Relationship between periodontal disease and dizziness in Taiwanese adults: A nationwide population-based cohort study.

Periodontal disease is often neglected and overlooking its initial symptoms can lead to tooth loss and systemic diseases. Patients with otitis media are at high risk of vestibular and balance dysfunction, consequently, and vertigo. Vertigo and dizziness are conditions with high reported incidences; they worsen with age and can burden health systems. The present study investigated whether periodontal disease causes dizziness. Research data covering 2008 through 2013 were retrieved from the National Health Insurance Research Database of Taiwan. Patients who were newly diagnosed as having periodontal disease or dizziness after at least 1 hospital admission or 3 outpatient visits were enrolled as participants. For our controls, we randomly selected individuals without periodontal disease who were sex- and age-matched with the investigated participants. In total, we enrolled 445 patients with periodontal disease and 1780 controls. The Kaplan-Meier curve indicated that the cumulative incidence of dizziness was significantly higher among the patients with periodontal disease relative to the controls. After adjustment for sex, age, income level, urbanization level, month of onset, and comorbidities, Cox proportional-hazards analysis revealed that patients with periodontal disease had an increased risk of dizziness (hazard ratio [HR]: 1.306, 95% confidence interval (CI): 1.155, 1.475). Compared with the controls, the risk of dizziness among patients with periodontal disease was higher for both female (HR: 1.439, 95%: 1.203, 1.720) and male patients (HR: 1.284, 95%: 1.123, 1.468); this risk was higher even when January (HR: 1.302, 95% CI: 1.145, 1.480), February (HR: 1.337, 95% CI: 1.178, 1.518), or March was excluded (HR: 1.308, 95% CI: 1.151, 1.487) and for patients without Ménière disease. Therefore, periodontal disease is not only a risk factor for dizziness but also an independent risk factor for dizziness. Future studies could clarify the mechanisms linking periodontal disease to dizziness.

Cytotoxicity and Apoptotic Mechanism of 2-Hydroxyethyl Methacrylate via Genotoxicity and the Mitochondrial-Dependent Intrinsic Caspase Pathway and Intracellular Reactive Oxygen Species Accumulation in Macrophages.

Macrophages are mainly active cells of the immune system and play a role in the defense of pathogens. However, the overactivation of macrophages by fatal pathogens can result in toxic responses. 2-hydroxyethyl methacrylate (HEMA), which is a hydrophilic monomer, is used in dental adhesive reagents and composite resins as well as biocompatible hydrogels. The mechanisms underlying the genotoxicity engendered by HEMA-induced apoptosis that leads to cytotoxicity remain unclear. Accordingly, this study was conducted to clarify such mechanisms. The results showed that HEMA induced cell toxicity in RAW264.7 macrophages depending on the concentration. A higher HEMA concentration was associated with a higher level of apoptosis and genotoxicity. Moreover, HEMA induced a concentration-dependent increase in mitochondrial dysfunction and the intrinsic caspase pathway, including the activation of caspase-3 and caspase-9. HEMA was also found to upregulate intracellular reactive oxygen species generation and to decrease the activity of antioxidant enzymes, including superoxide dismutase and catalase. Taken together, the mitochondrial-dependent intrinsic caspase pathway and intracellular reactive oxygen species accumulation were found to mediate HEMA-induced genotoxicity and apoptosis, leading to cytotoxicity in RAW264.7 macrophages.

Fucoxanthin decreases lipopolysaccharide-induced acute lung injury through the inhibition of RhoA activation and the NF-κB pathway.

