Protective effects of butein on corticosterone-induced cytotoxicity in Neuro2A cells.

A functional understanding of the relationship between glucocorticoids and neuronal apoptosis induced by the production of reactive oxygen species (ROS) may lead to a novel strategy for the treatment or prevention of depression. Previous reports suggest that butein, a type of flavonoids, may be a potent candidate against depression-related neuronal cell apoptosis caused by oxidative stress; however, the protective effects of butein on damaged corticosterone (CORT)-treated neuronal cells has not been elucidated. In the present study, we examined the protective effect of butein on CORT-induced cytotoxicity and neurite growth during cell differentiation of mouse neuroblastoma Neuro2A (N2A) cells. Moreover, the effect on cultured cells by high concentrations of butein was confirmed. Our results demonstrate that CORT treatment significantly decreases cell viability and induces cell death. CORT was suggested to induce apoptosis via mitochondrial dysfunction and caspase-3 activation; this apoptosis may be attributed to DNA damage by ROS generation, found in this study to be significantly inhibited by pretreatment with butein. We found that CORT produced significant growth suppression of retinoic acid-induced neurite outgrowth in N2A cells; however, butein significantly increased neurite length and induced dose-dependent apoptotic cytotoxicity in N2A cells. This study suggests that low concentration of butein can prevent CORT-induced cytotoxicity in N2A cells, and provides preliminary results supporting some of the beneficial roles of butein in neuroprotection.

Tetrandrine Increases the Sensitivity of Human Lung Adenocarcinoma PC14 Cells to Gefitinib by Lysosomal Inhibition.

BACKGROUND/AIM: Human lung adenocarcinoma PC14 cells without mutations in the epidermal growth factor receptor (EGFR) are less sensitive to gefitinib than PC9 cells with EGFR mutations. We report the involvement of tetrandrine in autophagy flux as a mechanism that enhances the sensitivity of PC14 cells to gefitinib. MATERIALS AND METHODS: Sensitivity to gefitinib was determined by a growth inhibition assay, and quantitative real-time PCR, western blotting, and fluorescent immunostaining were used to detect autophagy. RESULTS: In PC14 cells, combined treatment with gefitinib and tetrandrine caused a significant increase in gefitinib sensitivity and autophagy-related mRNAs and proteins (LC3, etc.), and the LC3 protein accumulated in lysosomes. Furthermore, an autophagy flux assay revealed that tetrandrine inhibited lysosomes and that gefitinib promoted autophagy. Finally, the sensitivity of PC14 cells to gefitinib was enhanced with chloroquine. CONCLUSION: Tetrandrine possibly increases the susceptibility of PC14 cells to gefitinib by lysosomal inhibition.

23-Hydroxyursolic Acid Isolated from the Stem Bark of Cussonia bancoensis Induces Apoptosis through Fas/Caspase-8-Dependent Pathway in HL-60 Human Promyelocytic Leukemia Cells.

The natural product 23-hydroxyursolic acid (23-HUA) is a derivative of ursolic acid, which is known to induce cancer cell apoptosis. However, apoptotic effects and mechanisms of 23-HUA have not been well characterized yet. Herein, we investigated the molecular mechanisms of 23-HUA-induced apoptosis in HL-60 human promyelocytic leukemia cells. 23-HUA-treated HL-60 cells showed apoptotic features including internucleosomal DNA condensation and fragmentation as well as externalization of phosphatidylserine residues. 23-HUA induced a series of mitochondrial events including disruption of mitochondrial membrane potential (ΔΨm), cytochrome c and Smac/DIABLO release and loss of balance between pro-apoptotic and anti-apoptotic Bcl-2 proteins in HL-60 cells. In addition, 23-HUA activated caspase-8, caspase-9 and caspase-3. Pretreatment with a broad caspase inhibitor (z-VAD-fmk), a caspase-3 inhibitor (z-DEVD-fmk), and a caspase-8 inhibitor (z-IETD-fmk) significantly attenuated 23-HUA-induced DNA fragmentation. After 23-HUA-induced apoptosis, proteins expression levels of FasL, Fas and FADD constituting the death-inducing signaling complex (DISC) were upregulated in HL-60 cells. Moreover, transfection with Fas or FADD siRNA significantly blocked 23-HUA-induced DNA fragmentation and caspases activation. Taken together, these findings indicate that 23-HUA induces apoptosis in HL-60 human promyelocytic leukemia cells through formation of DISC and caspase-8 activation leading to loss of ΔΨm and caspase-3 activation.

