Exposure to Iron Oxide Nanoparticles Coated with Phospholipid-Based Polymeric Micelles Induces Biochemical and Histopathological Pulmonary Changes in Mice

The biochemical and histopathological changes induced by the exposure to iron oxide nanoparticles coated with phospholipid-based polymeric micelles (IONPs-PM) in CD-1 mice lungs were analyzed. After 2, 3, 7 and 14 days following the intravenous injection of IONPs-PM (5 and 15 mg Fe/kg bw), lactate dehydrogenase (LDH) activity, oxidative stress parameters and the expression of Bax, Bcl-2, caspase-3 and TNF-α were evaluated in lung tissue. An increase of catalase (CAT) and glutathione reductase (GR) activities on the second day followed by a decrease on the seventh day, as well as a decline of lactate dehydrogenase (LDH), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity on the third and seventh day were observed in treated groups vs. controls. However, all these enzymatic activities almost fully recovered on the 14th day. The reduced glutathione (GSH) and protein thiols levels decreased significantly in nanoparticles-treated groups and remained diminished during the entire experimental period; by contrast malondialdehyde (MDA) and protein carbonyls increased between the 3rd and 14th day of treatment vs. control. Relevant histopathological modifications were highlighted using Hematoxylin and Eosin (H&E) staining. In addition, major changes in the expression of apoptosis markers were observed in the first week, more pronounced for the higher dose. The injected IONPs-PM generated a dose-dependent decrease of the mouse lung capacity, which counteracted oxidative stress, thus creating circumstances for morphopathological lesions and oxidation processes.

Histopatological alterations and oxidative stress in liver and kidney of Leuciscus cephalus following exposure to heavy metals in the Tur River, North Western Romania

Pollution of the aquatic environment by heavy metals is a great concern worldwide. Freshwater fish ingests various metals through gills, skin or diet. Our aim was to investigate the oxidative stress and histopathological injuries induced by Fe, Cu, Zn, Pb, Cd in the liver and kidney of Leuciscus cephalus. Fish samples were collected from two sites in the Tur River, NW Romania, in upstream and downstream of a pollution source. Metals were differently distributed in the liver and kidney of fish. The highest concentrations of Fe, Cu and Pb were found in liver, whereas Zn and Cd concentrations were the highest in kidney in specimens collected from the downstream site. The histopathological changes were associated with metal bioaccumulation, being more severe in kidney than liver. Malondialdehyde (MDA) and advanced oxidation protein products (AOPP) increased significantly in the liver and kidney of fish from downstream site compared to upstream one, whereas reduced glutathione (GSH) decreased. The activities of superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) increased significantly in livers, whereas SOD increased in kidney. Our study revealed that liver has a higher capacity and adaptability to counteract ROS compared to kidney. The more pronounced increase of hepatic SOD, CAT and GST activities is related milder structural changes observed in liver compared to kidney, where lesions were not reduced by antioxidant defense system.

Chrysin attenuates cardiomyocyte apoptosis and loss of intermediate filaments in a mouse model of mitoxantrone cardiotoxicity

Chrysin (CHR) is a natural flavonoid and is present in high concentration in honey, propolis and many plant extracts. The aim of the present study was to evaluate the effects of CHR to reduce cardiomyocyte apoptosis and loss of intermediate filaments in a mouse model of mitoxantrone cardiotoxicity. Morphology of the cardiomyocytes was determined by optic and transmission electron microscopy and biochemistry methods. The expression of Bcl-2, Bax and Caspase-3 were assessed by immunofluorecence. Tunel assay was used to assess apoptosis in cardiomyocytes. In addition, the distribution of desmin protein was evaluated using immunohistochemistry. Our results show that MTX treatment significantly increased serum levels of creatine kinase isoenzyme (CK-MB), indicator of cardiac injury and withdrawn under CHR protection. Expression levels of Bcl-2 decreased, while those of Bax and caspase-3 increased following MTX treatment. 50 mg/kg of daily CHR intake reduced Bax and caspase-3 immunopositivity and restored Bcl-2 levels to a value comparable to the control. TUNEL (+) cardiomyocyte nuclei of MTX group showed typical signs of apoptosis which almost completely disappeared in response to 50 mg/kg CHR treatment. In parallel, an irregular distribution and a weak expression of desmin is associated with MTX induced cardiotoxic effects which was also restored by CHR treatment. In conclusion chrysin inhibits MTX-triggered cardiomyocyte apoptosis via multiple pathways, including decrease of the Bax/Bcl-2 ratio and caspase-3 expression along with preservation of the desmin disarray.