Fucoxanthin is a natural pigment widely distributed in macroalgae and microalgae. An orange-colored xanthophyll, it has several bioactive effects, including anticancer, anti-obesity, oxidative stress reduction, and anti-inflammation. Acute lung injury (ALI) caused by acute infections or injurious stimuli to the lung tissues is a severe pulmonary inflammatory disease. To date, no evidence has shown ALI to be reduced by fucoxanthin through activation of Ras homolog family member A (RhoA) and the nuclear factor (NF)-κB pathway in lipopolysaccharide (LPS)-treated mice. Pretreatment with fucoxanthin inhibited histopathological changes in lung tissues and neutrophil infiltration into bronchoalveolar lavage fluid induced by LPS in ALI mice. Moreover, LPS-induced proinflammatory cytokine expression and neutrophil infiltration were inhibited by fucoxanthin in a concentration-dependent manner. Pretreatment of mice with fucoxanthin inhibited NF-κB phosphorylation and IκB degradation in the lungs of mice with LPS-induced ALI. We further found that phosphorylation of Akt and p38 mitogen-activated protein KINASE (MAPK) was inhibited by fucoxanthin. By contrast, the phosphorylation of extracellular signal-regulated kinase and c-Jun N-terminal kinase was not inhibited by fucoxanthin. Furthermore, we found that the activation of RhoA was inhibited by fucoxanthin in LPS-induced ALI. On the basis of these results, we propose that fucoxanthin disrupts the RhoA activation-mediated phosphorylation of Akt and p38 MAPK, leading to NF-κB activation in mice with LPS-induced ALI.

The Literacy-Based Scale for Measuring Reflections on a University Social Responsibility Curriculum: Development and Validation.

University Social Responsibility (USR) enhances educational development and the impact of universities on society. As a stakeholder in USR, it is imperative to develop a comprehensive literacy scale that reflects the development of students' citizenship in social engagement. Thus, this study aims to develop and validate the Health Promotion Literacy-based Scale for students in USR (HPLS-USR). A total of 200 students from USR with an average age of 19.27 participated in the study. The Exploratory Factor Analysis (EFA) was used to verify the scale's construct validity. Twenty-two items were maintained in EFA with an internal consistency Cronbach's α of 0.92. Construct validity was supported by EFA results, confirming that the four-factor structure of the 22-item scale (personal growth, responsibility of citizenship, social interaction, and intellectual growth) have reasonable correlations to each other, explaining 61.83% of the variance in the scale. The Kaiser-Meyer-Olkin index values of 0.908 and Bartlett's Test of Sphericity (p = 0.001) verified the normal distribution of the EFA and the adequacy of the EFA sampling. These items achieved adequate factor loadings ranging between 0.44 and 0.82. This study demonstrated that the HPLS-USR has satisfactory construct validity and reliability in measuring students' literacy abilities developed in USR participation.

Single-molecule binding characterization of primosomal protein PriA involved in replication restart.

DNA damage leads to stalled or collapsed replication forks. Replication restart primosomes re-initiate DNA synthesis at these stalled or collapsed DNA replication forks, which is important for bacterial survival. Primosomal protein PriA specifically recognizes the DNA fork structure and recruits other primosomal proteins to load the replicative helicase, in order to re-establish the replication fork. PriA binding on DNA is the first step to restart replication forks for proper DNA repair. Using a single-molecule fluorescence colocalization experiment, we measured the thermodynamic and real-time kinetic properties of fluorescence-labeled Gram-positive bacteria Geobacillus stearothermophilus PriA binding on DNA forks. We showed that PriA preferentially binds to a DNA fork structure with a fully duplexed leading strand at sub-nanomolar affinity (Kd = 268 ± 99 pM). PriA binds dynamically, and its association and dissociation rate constants can be determined using the appearance and disappearance of the fluorescence signal. In addition, we showed that PriA binds to DNA forks as a monomer using photobleaching step counting. This information offers a molecular basis essential for understanding the mechanism of replication restart.

Genotoxic effects of 1-nitropyrene in macrophages are mediated through a p53-dependent pathway involving cytochrome c release, caspase activation, and PARP-1 cleavage.