Mechanisms for the anti-obesity actions of bofutsushosan in high-fat diet-fed obese mice.

BACKGROUND: The Kampo medicine bofutsushosan (BTS; Pulvis ledebouriellae compositae; Fang Feng Tong Sheng San) has been used as an anti-obesity treatment in overweight patients. In this study, we assessed the underlying physiological changes induced by BTS in obese mice maintained on a high-fat diet. METHODS: Male ICR mice were fed a 60% kcal fat diet for 5 weeks starting at 4 weeks of age and then fed the same diet with administration of water (control) or aqueous BTS extract (1.0-2.0 g/kg) for 25 days. Body weight, wet weight of isolated white adipose tissue, and obesity-related serum parameters (glucose, lipids, leptin, adiponectin) were measured after treatment. The mRNA expression levels of leptin, adiponectin, and UCP1 in the adipose tissues were determined by quantitative real-time polymerase chain reaction after the first 5 days of treatment. RESULTS: Bofutsushosan (1.5-2.0 g/kg) significantly decreased total body weight and total wet weight of white adipose tissue isolated from subcutaneous (retroperitoneal) and visceral regions (epididymal, mesenteric, and perirenal). At 2.0 g/kg, BTS also decreased total fat mass, visceral fat mass, and ratio of fat mass to body weight as measured by computed tomography, and significantly decreased epididymal adipocyte size after 14 and 25 days' treatment. Twenty-five days' treatment lowered serum glucose, insulin, leptin, and triglycerides, and reduced homeostasis model assessment-insulin resistance. Alternatively, 2.0 g/kg BTS significantly increased mRNA levels of adiponectin, leptin, and UCP1 in interscapular brown adipose tissue but not epididymal white adipose tissue after 5 days' administration. CONCLUSION: In the early administration period, BTS increased mRNA expression levels of leptin, adiponectin, and UCP1 in brown adipose tissues. With longer administration, BTS improved insulin resistance, and subsequently reduced serum levels of leptin and triglyceride in parallel with decreased visceral white adipose tissue volume and adipocyte size.

Bone-targeting endogenous secretory receptor for advanced glycation end products rescues rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic inflammatory synovitis that leads to the destruction of bone and cartilage. The receptor for advanced glycation end products (RAGE) is a multiligand membrane-bound receptor for high-mobility group box-1 (HMGB1) associated with development of RA by inducing production of proinflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1 and IL-6. We developed a bone-targeting therapeutic agent by tagging acidic oligopeptide to a nonmembrane-bound form of RAGE (endogenous secretory RAGE [esRAGE]) functioning as a decoy receptor. We assessed its tissue distribution and therapeutic effectiveness in a murine model of collagen-induced arthritis (CIA). Acidic oligopeptide-tagged esRAGE (D6-esRAGE) was localized to mineralized region in bone, resulting in the prolonged retention of more than 1 wk. Weekly administration of D6-esRAGE with a dose of 1 mg/kg to RA model mice significantly ameliorated inflammatory arthritis, synovial hyperplasia, cartilage destruction and bone destruction, while untagged esRAGE showed little effectiveness. Moreover, D6-esRAGE reduced plasma levels of proinflammatory cytokines including TNF-α, IL-1 and IL-6, while esRAGE reduced the levels of IL-1 and IL-6 to a lesser extent, suggesting that production of IL-1 and IL-6 reduced along the blockade of HMGB1 receptor downstream signals by D6-esRAGE could be attributed to remission of CIA. These findings indicate that D6-esRAGE enhances drug delivery to bone, leading to rescue of clinical and pathological lesions in murine CIA.

Association between dopamine receptor 2 TaqIA polymorphisms and smoking behavior with an influence of ethnicity: a systematic review and meta-analysis update.

