RESUMO
Exposure to volatile organic compounds (VOCs) such as benzene, toluene, ethylbenzene, xylene, and formaldehyde from long-distance buses has been reported to adversely affect human health. This study investigates the concentrations of these five VOCs and evaluates their health risks to drivers and passengers on board. Ten trips from Taipei to Taichung were performed during the warm and cold seasons of 2021-2022. Two locations inside the bus were established to collect air samples by a 6-liter canister for drivers and passengers. Exposure concentrations of benzene, toluene, ethylbenzene, and xylene were analyzed via gas chromatography with a flame ionization detector and the formaldehyde concentration was monitored using a formaldehyde meter. Subsequently, a Monte Carlo simulation was conducted to evaluate the carcinogenic and non-carcinogenic risks of the five VOCs. Formaldehyde emerged as the highest detected compound (9.06 ± 3.77 µg/m3), followed by toluene (median: 6.11 µg/m3; range: 3.86-14.69 µg/m3). In particular, formaldehyde was identified to have the significantly higher concentration during non-rush hours (10.67 ± 3.21 µg/m3) than that during rush hours (7.45 ± 3.41 µg/m3) and during the warm season (10.71 ± 2.97 µg/m3) compared with that during the cold season (7.41 ± 4.26 µg/m3). Regarding non-carcinogenic risks to drivers and passengers, the chronic hazard indices for these five VOCs were under 1 to indicate an acceptable risk. In terms of carcinogenic risk, the median risks of benzene and formaldehyde for drivers were 2.88 × 10-6 (95% confidence interval [CI]: 2.11 × 10-6 - 5.13 × 10-6) and 1.91 × 10-6 (95% CI: 4.54 × 10-7 - 3.44 × 10-6), respectively. In contrast, the median carcinogenic risks of benzene and formaldehyde for passengers were less than 1 × 10-6 to present an acceptable risk. This study suggests that benzene and formaldehyde may present carcinogenic risks for drivers. Moreover, the non-carcinogenic risk for drivers and passengers is deemed acceptable. We recommended that the ventilation frequency be increased to mitigate exposure to VOCs in long-distance buses.
Assuntos
Poluentes Atmosféricos , Compostos Orgânicos Voláteis , Compostos Orgânicos Voláteis/análise , Humanos , Medição de Risco , Poluentes Atmosféricos/análise , Veículos Automotores , Taiwan , Exposição Ambiental/análise , Formaldeído/análise , Emissões de Veículos/análise , Exposição Ocupacional/análise , Monitoramento AmbientalRESUMO
Hepatocellular carcinoma has been known as the most frequent subtype of liver cancer with a high rate of spread, metastases, and recurrence, also dismal treatment effects. However, effective therapies for HCC are still required. Nowadays, natural products have been known as a valuable source for drug discovery. In this research, 44 sesquiterpene lactones isolated from the Elephantopus scaber Linn. (Asteraceae) were tested by MTT assay for the antitumor activities. Deoxyelephantopin (DET) was found to exert significant cytotoxicity on HepG2 and Hep3B cells. Moreover, we found that DET treatment markedly reduced the growth of HCC cells in a concentration-dependent manner, which was better than sorafenib. Furthermore, DET induced mitochondrial dysfunction, oxidative stress, and cellular apoptosis. Additionally, we found that DET and sorafenib synergistically induced apoptosis and mitochondrial dysfunction in HCC cells. DET combined with sorafenib was also efficacious in tumor xenograft model. Molecular docking experiments revealed that DET had a potentially high binding affinity with Hsp90α. Moreover, Drug Affinity Responsive Target Stability assay suggested that DET could directly target Hsp90α. Additionally, the expression of Hsp90α was both decreased in vitro and in vivo. Altogether, this study revealed that DET might be a promising agent for HCC therapy by targeting Hsp90α.
