Synthesis and in Vitro Toxicity Assessment of Different Nano-Calcium Phosphate Nanoparticles

Abstract Nanoscale biomaterials are commonly used in a wide range of biomedical applications such as bone graft substitutes, gene delivery systems, and biologically active agents. On the other hand, the cytotoxic potential of these particles hasn't yet been studied comprehensively to understand whether or not they exert any negative impact on the cellular structures. Here, we undertook the synthesis of beta-tricalcium phosphate (ß-TCP) and biphasic tricalcium phosphate (BCP) nanoparticles (NPs) and determine their concentration-dependent toxic effects in human fetal osteoblastic (hFOB 1.19) cell line. Firstly, BCP and β-TCP were synthesized using a water-based precipitation technique and characterized by X-Ray Diffraction (XRD), Raman Spectroscopy, and Transmission Electron Microscopy (TEM). The cytological effects of β-TCP and BCP at different concentrations (0-640 ppm) were evaluated by using 3- (4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. The total oxidative status (TOS) parameter was used for investigating oxidative stress potentials of the NPs. In addition, the study assessed the DNA damage product 8-hydroxy-2′-deoxyguanosine (8-Oxo-dG) level in hFOB 1.19 cell cultures. The results indicated that the β-TCP (above 320 ppm) and BCP (above 80 ppm) NPs exhibited cytotoxicity effects on high concentrations. It was also observed that the oxidative stress increased relatively as the concentrations of NPs increased, aligning with the cytotoxicity results. However, the NPs concentrations of 160 ppm and above increased the level of 8-OH-dG. Consequently, there is a need for more systematic in vivo and in vitro approaches to the toxic effects of both nanoparticles.

Beneficial effects of Cuscuta chinensis extract on glucocorticoid-induced osteoporosis through modulation of RANKL/OPG signals

Cuscuta chinensis Lam. (Convolvulaceae) is an important herbal medicine widely used to improve sexual function, treat osteoporosis, and prevent aging, and has been reported to exhibit anti-osteoporotic effects in vitro. However, the activity of Cuscuta chinensis Lam. on glucocorticoid-induced osteoporosis still remains unclear. The present study aimed to assess the protective effect and the underlying mechanism of action of Cuscuta chinensis extract (CCE) against glucocorticoid-induced osteoporosis in vivo. Sprague-Dawley rats were randomly divided into four groups as follows: control group, osteoporosis group, and 2 CCE-treated osteoporosis groups (100 mg·kg-1·day-1). Blood samples and femur bones were collected for immunohistochemistry, biochemical, mRNA expression, and western blot analysis. HPLC analysis revealed that chlorogenic acid, quercetin, and hyperin were the major constituents of CCE. The results indicated that CCE increased bone length, bone weight, and bone mineral density and suppressed dexamethasone (DEX)-induced reduction in body weight. In addition, TRAP staining indicated that CCE reduced osteoclasts in DEX-induced osteoporosis rats. Mechanistically, CCE treatment alleviated the increase of bone resorption markers and the decline of osteogenic markers, which might be partially mediated by regulation of RANKL/OPG and RunX2 pathways. These results suggest that CCE showed promising effects in the protection against glucocorticoid-induced osteoporosis through protecting osteoblasts and suppressing osteoclastogenesis.

Effect of Enrofloxacin on the Joint Fluid/Blood Oxidative Status and Organ Damage Markers

