Harnessing a paper-folding mechanism for reconfigurable DNA origami.

The paper-folding mechanism has been widely adopted in building of reconfigurable macroscale systems because of its unique capabilities and advantages in programming variable shapes and stiffness into a structure1-5. However, it has barely been exploited in the construction of molecular-level systems owing to the lack of a suitable design principle, even though various dynamic structures based on DNA self-assembly6-9 have been developed10-23. Here we propose a method to harness the paper-folding mechanism to create reconfigurable DNA origami structures. The main idea is to build a reference, planar wireframe structure24 whose edges follow a crease pattern in paper folding so that it can be folded into various target shapes. We realized several paper-like folding and unfolding patterns using DNA strand displacement25 with high yield. Orthogonal folding, repeatable folding and unfolding, folding-based microRNA detection and fluorescence signal control were demonstrated. Stimuli-responsive folding and unfolding triggered by pH or light-source change were also possible. Moreover, by employing hierarchical assembly26 we could expand the design space and complexity of the paper-folding mechanism in a highly programmable manner. Because of its high programmability and scalability, we expect that the proposed paper-folding-based reconfiguration method will advance the development of complex molecular systems.

Anti-Proliferative Effects of Standardized Cornus officinalis on Benign Prostatic Epithelial Cells via the PCNA/E2F1-Dependent Cell Cycle Pathway.

Cornus officinalis, widely used in traditional Chinese medicine, exhibits pharmacological effects against erectile dysfunction and pollakisuria, which are pathological symptoms of benign prostatic hyperplasia (BPH). Although traditional usage and a study on BPH have been reported, to our knowledge, no study has investigated the exact molecular mechanism(s) underlying the anti-proliferative effects of standardized C. officinalis on prostatic cells. We standardized C. officinalis 30% ethanol extract (COFE) and demonstrated the therapeutic effects of COFE on human BPH epithelial cells and testosterone-induced BPH in rats. In vitro studies using BPH-1 cells demonstrated an upregulation of BPH-related and E2F Transcription Factor 1(E2F1)-dependent cell cycle markers, whereas treatment with COFE clearly inhibited the proliferation of BPH epithelial cells and reduced the overexpression of G1 and S checkpoint genes. Additionally, COFE administration alleviated the androgen-dependent prostatic enlargement in a testosterone-induced BPH animal model. COFE exerted these anti-BPH effects by the inhibition of anti-apoptotic markers, suppression of PCNA expression, and regulation of E2F1/pRB-dependent cell cycle markers in rats with BPH. These results suggest that COFE exerts anti-proliferative effect by regulating PCNA/E2F1-dependent cell cycle signaling pathway both in vivo and in vitro. These findings reveal the therapeutic potential of COFE, which could be used as a substitute for BPH treatment.

HBX-6, Standardized Cornus officinalis and Psoralea corylifolia L. Extracts, Suppresses Benign Prostate Hyperplasia by Attenuating E2F1 Activation.

BACKGROUND: The aim of this study was to simplify and identify the contents of the herbal formula, HBX-5. This study was carried out to evaluate the therapeutic effects of HBX-6 in a mouse model of benign prostatic hyperplasia (BPH). Based on in vitro, we selected a candidate, reconstituted an experimental agent and investigated the effects on testosterone-induced BPH rats. Cell viability was determined by MTT assay in RWPE-1 and WPMY-1 cells. The expression of androgen receptor (AR) was measured in dihydrotestosterone-stimulated RWPE-1 and WPMY-1 cells. BPH was induced in mice by a subcutaneous injection of testosterone propionate for four weeks. Animals were divided into six groups: Group 1, control mice; Group 2, mice with BPH; Group 3, mice with BPH treated with finasteride; Group 4, mice with BPH treated with 200 mg/kg HBX-5; Group 5, mice with BPH treated with 100 mg/kg HBX-6; and Group 6, mice with BPH treated with 200 mg/kg HBX-6. Changes in prostate weight were measured after treatments, and the thickness of the epithelium was evaluated. The expression levels of proteins associated with prostatic cell proliferation and cell cycle-related proteins were determined. Based on previous reports and in vitro results, we selected Cornus officinalis and Psoralea corylifolia among HBX-5 components and reconstituted the experimental agent, and named it HBX-6. The result represented a new herbal formula, HBX-6 that suppressed the pathological alterations in BPH and showed a marked reduction in proliferation-related protein expression compared to mice with BPH. Our results indicate that HBX-6 has a better therapeutic effect in the BPH murine model than those of HBX-5 and finasteride, suggesting the role of HBX-6 as a new BPH remedial agent.

