Isoquercitrin isolated from newly bred Green ball apple peel in lipopolysaccharide-stimulated macrophage regulates NF-κB inflammatory pathways and cytokines.

Apple peel has several bioactive properties. The fruit is grown worldwide, and its ingredients are used medicinally. However, its anti-inflammatory activities are poorly characterized. In this study, isoquercitrin isolated from newly bred Green ball apple peel from Korea showed anti-inflammatory effects. To confirm its anti-inflammatory effects, isoquercitrin was treated with lipopolysaccharide, which induces proinflammatory factors in Raw 264.7 macrophage cells. Proinflammatory effects were measured by real-time polymerase chain reaction and Western blotting as well as enzyme-linked immunosorbent assay. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay to define the isoquercitrin concentration nontoxic to cells. Nitric oxide (NO) production, prostaglandin E2, inducible NO synthase, cyclooxygenase-2 (COX-2), and nuclear factor-κB p65 protein expression decreased in a concentration-dependent manner by isoquercitrin. mRNA expression of tumor necrosis factor-α, interleukin (IL)-1ß, IL-6, monocyte chemoattractant protein-1, and prostaglandin E synthase 2 (PTGES2) as proinflammatory factors significantly decreased. PTGES2, which was stimulated by COX-2 and involved in PGE2 expression, was inhibited. Therefore, this study rendered isoquercitrin isolated from the newly bred Green ball apple peel as a potential pharmacological alternative to treat inflammation-related diseases.

Correction to: Different apoptotic effects of saxifragifolin C in human breast cancer cells.

The authors regret that incorrect western band of Bax (MDA-MB-231) in Fig. 6a (right panel) was mistakenly uploaded in the original publication. The correct Fig. 6a is shown below. This correction does not change the conclusions of this manuscript. The authors would like to apologize for any inconvenience caused.

Allicin induces beige-like adipocytes via KLF15 signal cascade.

Under specific conditions, white adipose tissue (WAT) depots are readily converted to a brown-like state, which is associated with weight loss. However, whether diet-derived factors directly induce browning of white adipocytes has yet to be established. Thus, we investigated the effects of allicin, one of the major components of garlic, on brown-like adipocyte formation in inguinal WAT (iWAT), and prevention of obesity and related complications in animal models. Allicin significantly increased mRNA and/or protein expression of brown adipocyte markers including uncoupling protein 1 (UCP1) in differentiated mouse embryonic fibroblast cell line 3T3-L1 and differentiated iWAT stromal vascular cells (SVC), suggesting that allicin induced brown-like adipocyte formation in vitro. Concomitantly, allicin markedly enhanced the protein expression of KLF-15 and its interaction with UCP-1 promoter region. Such changes were absent in cells lacking KLF-15, suggesting the critical role of KLF15 in allicin action. Allicin also induced brown-like adipogenesis in vivo along with the appearance of multilocular adipocytes, increased UCP1 expression and increased lipid oxidation. In summary, our data suggest that allicin potentially prevents obesity and associated metabolic disorders such as type 2 diabetes mellitus by enhancing the expression of brown adipocyte-specific genes, including UCP-1, through KLF15 signal cascade.

Comparison of antioxidants potential, metabolites, and nutritional profiles of Korean fermented soybean (Cheonggukjang) with Bacillus subtilis KCTC 13241.

This study was carried out to determine the effect of different concentrations of Bacillus subtilis (0, 1, 3, 5, and 7%) on the antioxidant potential and biochemical constituents of traditional Korean fermented soybean, Cheonggukjang (CKJ). The antioxidant capacity was studied using the reducing power, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) assays and the total phenolic contents (TPC) were measured using the Folin-Ciocalteu method. CKJ prepared using 1% B. subtilis revealed the highest TPC (5.99 mg/g), total amino acids (7.43 mg/g), DPPH (94.24%), and ABTS (86.03%) radical-scavenging activity and had the highest value of palmitic acid (11.65%), stearic acid (2.87%), and linolenic acid (11.76%). Results showed that the calcium, iron, sodium, and zinc contents increased in the CKJ prepared using 7% B. subtilis from 1481.38 to 1667.32, 41.38 to 317.00, 48.01 to 310.07, and 32.82 to 37.18 mg/kg respectively. In conclusion, the present results indicate that the fermentation of soybean with B. subtilis (KCTC 13241) significantly augments the nutritional and antioxidant potential of CKJ and it can be recommended as a health-promoting food source.