Genotoxic stress from environmental pollutants plays a critical role in cytotoxicity. The most abundant nitro-polycyclic aromatic hydrocarbon in environmental pollutants, 1-nitropyrene (1-NP), is generated during fossil fuel, diesel, and biomass combustion under sunlight. Macrophages, the key regulators of the innate immune system, provide the first line of defense against pathogens. The toxic effects of 1-NP on macrophages remain unclear. Through a lactate dehydrogenase assay, we measured the cytotoxicity induced by 1-NP. Our results revealed that 1-NP induced genotoxicity also named DNA damage, including micronucleus formation and DNA strand breaks, in a concentration-dependent manner. Furthermore, 1-NP induced p53 phosphorylation and nuclear accumulation; mitochondrial cytochrome c release; caspase-3 and -9 activation and cleavage; and poly (ADP-ribose) polymerase-1 (PARP-1) cleavage in a concentration-dependent manner. Pretreatment with the PARP inhibitor, 3-aminobenzamide, significantly reduced cytotoxicity, genotoxicity, and PARP-1 cleavage induced by 1-NP. Pretreatment with the caspase-3 inhibitor, z-DEVD-fmk, significantly reduced cytotoxicity, genotoxicity, PARP-1 cleavage, and caspase 3 activation induced by 1-NP. Pretreatment with the p53 inhibitor, pifithrin-α, significantly reduced cytotoxicity, genotoxicity, PARP-1 cleavage, caspase 3 activation, and p53 phosphorylation induced by 1-NP. We propose that cytotoxicity and genotoxicity induced by 1-NP by PARP-1 cleavage via caspase-3 and -9 activation through cytochrome c release from mitochondria and its upstream p53-dependent pathway in macrophages.

Protective Effects of Kirenol against Lipopolysaccharide-Induced Acute Lung Injury through the Modulation of the Proinflammatory NFκB Pathway and the AMPK2-/Nrf2-Mediated HO-1/AOE Pathway.

Acute lung injury (ALI) is an acute and life-threatening inflammatory disease of the lung parenchyma that is associated with high mortality worldwide. No therapeutic strategies have been developed for the mitigation of the proinflammatory response that characterizes ALI. Kirenol has anti-inflammatory, antiarthritic, and immunoregulatory effects. In the present study, we investigated the protective effects of kirenol against lipopolysaccharides (LPS)-induced ALI in mice. Kirenol reduced the LPS-induced histopathology changes involving edema and thickening of the interstitial or alveolar walls, infiltration of leukocytes, formation of hyaline membrane. Pretreatment with kirenol reduced leukocytes infiltration in bronchoalveolar lavage fluid (BALF), the alveolar-capillary barrier disruption and lipid peroxidation in lung tissues induced by LPS. Kirenol significantly inhibited the secretion of cytokines, IL-1ß, IL6, and TNFα, into the BALF of the mice with LPS-induced ALI through NFκB activation. Moreover, kirenol attenuated the downregulation of the antioxidant enzymes, superoxide dismutase, glutathione peroxidase, and catalase that was induced by LPS. HO-1 expression and the phosphorylation of Nrf2 and AMPK2 were also induced by kirenol. The results indicate that kirenol can be developed as a treatment strategy for ALI, and its effects are induced through the inhibition of the NF-κB proinflammatory pathway and promotion of AMPK2/Nrf2-mediated HO-1 and antioxidant enzymes (AOE) activation.

Association Between PM2.5 Exposure Level and Primary Open-Angle Glaucoma in Taiwanese Adults: A Nested Case-Control Study.