INTRODUCTION: The relationship between dopamine receptor D2 (DRD2) gene TaqIA polymorphisms and smoking behavior remains controversial. The aim of this review was to update a previous meta-analysis on the effect of DRD2 polymorphisms on smoking behavior by considering the influence of ethnicity. METHODS: This review presents analyses stratified by ancestry, as the samples included individuals of different ethnicities. Pooled effect sizes were calculated using fixed- and random-effects models to verify heterogeneity. We investigated the association for the proportion of men and Caucasians by regression analysis using the effect sizes calculated by each meta-analysis. RESULTS: Analysis of smoking cessation revealed a significant effect, which suggested that ethnic differences between Caucasians and Asians moderate the effect of DRD2 polymorphisms. Smoking initiation and rate exhibited no relationship with DRD2 polymorphisms; furthermore, we detected heterogeneity. Although the analysis of smoking persistence indicated significant effects, heterogeneity was detected. The finding of heterogeneity for smoking persistence and rate suggests the possibility of gene-gene interactions arising from ethnic differences between the samples. We found a significant inverse relationship between the proportion of men and effect sizes among Caucasians for smoking persistence and rate. Gender differences between Caucasian samples may moderate the effect of DRD2 polymorphisms on smoking persistence and rate. CONCLUSIONS: Our findings indicate that the ethnicity of the participants alters the effect of DRD2 polymorphisms on smoking behavior. The observed heterogeneity may be associated with participant gender as a moderating factor, and the association may be specific to Caucasians.

Tetrandrine prevents bone loss in sciatic-neurectomized mice and inhibits receptor activator of nuclear factor κB ligand-induced osteoclast differentiation.

One of the mediators of osteoclast differentiation is receptor activator of nuclear factor κB ligand (RANKL), which is produced by osteoblasts. Binding of RANKL to its receptor, RANK, activates several signaling pathways, including those involving mitogen-activated protein kinases (MAPKs), nuclear factor κB (NF-κB), nuclear factor of activated T cells c1 (NFATc1) and Ca(2+)-calcineurin. In the present study, we found that tetrandrine, a bisbenzylisoquinoline alkaloid extracted from the root of Stephania tetrandra S. MOORE, significantly ameliorated the decrease of bone mass in sciatic-neurectomized osteoporosis model mice. It appears that tetrandrine acts directly on osteoclast precursors, since tetrandrine inhibited osteoclast differentiation not only in mouse bone marrow cells, but also in monocultures of murine macrophage RAW 264.7 cells without osteoblasts. Tetrandrine suppressed RANKL-induced amplification of NFATc1, a master regulator of osteoclast differentiation. However, it did not affect other signaling molecules such as MAPKs and NF-κB. These results suggest that tetrandrine is a candidate for the treatment of bone-destructive diseases, or at least a suitable lead compound for further development.

Enhanced renal clearance of vancomycin in rats with carcinogen-induced osteosarcoma.

Recently, it has been reported that total clearance (CLtot) of vancomycin is significantly higher in patients with malignancies compared to those without malignancies. In the present study, to clarify the mechanism of this enhancement in malignancy, we adopted rat animal models, using chemical carcinogen-induced osteosarcoma, selected lung metastatic lesions (C-SLM), transplanted into thigh muscles. The CLtot and renal clearance (CLr) of vancomycin in the tumor-bearing rats were increased compared to the ones of the control rats without tumor. However, there was no difference in the glomerular filtration rate. The plasma concentrations of interleukin (IL)-1ß and IL-6, were elevated in the tumor-bearing rats. When renal proximal tubular epithelial cells (RPTEC) were exposed to IL-1ß, IL-6, and tumor necrosis factor (TNF)-α simultaneously, the excretory ratio increased significantly. These findings suggest that tubular excretion or re-absorption by cytokines might be associated with changes in the vancomycin CLtot enhancement in the tumor-bearing rats.

Surfactants influence the distribution of taxanes in peritoneal dissemination tumor-bearing rats.

The effects of surfactants on the disposition kinetics of docetaxel and paclitaxel were examined in tumor-bearing rats. Taxol and Taxotere were administered intraperitoneally to AH130 tumor-bearing rats. Plasma and ascitic AUCs (AUC(p,0-24h) and AUC(a,0-24h)) of paclitaxel were approximately 2- and 6-fold larger than those of docetaxel, respectively. The AUC(a,0-24h,ascite)/AUC(p,0-24h) ratio of paclitaxel was approximately 3-fold larger than that of docetaxel. The first-order peritoneal cavity-systemic circulation absorption rate constant of paclitaxel was 1/8 that of docetaxel. Docetaxel concentrations in free and solid tumors in the peritoneal cavity were higher than those of paclitaxel. The in vitro uptake of paclitaxel by AH130 cells was inhibited by Cremophor EL and Polysorbate-80. Docetaxel uptake was only slightly affected by these surfactants. These results indicated that Taxol scarcely released paclitaxel, while Taxotere easily released docetaxel, enabling its distribution to tumors disseminated in the peritoneal cavity.