Resolvin D1 reduces mitochondrial damage to photoreceptors of primary retinal cells exposed to high glucose

No study has investigated the interaction of Resolvin D1 (RvD1) with mitochondrial damage of retinal cells caused by diabetes. This study aims to investigate the effects of RvD1 (50 nM) on morphological and biochemical indicators of mitochondrial damage in primary retinal cells exposed to 30 mM d-glucose high glucose (HG). HG-cells exhibited photoreceptor damage characterized by short and small mitochondria with prevalent mitochondrial disruption, fragmentation, and aggregation. The cells had low mitochondrial transporters TIMM44 and TOMM40, Connexin 43, NAD/NADH ratio, and ATP levels, whereas increased cytosolic cytochrome c. Moreover, they expressed high cytosolic metalloproteinase matrix metallopeptidase 9 (MMP-9) and MMP-2 activity. HG-cells treated with RvD1 (50 nM) showed reduced reactive oxygen species levels, improved mitochondrial morphology and function, promoted mitochondrial DNA repair by OGG1, and reduced cell apoptosis and metalloproteinase activity. Therefore, RvD1 induces protection from high glucose-load to the retinal cell and promotes their survival by decreasing cytosolic MMP and mitochondrial damage.

Graphene Oxide Enhances Chitosan-Based 3D Scaffold Properties for Bone Tissue Engineering

The main goal of bone tissue engineering (BTE) is to refine and repair major bone defects based on bioactive biomaterials with distinct properties that can induce and support bone tissue formation. Graphene and its derivatives, such as graphene oxide (GO), display optimal properties for BTE, being able to support cell growth and proliferation, cell attachment, and cytoskeleton development as well as the activation of osteogenesis and bone development pathways. Conversely, the presence of GO within a polymer matrix produces favorable changes to scaffold morphologies that facilitate cell attachment and migration i.e., more ordered morphologies, greater surface area, and higher total porosity. Therefore, there is a need to explore the potential of GO for tissue engineering applications and regenerative medicine. Here, we aim to promote one novel scaffold based on a natural compound of chitosan, improved with 3 wt.% GO, for BTE approaches, considering its good biocompatibility, remarkable 3D characteristics, and ability to support stem cell differentiation processes towards the bone lineage.

Pharmacokinetic Properties of Fluorescently Labelled Hydroxypropyl-Beta-Cyclodextrin

2-Hydroxypropyl-beta-cyclodextrin (HPBCD) is utilized in the formulation of pharmaceutical products and recently orphan designation was granted for the treatment of Niemann–Pick disease, type C. The exact mechanism of HPBCD action and side effects are not completely explained. We used fluorescently labelled hydroxypropyl-beta-cyclodextrin (FITC-HPBCD) to study its pharmacokinetic parameters in mice and compare with native HPBCD data. We found that FITC-HPBCD has fast distribution and elimination, similar to HPBCD. Interestingly animals could be divided into two groups, where the pharmacokinetic parameters followed or did not follow the two-compartment, first-order kinetic model. Tissue distribution studies revealed, that a significant amount of FITC-HPBCD could be detected in kidneys after 60 min treatment, due to its renal excretion. Ex vivo fluorescent imaging showed that fluorescence could be measured in lung, liver, brain and spleen after 30 min of treatment. To model the interaction and cellular distribution of FITC-HPBCD in the wall of blood vessels, we treated human umbilical vein endothelial cells (HUVECs) with FITC-HPBCD and demonstrated for the first time that this compound could be detected in the cytoplasm in small vesicles after 30 min of treatment. FITC-HPBCD has similar pharmacokinetic to HPBCD and can provide new information to the detailed mechanism of action of HPBCD.

Antioxidant and Anti-Inflammatory Properties of a Thuja occidentalis Mother Tincture for the Treatment of Ulcerative Colitis

Inflammatory bowel disease (IBD) represents a group of chronic autoimmune and idiopathic disorders that are characteristic of industrialized countries. In contrast to drug therapies, which exert several side effects, herbal remedies have constantly attracted the attention of researchers. Therefore, in the present study, a mother tincture (MT) from fresh, young, non-woody Thuja occidentalis L. branches with leaves was obtained using distillation-based techniques. Further, this was used to assess its in vitro and in vivo antioxidant activities and anti-inflammatory properties, and to validate it as a potential phytotherapeutic treatment for IBD. The characterization of the tincture included common phytochemical screening assays for antioxidant capacity measurement, cell viability assays on Caco-2 colon cells, and in vivo assessment of antioxidant and anti-inflammatory effects by histopathological and ultrastructural analysis of the intestinal mucosa, measurement of reduced glutathione, lipid peroxidation, and gene expression of the inflammation markers (interleukin-6 and tumor necrosis factor-α) in intestine after oral administration to an experimental mouse model of colon inflammation (colitis) developed by intrarectal administration of 2,4,6-trinitrobenzenesulfonic acid (TNBS). Our study proved that administration of 25 or 50 mg T. occidentalis MT/kg of body weight/day by gavage for 7 days succeeded in inhibiting the inflammatory process induced by TNBS in the intestine, most probably because of its rich contents of flavonoids and phenolic compounds. These data could contribute to the formulation of therapeutic products based on T. occidentalis that could come to the aid of IBD patients.