Primary open-angle glaucoma (POAG) is the most common type of glaucoma. However, little is known about POAG in adults and exposure to air pollution. The current study aims to investigate whether exposure to particulate matter with a mass median aerodynamic diameter of ≤2.5 µm (PM2.5) is associated with POAG diagnosis. Patient data were obtained from the Longitudinal Health Insurance Database 2010 (LHID2010) of Taiwan for the 2008-2013 period. PM2.5 concentration data, collected from the Ambient Air Quality Monitoring Network established by the Environmental Protection Administration of Taiwan, were categorized into four groups according to World Health Organization (WHO) exposure standards for PM2.5. We estimated the odds ratios (ORs) and 95% CIs for risk factors for POAG with logistic regression. The OR of per WHO standard level increase was 1.193 (95% CI 1.050-1.356). Compared with the normal level, the OR of WHO 2.0 level was 1.668 (95% CI 1.045-2.663, P < 0.05). After excluding confounding risk factors for POAG in this study, we determined that increased PM2.5 exposure is related to POAG risk (ORs > 1, P < 0.05). In this study, PM2.5 was an independent factor associated with open-angle glaucoma. Further research is required to better understand the mechanisms connecting PM2.5 and open-angle glaucoma.

Characterization of Streptococcus pneumoniae PriA helicase and its ATPase and unwinding activities in DNA replication restart.

DNA replication forks often encounter template DNA lesions that can stall their progression. The PriA-dependent pathway is the major replication restart mechanism in Gram-positive bacteria, and it requires several primosome proteins. Among them, PriA protein - a 3' to 5' superfamily-2 DNA helicase - is the key factor in recognizing DNA lesions and it also recruits other proteins. Here, we investigated the ATPase and helicase activities of Streptococcus pneumoniae PriA (SpPriA) through biochemical and kinetic analyses. By comparing various DNA substrates, we observed that SpPriA is unable to unwind duplex DNA with high GC content. We constructed a deletion mutant protein (SpPriAdeloop) from which the loop area of the DNA-binding domain of PriA had been removed. Functional assays on SpPriAdeloop revealed that the loop area is important in endowing DNA-binding properties on the helicase. We also show that the presence of DnaD loader protein is important for enhancing SpPriA ATPase and DNA unwinding activities.

Structural analyses of the bacterial primosomal protein DnaB reveal that it is a tetramer and forms a complex with a primosomal re-initiation protein.

The DnaB primosomal protein from Gram-positive bacteria plays a key role in DNA replication and restart as a loader protein for the recruitment of replisome cascade proteins. Previous investigations have established that DnaB is composed of an N-terminal domain, a middle domain, and a C-terminal domain. However, structural evidence for how DnaB functions at the atomic level is lacking. Here, we report the crystal structure of DnaB, encompassing the N-terminal and middle domains (residues 1-300), from Geobacillus stearothermophilus (GstDnaB1-300) at 2.8 Å resolution. Our structure revealed that GstDnaB1-300 forms a tetramer with two basket-like architectures, a finding consistent with those from solution studies using analytical ultracentrifugation. Furthermore, our results from both GST pulldown assays and analytical ultracentrifugation show that GstDnaB1-300 is sufficient to form a complex with PriA, the primosomal reinitiation protein. Moreover, with the aid of small angle X-ray scattering experiments, we also determined the structural envelope of full-length DnaB (GstDnaBFL) in solution. These small angle X-ray scattering studies indicated that GstDnaBFL has an elongated conformation and that the protruding density envelopes originating from GstDnaB1-300 could completely accommodate the GstDnaB C-terminal domain (residues 301-461). Taken together with biochemical assays, our results suggest that GstDnaB uses different domains to distinguish the PriA interaction and single-stranded DNA binding. These findings can further extend our understanding of primosomal assembly in replication restart.

Zerumbone reduced the inflammatory response of acute lung injury in endotoxin-treated mice via Akt-NFκB pathway.

Zerumbone, a cyclic eleven-membered sesquiterpene, is the major component of the essential oil isolated from the wild ginger, Zingiber zerumbet. There are several beneficial pharmacological activities of zerumbone including anti-inflammatory, antioxidant, and anticancer activities. Acute lung injury (ALI) is an acute pulmonary inflammatory disorder with high morbidity and mortality rate. In present study, we aimed to investigate the protective effects and mechanisms of zerumbone on endotoxin, lipopolysaccharide (LPS)-induced ALI. Mice were pretreated with zerumbone at various concentrations for 30 min followed by intratracheal administration of LPS for 6 h. Pretreatment with zerumbone not only reduced leukocytes infiltration into the alveolar space but also inhibited lung edema in LPS-induced ALI. Decreased secretion of proinflammatory cytokines such as TNFα and IL-6 caused by LPS were reversed by zerumbone. LPS-induced expressions of proinflammatory mediators, iNOS and COX-2, were inhibited by zerumbone. In addition, NFκB activation and Akt phosphorylation were inhibited by zerumbone in LPS-induced ALI. All these results suggested that the protective mechanisms of zerumbone on endotoxin-induced ALI were via inhibition of Akt-NFκB activation.