In vitro cytocompatibility evaluation of chitosan/graphene oxide 3D scaffold composites designed for bone tissue engineering

Extensively studied nowadays, graphene oxide (GO) has a benefic effect on cell proliferation and differentiation, thus holding promise for bone tissue engineering (BTE) approaches. The aim of this study was not only to design a chitosan 3D scaffold improved with GO for optimal BTE, but also to analyze its physicochemical properties and to evaluate its cytocompatibility and ability to support cell metabolic activity and proliferation. Overall results show that the addition of GO in the scaffold's composition improved mechanical properties and pore formation and enhanced the bioactivity of the scaffold material for tissue engineering. The new developed CHT/GO 3 wt% scaffold could be a potential candidate for further in vitro and in vivo osteogenesis studies and BTE approaches.

Magnetite nanoparticles induced adaptive mechanisms counteract cell death in human pulmonary fibroblasts

Magnetite nanoparticles (MNP) have attracted great interest for biomedical applications due to their unique chemical and physical properties, but the MNP impact on human health is not fully known. Consequently, our study proposes to highlight the biochemical mechanisms that underline the toxic effects of MNP on a human lung fibroblast cell line (MRC-5). The cytotoxicity generated by MNP in MRC-5 cells was dose and time-dependent. MNP-treated MRC-5 cells accumulated large amount of iron and reactive oxygen species (ROS) and exhibited elevated antioxidant scavenger enzymes. Reduced glutathione (GSH) depletion and enhanced lipid peroxidation (LPO) processes were also observed. The cellular capacity to counteract the oxidative damage was sustained by high levels of heat shock protein 60 (Hsp60), a protein that confers resistance against ROS attack and inhibition of cell death. While significant augmentations in nitric oxide (NO) and prostaglandine E2 (PGE2) levels were detected after 72 h of MNP-exposure only, caspase-1 was activated earlier starting with 24h post-treatment. Taken together, our results suggest that MRC-5 cells have the capacity to develop cell protection mechanisms against MNP. Detailed knowledge of the mechanisms induced by MNP in cell culture could be essential for their prospective use in various in vivo biochemical applications.

Hepatoprotective effects of a self-micro emulsifying drug delivery system containing Silybum marianum native seed oil against experimentally induced liver injury

The main purpose of this study was to certify the effect of native silymarin oil (SM-oil) formulated in a self-microemulsifying drug delivery system (SMEDDS). The optimal formulation was 25% of SM-oil, 33.3 % of Cremophor RH40, 20% of Transcutol HP, 16.6% of Labrasol and 5% of Capryol 90. In this novel formulation the SM-oil was the active substance and the lipid part. The in vivo study examined the preventive effects of SMEDDS containing SM native seeds oil against carbon tetrachloride (CC14) induced hepatotoxicity in mice. Determination of alanine aminotransferase (ALT), aspartate aminotransferase (AST) levels and also liver histology investigations have been done. The liver antioxidant status was determined with the concentrations of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), and glutathione (GSH) hepatic lipid peroxidation was examined and expressed in terms of malondialdehyde (MDA) content. The plasma levels of AST and ALT significantly diminished by pre-treatment with 500 mg/kg and 1000 mg/kg SMEDDS. The pre-treatment with 500 mg/kg and 1000 mg/kg SMEDDS increased GSH level by about 6% respectively 24% compared to the CC14 group. Due to preventive administration of 500 mg/kg and 1000 mg/kg of SMEDDS in the intoxicated animals, MDA levels were reduced by 22% respectively 58%. Also, an insignificant rise by almost 17% and 19% in the animals treated with the both doses of SMEDDS could be noticed. It can be concluded that hepatotoxicity may be avoided by the oral application of our formulation.

Antioxidant and hepatoprotective activity of milk thistle (Silybum marianum L. Gaertn.) seed oil

This study has assessed the protective efficacy of

Antioxidant and hepatoprotective effects of naringenin and its β-cyclodextrin formulation in mice intoxicated with carbon tetrachloride: a comparative study