Electrospun Polyethylene Terephthalate Nanofibers Loaded with Silver Nanoparticles: Novel Approach in Anti-Infective Therapy

Polyethylene terephthalate (PET) is a major pollutant polymer, due to its wide use in food packaging and fiber production industries worldwide. Currently, there is great interest for recycling the huge amount of PET-based materials, derived especially from the food and textile industries. In this study, we applied the electrospinning technique to obtain nanostructured fibrillary membranes based on PET materials. Subsequently, the recycled PET networks were decorated with silver nanoparticles through the chemical reduction method for antimicrobial applications. After the characterization of the materials in terms of crystallinity, chemical bonding, and morphology, the effect against Gram-positive and Gram-negative bacteria, as well as fungal strains, was investigated. Furthermore, in vitro and in vivo biocompatibility tests were performed in order to open up potential biomedical applications, such as wound dressings or implant coatings. Silver-decorated fibers showed lower cytotoxicity and inflammatory effects and increased antibiofilm activity, thus highlighting the potential of these systems for antimicrobial purposes.

Retinal and circulating miRNA expression patterns in diabetic retinopathy: An in silico and in vivo approach

BACKGROUND AND PURPOSE

Diabetic retinopathy, a secondary complication of diabetes mellitus, can lead to irreversible vision loss. Currently, no treatment is approved for early phases of diabetic retinopathy. Modifications of the expression pattern of miRNAs could be involved in the early retinal damage of diabetic subjects. Therefore, we aimed at identification of dysregulated miRNAs-mRNA interactions that might be biomarkers and pharmacological targets for diagnosis and treatment of early diabetic retinopathy.

METHODS

A focused set of miRNAs was predicted through a bioinformatic analysis accessing to Gene Expression Omnibus dataset and enrichment of information approach (GENEMANIA-Cytoscape). Identification of miRNAs-mRNA interactions was carried out with miRNET analysis. Diabetes was induced in C57BL6J mice by streptozotocin and samples analysed at 5 and 10 weeks after diabetes induction. Retinal ultrastructure of diabetic mice was analysed through electron microscopy. We used Real-time PCR, western blot analysis, elisa, and immunohistochemistry to study expression of miRNAs and possible targets of dysregulated miRNAs.

KEY RESULTS

We found that miR-20a-5p, miR-20a-3p, miR-20b, miR-106a-5p, miR-27a-5p, miR-27b-3p, miR-206-3p, and miR-381-3p were dysregulated in the retina and serum of diabetic mice. VEGF, brain-derived neurotrophic factor (BDNF), PPAR-α, and cAMP response element-binding protein 1 (CREB1) are targets of dysregulated miRNAs, which then modulated protein expression in diabetic retina. We found structural modifications in retinas from diabetic mice.

CONCLUSIONS AND IMPLICATIONS

Serum and retina of diabetic mice express eight dysregulated miRNAs, which modified the expression of VEGF, BDNF, PPAR-α, and CREB1, before vasculopathy in diabetic retinas.

Amorphous Silica Nanoparticles Obtained by Laser Ablation Induce Inflammatory Response in Human Lung Fibroblasts

Silica nanoparticles (SiO₂ NPs) represent environmentally born nanomaterials that are used in multiple biomedical applications. Our aim was to study the amorphous SiO₂ NP-induced inflammatory response in MRC-5 human lung fibroblasts up to 72 hours of exposure. The intracellular distribution of SiO₂ NPs was measured by transmission electron microscopy (TEM). The lactate dehydrogenase (LDH) test was used for cellular viability evaluation. We have also investigated the lysosomes formation, protein expression of interleukins (IL-1β, IL-2, IL-6, IL-8, and IL-18), COX-2, Nrf2, TNF-α, and nitric oxide (NO) production. Our results showed that the level of lysosomes increased in time after exposure to the SiO₂ NPs. The expressions of interleukins and COX-2 were upregulated, whereas the expressions and activities of MMP-2 and MMP-9 decreased in a time-dependent manner. Our findings demonstrated that the exposure of MRC-5 cells to 62.5 µg/mL of SiO₂ NPs induced an inflammatory response.

