• Journal of Periodontal and Implant Science
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• v.46 no.4
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• pp.220-233
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• 2016

Purpose: The aim of this study was to present new a model that allows the study of the bone healing process, with an emphasis on the biological behavior of different graft-to-host interfaces. A standardized "over-inlay" surgical technique combined with a differential histomorphometric analysis is presented in order to optimize the use of critical-size calvarial defects in pre-clinical testing. Methods: Critical-size defects were created into the parietal bone of 8 male Wistar rats. Deproteinized bovine bone (DBBM) blocks were inserted into the defects, so that part of the block was included within the calvarial thickness and part exceeded the calvarial height (an "over-inlay" graft). All animals were sacrificed at 1 or 3 months. Histomorphometric and immunohistochemical evaluation was carried out within distinct regions of interest (ROIs): the areas adjacent to the native bone (BA), the periosteal area (PA) and the central area (CA). Results: The animals healed without complications. Differential morphometry allowed the examination of the tissue composition within distinct regions: the BA presented consistent amounts of new bone formation (NB), which increased over time ($24.53%{\pm}1.26%$ at 1 month; $37.73%{\pm}0.39%$ at 3 months), thus suggesting that this area makes a substantial contribution toward NB. The PA was mainly composed of fibrous tissue ($71.16%{\pm}8.06%$ and $78.30%{\pm}2.67%$, respectively), while the CA showed high amounts of DBBM at both time points ($78.30%{\pm}2.67%$ and $74.68%{\pm}1.07%$, respectively), demonstrating a slow remodeling process. Blood vessels revealed a progressive migration from the interface with native bone toward the central area of the graft. Osterix-positive cells observed at 1 month within the PA suggested that the periosteum was a source of osteoprogenitor elements. Alkaline phosphatase data on matrix deposition confirmed this observation. Conclusions: The present model allowed for a standardized investigation of distinct graft-to-host interfaces both at vertically augmented and inlay-augmented sites, thus possibly limiting the number of animals required for pre-clinical investigations.

• Journal of Dental Anesthesia and Pain Medicine
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• v.16 no.1
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• pp.39-47
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• 2016

Background: Oxidative stress occurs during the aging process and other conditions such as bone fracture, bone diseases, and osteoporosis, but the role of oxidative stress in bone remodeling is unknown. Propofol exerts antioxidant effects, but the mechanisms of propofol preconditioning on oxidative stress have not been fully explained. Therefore, the aim of this study was to evaluate the protective effects of propofol against $H_2O_2$-induced oxidative stress on a human fetal osteoblast (hFOB) cell line via activation of autophagy. Methods: Cells were randomly divided into the following groups: control cells were incubated in normoxia (5% $CO_2$, 21% $O_2$, and 74% $N_2$) without propofol. Hydrogen peroxide ($H_2O_2$) group cells were exposed to $H_2O_2\;(200{\mu}M)$ for 2 h, propofol preconditioning (PPC)/$H_2O_2$ group cells were pretreated with propofol then exposed to $H_2O_2$, 3-methyladenine (3-MA)/PPC/$H_2O_2$ cells were pretreated with 3-MA (1 mM) and propofol, then were exposed to $H_2O_2$. Cell viability and apoptosis were evaluated. Osteoblast maturation was determined by assaying bone nodular mineralization. Expression levels of bone related proteins were determined by western blot. Results: Cell viability and bone nodular mineralization were decreased significantly by $H_2O_2$, and this effect was rescued by propofol preconditioning. Propofol preconditioning effectively decreased $H_2O_2$-induced hFOB cell apoptosis. However, pretreatment with 3-MA inhibited the protective effect of propofol. In western blot analysis, propofol preconditioning increased protein levels of collagen type I, BMP-2, osterix, and TGF-${\beta}1$. Conclusions: This study suggests that propofol preconditioning has a protective effect on $H_2O_2$-induced hFOB cell death, which is mediated by autophagy activation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.7
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• pp.1015-1021
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• 2013

Glycyrrhiza inflata Batal, an important species of licorice, is one of the most widely used medicinal plants for over 4000 years. Glycyrrhiza plant species has been well known for its various therapeutic activities such as anti-inflammatory, anti-allergic, and anti-ulcer. The purpose of this study was to determine the effects of Glycyrrhiza inflata Batal ethanol extracts (GBE) on adipocyte and osteoblast differentiation. Mesenchymal C3H10T1/2 cells were treated with sub-cytotoxic doses of GBE, and its effects on adipocyte differentiation were assessed. We found that GBE dose-dependently increased lipid accumulation and also induced the expression of adipocyte markers, such as $PPAR{\gamma}$ and its target genes, aP2, and adiponectin, in C3H10T1/2 cells. Consistently, similar effects of GBE on lipid accumulation were also observed in preadipocyte 3T3-L1 cells that further supports the pro-adipogenic activities of GBE. We also investigated the effects of GBE on osteoblast differentiation of mesenchymal C3H10T1/2 cells. As a results, we found that GBE increased the activity of alkaline phosphatase in a dose-dependent manner and also promoted the expression of osteoblast markers, such as ALP and RUNX2, during osteoblast differentiation of C3H10T1/2 cells. Similar pro-osteogenic effects of GBE were also observed in preosteoblast MC3T3-E1 cells. Finally, our data show that a major bioactive compound found in Glycyrrhiza inflata Batal, licochalcone A (LA) but not glycyrrhizic acid (GA), can mediate the pro-adipogenic and pro-osteogenic effects of GBE. Taken together, this study provides data to show the possibility of GBE and its bioactive component LA as putative strategies for type 2 diabetes and bone diseases.