Synergy effects of copper and L-arginine on osteogenic, angiogenic, and antibacterial activities.

Copper (Cu) ions have been found to exert antibacterial and angiogenic effects. However, some studies have indicated that it inhibits osteogenesis at high concentrations. On the other hand, L-arginine (Arg) is a semi-essential amino acid required for various biological processes, including osteogenic and angiogenic activities. As a result, we hypothesized that combining Arg with Cu ions would reduce its inhibitory effects on osteogenesis while increasing its angiogenic and antibacterial capabilities. To assess osteogenic and angiogenic activities, we employed rat bone marrow mesenchymal stem cells (MSCs) and human umbilical vein endothelial cells (HUVECs), respectively. The gram-positive bacteria Staphylococcus epidermidis (S. epidermidis), Staphylococcus aureus (S. aureus), and the gram-negative bacterium Escherichia coli (E. coli) were used to investigate bacterial behaviors. According to ALP activity and calcium deposition outcomes, copper ions inhibited osteogenic development of MSCs at 100 µM; however, Arg supplementation somewhat mitigated the inhibitory effects. Furthermore, Copper and Arg synergistically stimulated migration and tube formation of HUVECs. According to our findings, copper ions and Arg in the range of 1-100 µM had no antibacterial effect on any examined bacteria. However, at a dose of 20 mM, copper demonstrated antibacterial activity, which was boosted by Arg. Overall, these findings suggest that a combination of copper and Arg may be more beneficial for bone regeneration than either copper or Arg alone.

Fabrication and Characterization of a Three-Dimensional Fibrin Gel Model to Evaluate Anti-Proliferative Effects of Astragalus hamosus Plant Extract on Breast Cancer Cells.

BACKGROUND: Breast Cancer (BC) is a malignancy with high mortality among women. Recently, scaffold-based three-dimensional (3D) models have been developed for anti-cancer drug research. The present study aimed to investigate the anti-proliferative effects of Astragalus hamosus (A. hamosus) in 3D fibrin gel against MCF-7 cell line. We have also evaluated anti-proliferative effect of A. hamosus differences between 3D and 2D cultures. METHODS: The fibrin gel formulation was first optimized by testing the structural and mechanical properties. Then the cytotoxic effect of A. hamosus extract was assessed on MCF-7 cells by MTT assay. Cell apoptosis was evaluated using TUNEL method and flow cytometry. Cell cycle and proliferation were analyzed by flow cytometry. Apoptosis-related gene expression such as Bcl-2, caspase-3, -8 and -9 were quantified by real time-PCR. RESULTS: TUNEL staining showed a significant damage accompanied with cell apoptosis. Flow cytometry analysis revealed that apoptosis increased after treatment with A. hamosus extract in 3D culture model compared to 2D culture. The A. hamosus extract arrested cell cycle in the S and G2/M phases in 3D model while in the 2D culture G0/G1 phase was affected. Treatment with A. hamosus extract led to upregulation of the caspase-3, -8 and -9 genes and downregulation of the Ki-67 in the 3D-culture compared with the 2D culture. CONCLUSION: These results indicated that A. hamosus extract could be used as a therapeutic candidate for BC due to its anti-proliferative effects. Furthermore, 3D fibrin gel could be better than 2D-cultured cells in simulating important tumor characteristics in vivo, namely, anti-proliferative and anti-apoptotic features.