Protective effect of wogonin on endotoxin-induced acute lung injury via reduction of p38 MAPK and JNK phosphorylation.

Acute lung injury (ALI) is a serious inflammatory disorder which remains the primary cause of incidence and mortality in patients with acute pulmonary inflammation. However, there is still no effective medical strategy available clinically for the improvement of ALI. Wogonin, isolated from roots of Scutellaria baicalensis Georgi, is a common medicinal herb which presents biological and pharmacological effects, including antioxidation, anti-inflammation, and anticancer. Preadministration of wogonin inhibited not only lung edema but also protein leakage into the alveolar space in murine model of lipopolysaccharide (LPS)-induced ALI. Moreover, wogonin not only reduced the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 but also inhibited the phosphorylation of mitogen-activated protein kinase (MAPK) induced by LPS. We further found wogonin inhibited the phosphorylation of p38 MAPK and JNK at a concentration lower than ERK. In addition, inhibition of lung edema, protein leakage, expression of iNOS and COX-2, and phosphorylation of p38 MAPK and JNK were all observed in a parallel concentration-dependent manner. These results suggest that wogonin possesses potential protective effect against LPS-induced ALI via downregulation of iNOS and COX-2 expression by blocking phosphorylation of p38 MAPK and JNK. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 397-403, 2017.

Bacillus licheniformis trehalose-6-phosphate hydrolase structures suggest keys to substrate specificity.

Trehalose-6-phosphate hydrolase (TreA) belongs to glycoside hydrolase family 13 (GH13) and catalyzes the hydrolysis of trehalose 6-phosphate (T6P) to yield glucose and glucose 6-phosphate. The products of this reaction can be further metabolized by the energy-generating glycolytic pathway. Here, crystal structures of Bacillus licheniformis TreA (BlTreA) and its R201Q mutant complexed with p-nitrophenyl-α-D-glucopyranoside (R201Q-pPNG) are presented at 2.0 and 2.05 Å resolution, respectively. The overall structure of BlTreA is similar to those of other GH13 family enzymes. However, detailed structural comparisons revealed that the catalytic site of BlTreA contains a long loop that adopts a different conformation from those of other GH13 family members. Unlike the homologous regions of Bacillus cereus oligo-1,6-glucosidase (BcOgl) and Erwinia rhapontici isomaltulose synthase (NX-5), the surface potential of the BlTreA active site exhibits a largely positive charge contributed by the four basic residues His281, His282, Lys284 and Lys292. Mutation of these residues resulted in significant decreases in the enzymatic activity of BlTreA. Strikingly, the (281)HHLK(284) motif and Lys292 play critical roles in substrate discrimination by BlTreA.

Delivery and targeting of nanoparticles into hair follicles.

It has been demonstrated that nanoparticles used for follicular delivery provide some advantages over conventional pathways, including improved skin bioavailability, enhanced penetration depth, prolonged residence duration, fast transport into the skin and tissue targeting. This review describes recent developments using nanotechnology approaches for drug delivery into the follicles. Different types of nanosystems may be employed for management of follicular permeation, such as polymeric nanoparticles, metallic nanocrystals, liposomes, and lipid nanoparticles. This review systematically introduces the mechanisms of follicles for nanoparticulate penetration, highlighting the therapeutic potential of drug-loaded nanoparticles for treating skin diseases. Special attention is paid to the use of nanoparticles in treating appendage-related disorders, in particular, nanomedical strategies for treating alopecia, acne, and transcutaneous immunization.