Influence of Matrigel on Single- and Multiple-Spheroid Cultures in Breast Cancer Research

This study aimed to develop and compare single and multiple 3D models such as multicellular tumor spheroids and to investigate the influence of Matrigel on their morphological and functional behavior. MDA-MB-231 3D models were generated in the presence and absence of Matrigel and their key biological properties within 6 days of culture were monitored. Our results revealed the formation of well-defined 3D models in the presence of Matrigel, with a uniform morphology, increased diameter, good circularity, and increased expression of a proliferation marker (PCNA). In comparison, 3D models generated without Matrigel were characterized by an irregular border, reduced dimensions and circularity, and a decrease of PCNA expression. Similarities between the single and multiple 3D cultures were found in their viability, Nrf2 expression, and glutathione (GSH) content. The influence of Matrigel on MDA-MB-231 spheroids metabolism under hypoxic conditions was highlighted by released lactate dehydrogenase and nitric oxide, GSH levels and expression of Nrf2 and Hsp70 proteins. Based on the increased expression of PCNA and the development of the hypoxia process in the presence of extracellular matrix, our study showed that the addition of Matrigel improves the growing environment of tumor spheroids, making it closer to that of in vivo tumor conditions.

Paracellular and transcellular migration of metastatic cells through the cerebral endothelium

Breast cancer and melanoma are among the most frequent cancer types leading to brain metastases. Despite the unquestionable clinical significance, important aspects of the development of secondary tumours of the central nervous system are largely uncharacterized, including extravasation of metastatic cells through the blood-brain barrier. By using transmission electron microscopy, here we followed interactions of cancer cells and brain endothelial cells during the adhesion, intercalation/incorporation and transendothelial migration steps. We observed that brain endothelial cells were actively involved in the initial phases of the extravasation by extending filopodia-like membrane protrusions towards the tumour cells. Melanoma cells tended to intercalate between endothelial cells and to transmigrate by utilizing the paracellular route. On the other hand, breast cancer cells were frequently incorporated into the endothelium and were able to migrate through the transcellular way from the apical to the basolateral side of brain endothelial cells. When co-culturing melanoma cells with cerebral endothelial cells, we observed N-cadherin enrichment at melanoma-melanoma and melanoma-endothelial cell borders. However, for breast cancer cells N-cadherin proved to be dispensable for the transendothelial migration both in vitro and in vivo. Our results indicate that breast cancer cells are more effective in the transcellular type of migration than melanoma cells.

The activation of retinal HCA2 receptors by systemic beta-hydroxybutyrate inhibits diabetic retinal damage through reduction of endoplasmic reticulum stress and the NLRP3 inflammasome

OBJECTIVE

The role of the hydroxycarboxylic acid receptor 2 (HCA2) in the retinal damage induced by diabetes has never been explored. In this context, the present study highlights an upregulation of retinal HCA2 receptors in diabetic C57BL6J mice. Moreover, we illustrate that HCA2 receptors exert an anti-inflammatory effect on the retinal damage induced by diabetes when activated by the endogenous ligand β-hydroxybutyrate.

METHODOLOGY

Seven-to-10-week-old C57BL6J mice were rendered diabetic by a single intraperitoneal injection of streptozotocin (75 mg/kg of body weight) and monitored intermittently over a 10-week period extending from the initial diabetes assessment. Mice with a fasting blood glucose level higher than 250 mg/dl for 2 consecutive weeks after streptozotocin injection were treated twice a week with intraperitoneal injections of 25-50-100 mg/kg β-hydroxybutyrate.

RESULTS

Interestingly, while the retinal endoplasmic reticulum stress markers (pPERK, pIRE1, ATF-6α) were elevated in diabetic C57BL6J mice, their levels were significantly reduced by the systemic intraperitoneal treatment with 50 mg/kg and 100 mg/kg β-hydroxybutyrate. These mice also exhibited high NLRP3 inflammasome activity and proinflammatory cytokine levels. In fact, the elevated levels of retinal NLRP3 inflammasome activation markers (NLRP3, ASC, caspase-1) and of the relative proinflammatory cytokines (IL-1β, IL-18) were significantly reduced by 50 mg/kg and 100 mg/kg β-hydroxybutyrate treatment. These doses also reduced the high apoptotic cell number exhibited by the diabetic mice in the retinal outer nuclear layer (ONL) and increased the ONL low connexin 43 expression, leading to an improvement in retinal permeability and homeostasis.

CONCLUSIONS

These data suggest that the systemic treatment of diabetic C57BL6J mice with BHB activates retinal HCA2 and inhibits local damage.