The present study evaluated the antioxidant and hepatoprotective effects of the flavonoid naringenin (NGN) and its β-cyclodextrin formulation at a dose of 50 mg/kg b.w. The assessment was done by the investigation of serum-enzymatic and liver antioxidant activity, histopathological and ultrastructural changes in male Swiss mice, which were subjected to acute experimental intoxication with CCl4. Formulated and free flavonoid were orally given to mice for 7 days and then were intraperitoneally injected with 1.0 mL/kg CCl4 on the 8th day. After 24 h of CCl4 administration, an increase in the levels of transaminases aspartate aminotransferase and alanine aminotransferase activities and malondialdehyde concentration occurred and a significant decrease in superoxide dismutase, catalase glutathione-peroxidase activities, and glutathione levels was detected as well. These were accompanied by extended centrilobular necrosis, steatosis, fibrosis, and an altered ultrastructure of hepatocytes. Pretreatment with formulated or free flavonoid retained the biochemical markers to control values. Histopathological and electron-microscopic examination confirmed the biochemical results. In conclusion, both NGN and NGN/β-cyclodextrin complex showed antioxidant and hepatoprotective effects against injuries induced by CCl4.

Structural properties of silver doped hydroxyapatite and their biocompatibility

The aim of this study was to obtain a novel hydroxyapatite-based material with high biocompatibility. The structural properties of the samples were well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). The X-ray diffraction studies revealed the characteristic peaks of hydroxyapatite in each sample. Other phases or impurities were not observed. The scanning electron microscopy observations suggest that the doping components have no influence on the surface morphology of the samples, which reveals a homogeneous aspect of the synthesized particles for all samples. The presence of calcium (Ca), phosphor (P), oxygen (O) and silver (Ag) in the Ag:HAp is confirmed by energy dispersive X-ray (EDAX) and X-ray Photoelectron Spectroscopy analyses. Nanocrystalline silver doped HAp stimulated viability and potentiated the activation of murine macrophages.

Depletion of intracellular glutathione and increased lipid peroxidation mediate cytotoxicity of hematite nanoparticles in MRC-5 cells

Particles generated from numerous anthropogenic and/or natural sources, such as crystalline α-Fe₂O₃ nanoparticles, have the potential to damage lung cells. In our study we investigated the effects of these nanoparticles (12.5 µg/ml) on lipid peroxidation and the antioxidative system in MRC-5 lung fibroblast cells following exposure for 24, 48 or 72h. Exposure to α-Fe₂O₃ nanoparticles increased lipid peroxidation by 81%, 189% and 110% after 24, 48 and 72h, respectively. Conversely, the reduced glutathione concentration decreased by 23.2% and 51.4% after 48 and 72h of treatment, respectively. In addition, an augmentation of the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione transferase and glutathione reductase within the interval between 48-72h was noticed. Taking into account that the reduced glutathione level decreased and the malondialdehyde level, a lipid peroxidation product, remained highly increased up to 72h of exposure, it would appear that the MRC-5 antioxidant defense mechanisms did not efficiently counteract the oxidative stress induced by exposure to hematite nanoparticles.

Depletion of intracellular glutathione and increased lipid peroxidation mediate cytotoxicity of hematite nanoparticles in MRC-5 cells

Particles generated from numerous anthropogenic and/or natural sources, such as crystalline α-Fe₂O₃ nanoparticles, have the potential to damage lung cells. In our study we investigated the effects of these nanoparticles (12.5 µg/ml) on lipid peroxidation and the antioxidative system in MRC-5 lung fibroblast cells following exposure for 24, 48 or 72h. Exposure to α-Fe₂O₃ nanoparticles increased lipid peroxidation by 81%, 189% and 110% after 24, 48 and 72h, respectively. Conversely, the reduced glutathione concentration decreased by 23.2% and 51.4% after 48 and 72h of treatment, respectively. In addition, an augmentation of the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione transferase and glutathione reductase within the interval between 48-72h was noticed. Taking into account that the reduced glutathione level decreased and the malondialdehyde level, a lipid peroxidation product, remained highly increased up to 72h of exposure, it would appear that the MRC-5 antioxidant defense mechanisms did not efficiently counteract the oxidative stress induced by exposure to hematite nanoparticles.

Bionanomaterials: Thermal Stability of the Oleic Acid / alpha- and beta-cyclodextrin Complexes

This paper presents the thermal stability of the oleic acid encapsulated in a- and b - cyclodextrin. The complexation of the oleic acid was achieved by the ethanol-water solution method and the nanoparticles were analyzed by DSC. The free oleic acid and the encapsulated one were subjected to the thermal degradation in the range of 50-150�C and the degradation products were identified and quantified by GC-MS analysis of the fatty acid esters obtained by deriving with methanol/boron trifluoride, both for free compounds and for the encapsulated ones. The oleic acid complexes were very stable in this range of temperature.