Anti-Proliferative Effects of HBX-5 on Progression of Benign Prostatic Hyperplasia.

Benign prostatic hyperplasia (BPH), an age-dependent disorder with a prevalence percentage of 60% in the 60s, has been found to involve an androgenic hormone imbalance that causes confusion between cell apoptosis and proliferation. Because general medications for BPH treatment have undesirable side effects, the development of effective alternative medicines has been considered. HBX-5 is a newly developed formula with the aim of improving BPH, and is composed of nine medicinal herbs. BPH was induced in the rats by intramuscular injection of testosterone propionate after castration. Rats were divided into six groups, and the efficacy of HBX-5 on testosterone-induced BPH in rats was estimated. In addition, RWPE-1 and WPMY-1 cells were used to demonstrate the effect of HBX-5 on BPH in vitro model. Compared with the control group, HBX-5 administration group suppressed BPH manifestations, such as excessive development of prostate, and increase of serum dihydrotestosterone and 5α-reductase concentrations. Furthermore, immunohistochemistry analysis revealed that HBX-5 significantly decreased the expression of androgen receptor (AR) and proliferating cell nuclear antigen (PCNA). In addition, results of RWPE-1 and WPMY-1 cells showed that HBX-5 inhibited the over-expression of AR and PSA in DHT-induced prostate hyperplastic microenvironments.

Assessment of dermal safety of Scutellaria baicalensis aqueous extract topical application on skin hypersensitivity.

Scutellaria baicalensis has been used as a traditional herbal medicine for bronchitis, hepatitis, and allergic diseases. The root of Scutellaria baicalensis contains active flavonoid components, including baicalin, baicalein, wogonoside, and wogonin, which have pharmaceutical properties. In the present study, the antiallergic properties of a standardized aqueous extract of S. baicalensis were evaluated, and the skin toxicity of its dermal application was also determined. The in vivo and in vitro assays were performed by using the ß-hexosaminidase assay in rat basophilic leukemia cells (RBL-2H3) and cutaneous skin reaction in BALB/c mice, respectively. In addition, the acute dermal irritation/corrosion test was carried out in New Zealand white rabbits, and the skin sensitization test was conducted by Buhler's method in Hartley guinea pigs to estimate the safety of the standardized aqueous extract of S. baicalensis for topical application. ß-Hexosaminidase release in RBL-2H3 was markedly decreased following treatment with the standardized aqueous extract of S. baicalensis. It also ameliorated antigen-induced ear swelling compared with the control group in BALB/c mice. In the toxicological studies, it did not induce any dermal irritation/corrosion in rabbits or skin sensitization in guinea pigs. Although still limited, these results concerning the toxicological effects of S. baicalensis could be an initial step toward the topical application of S. baicalensis extracts on hypersensitive skin.

Protective effect of the aqueous extract from the root of Platycodon grandiflorum on cholestasis-induced hepatic injury in mice.

CONTEXT: The root of Platycodon grandiflorum (Jacq.) A. DC. (Campanulaceae) has been widely studied for its hepatoprotective effects against various hepatotoxicants. OBJECTIVE: The present study evaluated the protective effect of the standardized aqueous extract of P. grandiflorum (BC703) on cholestasis-induced hepatic injury in mice. MATERIALS AND METHODS: BC703 is a standardized aqueous extract of P. grandiflorum in reference to platycodin D (at least 0.8%). The mice were allocated into five groups as follows: Sham-operated, bile duct ligation (BDL) alone, and BDL with BC703 (1, 5, and 10 mg/kg BW) treated group. BC703 was given for 3 consecutive days before BDL operation. The animals were sacrificed by CO2 anesthesia post-24 h of BDL operations. RESULTS AND DISCUSSION: Serum alanine aminotransferase and serum aspartate aminotransferase increased to 395.2 ± 90.0 and 266.0 ± 45.6 Unit/L in the BDL alone group and decreased with BC703 in a dose-dependent manner. Especially the 10 mg/kg of BC703-treated mice showed a 77% decrease of serum alanine aminotransferase and 56% of aspartate aminotransferase as compared with BDL alone. Decreased antioxidant enzyme levels in BDL alone group were elevated in BC703-treated groups ranging from 7 to 29% for glutathione and from 13 to 25% for superoxide dismutase. BC703 treatment also attenuated malondialdehyde (from 3 to 32%) and nitric oxide levels (from 32 to 50%) as compared with BDL alone. Histopathological studies further confirmed the hepatoprotective effect of BC703 in BDL-induced cholestesis. CONCLUSION: BC703 could attenuate liver injury by BDL in mice, and test results indicate that BC703 might be useful in cholestatic liver injury.