Assuntos
Asteraceae , Carcinoma Hepatocelular , Neoplasias Hepáticas , Sesquiterpenos , Humanos , Sesquiterpenos de Germacrano/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Sorafenibe/farmacologia , Simulação de Acoplamento Molecular , Neoplasias Hepáticas/tratamento farmacológico , Apoptose , Lactonas/farmacologia , Lactonas/química , Sesquiterpenos/farmacologia , Sesquiterpenos/química , Mitocôndrias , Asteraceae/química , Linhagem Celular TumoralRESUMO
Small molecule accurate recognition technology (SMART) is an emerging method for the rapid structural prediction of major constituents from crude extracts and fractions. In the present study, a targeted isolation of an Elephantopus scaber extract by SMART resulted in the obtention of 15 new (1-15) and five known germacranolide sesquiterpenes (16-20). Their structures were assigned by extensively analyzing HRESIMS, NMR, X-ray crystallographic analyses, modified Mosher's method results, and quantum chemical calculate electronic circular dichroism (ECD) spectra. All germacranolide sesquiterpenes were screened to determine their inhibitory effects with two hepatoma cell lines (HepG2 and Hep3B), and compounds 14, 16, 18, 19 and 20 showed significant cytotoxic activities against the HepG2 (IC50, 3.3-9.9 µM) and Hep3B (IC50, 4.5-8.6 µM) cell lines. Further study suggested that 18 can induce the apoptosis of hepatoma cells via mitochondrial dysfunction.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Asteraceae/química , Extratos Vegetais/farmacologia , Sesquiterpenos de Germacrano/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Modelos Moleculares , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Sesquiterpenos de Germacrano/química , Sesquiterpenos de Germacrano/isolamento & purificação , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/isolamento & purificação , Relação Estrutura-AtividadeRESUMO
Seven new tirucallane-type triterpenoids (1-7), kumuquassin A-G, along with 20 known analogues (8-27) were isolated from the stems of Picrasma quassioides. The structures and the absolute configurations of new compounds were elucidated by spectroscopic data, electronic circular dichroism (ECD) spectroscopic analyses and quantum ECD calculations. Notably, kumuquassin A (1) contains a rare Δ17, 20 double bond, kumuquassin B (2) is the first example of tirucallane triterpenoid possessing a 5/3 biheterocyclic ring system at the side chain. All the compounds were screened for the cytotoxicity against two human hepatoma cell lines, HepG2 and Hep3B, and several compounds exhibited promising activity. The most potential compound 3 was selected for cell cycle analysis, which showed that 3 could cause an accumulation of HepG2 cells at subG1 peak. Annexin V-FITC/PI staining further confirmed that compound 3 caused death of hepatoma cells through apoptosis induction.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Picrasma/química , Triterpenos/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Conformação Molecular , Picrasma/metabolismo , Caules de Planta/química , Caules de Planta/metabolismo , Triterpenos/isolamento & purificação , Triterpenos/farmacologiaRESUMO
Four pairs of ß-carboline enantiomers (1A: /1B: -4A: /4B: ), 2 ß-carboline derivatives (5: â-â6: ) with a single enantiomeric configuration, together with 2 known achiral congeners (7: â-â8: ) were isolated from the stems of Picrasma quassioides. Their structures were elucidated on the basis of extensive spectroscopic analyses and quantum mechanical calculations. Compound 5: possesses a 4,5-seco ß-carboline framework and represents the first example of this type of ß-carboline alkaloids from nature. A possible biosynthetic pathway is proposed to generate the racemate 4: and the enantiomerically pure compounds 5: and 6: . All isolates were screened for their cytotoxicity against hepatocellular carcinoma Hep3B and HepG2 cells, which revealed that enantiomeric compounds 4A: and 4B: had distinctive effects in HepG2 cells. Further investigation showed that 4B: could induce apoptosis in HepG2 cells.