Characterization of Nanoparticle Intestinal Transport Using an In Vitro Co-Culture Model

We aimed to obtain a tunable intestinal model and study the transport of different types of nanoparticles. Caco-2/HT29-MTX co-cultures of different seeding ratios (7:3 and 5:5), cultured on Transwell® systems, were exposed to non-cytotoxic concentration levels (20 μg/mL) of silicon quantum dots and iron oxide (α-Fe₂O₃) nanoparticles. Transepithelial electric resistance was measured before and after exposure, and permeability was assessed via the paracellular marker Lucifer Yellow. At regular intervals during the 3 h transport study, samples were collected from the basolateral compartments for the detection and quantitative testing of nanoparticles. Cell morphology characterization was done using phalloidin-FITC/DAPI labeling, and Alcian Blue/eosin staining was performed on insert cross-sections in order to compare the intestinal models and evaluate the production of mucins. Morphological alterations of the Caco-2/HT29-MTX (7:3 ratio) co-cultures were observed at the end of the transport study compared with the controls. The nanoparticle suspensions tested did not diffuse across the intestinal model and were not detected in the receiving compartments, probably due to their tendency to precipitate at the monolayer surface level and form visible aggregates. These preliminary results indicate the need for further nanoparticle functionalization in order to appropriately assess intestinal absorption in vitro.

Gene expression involved in the sexual development of Best Beluga hybrid sturgeons

The scope of this study is to investigate the expression of dmrt1, foxl2, ar, star and sox9 genes in the context of the gonad development stage of 21 month-old Best Beluga individuals. No significant difference was observed between males and females but the cyp17a1 gene showed higher expression in male than in female gonads. The results suggest that during sampling the females were in perinucleolar stage and the males in early spermatogenesis stage which led to specific patterns of expression for the investigated genes.

The Melanocortin MC5R as a New Target for Treatment of High Glucose-Induced Hypertrophy of the Cardiac H9c2 Cells

The study explored the anti-hypertrophic effect of the melanocortin MC5R stimulation in H9c2 cardiac myocytes exposed to high glucose. This has been done by using α-MSH and selective MC5R agonists and assessing the expression of GLUT4 and GLUT1 transporters, miR-133 and urotensin receptor levels as a marker of cardiac hypertrophy. The study shows for the first time an up-regulation of MC5R expression levels in H9c2 cardiomyocytes exposed to high glucose medium (33 mM D-glucose) for 48 h, compared to cells grown in normal glucose medium (5.5 mM D-glucose). Moreover, H9c2 cells exposed to high glucose showed a significant reduction in cell viability (-40%), a significant increase in total protein per cell number (+109%), and an increase of the urotensin receptor expression levels as an evidence of cells hypertrophy. The pharmacological stimulation of MC5R with α-MSH (90 pM)of the high glucose exposed H9c2 cells increased the cell survival (+50,8%) and reduced the total protein per cell number (-28,2%) with respect to high glucose alone, confirming a reduction of the hypertrophic state as per cell area measurement. Similarly, PG-901 (selective agonist, 10^-10 M) significantly increased cell viability (+61,0 %) and reduced total protein per cell number (-40,2%), compared to cells exposed to high glucose alone. Interestingly, the MC5R agonist reduced the GLUT1/GLUT4 glucose transporters ratio on the cell membranes exhibited by the hypertrophic H9c2 cells and increased the intracellular PI3K activity, mediated by a decrease of the levels of the miRNA miR-133a. The beneficial effects of MC5R agonism on the cardiac hypertrophy caused by high glucose was also observed also by echocardiographic evaluations of rats made diabetics with streptozotocin (65 mg/kg i.p.). Therefore, the melanocortin MC5R could be a new target for the treatment of high glucose-induced hypertrophy of the cardiac H9c2 cells.

Enhancement of Silymarin Anti-fibrotic Effects by Complexation With Hydroxypropyl (HPBCD) and Randomly Methylated (RAMEB) β-Cyclodextrins in a Mouse Model of Liver Fibrosis