Hymenobacter rufus sp. nov., a bacterium isolated from soil.

A bacterial strain, S1-2-2-6T, was isolated from a soil sample collected in Jeollabuk-do province, Republic of Korea. Cells of this strain were observed to be Gram-stain-negative, short and rod-shaped, and colonies were red to pink in colour. Analysis of 16S rRNA gene sequences identified this strain as representing a member of the genus Hymenobacter in the family Cytophagaceae, with the highest levels of sequence similarity being observed in relation to Hymenobacter terrae DG7AT (98.2 %), Hymenobacter rubidus DG7BT (97.9 %), Hymenobacter soli PB17T (97.7 %), and Hymenobacter daeguensis 16F3Y-2T (97.3 %). Growth of S1-2-2-6T was observed at 4-30 °C, pH 6-8 and in the presence of 0-0.5 % NaCl. The predominant respiratory quinone of this strain was menaquinone-7, the major fatty acids were C15 : 0 iso, C15 : 0 anteiso, and Summed feature 3 (C16 : 1ω7c/C16 : 1ω6c), and the major polar lipid was phosphatidylethanolamine. The genomic DNA G+C content of S1-2-2-6T was 60.7 mol%. DNA-DNA hybridization experiments with H. terrae, H. rubidus, H. soli and H. daeguensisresulted in relatedness values of 35.9 and 38.4 %, 34.2 and 30.4 %, 28.3 and 33.1 %, and 23.5 and 27.9 %, respectively. These DNA-DNA hybridization results, in addition to some differentiating phenotypic properties, clearly indicate that S1-2-2-6T is a representative of a novel species of the genus Hymenobacter, for which the name Hymenobacter rufus sp. nov. is proposed. The type strain is S1-2-2-6T (=KCTC 52736T=JCM 32196T).

Hymenobacter segetis sp. nov., isolated from soil.

A polyphasic taxonomic study was performed on a novel strain designated as S7-3-11T, which was isolated from soil of the Gyeongsangnam-do province in Republic of Korea. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain S7-3-11T belongs to the genus Hymenobacter and is most closely related to Hymenobacter ruber PB156T (97.9%), Hymenobacter daeguensis 16F3Y-2T (97.8%), Hymenobacter glaciei VUG-A130T (97.7%), Hymenobacter soli PB17T (97.5%), Hymenobacter terrae DG7AT (97.5%), and Hymenobacter antarcticus VUG-A42aaT (97.3%). However, DNA-DNA hybridization results showed less than 50% relatedness with respect to the type strains of the six most closely related species. The DNA G + C content of strain S7-3-11T was 60.2 mol%. MK-7 was identified as the predominant respiratory quinone, and summed feature 3 (C16:1 ω7c/C16:1 ω6c; 21.5%), C15:0 iso (16.8%), C15:0 anteiso (16.2%), and C15:1 iso G (10.8%) were the major fatty acids. Phosphatidylethanolamine, an unidentified aminolipid, and an unidentified aminophospholipid were detected as major polar lipids. On the basis of the polyphasic evidence presented, strain S7-3-11T is considered to represent a novel species of the genus Hymenobacter, for which the name Hymenobacter segetis sp. nov. is proposed. The type strain is S7-3-11T (= KCTC 52732T = JCM 32197T).

Hymenobacter pedocola sp. nov., a novel bacterium isolated from soil.