Assuntos
Alcaloides/isolamento & purificação , Antineoplásicos Fitogênicos/isolamento & purificação , Carbolinas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Picrasma/química , Alcaloides/química , Alcaloides/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Carbolinas/química , Carbolinas/farmacologia , Cromatografia , Ensaios de Seleção de Medicamentos Antitumorais , Células Hep G2 , Humanos , Estrutura Molecular , EstereoisomerismoRESUMO
The Internet of Things (IoT) and low-cost sensor technology have become common tools for environmental exposure monitoring; however, their application in measuring respirable dust (RD) in the workplace remains limited. This study aimed to develop a predictive model for RD using artificial intelligence (AI) algorithms and low-cost sensors and subsequently assess its validity using a standard sampling approach. Various low-cost sensors were combined into an RD sensor module and mounted on a portable aerosol monitor (GRIMM 11-D) for two weeks. AI algorithms were used to capture data per minute over 14 days to establish predictive RD models. The best-fitting model was validated using an aluminum cyclone equipped with an air pump and polytetrafluoroethylene filters to sample the 8-hour RD for 5 days at an aircraft manufacturing company. This module was continuously monitored for two weeks to evaluate its stability. The RD concentration measured by GRIMM 11-D in a general outdoor environment over two weeks was 28.1 ± 16.1 µg/m3 (range: 2.4-85.3 µg/m3). Among the various established models, random forest regression was observed to have the best prediction capacity (R2 = 0.97 and root mean square error = 2.82 µg/m3) in comparison to the other 19 methods. Field-based validation revealed that the predicted RD concentration (35.9 ± 4.1 µg/m3, range: 32.7-42.9 µg/m3) closely approximated the results obtained by the traditional method (38.1 ± 8.9 µg/m3, range: 28.1-52.5 µg/m3), and a strong positive Spearman correlation was observed between the two (rs = 0.70). The average bias was -2.2 µg/m3 and the precision was 5.8 µg/m3, resulting in an accuracy of 6.2 µg/m3 (94.2 %). Data completeness was 99.7 % during the continuous two-week monitoring period. The developed sensor module of RD exhibited excellent predictive performance and good data stability that can be applied to exposure assessments in occupational epidemiological studies.
Assuntos
Poluentes Ocupacionais do Ar , Exposição Ocupacional , Poeira/análise , Exposição Ocupacional/análise , Inteligência Artificial , Exposição Ambiental , Monitoramento Ambiental/métodos , Local de Trabalho , Exposição por Inalação/análiseRESUMO
The purposes of this study were to elucidate the associations between exposure to particulate matter, gaseous pollutants, and road traffic noise and asthma prevalence and to determine the interaction between exposure to multiple pollutants and asthma in children. A total of 3,246 children were recruited from 11 kindergartens in New Taipei City, Taiwan. Land use regression (LUR) was used to establish predictive models for estimating individual exposure levels of particulate matter, gaseous pollutants, and the 24 h A-weighted equivalent sound pressure level (LAeq,24). Multiple logistic regression was performed to test the associations between exposure to these environmental factors and asthma prevalence in children. Multiple-exposure models revealed that an interquartile-range (IQR) increase in PM2.5 (1.17 µg/m3) and PM10 (10.69 µg/m3) caused a 1.34-fold (95% confidence interval [CI] = 1.05-1.70) and 1.17-fold (95% CI = 1.01-1.36) increase in risk of asthma prevalence in children after adjusting for LAeq,24 and NO2. Co-exposure to PM2.5, LAeq,24, and O3, SO2, or CO, as well as co-exposure to PM10, LAeq,24, and CO produced similar findings. Only exposure to one IQR of SO2 (0.15 ppb) was observed a significant association (odds ratio = 1.16, 95% CI = 1.00-1.34) with the asthma prevalence in children after adjusting for PM10 and LAeq,24. Exposure to PM2.5, PM10, and SO2 may be associated with a higher asthma prevalence in children, while other gaseous pollutants and road traffic noise did not demonstrate significant associations. The interaction of exposure to air pollutants and road traffic noise on asthma prevalence in children was not observed in this study.