Silymarin (Sy) shows limited water solubility and poor oral bioavailability. Water-soluble hydroxypropyl (HPBCD) and randomly methylated (RAMEB) β-cyclodextrins were designed to enhance anti-fibrotic efficiency of silymarin in CCl₄-induced liver fibrosis in mice. Experimental fibrosis was induced by intraperitoneal injection with 2 ml/kg CCl₄ (20% v/v) twice a week, for 7 weeks. Mice were orally treated with 50 mg/kg of Sy-HPBCD, Sy-RAMEB and free silymarin. For assessment of the spontaneous reversion of fibrosis, CCl₄ treated animals were investigated after 2 weeks of recovery time. The CCl₄ administration increased hepatic oxidative stress, augmented the expression of transforming growth factor-β1 (TGF-β1) and Smad 2/3, and decreased Smad 7 expression. Furthermore, increased α-smooth muscle actin (α-SMA) expression indicated activation of hepatic stellate cells (HSCs), while up-regulation of collagen I (Col I) and matrix metalloproteinases (MMPs) expression led to an altered extracellular matrix enriched in collagen, confirmed as well by trichrome staining and electron microscopy analysis. Treatment with Sy-HPBCD and Sy-RAMEB significantly reduced liver injury, attenuating oxidative stress, restoring antioxidant balance in the hepatic tissue, and significantly decreasing collagen deposits in the liver. The levels of pro-fibrogenic markers' expression were also significantly down-regulated, whereas in the group for spontaneous regression of fibrosis, they remained significantly higher, even at 2 weeks after CCl₄ administration was discontinued. The recovery was significantly lower for free silymarin group compared to silymarin/β cyclodextrins co-treatments. Sy-HPBCD was found to be the most potent anti-fibrotic complex. We demonstrated that Sy-HPBCD and Sy-RAMEB complexes decreased extracellular matrix accumulation by inhibiting HSC activation and diminished the oxidative damage. This might occur via the inhibition of TGF-β1/Smad signal transduction and MMP/tissue inhibitor of MMPs (TIMP) rebalance, by blocking the synthesis of Col I and decreasing collagen deposition. These results suggest that complexation of silymarin with HPBCD or RAMEB represent viable options for the its oral delivery, of the flavonoid as a potential therapeutic entity candidate, with applications in the treatment of liver fibrosis.

Dose-Dependent Antifibrotic Effect of Chrysin on Regression of Liver Fibrosis: The Role in Extracellular Matrix Remodeling

Liver fibrosis represents an overaccumulation of extracellular matrix (ECM). This study was designed to investigate the effect of chrysin on established ECM overproduction in carbon tetrachloride (CCl₄) mouse liver fibrosis. Experimental fibrosis was induced by intraperitoneal injection of 2 mL/kg CCl₄ twice a week, for 7 weeks. Mice were orally treated with 3 doses of chrysin (5,7-dihydroxyflavone). For the assessment of the spontaneous reversion of fibrosis, CCl₄-treated mice were investigated after 2 weeks of recovery time. Silymarin was used as a standard of liver protection. In fibrotic livers, the results showed the upregulation of collagen I (Col I) and tissue inhibitors of metalloproteinase 1 (TIMP-1) and modulation of matrix metalloproteinases (MMPs), which led to an altered ECM enriched in Col, confirmed as well by electron microscopy investigations. Treatment with chrysin significantly reduced ultrastructural changes, downregulated Col I, and restored TIMP-1/MMP balance, whereas in the group observed for the spontaneous regression of fibrosis, they remained in the same pattern with fibrotic livers. In this study, we have shown chrysin efficacy to attenuate dose-dependent CCl₄-stimulated liver ECM accumulation by regulation of MMP/TIMP imbalance and inhibition of Col production. We have shown the dose-dependent chrysin efficiency in attenuation of CCl4-induced liver ECM accumulation by regulation of MMP/TIMP imbalance and inhibition of Col production. Our findings suggest that chrysin oral administration may introduce a new strategy for treating liver fibrosis in humans.

Plant-Derived Biomolecules and Drug Delivery Systems in the Treatment of Liver and Kidney Diseases

Chronic liver and kidney diseases are among the most fearful pathologies affecting an increasing number of people, having severe consequences on life quality. Although much progress has been made in recent years, availability of cost-effective and innovative therapies is still an unmet medical need. One of the major challenges in the therapy of liver and kidney diseases is to selectively deliver drugs to achieve therapeutically relevant concentration in the target organ, in order to decrease the amount of drug needed and to reduce unwanted side effects. In this review we summarize recent advances in selective drug targeting to liver or to kidney including cell-selective therapeutic approaches as well. We pay special attention to plant-derived bioactive molecules which constitute promising tools for the treatment of chronic liver and kidney diseases. We discuss cellular, subcellular and molecular mechanisms underlying the observed pharmacological effects of plant-derived drugs and give an overview of formulations, which can increase therapeutic effectiveness of these biomolecules in the treatment of chronic liver and kidney disorders.

