, and BJ cell lines.

Antipsychotics drug aripiprazole as a lead against breast cancer cell line (MCF-7) in vitro.

Breast cancer is the second leading cause of death among women globally. The existing treatment options for breast cancer are largely associated with severe toxicities, and lower efficacies. Therefore, there is an urgent need for the development of non-toxic effective drugs against breast cancer. For this purpose, drug repositioning strategy was used to evaluate the anti-cancer potential of a library of heterocyclic drugs. The major advantage of drug repurposing is that the pharmacokinetic, pharmacodynamic, and toxicity profiles of drugs are well documented. In the current study, we screened 97 drugs of different chemical classes, and among them aripiprazole, an antipsychotic drug, was found to be sufficiently active against breast cancer cell line MCF-7. Aripiprazole showed a cytotoxicity (IC50 = 12.1 ± 0.40 µM) to MCF-7 cells, comparable to the standard anticancer drug doxorubicin (IC50 = 1.25 ± 0.34 µM). Aripiprazole was also found to be active against other cancer cell lines, including MDA-MB-231 (IC50 = 19.83 ± 0.27 µM), AU565 (IC50 = 18.02 ± 0.44 µM), and BT-474 (IC50 = 36.42 ± 0.12 µM). Aripiprazole significantly inhibited the cell cycle progression at subG0G1 phase, and enhanced apoptosis in MCF-7 breast cancer cells. The drug was also able to significantly increase the nuclear condensation, and modulated the expression of certain genes involved in breast cancer, such as caspases 3, and 9, BAK-1, C-MYC, BCL2L1, BCL-10, and BCL-2. Further studies are needed to explore the effect of aripiprazole on intrinsic and extrinsic pathways of apoptosis in cancer cells.

In silico identification of potential inhibitors of key SARS-CoV-2 3CL hydrolase (Mpro) via molecular docking, MMGBSA predictive binding energy calculations, and molecular dynamics simulation.

The incidence of 2019 novel corona virus (SARS-CoV-2) has created a medical emergency throughout the world. Various efforts have been made to develop the vaccine or effective treatments against the disease. The discovery of crystal structure of SARS-CoV-2 main protease has made the in silico identification of its inhibitors possible. Based on its critical role in viral replication, the viral protease can prove to be a promising "target" for antiviral drug therapy. We have systematically screened an in-house library of 15,754 natural and synthetic compounds, established at International Center for Chemical and Biological Sciences, University of Karachi. The in silico search for potential viral protease inhibitors resulted in nine top ranked ligands (compounds 1-9) against SARS-CoV-2 main protease (PDB ID: 6LU7) based on docking scores, and predictive binding energies. The in silico studies were updated via carrying out the docking, and predictive binding energy estimation, with a recently reported crystal structure of main protease (PDB ID: 6Y2F) at a better resolution i.e., 1.95 Å. Compound 2 (molecular bank code AAA396) was found to have highest negative binding energy of -71.63 kcal/mol for 6LU7. While compound 3 (molecular bank code AAD146) exhibited highest negative binding energy of -81.92 kcal/mol for 6Y2F. The stability of the compounds- in complex with viral protease was analyzed by Molecular Dynamics simulation studies, and was found to be stable over the course of 20 ns simulation time. Compound 2, and 3 were predicted to be the significant inhibitors of SARS-CoV-2 3CL hydrolase (Mpro) among the nine short listed compounds.