Strain S12-2-1T was isolated from a soil sample collected in the Gyeongsangnam-do province of the Republic of Korea. The isolate is a Gram-stain-negative, aerobic, short, rod-shaped bacterium, and its colonies are red to pink in colour. Analysis of the 16S rRNA gene identified strain S12-2-1T as a member of the genus Hymenobacter in the family Cytophagaceae, with high levels of 16S rRNA gene sequence similarity to Hymenobacter arizonensis OR362-8T (97.7 %), Hymenobacter sedentarius DG5BT (97.4 %) and Hymenobacter humi DG31AT (97.2 %). The isolate was positive for catalase and oxidase, but negative for acid production from glucose. The growth of strain S12-2-1T was supported at 4-30 °C, pH 7-10 and in the presence of 0-0.5 % NaCl. Strain S12-2-1T contained menaquinone-7 as the predominant respiratory quinone, sym-homospermidine as the major polyamine and iso-C15 : 0, anteiso-C15 : 0 and summed feature 3 (C16 : 1ω7c/C16 : 1ω6c) as the major fatty acids. Phosphatidylethanolamine was the major polar lipid. The genomic DNA G+C content was 58.7 mol%. Phenotypic and chemotaxonomic data supported the assignment of the isolate to the genus Hymenobacter. However, strain S12-2-1T exhibited a relatively low level of DNA-DNA relatedness with H. humi (31.7 %), H. arizonensis (24.4 %) and H. sedentarius (21.3 %). Based on its phenotypic and genotypic properties, along with its phylogenetic distinctiveness, strain S12-2-1T should be considered a novel species in the genus Hymenobacter, for which the name Hymenobacter pedocola sp. nov. is proposed. The type strain is S12-2-1T (=KCTC 52730T=JCM 32198T).

Hymenobacter terrigena sp. nov., isolated from soil.

A Gram-stain-negative, non-motile, non-spore-forming, rodshaped, aerobic bacterial strain, designated S1-2-2-5T, was isolated from the Jeollabuk-do province, Republic of Korea, and was characterized taxonomically using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain S1-2-2-5T belonged to the family Cytophagaceae in phylum Bacteroidetes, and was most closely related to Hymenobacter terrae DG7AT (98.2%), Hymenobacter rubidus DG7BT (98.0%), Hymenobacter soli PB17T (97.7%), Hymenobacter daeguensis 16F3Y-2T (97.2%) and Hymenobacter saemangeumensis GSR0100T (97.0%). The G + C content of the genomic DNA of strain S1-2-2-5T was 59.4 mol%. The detection of menaquinone MK-7 as the predominant respiratory quinone, a fatty acid profile with summed feature 3 (C16:1ω7c/C16:1ω6c; 32.0%), C15:0 iso (19.0%), and C15:0 anteiso (15.0%) as the major components, and a polar lipid profile with phosphatidylethanolamine as the major component supported the affiliation of strain S1-2-2-5T to the genus Hymenobacter. The DNA-DNA relatedness between strain S1-2-2-5T and H. terrae KCTC 32554T, H. rubidus KCTC 32553T, H. soli KCTC 12607T, H. daeguensis KCTC 52537T, and H. saemangeumensis KACC 16452T were 49.5, 48.2, 34.1, 28.1, and 31.8% respectively, clearly showing that the isolate is not related to them at the species level. Strain S1-2-2-5T could be clearly differentiated from its closest neighbors on the basis of its phenotypic, genotypic and chemotaxonomic features. Therefore, strain S1-2-2-5T represents a novel species of the genus Hymenobacter, for which the name Hymenobacter terrigena sp. nov. is proposed. The type strain is S1-2-2-5T (= KCTC 52737T = JCM 32195T).

Inhibitory effect of sinigrin on adipocyte differentiation in 3T3-L1 cells: Involvement of AMPK and MAPK pathways.