Chitosan-Graphene Oxide 3D scaffolds as Promising Tools for Bone Regeneration in Critical-Size Mouse Calvarial Defects

Limited self-regenerating capacity of human skeleton makes the reconstruction of critical size bone defect a significant challenge for clinical practice. Aimed for regenerating bone tissues, this study was designed to investigate osteogenic differentiation, along with bone repair capacity of 3D chitosan (CHT) scaffolds enriched with graphene oxide (GO) in critical-sized mouse calvarial defect. Histopathological/histomorphometry and scanning electron microscopy(SEM) analysis of the implants revealed larger amount of new bone in the CHT/GO-filled defects compared with CHT alone (p < 0.001). When combined with GO, CHT scaffolds synergistically promoted the increase of alkaline phosphatase activity both in vitro and in vivo experiments. This enhanced osteogenesis was corroborated with increased expression of bone morphogenetic protein (BMP) and Runx-2 up to week 4 post-implantation, which showed that GO facilitates the differentiation of osteoprogenitor cells. Meanwhile, osteogenesis was promoted by GO at the late stage as well, as indicated by the up-regulation of osteopontin and osteocalcin at week 8 and overexpressed at week 18, for both markers. Our data suggest that CHT/GO biomaterial could represent a promising tool for the reconstruction of large bone defects, without using exogenous living cells or growth factors.

Biochemical, Histopathological and Molecular Responses in Gills of Leuciscus cephalus Exposed to Metals

Gills are major targets for acute metal toxicity in fish, due to their permanent contact with aquatic pollutants. To assess the effects of metals on gills of the Leuciscus cephalus (chub), fish individuals were collected from two sites in the Tur River, Romania, in upstream (site 1) and downstream (site 2) of a metal pollution source. Quantitative and hyperspectral analyses showed that Zn, Sr, and Fe concentrations were significantly higher in gills from site 2 compared with site 1. Malondialdehyde and advanced oxidation protein products levels increased 17 and 28%, respectively, whereas reduced glutathione level diminished significantly in the gills of fish collected from site 2 compared to site 1. The activities of superoxide dismutase, catalase, and glutathione-S-transferase increased significantly at 41, 21, and 28%, respectively. Proliferating cell nuclear antigen (PCNA) protein levels, as well as the amount of DNA damage, were significantly increased for site 2 compared with site 1. The induced oxidative stress generated hyperplasia, hypertrophy, and inflammation in the epithelial cells and apoptosis. Hence, this could suggest that gill cells have tried to counteract the oxidative stress-induced DNA fragmentation by PCNA up-regulation, but the PCNA expression decreased on longer time due to the low level of GSH, resulting in apoptosis.

Acute cardiotoxicity induced by doxorubicin in right ventricle is associated with increase of oxidative stress and apoptosis in rats

Doxorubicin (DOX) is one of the most effective chemotherapeutic agents, but its efficiency is seriously limited by the risk of developing cardiomyopathy. The most recognized cardiotoxic effect is left ventricular (LF) dysfunction, but MRI and echocardiography data demonstrated significant right ventricle (RV) function impairment. In order to clarify this aspect, the present study investigated the potential of DOX to induce acute RV cardiotoxicity at the same time as LV impairment. Rats were intraperitoneally (i.p.) injected with a single dose of 15 mg/kg DOX. DOX-treated rats were characterized by decreased body and heart weights, elevated levels of creatine kinase (CK-MB) and lactate dehydrogenase (LDH) activities compared to controls. Biochemical analyses on RV tissue revealed that the level of malondialdehyde (MDA) was significant increased (p<0.05) and activities of catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPX) antioxidant enzymes were decreased by 13%, 27% and 18%, respectively, compared to control. Histopathogical and electron microscopic studies revealed DOX-induced damage in both ventricles and an increase of interstitial collagen fibers compared to controls (p<0.001), whereas immunohistochemical analysis showed weak and irregular desmin expression. Furthermore, mitochondrion-induced apoptotic pathways were also activated in both ventricles, as reflected by the up-regulation of Bax/Bcl-2 mRNA expression ratio (p<0.001) and increase of Bax and caspase-3 protein expression, as well as by the significant elevation of TUNEL positive nuclei, compared to controls (p<0.001). The results showed that DOX exerted RV toxic effects at the same time as those reported in the LV, which might be mediated through the mitochondrial-dependent apoptosis.

