Plant-derived polyphenols are being tested as chemopreventive agents; some polyphenols arrest the cell cycle at G1 phase, whereas others inhibit cell cycle proliferation at G2/M phase. Therefore, polyphenols have been proposed to inhibit cell cycle progression at different phases via distinct mechanisms. Indeed, our previous studies showed that small structural differences in polyphenols cause large differences in their biological activities; however, the details of the structural properties causing G1 cell cycle arrest remain unknown. In this study, we prepared 27 polyphenols, including eight different scaffolds, to gain insight into the structural conditions that arrest the cell cycle at G1 phase in a quantitative structure–activity relationship study. We used cell cycle profiles to determine the biophores responsible for G1 cell cycle arrest and believe that the biophores identified in this study will help design polyphenols that cause G1 cell cycle arrest.

Oral finasteride and topical minoxidil are single components approved by the US FDA for treating hair loss. Some other compounds originating from natural products are also traditionally used for promoting hair growth. In this study, observations of treated keratinocyte cells were used to demonstrate that tocopherol acetate, L-menthol, and stevioside exert an effect on cell regeneration. Furthermore, these were topically applied to the shaved skin of C57BL/6 mice to observe their effects on hair growth. A mixture of tocopherol acetate, L-menthol, and stevioside showed the highest potential for promoting hair growth in vivo. In in vivo experiments, the mixture of tocopherol acetate, L-menthol, and stevioside was more effective than tocopherol acetate or L-menthol alone in promoting hair growth. The transcriptome analysis of skin from the dorsal side of a mouse treated with tocopherol acetate or L-menthol versus vehicle revealed key changes in keratin, keratin-associated protein, forkhead box, sonic hedgehog, fibroblast growth factor 10, desmoglein 4, deoxyribonuclease 1-like 2, and cadherin 3, known to play roles in promoting hair growth.

Members of the aurora kinase family are Ser/Thr kinases involved in regulating mitosis. Multiple promising clinical trials to target aurora kinases are in development. To discover flavones showing growth inhibitory effects on cancer cells, 36 flavone derivatives were prepared, and their cytotoxicity was measured using a long-term clonogenic survival assay. Their half-maximal growth inhibitory effects against HCT116 human colon cancer cells were observed at the sub-micromolar level. Pharmacophores were derived based on three-dimensional quantitative structure–activity calculations. Because plant-derived flavones inhibit aurora kinase B, we selected 5-methoxy-2-(2-methoxynaphthalen-1-yl)-4H-chromen-4-one (derivative 31), which showed the best half-maximal cell growth inhibitory effect, and tested whether it can inhibit aurora kinases in HCT116 colon cancer cells. We found that derivative 31 inhibited the phosphorylation of aurora kinases A, aurora kinases B and aurora kinases C, suggesting that derivative 31 is a potential pan-aurora kinase inhibitor. The results of our analysis of the binding modes between derivative 31 and aurora A and aurora B kinases using in-silico docking were consistent with the pharmacophores proposed in this study.

Exosomes are small membrane vesicles between 30 and 100 nm in diameter secreted by many cell types, and are associated with a wide range of physiological and/or pathological processes. Exosomes containing proteins, lipids, mRNA, and microRNA contribute to cell-to-cell communication and cell-to-environment regulation, however, their biological functions are not yet fully understood. In this report, exosomes in the glioblastoma cell line, U-87MG, were isolated and the proteome was investigated. In addition, exosome proteome changes in U-87MG cells exposed to a low temperature were investigated to elucidate whether the exosome proteome could respond to an external stimulus. Cell culture medium was collected, and exosomes were isolated by continuous centrifugation eliminating cell debris, nucleic acids, and other particles. The morphology of exosomes was observed by cryo-tunneling electron microscopy. According to 2-dimensional electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry, certain proteins including collagen type VI alpha 1, putative RNA-binding protein 15B chain A, substrate induced remodeling of the active site regulates HTRA1, coatomer protein complex-subunit beta 2, myosin-heavy chain 1, and keratin-type I cytoskeletal 9 showed differences between the control proteome and the low temperature-exposed proteome.