Adipocyte differentiation is a critical adaptive response to nutritional overload and affects the metabolic outcome of obesity. Sinigrin (2-propenyl glucosinolate) is a glucosinolate belong to the glucoside contained in broccoli, brussels sprouts, and black mustard seeds. We investigated the effects of sinigrin on adipogenesis in 3T3-L1 preadipocytes and its underlying mechanisms. Sinigrin remarkably inhibited the accumulation of lipid droplets and adipogenesis by downregulating the expression of CCAAT-enhancer-binding protein α (C/EBPα), peroxisome proliferator-activated receptor gamma (PPARγ), leptin and aP2. Sinigrin arrested cells in the G0/G1 phase of the cell cycle and increased the expression of p21 and p27. CDK2 expression was suppressed by sinigirn in MDI-induced adipocytes. Sinigrin increased the phosphorylation of adenosine monophosphate-activated protein kinase (AMPK), mitogen-activated protein kinase (MAPK) and acetyl-CoA carboxylase (ACC) in the early stage of adipocyte differentiation, suggesting that sinigrin has anti-adipogenic effects through AMPK, MAPK and ACC activation. Sinigrin also inhibited the production of pro-inflammatory cytokines including tumor necrosis factor -alpha (TNF-α) and interleukin (IL)-6, IL-1ß and IL-18. Taken together, these data suggest that sinigrin inhibits early-stage adipogenesis of 3T3-L1 adipocytes through the AMPK and MAPK signaling pathways.

Spirosoma lituiforme sp. nov., isolated from soil.

A Gram-staining-negative, non-motile, curved rod-shaped, aerobic bacterium, designated S1-2-4T, was isolated from soil in Jeollabuk-do province, Republic of Korea, and was characterized taxonomically using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain S1-2-4T was a member of the family Cytophagaceae and most closely related to 'Spirosoma radiotolerans' DG5A (97.2%), Spirosoma fluviale MSd3T (96.4%), and Spirosoma linguale DSM 74T (96.3%). The genomic DNA G + C content of strain S1-2-4T was 49.7 mol%. The major fatty acids were summed feature 3 (C16:1 ω7c/C16:1 ω6c), C16:1 ω5c, and C16:0, and the major polar lipid was phosphatidylethanolamine. MK-7 was the predominant respiratory quinone. Phenotypic and chemotaxonomic data supported the affiliation of strain S1-2-4T with the genus Spirosoma. DNA-DNA hybridization between strain S1-2-4T and 'Spirosoma radiotolerans' showed relatively low DNA-DNA relatedness (31%). Strain S1-2-4T could be distinguished from its closest phylogenetic neighbors based on its phenotypic, genotypic, and chemotaxonomic features. Therefore, strain S1-2-4T represents a novel member of the genus Spirosoma, for which the name Spirosoma lituiforme sp. nov. is proposed. The type strain is S1-2-4T (= KCTC 52724T = JCM 32128T).

Flaviaesturariibacter terrae sp. nov., isolated from mountain soil.

A Gram-stain-negative, aerobic, rod-shaped, non-motile and pale yellow-pigmented bacterial strain, designated as HY03T, was isolated from mountain soil. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain HY03T belonged to the family Chitinophagaceae in the phylum Bacteroidetes and was most closely related to Flaviaesturariibacter amylovorans GCR0105T at a similarity of 95.4 %. The genomic DNA G+C content of strain HY03T was 43.2 mol%. The major fatty acids of the isolate were iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH. The polar lipid profile of strain HY03T consisted of the major compound phosphatidylethanolamine and moderate amounts of an unknown aminophospholipid, unknown phospholipids and unknown lipids. The predominant respiratory quinone was menaquinone 7 (MK-7). Phylogenetic, genotypic, phenotypic and chemotaxonomic characteristics indicated that strain HY03T represents a novel species within the genus Flaviaesturariibacter, for which the name Flaviaesturariibacter terrae sp. nov. is proposed. The type strain is HY03T (=KCTC 52511T=JCM 31723T).

Sinigrin attenuates the progression of atherosclerosis in ApoE-/- mice fed a high-cholesterol diet potentially by inhibiting VCAM-1 expression.

