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.

Protective Effect of Selenium-L-methionine on Radiation-induced Acute Pneumonitis and Lung Fibrosis in Rat.

BACKGROUND: In this study, we aimed to detect the changes in the level of interleukin (IL)-4 and IL-13 cytokines and their downstream genes including interleukin-13 receptor subunit alpha-2 (IL13Ra2), interleukin-4 receptor subunit alpha-1 (IL4Ra1), dual oxidase 1 (DUOX1) and dual oxidase 2 (DUOX2). The protective effects of Selenium-L-methionine on radiation-induced histopathological damages and changes in the level of these cytokines and genes were detected. METHODS: Four groups of 20 rats (5 rats in each) namely, control; Selenium-L-methionine, radiation and radiation plus Selenium-L-methionine were used in this study. 4 mg/kg of Selenium-Lmethionine was administered 1 day before irradiation and five consecutive days after irradiation. Irradiation was done using a dose of 15 Gy 60Co gamma rays at 109 cGy/min. All rats were sacrificed 10 weeks after irradiation for detecting changes in IL-4 and IL-13 cytokines, the expressions of IL13Ra2, IL4Ra1, Duox1 and Duox2 and histopathological changes. RESULTS: The level of IL-4 but not IL-13 increased after irradiation. This was associated with increased expression of IL4Ra1, Duox1 and Duox2, in addition to changes in morphological properties. Selenium-L-methionine could attenuate all injury markers following lung irradiation. CONCLUSION: Selenium-L-methionine can protect lung tissues against toxic effects of ionizing radiation. It is possible that the modulation of immune responses and redox interactions are involved in the radioprotective effect of this agent.