Characterizing and Harnessing the Mechanical Properties of Short Single-Stranded DNA in Structured Assemblies.

Precise engineering of DNA structures is of growing interest to solve challenging problems in biomolecular applications and beyond. The introduction of single-stranded DNA (ssDNA) into the DNA structure can play a pivotal role in providing high controllability of critical structural features. Herein, we present a computational model of ssDNA with structural applications to harness its characteristics. The nonlinear properties of nucleotide gaps are systematically characterized to construct a structural model of the ssDNA across length scales with the incorporation of a finite element framework. The proposed method shows the programmability of structural bending, twisting, and persistence length by implementing the ssDNA in various DNA structures with experimental validation. Our results have significant implications for DNA nanotechnology in expanding the boundary of design and analysis of structural shape and stiffness.

Pharmacokinetics of toltrazuril and its metabolites, toltrazuril sulfoxide and toltrazuril sulfone, after a single oral administration to pigs.

Toltrazuril (TZR) is a triazine-based antiprotozoal agent. Following a single oral administration of TZR at 10 and 20 mg/kg to male pigs, the mean TZR concentration in plasma peaked at 4.24 and 8.18 microg/ml at 15.0 and 12.0 hr post-dose, respectively. TZR absorbed was rapidly converted to the short-lived intermediary metabolite toltrazuril sulfoxide (TZR-SO), and then metabolized to the reactive toltrazuril sulfone (TZR-SO2). TZR-SO2 was actually more slowly eliminated, with average half-lives of 231 and 245 hr, compared with TZR (48.7 and 68.9 hr) or TZR-SO (51.9 and 53.2 hr) in the 10 and 20 mg/kg groups, respectively. This study demonstrates that TZR metabolizes to TZR-SO2 having a long-terminal half-life, enabling the persistent clinical efficacy in the treatment of I. suis infection. In contrast, special consideration should be given to the residual of TZR-SO2.

Anti-inflammatory effects of talosin A via inhibition of NF-kappaB activation in lipopolysaccharide-stimulated RAW264.7 cells.

Aim of work To determine whether talosin A inhibits production of pro-inflammatory cytokines and nitric oxide (NO) in lipopolysaccharide (1 mug/ml)-stimulated RAW 264.7 macrophages. Talosin A (10 and 50 mug/ml) significantly reduced LPS-induced overproduction of tumor necrosis factor-alpha, interleukin IL-1beta, -6 and NO in a dose-dependent manner (P < 0.01). Talosin A had a direct NO-scavenging activity in the cell-free system. In RT-PCR analysis, gene expressions were inhibited at a transcriptional level. Moreover, the activation of nuclear factor-kappa B (NF-kappaB) was significantly suppressed by talosin A in LPS-stimulated macrophage cells (P < 0.05). Therefore, we confirmed anti-inflammatory activity of talosin A was via suppression of pro-inflammatory cytokines, NO production and NF-kappaB activation, suggesting a therapeutic candidate for inflammatory disorders.

Pharmacokinetics of florfenicol and its metabolite, florfenicol amine, in dogs.

A study on the bioavailability and pharmacokinetics of florfenicol was conducted in six healthy dogs following a single intravenous (i.v.) or oral (p.o.) dose of 20 mg kg(-1) body weight (b.w.). Florfenicol concentrations in serum were determined by a high-performance liquid chromatography/mass spectrometry. Plasma concentration-time data after p.o. or i.v. administration were analyzed by a non-compartmental analysis. Following i.v. injection, the total body clearance was 1.03 (0.49) L kg(-1)h(-1) and the volume of distribution at steady-state was 1.45 (0.82) L kg(-1). Florfenicol was rapidly distributed and eliminated following i.v. injection with 1.11 (0.94)h of the elimination half-life. After oral administration, the calculated mean C(max) values (6.18 microg ml(-1)) were reached at 0.94 h in dogs. The elimination half-life of florfenicol was 1.24 (0.64) h and the absolute bioavailability (F) was achieved 95.43 (11.60)% after oral administration of florfenicol. Florfenicol amine, the major metabolite of florfenicol, was detected in all dogs after i.v. and p.o. administrations.

Lipopolysaccharide-binding and neutralizing activities of surfactin C in experimental models of septic shock.