Assuntos
Poluentes Atmosféricos , Poluição do Ar , Asma , Poluentes Ambientais , Ruído dos Transportes , Humanos , Material Particulado/análise , Poluição do Ar/análise , Gases , Prevalência , Exposição Ambiental/análise , Poluentes Atmosféricos/análise , Asma/epidemiologia , Dióxido de Nitrogênio/análiseRESUMO
BACKGROUND: Our previous study reported that the single-nucleotide polymorphism (SNP) rs155979 GC in the promoter region of long-chain non-coding RNA (lncRNA) NONHSAT102891 affects depression susceptibility in a Chinese population. AIM: To explored associations of two SNPs and haplotypes in the lncRNA NONHSAT102891 promoter region with depression susceptibility in Chinese population. METHODS: This this case-control association study was approved by the Ethics Committee of Chengdu Medical College (approval number: 201815). Patient diagnosis was based on DSM-IV criteria. We selected a total of 480 patients with depression and 329 healthy controls with no history of psychopathology, and performed genotyping of two SNPs by extracting peripheral venous blood samples from the subjects. The function of the two lncRNA NONHSAT102891 promoter G/C and A/T haplotypes was detected by dual-luciferase reporter assays of human embryonic kidney 293T transfected cells. RESULTS: Stratified analysis of clinical and genotypic characteristics of our cohort showed that the degree of mild depressive episodes associated with the rs6230 TC/CC genotype increased by 1.59 times [TC/CC vs TT: odds ratio (OR) = 1.59, 95% confidence interval (CI): 1.08-2.35, P = 0.019]. The haploid analysis revealed linkage disequilibrium between rs3792747 and rs6230, and the double SNP CG haplotype was more common in the control group compared to case group, indicating that this haplotype significantly reduced the risk of depression (C/G vs T/A: OR = 0.42, 95%CI: 0.21-0.83, P = 0.01). There was no significant difference in the dual-luciferase reporter activity of the G/C and A/T haplotypes compared with the control group (P > 0.05), indicating that the double SNP haplotype has no transcriptional activity. CONCLUSION: The rs3792747 and rs6230 CG haplotypes of the lncRNA NONHSA T102891 promoter may be related to a reduced risk of depression in the Han Chinese population.
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Pneumocystis jirovecii was detected in sputum samples and bronchoalveolar lavage fluid (BALF) obtained from HIV/AIDS patients complicated with Pneumocystis jirovecii pneumonia by Giemsa staining. CD4+ T lymphocytes of 500 patients were counted by flow cytometer. P. jirovecii positive rate in sputum samples (46.8%, 845/1 806) significantly lower than that of BALF (55.8%, 10(6)/190) (P < 0.05). The proportion of patients developing clinical symptoms in P. jirovecii positive cases (96.6%, 816/845) was higher than that of P. jirovecii negative cases (64.0%, 615/961) (P < 0.05). P. jirovecii positive rate increased with the decrease of CD4+ T lymphocyte number. P. jirovecii positive rates in cases with CD4+ > 200 x 10(6)/L, CDC 200 x 10(6)/L-100 x 10(6)n/L, and CD4+ < 100x10(6)/12.0% (6/50), 39.0%( 39/100), 54.6% (191/350), respectively (P < 0.05). Giemsa staining is an efficient, simple and feasible method for P. jirovecii detection, relying on the experience and skill of the operator.
Assuntos
Síndrome da Imunodeficiência Adquirida/diagnóstico , Síndrome da Imunodeficiência Adquirida/microbiologia , Coinfecção/diagnóstico , Pneumonia por Pneumocystis/diagnóstico , Síndrome da Imunodeficiência Adquirida/complicações , Adolescente , Adulto , Idoso , Líquido da Lavagem Broncoalveolar/microbiologia , Linfócitos T CD4-Positivos , Coinfecção/microbiologia , Coinfecção/virologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pneumocystis carinii , Pneumonia por Pneumocystis/complicações , Escarro/microbiologia , Coloração e Rotulagem , Adulto JovemRESUMO
The aim of this study was to determine the relationship between relative peripheral refraction and retinal shape by 2-D magnetic resonance imaging in high myopes. Thirty-five young adults aged 20 to 30 years participated in this study with 16 high myopes (spherical equivalent < -6.00 D) and 19 emmetropes (+0.50 to -0.50 D). An open field autorefractor was used to measure refractions from the center out to 60° in the horizontal meridian and out to around 20° in the vertical meridian, with a step of 3 degrees. Axial length was measured by using A-scan ultrasonography. In addition, images of axial, sagittal, and tangential sections were obtained using 2-D magnetic resonance imaging. The highly myopic group had a significantly relative peripheral hyperopic refraction and showed a prolate ocular shape compared to the emmetropic group. The highly myopic group had relative peripheral hyperopic refraction and showed a prolate ocular form. Significant differences in the ratios of height/axial (1.01 ± 0.02 vs. 0.94 ± 0.03) and width/axial (0.99 ± 0.17 vs. 0.93 ± 0.04) were found from the MRI images between the emmetropic and the highly myopic eyes (p < 0.001). There was a negative correlation between the retina's curvature and relative peripheral refraction for both temporal (Pearson r = -0.459; p < 0.01) and nasal (Pearson r = -0.277; p = 0.011) retina. For the highly myopic eyes, the amount of peripheral hyperopic defocus is correlated to its ocular shape deformation. This could be the first study investigating the relationship between peripheral refraction and ocular dimension in high myopes, and it is hoped to provide useful knowledge of how the development of myopia changes human eye shape.