Flucytosine and Amphotericin B Coadministration Induces Dose-Related Renal Injury

Invasive fungal infections remain an important clinical problem, and despite recent approaches, they bring high morbidity and mortality. Combination therapies are the most effective; however, adverse effects need to be considered. In this study, we aimed to evaluate the nephrotoxicity induced by combined therapy of flucytosine (FL) and amphotericin B (AMF) at 3 different doses administered to mice for 14 days: 300 μg/kg AMF+50 mg/kg FL; 600 μg/kg AMF+100 mg/kg FL; 900 μg/kg AMF+150 mg/kg FL. Antifungal coadministration triggered nuclear translocation of NF-κB and upregulated nuclear factor kappa-light-chain-enhancer of activated B cells subunit p65 (NF-κB p65) messenger RNA mRNA level in dose-dependent manner. The immunopositivity of tumor necrosis factor-α and interleukin-6 (IL-6), together with IL-6 gene expression, increased both in tubular and glomerular cells. Amphotericin B–flucytosine cotreatment increased significantly the number of terminal deoxy-nucleotidyl transferase (TdT)-mediated dUTP nick end-labeling positive nuclei. Apoptotic cells in renal tubuli were confirmed by electron microscopy. Histopathological analysis revealed collagen accumulation at the glomerular level. Collagen was also evidenced in the glomeruli at the dose of 900 μg/kg AMF+150mg/kg FL by Masson-Goldner trichrome staining and electron microscopy. Moreover, antifungal cotherapy induced upregulation of transforming growth factor beta 1 (TGF-β1) gene expression in a dose-dependent manner. Inflammation and epithelial tubular apoptosis are associated with TGF-β1 activation and initiation of the early stage of glomerular fibrosis at higher doses, leading to tubule–interstitial fibrosis.

Berberis vulgaris extract/β-cyclodextrin complex increases protection of hepatic cells via suppression of apoptosis and lipogenesis pathways

Berberis vulgaris (Bv) is well known worldwide for its healing properties. However, limited information is available concerning its mechanism of action and the increased hepatoprotective activity of formulated extracts. This study evaluated the protective effect of Bv bark extract against CCl₄-induced cytotoxicity in Huh7 cells, as well whether β-cyclodextrin complexation of the extract resulted in increased hepatoprotective effects. Huh7 cells were incubated for 48 h with 5, 7.5 and 10 µg/ml of unformulated or formulated Bv extract alone and in co-treatment with CCl₄. The effects on Huh7 cell growth and apoptosis were evaluated by MTT assay, caspase-3/7 activity and caspase-3 expression, whereas fatty acid changes were investigated by Oil red O staining and the detection of peroxisome proliferator-activated receptor-γ (PPARγ) expression using immunofluorescence. Ultrastructural alterations were observed by electron microscopy. The MTT assay showed that co-exposure to CCl₄ and 7.5 µg/ml formulated extract led to a 1.25-fold increase in cell viability compared with the non-formulated extract. Caspase-3/7 activity decreased by 50% and 70% following co-treatment with unformulated or formulated extract, compared with that in cells treated with CCl₄ alone. Furthermore, hepatocyte ultrastructure was protected from CCl₄-induced injury in the two co-treated groups, intracytoplasmic lipid accumulation decreased significantly and PPARγ expression was restored, in comparison with CCl₄-treated cells alone. Formulated and unformulated extracts were efficient against the anti-proliferative and pro-apoptotic actions of CCl₄ through suppression of CCl₄-induced caspase-3 activation and lipid accumulation. The protective effect of the formulated extract was more pronounced than that of the unformulated one, which may be due to its increased solubility.

Hepatoprotective activity of chrysin is mediated through TNF-α in chemically-induced acute liver damage: An in vivo study and molecular modeling

Chrysin (5,7-dihydroxyflavone) is a naturally occurring flavonoid present at high levels in honey, propolis and numerous plant extracts. Chrysin is known to have hepatoprotective activity, however, the mechanisms by which it exerts this effect remain unclear. In the present study, the effects of chrysin in carbon tetrachloride (CCl₄)-induced acute liver damage were investigated and the results used to infer a possible mechanism behind chrysin's hepatoprotective activity. Prior to an intraperitoneal injection of CCl4 (1 ml/kg) to induce acute liver damage, chrysin (50 mg/kg) was administered orally to mice for 7 days. The positive control group was given 50 mg/kg standardized silymarin, a well-studied hepatoprotective flavonoid. Twenty-four h following CCl4 administration, an increase in the activity levels of serum aspartate-amino-transferase and alanine-amino-transferase was found. This was accompanied by extended centrilobular necrosis, steatosis and an altered hepatocyte ultrastructure. In addition, CCl4-induced acute hepatotoxicity was associated with an increase in hepatic tumor necrosis factor-α (TNF-α) and α-smooth muscle actin (α-SMA) protein expression, which was significantly decreased in the livers of mice pre-treated with chrysin (P<0.001), similar to the results of the silymarin pre-treated group (P<0.001). Treatment with chrysin prior to CCl4 exposure significantly reduced the activity of enzymes used as biochemical markers of poor liver function compared with the group which did not receive pre-treatment (P<0.001). In addition, the results of histopathological and electron microscopy liver examination showed chrysin pre-treatment reduced the effects of CCl4 treatment. Molecular modeling results demonstrated that the hepatoprotective activity of chrysin is mediated through TNF-α, as it reduces soluble TNF-α generation via blocking TNF-α-converting enzyme activity. In conclusion, the results of the present study suggest that inflammatory pathways are activated in CCl4-induced acute liver damage, which are ameliorated by chrysin pre-treatment. This indicates that chrysin is a potent hepatoprotective agent, similarly to silymarin at the same dose, which has the potential to be a viable alternative to conventional hepatoprotective treatments.