To evaluate the anti-endotoxin activity of surfactin C, we studied its lipopolysaccharide-binding activity in vitro and therapeutic efficacy in experimental models of gram-negative septic shock. The ability of surfactin C to bind LPS from Escherichia coli O111:B4 was determined using a limulus chromogenic assay. Male ICR mice and Sprague-Dawley rats were given intraperitoneal administration of 1x10(9) colony forming units of E. coli ATCC 25922. After bacterial challenge, all animals were randomized to receive intraperitoneally saline, polymyxin B or surfactin C. Surfactin C not only completely bound to the LPS (its median effective concentration being 13.75 microM) but also improved the survival and reduced of the number of inoculated bacteria in the mouse model of septic shock. Surfactin C reduced the plasma endotoxin, tumor necrosis factor-alpha and nitric oxide levels in response to septic shock in rats.

Topical application of Scutellaria baicalensis suppresses 2,4-dinitrochlorobenzene-induced contact dermatitis.

Allergic contact dermatitis (ACD) is a prototypic T-cell-mediated cutaneous inflammatory response. In the present study we describe the anti-allergic effect of topically applied Scutellaria bacalensis aqueous extract (WSBE) in suppressing 2,4-dinitrochlorobenzene (DNCB)-induced ACD in BALB/c mice. Topically applied WSBE attenuated the epidermal thickness and mast cell infiltration into the skin in DNCB-induced contact dermatitis. Furthermore, WSBE suppressed DNCB-induced production of serum IgE as well as IL-4, IFN-γ, and TNF-α in the skin. Topical application of WSBE also ameliorated the significant decrease in dermal glutathione and superoxide dismutase levels. Moreover, present results demonstrated that the baicalin, bioactive compound of WSBE, was able to penetrate into the skin following topical application, which was confirmed by the HPLC analysis using rat model. Taken together, topical application of WSBE exerts beneficial effects in contact dermatitis model, suggesting that WSBE might be a candidate for the treatment of contact dermatitis.

The anti-thrombotic activity of surfactins.

Platelet aggregation was inhibited and the density of platelet-rich plasma (PRP) clots was decreased by the preincubation of PRP with surfactins, an acidic lipopeptide of Bacillus subtilis complex BC1212 isolated from soybean paste, in dose-dependent manner. Our findings suggest that surfactins are able to prevent a platelet aggregation leading to an inhibition of additional fibrin clot formation, and to enhance fibrinolysis with facilitated diffusion of fibrinolytic agents.

Effect of orange oil on the oral absorption of enrofloxacin in rats.

This study was conducted to evaluate the oral absorption of enrofloxacin (ENFX) in rats when administered with orange oil or its main component, limonene. Compared with the group administered ENFX alone, the ENFX + limonene group did not show any significant difference in the absorption of ENFX, whereas the extent and rate of absorption of ENFX were significantly decreased in the ENFX + orange oil group (C(max), -43%; T(max), 129%). In addition, t(1/2λz) and MRT of ENFX were prolonged by the concomitant administration of orange oil. The AUCs of ENFX were not affected in the ENFX + orange oil group. These results suggest that decreased oral absorption could reduce the efficacy of ENFX therapy in animals.

Single-dose oral toxicity of fermented scutellariae radix extract in rats and dogs.

The aim of this study was to investigate the acute oral toxicity of fermented Scutellariae Radix (JKTMHGu- 100) in rats and dogs. JKTM-HGu-100 was orally administered at a dose of 2,000 mg/kg in Sprague-Dawley rats. An escalating single-dose oral toxicity test in beagle dogs was performed at doses of 500, 1000, and 2000 mg/kg with 4-day intervals. Clinical signs, changes in body weight, mortality, and necropsy findings were examined for 2 weeks following oral administration. No toxicological changes related to the test substance nor mortality was observed after administration of a single oral dose of JKTM-HGu-100 in rats or dogs. Therefore, the approximate lethal dose (LD) for oral administration of JKTMHGu-100 in rats was considered to be over 2,000 mg/kg, and the maximum tolerance doses (MTDs) in rats and dogs were also estimated to be over 2,000 mg/kg. These results indicate that JKTM-HGu-100 shows no toxicity in rodents or non-rodents at doses of 2,000 mg/kg or less.

Hepatoprotective and anti-hepatitis C viral activity of Platycodon grandiflorum extract on carbon tetrachloride-induced acute hepatic injury in mice.

The present study aims to evaluate the anti-HCV activity of hotwater extract from Platycodon grandiflorum (BC703) with HCV genotype 1b subgenomic replicon system and investigate its hepatoprotective activity on carbon tetrachloride (CCl(4))-induced acute liver damage in mice. BC703 produced significant hepatoprotective effects against CCl(4)-induced acute hepatic injury by decreasing the activities of serum enzymes, nitric oxide and lipid peroxidation. Histopathological studies further substantiated the protective effect of BC703. Furthermore, BC703 inhibited the HCV RNA replication with an EC(50) value and selective index (CC(50)/EC(50)) of 2.82 µg/mL and above 35.46, respectively. However, digested BC703 using a simulated gastric juice showed poor protective effect against CCl(4)-induced hepatotoxicity in mice and decreased anti-HCV activity as compared to the intact BC703. Although further studies are necessary, BC703 may be a beneficial agent for the management of acute hepatic injury and chronic HCV infection.