Atherosclerosis is a complex inflammatory disease associated with elevated levels of atherogenic molecules for leukocyte recruitment. Sinigrin (2-propenylglucosinolate) is found mainly in broccoli, brussels sprouts, and black mustard seeds. Recently, sinigrin has received attention for its role in disease prevention and health promotion. In this study, we examined the effect of sinigrin on development of atherosclerosis in ApoE-/- mice and the expression of adhesion molecules in vascular smooth muscle cells (VSMCs). The serum concentrations of lactate dehydrogenase (LDH), triglyceride (TG), total cholesterol (TC), low density lipoprotein (LDL), calcium (Ca2+), and pro-inflammatory cytokines were reduced by sinigrin treatment in ApoE-/- mice. In addition, oral administration of sinigrin attenuated the mRNA expression of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), C-C motif chemokine ligand 2 (CCL2), and CCL5 on aorta tissues and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR), liver X receptor (LXR), sterol regulatory element-binding protein-2 (SREBP-2), and low density lipoprotein receptor (LDLR) on liver tissues in ApoE-/- mice. To provide a potential mechanism underlying the action of sinigrin, we evaluated the in vitro effect of sinigrin on the expression of the VCAM-1 in TNF-α-induced VSMCs. The increased expression of VCAM-1 by TNF-α stimulation was significantly suppressed by the treatment of sinigrin (1-100 µg/ml) and sinigrin inhibited the nuclear translocation of NF-κB and the phosphorylation of p38 MAPK and JNK pathways, suggesting that sinigrin decreases the TNF-α-stimulated VCAM-1 expression through the suppression of NF-κB and MAP kinases signaling pathways. Overall, sinigrin has the potential to be used in reducing the risks of atherosclerosis.

Pneumolysin induces cellular senescence by increasing ROS production and activation of MAPK/NF-κB signal pathway in glial cells.

Senescence is an irreversible proliferation arrest that is induced by various stress stimuli including genotoxin. Pneumolysin (PLY) is a pathogenicity factor unique to Streptococcus pneumoniae that is important in pneumococcal-induced diseases such as otitis media, meningitis and pneumonia. However, the cell fate response to the toxin is mechanistically unclear. We investigated the effect of PLY on cellular senescence in BV-2 microglial cells. Exposure to PLY resulted in changes in the expression of phospho-p53, p21, p16, pRb and CDK2 and increased the number of senescence associated ß-gal positive cells. PLY-treatment also increased PAI-1 expression and cell proliferation arrest in concentration- and time-dependent manners. PLY induced NF-κB activation and phosphorylation of SIRT-1, ERK1/2, JNK, and p38 MAPK. In addition, PLY increased the production of reactive oxygen species. Overall, the results suggest that PLY regulates microglial cellular senescence by enhancing production of reactive oxygen species, activation of MAPK and NF-κB, and phosphorylation of SIRT-1.

Spirosoma knui sp. nov., a radiation-resistant bacterium isolated from the Han River.

A Gram-stain-negative, non-motile, non-spore-forming, rod-shaped, aerobic bacterium, designated 15J8-12T, was isolated from a water sample after exposure to 3 kGy of gamma radiation. The strain showed resistance to gamma radiation with a dose required to reduce the bacterial population 10 fold (D10) value of 4.7 kGy. The results of comparative 16S rRNA gene sequence analysis indicated that strain 15J8-12T represented a member of the family Cytophagaceae, phylum Bacteroidetes, and was most closely related to 'Spirosomafluminis' 15J17 (97.92 %) and Spirosoma arcticum R2-35T (92.22 %). The G+C content of the genomic DNA of 15J8-12T was 51.3 mol%. The detection of menaquinone MK-7 as the predominant respiratory quinone, a fatty acid profile with summed feature 3 (C16 : 1ω7c/C16 : 1ω6c; 40.5 %), C16 : 1ω5c (35.3 %), C15 : 0 iso (6.9 %) and C16 : 0 (6.8 %) as the major components and phosphatidylethanolamine as the major polar lipid also supported the affiliation of 15J8-12T with the genus Spirosoma. The DNA-DNA relatedness between 15J8-12T and 'Spirosoma fluminis' 15J17 was 27.8 %. On the basis of its phenotypic and genotypic properties, together with its phylogenetic distinctiveness, 15J8-12T should be considered to be a representative of a novel species of the genus Spirosoma, for which the name Spirosoma knui sp. nov. is proposed. The type strain is 15J8-12T (=KCTC 52510T=JCM 31407T).

