Natural phytochemicals of plant origin, including flavonoids, have been found to be potent antioxidants providing beneficial effects against oxidative stress-related diseases. The present study was carried out to investigate the antioxidant properties of morin, a flavonoid originally isolated from the flowering plants of the Moraceae family. Superoxide dismutase (SOD)‑like activity and 2,2'‑azino‑bis‑(3‑ethylbenzothiazoline‑6‑sulfonic acid) (ABTS•+) radical scavenging activity were determined. We also investigated the cytoprotective effects of morin against hydrogen peroxide (H2O2)‑induced DNA damage and apoptosis in V79‑4 Chinese hamster lung fibroblasts. Our results demonstrated that morin had strong scavenging effects against ABTS•+ radicals with enhanced SOD activity, which varied in a dose-dependent manner. Morin was found to reduce H2O2‑induced intracellular reactive oxygen species generation and nuclear DNA damage, and it recovered cell viability damaged by H2O2 via inhibition of mitochondrial dysfunction‑mediated apoptosis. Notably, the treatment of V79‑4 cells with morin markedly enhanced the expression of heme oxygenase‑1 (HO‑1) but not quinone oxidoreductase-1, which was associated with the increased expression and phosphorylation of nuclear factor-erythroid 2-related factor 2 (Nrf2) and the downregulation of Kelch‑like ECH‑associated protein 1 expression. Based on our findings, we conclude that morin effectively ameliorated oxidative stress‑induced DNA damage through intrinsic free radical scavenging activity and activation of the Nrf2/HO-1 pathway.

Abstract. Secretory leukocyte protease inhibitor (SLPI) protects tissue from proteases, and promotes cell proliferation and healing during inflammatory response. SLPI is also overexpressed in gastric, lung and ovarian cancers, which accelerates the metastasis of cancer cells. Matrix metalloproteinases-2, -9 (MMP-2 and MMP-9) are overexpressed in high metastatic cancers, and promote the migration of cancer cells through collagen degradation. SLPI and MMP-2, -9 are critical factors in stimulating the metastatic processes but there are no reports of a direct correlation between these molecules. Therefore, this study examined the role of SLPI related to MMP-2 and MMP-9 using two gastric cancer cell lines, such as characterized non-metastatic SNU484 and highly metastatic SNU638 cells. SLPI, MMP-2 and MMP-9 mRNA and protein expression were higher in SNU638 cells than in SNU484 cells. In addition, the rate of cell migration and invasion was higher in the SNU638 cells than in SNU484 cells. Interestingly, after treatment with SLPI, the rate of migration and invasion was higher in the SNU484 cells than in the positive control (PC) SNU484 cells. The rate of migration was also higher in the SNU638 cells after SLPI treatment than in the SNU638 cells (PC) but the invasion rate was not changed. The expression and secretion of MMP-2 and MMP-9 as well the rate of cell migration and invasion were significantly lower in SLPIsiRNA transfected SNU638 cells (si-SLPI/SNU638) but higher in SLPI-treated SNU484 cells (SNU484 + SLPI). Strong Elk-1 phosphorylation was detected in SNU484 + SLPI and SNU638 cells but was barely detectable in SNU484 and si-SLPI/SNU638 cells. These results show that SLPI promotes the metastasis of SNU638 gastric cancer cells by increasing MMP-2 and MMP-9 expression through Elk-1 signaling, indicating its role as a signaling molecule not a protease inhibitor. IntroductionThe metastatic cascade of cancer cells is viewed as a series of sequential and interrelated steps, which include the following: epithelial-mesenchymal transition (EMT), degradation of the basement membrane; dissociation of tumor cells from the primary site; invasion of the neighboring tissue; intravasation into the blood and lymph vessels; transport through the vessels; extravasation from the vessels; and proliferation at a distant site. Among these processes, tumor cells invading the neighboring tissue after degrading the basement membrane is a major development (1).Secretory leukocyte protease inhibitor (SLPI) is an 11.7-kDa cystein-rich protein and an epithelial cell product found in saliva, seminal plasma and in the cervical, nasal, and bronchial mucus. SLPI inhibits the serine protease activity, such as chymotrypsin, trypsin, pancreatic elastase, cathepsin G, mast cell chymase (2). Recently, SLPI was reported to be an anti-inflammatory factor that contributes at the early inflammatory response in odontoblasts (3). In addition, SLPI was reported to play a role not only in protecting the tissues from the protease (4) but also in promoting wou...

