Ciprian Valentin Mihali

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.

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

Abstract This study has assessed the protective efficacy of Silybum marianum seed oil (SMSO) in the context of CCl4-induced injury and oxidative stress in murine liver. Based on the GC-MS analysis, linoleic and stearic acids, tocopherol, ascorbic acid 2,6 dihexadecanoate and other constituents were identified in SMSO. Swiss mice received oral doses of SMSO daily for 21 days (10 g/kg b.w.) and subsequently injected i.p. with CCl4 (50% v/v in olive oil; 1 ml/kg) on the 22nd day. CCl4 administration induced an elevation of serum amino- and glutamyl transferases activities and an increased peroxidation, as well as a decrease of SOD, CAT, GPx, GR and GST activities in liver. SMSO successfully prevented oxidative stress and restored the biochemical parameters, hepatic architecture and expression of TNF-alpha. These findings suggest that SMSO was effective in counteracting the damaging effects of CCl4-induced injury in hepatocytes, probably due to its inherent antioxidant properties.

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.