Inhibitory Effect of Methyl 2-(4'-Methoxy-4'-oxobutanamide) Benzoate from Jerusalem Artichoke (Helianthus tuberosus) on the Inflammatory Paracrine Loop between Macrophages and Adipocytes.

The interaction between macrophages and adipocytes is known to aggravate inflammation of the adipose tissue, leading to decreased insulin sensitivity. Hence, attenuation of the inflammatory paracrine loop between macrophages and adipocytes is deemed essential to ameliorate insulin resistance and diabetes mellitus type 2. Methyl 2-(4'-methoxy-4'-oxobutanamide) benzoate (compound 1), a newly isolated compound from Jerusalem srtichoke (JA), has not been biologically characterized yet. Here, we investigated whether JA-derived compound 1 attenuates the inflammatory cycle between RAW 264.7 macrophages and 3T3-L1 adipocytes. Compound 1 suppressed the inflammatory response of RAW 264.7 cells to lipopolysaccharide through decreased secretion of IL-1ß, IL-6, and TNF-α. Moreover, the mRNA expression of TNF-α, IL-6, IL-1ß, MCP-1, and Rantes and MAPK pathway activation in 3T3-L1 adipocytes, incubated in macrophage-conditioned media, were inhibited. These findings suggest an anti-inflammatory effect of a newly extracted compound against adipose tissue inflammation and insulin resistance.

Different apoptotic effects of saxifragifolin C in human breast cancer cells.

Breast cancer is currently the most common form of cancer affecting women. Recent studies have reported that triterpenoid saponins isolated from Androsace umbellata exhibit anti-proliferative effects in several types of cancer cells. However, the cytotoxic effect of saxifragifolin C (Saxi C) on breast cancer cells remains unclear. The purpose of this study is to evaluate the in vitro anti-tumor activity of Saxi C in human breast cancer cells. Our data indicated that MDA-MB-231 cells were more sensitive than MCF-7 cells to Saxi C treatment. In addition, Saxi C inhibited cell survival through the induction of reactive oxygen species and the caspase-dependent pathway in the MDA-MB-231 cells, whereas MCF-7 cells treated with Saxi C underwent the apoptotic cell death in a caspase-independent manner. Although Saxi C treatment resulted in the induction of activation of MAPKs in both types of human breast cancer cells, p38 MAPK and JNK, but not ERK1/2, appeared to be involved in Saxi C-induced apoptosis. Moreover, ERα-overexpressing MDA-MB-231 cells remained alive, whereas the survival of shERα-transfected MCF-7 cells decreased. Taken together, Saxi C induced apoptosis in MCF-7 cells and MDA-MB-231 cells via different regulatory mechanisms, and ERα status might be essential for regulating Saxi C-induced apoptosis in breast cancer cells. Thus, Saxi C is a potential chemotherapeutic agent in breast cancer.

Ramalin inhibits VCAM-1 expression and adhesion of monocyte to vascular smooth muscle cells through MAPK and PADI4-dependent NF-kB and AP-1 pathways.

Cell adhesion molecules play a critical role in inflammatory processes and atherosclerosis. In this study, we investigated the effect of ramalin, a chemical compound from the Antarctic lichen Ramalina terebrata, on vascular cell adhesion molecule-1 (VCAM-1) expression induced by TNF-α in vascular smooth muscular cells (VSMCs). Pretreatment of VSMCs with ramalin (0.1-10 µg/mL) concentration-dependently inhibited TNF-α-induced VCAM-1 expression. Additionally, ramalin inhibited THP-1 (human acute monocytic leukemia cell line) cell adhesion to TNF-α-stimulated VSMCs. Ramalin suppressed TNF-α-induced production of reactive oxygen species (ROS), PADI4 expression, and phosphorylation of p38, ERK, and JNK. Moreover, ramalin inhibited TNF-α-induced translocation of NF-κB and AP-1. Inhibition of PADI4 expression by small interfering RNA or the PADI4-specific inhibitor markedly attenuated TNF-α-induced activation of NF-κB and AP-1 and VCAM-1 expression in VSMCs. Our study provides insight into the mechanisms underlying ramalin activity and suggests that ramalin may be a potential therapeutic agent to modulate inflammation within atherosclerosis.