To find out the effect of commercially available energy drinks on tooth enamel erosion, analyzed pH, buffering capacity, and the content of some of the inorganic components selecting 4 energy drinks that has high affinity of the products currently being sold. In addition, by observing the degree of erosion before and after immersion in energy drink by surface microhardness and scanning electron microscope (SEM) the results were as follows: Acidity of energy drink ʻBurn Intenseʼ was the lowest as 2.78±0.01 highest on distilled water as 6.475±0.01. ʻBurn Intenseʼ buffering capacity was 3.48±0.155 at pH 5.5, 1.88±0.15 at pH 7.0 which is the highest, and ʻHot6ʼ was 1.71±0.37, 1.23±0.35 on each of it showing the lowest points. Ca content on energy drink was the highest at ʻVolt Energyʼ as (77.21±2.70 mg/kg), the lowest at ʻHot6ʼ as (0.98±0.05 mg/kg). P content was the highest on ʻHot6ʼ(1.34±0.05 mg/kg) and detected at ʻRed Bullʼ. Enamel surface hardness variation of the energy drinks before and after immersion showed rapid decrease at ʻRed Bullʼ (66.65±35.60), and ʻVolt Energyʼ (61.96±31.42), ʻBurn Intenseʼ (58.53±24.84), ʻHot6ʼ (53.99±60.26) was in order. Distilled water, the control group, showed significant difference with the experimental group (p＜0.05). But there was no significant difference between energy drinks. At SEM observation and analysis, ʻBurn Intenseʼ was the most severe demineralization, ʻVolt Energyʼ, ʻHot6ʼ, ʻRed Bullʼ, distilled water was in order. In the above results, taken together there were no statistically differences between energy drinks but significant difference in comparison with distilled water. In addition, at SEM observation and analysis all energy drink caused dental erosion, especially ʻBurn Intenseʼ, has the lowest acidity, was serious. Thus, it is believed to provide a variety of oral health education and information about energy drinks that can affect the erosion of the teeth so public have the right to be recognized and reasonable dental care.

Mineralized bone matrix constituted with collagenous and non-collagenous proteins was synthesized by osteoblasts differentiated from mesenchymal stem cells. Secretory leukocyte protease inhibitor (SLPI), a serine protease inhibitor, promotes cell migration and proliferation, and suppresses the inflammatory response. Recent studies reported that SLPI regulates the formation of dentin and mineralization by odontoblasts and increases the adhesion and viability of preosteoblasts on a titanium (Ti) surface. Ti and its alloys are widely used implant materials in artificial joints and dental implants owing to their biocompatibility with bone. Therefore, this study aimed to examine whether SLPI can be an effective molecule in promoting differentiation and mineralization of osteoblasts on a Ti surface. In order to investigate the effects of SLPI on osteoblasts, an MTT assay, PCR, western blotting and Alizarin Red S staining were performed. The results demonstrated that SLPI increased the viability of osteoblasts during differentiation on Ti discs compared with that of the control. The expression levels of SLPI mRNA and protein were higher than that of the control after treatment of osteoblasts with SLPI on Ti discs during differentiation. SLPI increased the formation of mineralized nodules and mRNA expression of alkaline phosphatase, dentin sialophosphoprotein, dentin matrix protein 1, bone sialoprotein, and collagen I in osteoblasts on Ti discs compared with that of the control. In conclusion, SLPI increases the viability and promotes the differentiation and mineralization of osteoblasts on Ti surfaces, suggesting that SLPI is an effective molecule for achieving successful osseointegration between osteoblasts and a Ti surface.

Preclinical Research Sanguinarine, an alkaloid isolated from the root of Sanguinaria canadensis and other plants of the Papaveraceae family, selectively induces apoptotic cell death in a variety of human cancer cells, but its mechanism of action requires further elaboration. The present study investigated the pro-apoptotic effects of sanguinarine in human oral squamous cell carcinoma KB cells. Sanguinarine treatment increased DR5/TRAILR2 (death receptor 5/TRAIL receptor 2) expression and enhanced the activation of caspase-8 and cleavage of its substrate, Bid. Sanguinarine also induced the mitochondrial translocation of pro-apoptotic Bax, mitochondrial dysfunction, cytochrome c release to the cytosol, and activation of caspase-9 and -3. However, a pan-caspase inhibitor, z-VAD-fmk, reversed the growth inhibition and apoptosis induced by sanguinarine. Sanguinarine also suppressed the phosphorylation of phosphoinositide 3-kinase (PI3K) and Akt in KB cells, while co-treatment of cells with sanguinarine and a PI3K inhibitor revealed synergistic apoptotic effects. However, pharmacological inhibition of AMP-activated protein kinase and mitogen-activated protein kinases did not reduce or enhance sanguinarine-induced growth inhibition and apoptosis. Collectively, these findings indicate that the pro-apoptotic effects of sanguinarine in KB cells may be regulated by a caspase-dependent cascade via activation of both intrinsic and extrinsic signaling pathways and inactivation of PI3K/Akt signaling. Drug Dev Res 77 : 227-240, 2016.   © 2016 Wiley Periodicals, Inc.