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Daphne giraldii Nitsche, belongs to Daphne genus, has been reported to exert anti-tumor activities. Our previous study suggested that flavones from Daphne giraldii have significant inhibitory effects on hepatocellular carcinoma (HCC) cells. However, the potential target of this type flavone was still unknown. In this study, 74 flavonoids compounds of Daphne giraldii and 41 potential targets of HCC were analyzed by the network, the most potential target was histone deacetylase 6 (HDAC6). Considering the cytotoxicity, compound 70 (Daphnegiravone D, DGD) was chosen for further confirmation. Molecular docking study revealed that DGD formed high binding affinity with HDAC6. Concomitantly, pharmacological studies indicated that DGD could inhibit the expression of HDAC6 in vitro and in vivo. In this study, network pharmacology along with experimental validation predicted and verified HDAC6 as one of potential targets of flavones, these investigations provide a new insight for further study of Daphne giraldii on HCC treatment.
Assuntos
Carcinoma Hepatocelular , Daphne , Flavonas , Desacetilase 6 de Histona/antagonistas & inibidores , Neoplasias Hepáticas , Carcinoma Hepatocelular/tratamento farmacológico , Linhagem Celular Tumoral , Daphne/química , Flavonas/isolamento & purificação , Flavonas/farmacologia , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Simulação de Acoplamento Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologiaRESUMO
Vibsane-type diterpenes, the characteristic compounds of Viburnum odoratissimum, exhibited significant cytotoxicity in many cancer cells. To search for the potential target of vibsane-type diterpenes on lung cancer, we combined methods of network pharmacology prediction and experimental verification. 80 active ingredients, 23 potential targets and 39 related pathways were analyzed through constructing the compound-target network and target-pathway network, and the potential target (EGFR) and key pathway (PI3K/Akt) were identified. Vibsanol C, an isolated vibsane-type diterpene with excellent cytotoxicity against lung cancer cells was chosen for further confirmation. Molecular docking study and drug affinity responsive target stability (DARTS) approach further indicated that EGFR is a direct target of Vibsanol C. Moreover, mechanistic studies revealed Vibsanol C might affect PI3K/Akt pathway by Western blot analysis. In conclusion, this study successfully predicted and confirmed the potential target of Vibsane-type diterpenes on lung cancer.
Assuntos
Antineoplásicos/farmacologia , Diterpenos/farmacologia , Viburnum/química , Linhagem Celular Tumoral , Diterpenos/isolamento & purificação , Humanos , Simulação de Acoplamento Molecular , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Chemical investigation of 75% EtOH exact of the root bark of Ailanthus altissima (Mill.) Swingle led to the isolation and identification of two new phenylpropanoids (1-2), along with six known compounds (3-8). Their chemical structures were elucidated by extensive spectroscopic data analyses including NMR experiments and HRESIMS analyses, as well as computer-assisted structure elucidation software (ACD/Spectrus Processor). All compounds were evaluated for cytotoxic activities against Hep 3B and Hep G2 cells. Compound 1 and 7 displayed weak cytotoxic activities against the Hep 3B cell line.