Kobophenol A enhances proliferation of human osteoblast-like cells with activation of the p38 pathway.

Bone cell proliferation, bone formation, and bone resorption are the main factors involved in the homeostasis of the bone mass. Osteoblast death is a problem experienced by postmenopause women. Herbal medicines have attracted considerable attention for use as a drug or a drug substitute in the treatment of bone-related diseases, such as osteoporosis. This study investigated the effects of kobophenol A on the proliferation in human osteoblast cells. Kobophenol A stimulated the proliferation of osteoblast cells by the increases in DNA synthesis and the enhancement of cell cycle progression. Kobophenol A stimulation induced the expression of the cyclin B1 and cyclin-dependent kinase 1 (CDK1). Treatment of osteoblast cells with p38 MAPK inhibitor SB203580 significantly inhibited kobophenol A-enhanced proliferation. In addition, kobophenol A induced phosphorylation of p38 MAPK. Treatment of osteoblast cells with kobophenol A resulted in improvement of ROS scavenging activity. Moreover, kobophenol A treatment up-regulated the Bcl-2 level, but down-regulated the level of Bax expression. We also demonstrate that kobophenol A increased alkaline phosphatase (ALP) activity after 2 days. Taken together, the results of this study reveal that kobophenol A has proliferative effects and enhances ALP activity in osteoblast cells and these findings provide insights into the development of a therapeutic approach of kobophenol A in the prevention of osteoporosis and other bone disorders.

Ethanol induces cell cycle arrest and triggers apoptosis via Sp1-dependent p75NTR expression in human neuroblastoma cells.

Ethanol exposure has deleterious effects on the central nervous system. Although several mechanisms for ethanol-induced damage have been suggested, the precise mechanism underlying ethanol-induced neuronal cell death remains unclear. Recent studies indicate that the p75 neurotrophin receptor (p75NTR) has a critical role in the regulation of neuronal survival. This study was designed to examine the role of p75NTR in ethanol-induced apoptotic signaling in neuroblastoma cells. Ethanol caused highly increased level of p75NTR expression. The use of small interfering RNA to inhibit p75NTR expression markedly attenuated ethanol-induced cell cycle arrest and apoptosis. DNA binding activity of Sp1 was increased by ethanol, whereas inhibition of Sp1 activity by mithramycin, a Sp1 inhibitor, or short hairpin RNA suppressed ethanol-induced p75NTR expression. In addition, inhibitors of casein kinase 2 (CK2) and extracellular signal-regulated kinase (ERK) augmented ethanol-induced p75NTR expression. Our results also demonstrate that inhibition of ERK and CK2 caused a further increase in the activation of the p75NTR proximal promoter induced by ethanol. This increased activation was partially suppressed by the deletion of the Sp1 binding sites. These results suggest that Sp1-mediated p75NTR expression is regulated at least in part by ERK and CK2 pathways. The present study also showed that treatment with ethanol resulted in significant increases in the expression of p21, but not the levels of p53 and p53 target genes such as Bax, Puma, and Bcl-2. Furthermore, the inhibition of p75NTR expression or Sp1 activity suppressed ethanol-induced p21 expression, cell cycle arrest, and apoptosis. These data suggest that ethanol increases p75NTR expression, and CK2 and ERK signaling inversely regulate Sp1-mediated p75NTR expression in ethanol-treated neuroblastoma cells. Thus, our study provides more insight into the mechanisms underlying ethanol actions.