Nitric oxide (NO) is important in the regulation of bone remodeling, whereas high concentration of NO promotes cell death of osteoblast. However, it is not clear yet whether NO-induced autophagy is implicated in cell death or survival of osteoblast. The present study is aimed to examine the role of NO-induced autophagy in the MC3T3-E1 cells and their underlying molecular mechanism. The effect of sodium nitroprusside (SNP), an NO donor, on the cytotoxicity of the MC3T3-E1 cells was determined by MTT assay and expression of apoptosis or autophagy associated molecules was evaluated by western blot analysis. The morphological observation of autophagy and apoptosis by acridine orange stain and TUNEL assay were performed, respectively. Treatment of SNP decreased the cell viability of the MC3T3-E1 cells in dose- and time-dependent manner. SNP increased expression levels of p62, ATG7, Beclin-1 and LC3-II, as typical autophagic markers and augmented acidic autophagolysosomal vacuoles, detected by acridine orange staining. However, pretreatment with 3-methyladenine (3MA), the specific inhibitor for autophagy, decreased cell viability, whereas increased the cleavage of PARP and caspase-3 in the SNP-treated MC3T3-E1 cells. AMP-activated protein kinase (AMPK), a major autophagy regulatory kinase, was activated in SNP-treated MC3T3-E1 cells. In addition, pretreatment with compound C, an inhibitor of AMPK, decreased cell viability, whereas increased the number of apoptotic cells, cleaved PARP and caspase-3 levels compared to those of SNP-treated MC3T3-E1 cells. Taken together, it is speculated that NO-induced autophagy functions as a survival mechanism via AMPK activation against apoptosis in the MC3T3-E1 cells.

The objective of this study was to evaluate the permeability of small molecules into the brain via the blood-brain barrier in zebrafish and to investigate the possibility of using this animal model as a screening tool during the early stages of drug discovery. Fifteen compounds were used to understand the permeation into the brain in zebrafish and mice. The ratio of brain-to-plasma concentration was compared between the two animal models. The partition coefficient (K), estimated using the concentration ratio at designated times (0.167, 0.25, 0.5, or 2 h) after oral administrations (per os, p.o), ranged from 0.099 to 5.68 in zebrafish and from 0.080 to 11.8 in mice. A correlation was observed between the K values obtained from the zebrafish and mice, suggesting that zebrafish can be used to estimate K to predict drug penetration in humans. Furthermore, in vivo transport experiments to understand the permeability glycoprotein (P-gp) transporter-mediated behavior of loperamide (LPM) in zebrafish were performed. The zebrafish, K of LPM was determined to be 0.099 ± 0.069 after dosing with LPM alone, which increased to 0.180 ± 0.115 after dosing with LPM and tariquidar (TRQ, an inhibitor of P-gp). In mouse, the K of LPM was determined to be 0.080 ± 0.004 after dosing with LPM alone and 0.237 ± 0.013 after dosing with LPM and TRQ. These findings indicate that the zebrafish could be used as an effective screening tool during the discovery stages of new drugs to estimate their distribution in the brain.

No abstract

KDZ-001 inhibits melanin synthesis and has a potential for use in skin-whitening cosmetics.

Waste management is a major part of the food industry. The present study was designed to utilize the discarded byproduct of Schisandra chinensis Baillon. The antioxidant and anti-inflammatory effects of a 30% ethanol fraction (RPG-OM-30E) from the fermented hot water extraction of the Schisandra chinensis Baillon byproduct were investigated using RAW 264.7 cells and zebrafish larvae. RPG-OM-30E reduced lipopolysaccharide (LPS)-induced nitric oxide production in the RAW 264.7 cells. Additionally, RPG-OM-30E inhibited mRNA expression and protein secretion of pro-inflammatory cytokines, such as interleukin-6 (Il-6) and interleukin-1b (Il-1b). The anti-inflammatory effects of RPG-OM-30E were tested in Tg(mpx::EGFP) i114 zebrafish larvae. Neutrophil migration to a wound site was decreased by RPG-OM-30E. Neutrophil aggregation was also inhibited by RPG-OM-30E after induction of an LPS-induced immune response in the yolk. Finally, the antioxidant and hepatoprotective effects of RPG-OM-30E were examined in vivo. Mice with induced oxidative damage recovered from the stress following RPG-OM-30E treatment.