Assuntos
Ailanthus/química , Casca de Planta/química , Raízes de Plantas/química , Propanóis/isolamento & purificação , Antineoplásicos/farmacologia , Morte Celular/efeitos dos fármacos , Células Hep G2 , Humanos , Propanóis/química , Propanóis/farmacologia , Espectroscopia de Prótons por Ressonância MagnéticaRESUMO
Chromatographic purification of Elephantopus scaber led to 16 new germacrane-type sesquiterpene lactones (1-16), named elephantopinolide A-P, along with a known analogue (17). Their structures were confirmed by comprehensive spectroscopic analyses, single-crystal X-ray diffraction, and comparison between the experimental and calculated ECD spectra. Their hepatocellular inhibition activities against Hep3B and HepG2 cells were screened by MTT assay, and the structure-activity relationships were examined. The results revealed that 10 (IC50 value of 2.83 µM and 1.98 µM) is more potent than sorafenib. The underlying mechanism study demonstrated that 10 could markedly induce apoptosis accompanied by increased ROS production and decreased mitochondrial membrane potential, resulting in the autophagy and G2/M phase cell arrest in Hep3B and HepG2 cells. Furthermore, signal pathways including MAPKs and AKT may play important roles in 10-induced hepatocellular carcinoma cells death.
Assuntos
Antineoplásicos/síntese química , Carcinoma Hepatocelular/tratamento farmacológico , Lactonas/química , Neoplasias Hepáticas/tratamento farmacológico , Magnoliopsida/química , Extratos Vegetais/síntese química , Sesquiterpenos/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Fase G2 , Humanos , Sistema de Sinalização das MAP Quinases , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Modelos Moleculares , Extratos Vegetais/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sesquiterpenos de Germacrano/química , Relação Estrutura-AtividadeRESUMO
Seven undescribed terpenylated coumarins, named altissimacoumarin I-O, together with seven known compounds, altissimacoumarin C, altissimacoumarin E, altissimacoumarin G, altissimacoumarin H, puberulin, 7-(3-Methyl-2-butenyloxy)-6-methoxycoumarin and artelin were isolated from the root bark of Ailanthus altissima (Mill.) Swingle. Their structures were elucidated by comprehensive spectra data analysis, NMR calculation, DP4+ analysis and ACD/Structure Elucidator software simulation. The absolute configurations of altissimacoumarins K, L, M and N were determined by modified Mosher's method. All isolates were tested for their cytotoxic effect against two hepatoma carcinoma cell lines (HepG2, Hep3B). Altissimacoumarin C exhibited moderate cytotoxic effect against Hep3B cells, with IC50 of 45.21 µM.
Assuntos
Ailanthus , Cumarínicos , Casca de Planta , Extratos VegetaisRESUMO
OBJECTIVE: Magnetic drug targeting (MDT) has attracted a lot of attention in recent years as a treatment to reduce side effects and improve efficacy. To realize successful MDT, a magnet system that can create suitable magnetic field is necessary. However, the existing technology has some shortcomings such as low targeting efficiency and unsatisfactory targeting effect. The method of using time-varying magnetic field proposed in this paper provides a new solution to this problem. METHODS: In this work, a permanent magnet system providing rotational magnetic field (a time-varying magnetic field) was designed and constructed. Focusing experiments of Fe3O4 particles were carried out in this system, and the mechanism of the focusing was discussed via a simplified model. RESULTS: By using the rotational magnetic field, superparamagnetic Fe3O4 particles can be successfully driven to the designated site within a short time. Our work showed that the time-varying magnetic field can drive the superparamagnetic particles to a focusing site, which is not possible under the same magnetic field without rotation, and the aggregation speed and effect are better than those under static field. CONCLUSION AND SIGNIFICANCE: Our results indicate that time-varying magnetic field can be a good choice for designing magnet systems for MDT. Moreover, the idea of using time-varying magnetic field for focusing superparamagnetic particles may be applicable in non-contact processings or manipulations of paramagnetic, superparamagnetic, or even ferromagnetic materials or objects in preparation of novel materials, robotic control of objects, and so on.
Assuntos
Campos Magnéticos , Magnetismo , Nanopartículas Magnéticas de Óxido de Ferro , Imãs , RotaçãoRESUMO
Seven undescribed germacranolides, named as scabertopinolide A-G were obtained from whole herbs of Elephantopus scaber L. The determination of their structures was conducted via comprehensive spectroscopic analyses combined with experimental electronic circular dichroism (ECD) spectroscopic data and quantum mechanical ECD calculations. The absolute configuration of scabertopinolide A was determined by X-ray crystallography data analysis. The cytotoxicity of all compounds was evaluated against three human cancer cell lines HepG2, Hep3B (human hepatocellular carcinoma cell lines), and MCF-7 (human breast adenocarcinoma cell line). Scabertopinolide G exhibited the most significant cytotoxic activities against the three cancer cell lines with IC50 values between 7.0 and 10.3 µM. Furthermore, flow cytometry analysis has suggested that scabertopinolide G may cause death of cancer cells through apoptosis induction.