In vivo metabolism of Talosin A, new isoflavonol glycoside from Kitasatospora kifunensis, in rats.

The isoflavonol glycoside Talosin A, genistein (GT)-7-α-L-6-deoxy talopyranose (GT-Tal), was first isolated from the culture broth of Kitasatospora kifunensis MJM341. The aim of the present study was to evaluate the oral absorption and metabolism of the newly isolated isoflavonol glycoside, GT-Tal compared to genistin (GT-7-O-ß-D-glucopyranoside; GT-Glu). Free GT-Glu and GT-Tal could not be detected prior to enzymatic hydrolysis of the corresponding conjugates in rat plasma. Following oral administration of GT-Tal (15 min), GT-Tal was rapidly absorbed through the gastrointestinal tract and metabolized into GT-Tal conjugates with a mean C(max) of 2.74 µg/mL. GT-Tal was further metabolized to its aglycone, free GT and conjugated GT. After oral administration, GT-Glu was absorbed after being converted to its aglycone and then further metabolized into its conjugate metabolites (free GT with a mean C(max) of 0.24 mg/mL at 1.25 h; conjugated GT with a mean C(max) of 1.31 mg/mL at 2.00 h). Significant differences in absorption and metabolism of GT-Tal and GT-Glu were observed. GT-Tal was metabolized into its corresponding conjugates or underwent deglycosylation to form GT, whereas GT-Glu was metabolized into its aglycone, GT.

Protective Effects of Platycodon grandiflorum Aqueous Extract on Thioacetamide-induced Fulminant Hepatic Failure in Mice.

The aim of the present study was to evaluate the protective activity of aqueous extract from Platycodon grandiflorum (BC703) on thioacetamide (TA)-induced hepatotoxicity in mice. We found that BC703 significantly decreased mortality and the change in serum transaminase following TA administration. The group treated with BC703 at doses of 1, 5, and 10 mg/kg produced significant hepatoprotective effects against TA-induced liver damage by decreasing the activities of serum enzymes, nitric oxide and lipid peroxidation in dose-dependent manners. Histopathological studies further substantiated the protective effect of BC703. These results show the hepatoprotective activity of aqueous extract from Platycodon grandiflorum on thioacetamide-induced fulminant hepatic failure.

Plasma disposition of toltrazuril and its metabolites, toltrazuril sulfoxide and toltrazuril sulfone, in rabbits after oral administration.

The objective of this study was to evaluate the pharmacokinetic profiles of toltrazuril (TZR), and its major metabolites toltrazuril sulfoxide (TZR x SO) and toltrazuril sulfone (TZR x SO(2)) in rabbits after oral administrations. Rabbits were dosed once with 10 and 20mg/kg TZR via stomach tube with manual restraint. The plasma concentrations of TZR, TZR x SO and TZR x SO(2) were determined by liquid chromatography/mass spectrometry. Plasma concentration-time data after single oral administration were analyzed by a non-compartmental analysis. Plasma peak concentrations of TZR, TZR x SO and TZR x SO(2) were 30.2+/-1.5microg/mL at 20.0+/-6.9h, 8.9+/-1.3microg/mL at 20.0+/-6.9h and 14.7+/-3.9microg/mL at 96.0+/-0.0h after oral administration of TZR with 10mg/kg bw, respectively. The terminal elimination half-lives for TZR, TZR x SO and TZR x SO(2) after oral dose of 10mg/kg were 52.7+/-3.6, 56.1+/-10.7 and 76.7+/-7.5h, respectively. Plasma peak concentrations of TZR, TZR x SO and TZR x SO(2) were 39.4+/-1.2microg/mL at 28.0+/-6.9h, 12.5+/-3.9microg/mL at 20.0+/-6.9h and 24.9+/-8.74microg/mL at 112.0+/-6.9h after oral administration of TZR with 20mg/kg bw, respectively. The terminal elimination half-lives for TZR, TZR x SO and TZR x SO(2) after oral dose of 20mg/kg were 56.7+/-1.9, 68.8+/-12.5 and 82.3+/-12.6h, respectively. In conclusion, TZR was very well-absorbed through the gastrointestinal tract and rapidly metabolized to TZR x SO and TZR x SO(2) in rabbits after oral administration. TZR x SO(2) was actually more slowly eliminated than TZR and TZR x SO.