Background: Alendronate (AL) is the most widely used bisphosphonate in the treatment of osteoporosis (OP). However, the role of circular RNAs (circRNAs) in the treatment of OP with AL remains unclear. Methods: In this study, we showed that osteoclast (OC) precursors (OPCSs) could be induced into OCs with macrophage colony-stimulating factor (MCSF) and receptor activator of nuclear factor-κB ligand (RANKL) treatment. Subsequently, the OCs were treated with AL. OC differentiation-related biomarkers including RANK, tartrate-resistant acid phosphatase (TRAP), and cathepsin K (CTSK) were analyzed with TRAP staining, quantitative real-time (qPCR), and western blotting. Differentially expressed circRNAs (DECs) were identified among the OPCS, OC, and OC + AL groups. In addition, the expression levels of 10 DECs related to OC differentiation were verified by qPCR. Results: TRAP staining showed that MCSF and RANKL treatment effectively induced OPCSs to differentiate into OCs. In addition, qPCR and western blot analysis revealed that the three biomarkers of OC (RANK, TRAP, and CTSK) were expressed significantly more in the OC group than those in the OPCS group. In contrast, the mRNA and protein expression levels of these three biomarkers decreased significantly in OCs treated with AL compared with those non-treated OCs. GO analysis of the DECs in the OPCS group vs. the OC group revealed that their functions were mainly related to cell, cell part, binding, and single-organism terms. KEGG analysis of the top 20 DECs in a comparison between the OPCS and OC groups showed that genes involved in mitogen-activated protein kinase signaling were the most common. Results of functional analyses of DECs in an OC vs. OC + AL comparison were similar to those in the OPCS vs. OC comparison. Finally, qPCR showed that, in the OC + AL vs. OC group comparison, the expression levels of seven and three DECs significantly decreased and increased, respectively. Conclusions: Having successfully induced OPCSs to differentiate into OCs, we showed that AL suppresses the differentiation of OPCS into OC and that 10 DECs were involved in the regulation of this process. This indicates that these DECs might be important to the treatment of OP.

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The pericarp of Citrus reticulata "Chachi" (CRCP) is used as nutritional food and traditional medicine in China, usually harvested at three periods, namely, immature (CRCP-G1), semi-mature (CRCP-G2), and fully mature (CRCP-G3). Traditionally, if the CRCP is stored for a longer period, then the quality will be better. In this study, the dynamic variation of phytochemical and volatile compounds was profiled in the same batches of CRCP during 2 years of storage. Results illustrated that most of the phytochemical compounds showed a decreasing trend during storage, that is, total flavonoids, total phenolic acids, hesperidin,

Xinhui chenpi (XHCP), the sun‐dried peel of the mandarin orange, Citrus reticulata “Chachi,” is the most famous crude drug, as well as a traditional seasoning in Chinese cooking. The main cultivation methods of XHCP are cutting and grafting, but it is generally considered that the quality of XHCP after cutting is superior to that obtained from plants propagated by graftings, which had a negative impact on the marketing of the finished product. In our study, a total of 25 samples of XHCP obtained from plants cultivated by either traditional methods (i.e., from cuttings) or by grafting were collected to compare the contents of four types of metabolites (essential oils, flavonoids, synephrine, and total polysaccharides) as well as antioxidant activity. The results revealed that the quality of XHCP did not decline after cutting, and marked individual differences between XHCP samples, even when prepared from plants grown in the same way. In general, grafting had no significant effect on the most essential oils components, total polysaccharides, synephrine, total flavonoids, total polymethoxylated flavones, hesperidin, nobiletin, tangeretin content, and antioxidant activity. Nevertheless, five volatile compounds can be used as potential chemical markers ( p < 0.05) to distinguish between cutting XHCP and grafted XHCP, while four volatile compounds showed high content in grafted XHCP. Our study is expected to provide a theoretical basis for XHCP breeding and cultivation, and thereby further standardize the market of XHCP.