Aim: It has been hypothesized that chondrotoxicity, the main side effect of enrofloxacin use, may be derived from oxidative stress, and this side effect can be confirmed by measuring malondialdehyde and endogen antioxidants following drug application. The primary aim of this research is to determine the effect of enrofloxacin on the joint fluid and blood oxidative status parameters, and it is also to determine the effect on the organ damage parameters. Materials and Methods: In the study, 10 rams received enrofloxacin (10 mg/kg/day, SC) for 14 days. Blood and joint fluids were taken on day 0 (Control) before drug application and 1.5 hours after the last drug application. Plasma and joint fluid malondialdehyde, total antioxidant status, superoxide dismutase, glutathione peroxidase and catalase levels were determined by an ELISA reader. Cardiac (CK-MB mass, troponin I), liver (AST, ALT, ALP, GGT, total protein, albumin) and kidney (Creatinine, BUN) damage markers and hemogram (WBC, RBC, platelet, hematocrit, haemoglobin) values were measured. Results: Enrofloxacin decreased the joint fluid catalase level (P<0.05), while there was no effect observed in the other oxidative status parameters of joint fluid or blood samples. Statistically significant changes (P<0.05) were found in some hemogram and biochemical parameters within the reference range. However, enrofloxacin increased (P<0.05) the levels of cardiac damage markers (CK-MB mass, troponin I). Conclusion: It may be stated that enrofloxacin does not cause oxidative stress in the joint fluid and blood in rams, and it is generally accepted to be safe when the effect on the organ/system is considered, but the long-term use and high doses require caution in terms of possible heart related damage.

The investigation of cytogenetic and oxidative effects of diffractaic acid on human lymphocyte cultures

Diffractaic acid (DA) is a naturally occurring depside derivative found in several lichen species. It has a wide range of important biological effects such as analgesic and antiviral properties, although its cytotoxic, cytogenetic and oxidative effects have not been investigated in human blood tissue yet. Therefore, increasing concentrations (1, 5, 10, 25, 50, 100 and 200 mgL-1) of DA was added into human whole blood cultures. 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyl tetrazolium bromide (MTT) assay was used to assess the cell viability and/or cytotoxicity and genotoxic damage potential of DA using chromosome aberration (CA) and micronucleus (MN) tests were performed. In addition, oxidative alterations were determined by the total antioxidant capacity (TAC) and total oxidant status (TOS) assays. The results revealed that DA reduced cell viability at higher concentrations than 50 mgL-1. The all tested concentrations of DA were non-genotoxic. In vitro treatments with DA led to increases of TAC levels in the cultured blood cells without changing the TOS levels as compared to the control group. Consequently, DA exhibited a significant non-mutagenic and antioxidant potential in vitro.

Significance of p27(kip1) as potential biomarker for intracellular oxidative status

Our previous proteomic study demonstrated that oxidative stress and antioxidant delphinidin regulated the cellular level of p27(kip1) (referred to as p27) as well as some heat shock proteins in human colon cancer HT 29 cells. Current study was conducted to validate and confirm the regulation of these proteins using both in vitro and in vivo systems. The level of p27 was decreased by hydrogen peroxide in a dose-dependent manner in human colon carcinoma HCT 116 (p53-positive) cells while it was increased upon exposure to hydrogen peroxide in HT 29 (p53-negative) cells. However, high concentration of hydrogen peroxide (100 micrometer) downregulated p27 in both cell lines, but delphindin, one of antioxidative anthocyanins, enhanced the level of p27 suppressed by 100 micrometer hydrogen peroxide. ICR mice were injected with varying concentrations of hydrogen peroxide, delphinidin and both. Western blot analysis for the mouse large intestinal tissue showed that the expression of p27 was upregulated by 25 mg/kg BW hydrogen peroxide. To investigate the association of p27 regulation with hypoxia-inducible factor 1-beta (HIF-1beta), the level of p27 was analyzed in wild-type mouse hepatoma hepa1c1c7 and Aryl Hydrocarbon Nuclear Translocator (arnt, HIF-1beta)-defective mutant BPRc1 cells in the absence and presence of hydrogen peroxide and delphinidin. While the level of p27 was responsive to hydrogen peroxide and delphinidin, it remained unchanged in BPRc1, suggesting that the regulation of p27 requires functional HIF-1beta. We also found that hydrogen peroxide and delphinidin affected PI3K/Akt/mTOR signaling pathway which is one of upstream regulators of HIFs. In conclusion, hydrogen peroxide and antioxidant delphinidin seem to regulate intracellular level of p27 through regulating HIF-1 level which is, in turn, governed by its upstream regulators comprising of PI3K/Akt/mTOR signaling pathway. The results should also encourage further study for the potential of p27 as a biomarker for intracellular oxidative or antioxidant status.