Protective effects of silymarin against bisphenol A-induced hepatotoxicity in mouse liver

Bisphenol A (BPA) is an endocrine-disrupting chemical released into the environment, with severe consequences for human health, including metabolic syndrome and associated pathological conditions. Due to limited information on BPA-induced hepatotoxicity, the present study focused on investigating the association between BPA-induced toxicity and inflammatory markers in the liver, and how these injuries may be alleviated using the natural agent silymarin, a flavonoid with antioxidant properties obtained from Silybum marianum. Administration of BPA to male CD-1 mice for 10 days caused a significant increase in the number of cells immunopositive for interleukin 6 and tumor necrosis factor-α, pro-inflammatory cytokines that mediate the hepatic inflammatory response. Treatment with 200 mg/kg of silymarin concurrently with BPA for 10 days resulted in a diminished level of pro-inflammatory cytokines and in significantly reduced ultrastructural injuries. Additionally, silymarin was able to restore the significantly decreased glycogen deposits observed following BPA exposure to normal levels, thus favoring hepatic glycogenesis. This study represents the first report of silymarin ability to reduce hepatic lesions and to counteract inflammation caused by BPA in mice. A dose of 200 mg/kg silymarin was sufficient to induce a protective effect against structural and ultrastructural injuries induced by BPA and to lower the levels of pro-inflammatory cytokines observed in murine liver tissue following exposure to BPA.

MODERATE PHYSICAL ACTIVITY IMPROVES RAT BONE ULTRASTRUCTURE IN EXPERIMENTAL OSTEOPOROSIS

CONTEXT AND OBJECTIVE

In this study, we aimed to investigate how moderate physical activity improves the bone ultrastructural parameters in rats with glucocorticoid-induced secondary osteoporosis.

ANIMALS AND METHODS

Research has been carried out on Wistar female rats. Secondary osteoporosis was induced through daily i.m.1.5 mg/kgbw methylprednisolone, over a period of 30 days. A group of rats with induced secondary osteoporosis were subjected to physical activity (swimming) for one hour/day for 30 days. Rats were sacrificed 24 hours after the last administration and femoral bones were used for electron microscopy analysis.

RESULTS

The ultrastructural findings obtained from the rats with osteoporosis showed varying degrees of alteration in all cellular components. A moderate physical effort led to the overall maintenance of the normal ultrastructure of the cells and connective components, protecting the lamellar structure of the compact bone from the deleterious effects of glucocorticoid. The shape and components of osteocytes were also preserved and the accumulation of lipids in the bone marrow diminished.

CONCLUSIONS

Physical exercise has been shown to have a protective role by lowering the development of structural alterations specific to osteoporosis. Therefore, moderate physical exercises are recommended for improving the structure of the bone mass affected by glucocorticoid treatment.

Fabrication and toxicity characterization of a hybrid material based on oxidized and aminated MWCNT loaded with carboplatin

This study focused on the fabrication and toxicity characterization of a hybrid material-based on the multiple functionalizations of multiwalled carbon nanotubes (MWCNTs) with carboxyl or amino groups and the anti-tumor drug carboplatin (CP). The functionalization was evidenced by Fourier transformed infrared spectroscopy (FTIR) and high performance liquid chromatography (HPLC). The amount of platinum ions released in the simulated body fluid (SBF) was assessed by inductively coupled plasma mass spectrometry (ICP-MS). Cell viability, nanotubes cellular uptake, cell proliferation, superoxide anion production, SOD activity, intracellular glutathione and protein expression of several molecules involved in breast tumor cell survival and death were investigated after 24h exposure. Exposure to the aminated carbon nanotubes loaded with carboplatin resulted in a greater decrease of viability compared to oxidized carbon nanotubes loaded with the same drug, which was in an inversely proportional relationship with the production of superoxide anions in breast cancer cells. The inhibition of Hsp60, Hsp90, p53 and Mdm2 protein expression was induced as a consequence of the cytoprotection mechanism failure. Overexpression of Beclin1 and the reduction of Bcl2 expression were also observed, suggesting that functionalized MWCNT loaded with CP trigger cell death via autophagy in breast cancer cells.