Assuntos
Antineoplásicos Fitogênicos , Antineoplásicos , Asteraceae , Neoplasias Hepáticas , Linhagem Celular Tumoral , Humanos , Sesquiterpenos de GermacranoRESUMO
Timosaponin AIII (TAIII), a steroidal saponin isolated from the rhizome of Anemarrhena asphodeloides, exerted cytotoxic effect in many cancer cell lines. However, the effect of TAIII on resistant tumor cancer cells was unclear. In this study, MTT assay showed that TAIII exhibited significant cytotoxicity against A549/Taxol and A2780/Taxol cells in vitro. Annexin V-FITC/PI staining revealed that TAIII induced apoptosis in A549/T and A2780/T cells. Furthermore, Western blot analysis demonstrated that TAIII inhibited the expressions of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), mammalian target of rapamycin (mTOR) as well as Ras, Raf, mitogen-activated protein kinase (MEPK), extracellular regulated protein kinases (ERK) in two taxol-resistant cancer cell lines. Besides, in vivo studies demonstrated that TAIII inhibited tumor growth in a nude mouse xenograft model. Additionally, TAIII (2.5 and 5â¯mg/kg) also down-regulated the protein expressions of PI3K/AKT/mTOR and Ras/Raf/MEK/ERK pathways in vivo. Taken together, these findings demonstrated that TAIII exhibited significant anti-tumor effect on taxol-resistant cells.
Assuntos
Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Paclitaxel/farmacologia , Saponinas/farmacologia , Esteroides/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Silver is a toxic but precious heavy metal that has been implemented in diverse biomedical and environmental sectors. Extensive use of this metal has provoked severe environmental concerns. Hence there is an increasing demand for the development of a simple, inexpensive and eco-friendly approach for the remediation and recovery of silver. In this study, novel bacterial strains Enterobacter cloacae SMP1, Cupriavidus necator SMP2, and Bacillus megaterium SMP3 were isolated from silver mining site for the sake of silver remediation. Various experimental factors including temperature, pH and inoculum size (I_S) were optimized for silver remediation by SMP1 using central composite design (CCD) based on response surface methodology (RSM). For maximum 100% removal of silver the optimized values of temperature, pH and I_S were 23.5 °C, 7.5 and 2% (v/v) respectively in less than 10 h of incubation. Simultaneously, silver nanoparticles (AgNPs) were harvested through centrifugation (M1) and by applying voltage (M2) to the crude remediation mixture. The AgNPs, characterized by UV-vis spectroscopy, dynamic light scattering (DLS), and cryo-scanning transmission electron microscopy (Cryo-SETM), were spherical shaped and 1.75-8.7 nm in diameter. The average zeta potentials (ZP) of AgNPs isolated by M1, and M2 were -35.8 mV and -45.2 mV respectively.
Assuntos
Bactérias/metabolismo , Nanopartículas Metálicas , Prata/isolamento & purificação , Água/química , Adaptação Fisiológica , SoluçõesRESUMO
Four pairs of enantiomeric ß-carboline alkaloids, (+/-)-kumudine A-D, along with their biosynthesis-related compound kumudine E, were obtained from the stems of Picrasma quassioides. Their structures, including the absolute configurations, were determined via extensive spectroscopic data combined with electronic circular dichroism (ECD) spectroscopic analyses and quantum mechanical ECD calculations. (+/-)-Kumudine A possessed a scaffold of ß-carboline-phenylpropanoid adduct, which were the first examples of this type of ß-carboline alkaloid from nature. The cytotoxicity assay against hepatocellular carcinoma Hep3B and HepG2 cells was evaluated by SRB assay, which showed that (-)-Kumudine B had stronger effect than its enantiomer (+)-Kumudine B in Hep3B cells. Moreover, further flow cytometry analysis also supported the enantioselectivity between (+)-Kumudine B and (-)-Kumudine B, suggesting that the compounds caused death of hepatoma cells through apoptosis induction.