Erbium-yttrium-aluminum-garnet laser irradiation ameliorates skin permeation and follicular delivery of antialopecia drugs.

Alopecia usually cannot be cured because of the available drug therapy being unsatisfactory. To improve the efficiency of treatment, erbium-yttrium-aluminum-garnet (Er-YAG) laser treatment was conducted to facilitate skin permeation of antialopecia drugs such as minoxidil (MXD), diphencyprone (DPCP), and peptide. In vitro and in vivo percutaneous absorption experiments were carried out by using nude mouse skin and porcine skin as permeation barriers. Fluorescence and confocal microscopies were used to visualize distribution of permeants within the skin. Laser ablation at a depth of 6 and 10 µm enhanced MXD skin accumulation twofold to ninefold depending on the skin barriers selected. DPCP absorption showed less enhancement by laser irradiation as compared with MXD. An ablation depth of 10 µm could increase the peptide flux from zero to 4.99 and 0.33 µg cm(-2) h(-1) for nude mouse skin and porcine skin, respectively. The laser treatment also promoted drug uptake in the hair follicles, with DPCP demonstrating the greatest enhancement (sixfold compared with the control). The imaging of skin examined by microscopies provided evidence of follicular and intercellular delivery assisted by the Er-YAG laser. Besides the ablative effect of removing the stratum corneum, the laser may interact with sebum to break up the barrier function, increasing the skin delivery of antialopecia drugs. The minimally invasive, well-controlled approach of laser-mediated drug permeation offers a potential way to treat alopecia. This study's findings provide the basis for the first report on laser-assisted delivery of antialopecia drugs.

Structural dynamics of the two-component response regulator RstA in recognition of promoter DNA element.

The RstA/RstB system is a bacterial two-component regulatory system consisting of the membrane sensor, RstB and its cognate response regulator (RR) RstA. The RstA of Klebsiella pneumoniae (kpRstA) consists of an N-terminal receiver domain (RD, residues 1-119) and a C-terminal DNA-binding domain (DBD, residues 130-236). Phosphorylation of kpRstA induces dimerization, which allows two kpRstA DBDs to bind to a tandem repeat, called the RstA box, and regulate the expression of downstream genes. Here we report the solution and crystal structures of the free kpRstA RD, DBD and DBD/RstA box DNA complex. The structure of the kpRstA DBD/RstA box complex suggests that the two protomers interact with the RstA box in an asymmetric fashion. Equilibrium binding studies further reveal that the two protomers within the kpRstA dimer bind to the RstA box in a sequential manner. Taken together, our results suggest a binding model where dimerization of the kpRstA RDs provides the platform to allow the first kpRstA DBD protomer to anchor protein-DNA interaction, whereas the second protomer plays a key role in ensuring correct recognition of the RstA box.

Interactions that influence the binding of synthetic heparan sulfate based disaccharides to fibroblast growth factor-2.

Heparan sulfate (HS) is a linear sulfated polysaccharide that mediates protein activities at the cell-extracellular interface. Its interactions with proteins depend on the complex patterns of sulfonations and sugar residues. Previously, we synthesized all 48 potential disaccharides found in HS and used them for affinity screening and X-ray structural analysis with fibroblast growth factor-1 (FGF1). Herein, we evaluated the affinities of the same sugars against FGF2 and determined the crystal structures of FGF2 in complex with three disaccharides carrying N-sulfonated glucosamine and 2-O-sulfonated iduronic acid as basic backbones. The crystal structures show that water molecules mediate different interactions between the 3-O-sulfonate group and Lys125. Moreover, the 6-O-sulfonate group forms intermolecular interactions with another FGF2 unit apart from the main binding site. These findings suggest that the water-mediated interactions and the intermolecular interactions influence the binding affinity of different disaccharides with FGF2, correlating with their respective dissociation constants in solution.

Rutin decreases lipopolysaccharide-induced acute lung injury via inhibition of oxidative stress and the MAPK-NF-κB pathway.

Acute lung injury (ALI) is a serious disease with unacceptably high mortality and morbidity rates. Up to now, no effective therapeutic strategy for ALI has been established. Rutin, quercetin-3-rhamnosyl glucoside, expresses a wide range of biological activities and pharmacological effects, such as anti-inflammatory, antihypertensive, anticarcinogenic, vasoprotective, and cardioprotective activities. Pretreatment with rutin inhibited not only histopathological changes in lung tissues but also infiltration of polymorphonuclear granulocytes into bronchoalveolar lavage fluid in lipopolysaccharide (LPS)-induced ALI. In addition, LPS-induced inflammatory responses, including increased secretion of proinflammatory cytokines and lipid peroxidation, were inhibited by rutin in a concentration-dependent manner. Furthermore, rutin suppressed phosphorylation of NF-κB and MAPK and degradation of IκB, an NF-κB inhibitor. Decreased activities of antioxidative enzymes such as superoxide dismutase, catalase, glutathione peroxidase, and heme oxygenase-1 caused by LPS were reversed by rutin. At the same time, we found that ALI amelioration by chelation of extracellular metal ions with rutin is more efficacious than with deferoxamine. These results indicate that the protective mechanism of rutin is through inhibition of MAPK-NF-κB activation and upregulation of antioxidative enzymes.

Wogonin attenuates endotoxin-induced prostaglandin E2 and nitric oxide production via Src-ERK1/2-NFκB pathway in BV-2 microglial cells.

Microglia are the major component of intrinsic brain immune system in neuroinflammation. Although wogonin expresses anti-inflammatory function in microglia, little is known about the molecular mechanisms of the protective effect of wogonin against microglia activation. The aim of this study was to evaluate how wogonin exerts its anti-inflammatory function in BV2 microglial cells after LPS/INFγ administration. Wogonin not only inhibited LPS/ INFγ-induced PGE2 and NO production without affecting cell viability but also exhibited parallel inhibition on LPS/INFγ-induced expression of iNOS and COX-2 in the same concentration range. While LPS/INFγ-induced expression of P-p65 and P-IκB was inhibited by wogonin-only weak inhibition on P-p38 and P-JNK were observed, whereas it significantly attenuated the P-ERK1/2 and its upstream activators P-MEK1/2 and P-Src in a parallel concentration-dependent manner. These results indicated that the blockade of PGE2 and NO production by wogonin in LPS/INFγ-stimulated BV2 cells is attributed mainly to interference in the Src-MEK1/2-ERK1/2-NFκB-signaling pathway.

Cytotoxicity and genotoxicity of chlorhexidine on macrophages in vitro.

Chlorhexidine (CHX) is the most widely used antiseptic for wound, skin disinfection, and dental hygiene. The aim of this study is to investigate the possible correlation between CHX-induced cytogenotoxicity and alterations in normal cell cycle on RAW264.7 macrophages. The cytotoxicity, mechanism of cell death, mitotic activity, and reactive oxygen species (ROS) generation were determined by tetrazolium bromide reduction assay, flow cytometry, cytokinesis-block proliferation index, and superoxide dismutase-inhibitable reduction of ferricytochrome c, respectively. The genotoxicity was measured using comet assay and cytokinesis-block micronucleus assay. The cytotoxicity of CHX in RAW264.7 cells presented a dose- and time-dependent manner (p < 0.05). The mode of cell death shifted from apoptosis to necrosis when the dosage of CHX increased. The genotoxicity of CHX in RAW264.7 cells had shown DNA damage in a dose-dependent manner (p < 0.05). Prolongation of cell cycle and the increase of ROS generation also expressed in a dose-dependent manner (p < 0.05). Taken together, the data suggested that CHX-induced cytotoxicity and genotoxicity on macrophages may be via ROS generation.