Nobiletin and its derivatives overcome multidrug resistance (MDR) in cancer: total synthesis and discovery of potent MDR reversal agents

Our recent studies demonstrated that the natural product nobiletin (NOB) served as a promising multidrug resistance (MDR) reversal agent and improved the effectiveness of cancer chemotherapy in vitro. However, low aqueous solubility and difficulty in total synthesis limited its application as a therapeutic agent. To tackle these challenges, NOB was synthesized in a high yield by a concise route of six steps and fourteen derivatives were synthesized with remarkable solubility and efficacy. All the compounds showed improved sensitivity to paclitaxel (PTX) in P-glycoprotein (P-gp) overexpressing MDR cancer cells. Among them, compound 29d exhibited water solubility 280-fold higher than NOB. A drug-resistance A549/T xenograft model showed that 29d, at a dose of 50 mg/kg co-administered with PTX (15 mg/kg), inhibited tumor growth more effective than NOB and remarkably increased PTX concentration in the tumors via P-gp inhibition. Moreover, Western blot experiments revealed that 29d inhibited expression of NRF2, phosphorylated ERK and AKT in MDR cancer cells, thus implying 29d of multiple mechanisms to reverse MDR in lung cancer.     

吹扫捕集-气相色谱-质谱联用法测定生活饮用水中的二氯甲烷

目的建立生活饮用水中二氯甲烷的吹扫捕集-气相色谱-质谱联用测定方法。方法采用吹扫捕集富集水中二氯甲烷,解吸后用气相色谱-质谱测定,选择离子扫描方式下用标准曲线法进行定量分析。结果该方法操作简便,检出限低(0.005ng/mL),回收率均大于97%,相对标准偏差小于5%。结论该方法适合生活饮用水中的二氯甲烷的测定。     

Penta-block copolymer microspheres: Impact of polymer characteristics and process parameters on protein release

Here, we aimed to develop protein loaded microspheres (MSs) using penta-block PLGA-based copolymers to obtain sustained and complete protein release. We varied MS morphology and studied the control of protein release. Lysozyme was used as a model protein and MSs were prepared using the solid-in-oil-in-water emulsion solvent extraction method. We synthesized and studied various penta-block PLGA-based copolymers. Copolymer characteristics (LA/GA ratio and molecular weight of PLGA blocks) influenced MS morphology. MS porosity was influenced by process parameters (such as solvent type, polymer concentration, emulsifying speed), whereas the aqueous volume for extraction and stabilizer did not have a significant effect. MSs of the same size, but different morphologies, exhibited different protein release behavior, with porous structures being essential for the continuous and complete release of encapsulated protein. These findings suggest strategies to engineer the morphology of MSs produced from PLGA-based multi-block copolymers to achieve appropriate release rates for a protein delivery system.     

顶空气相色谱法测定米非司酮中有机残留溶剂含量

目的建立米非司酮中残留有机溶剂的检测方法。方法采用顶空进样毛细管气相色谱法.以为1%的盐酸水为溶解介质,色谱柱为DB-Waxetr PEG2000,载气为氮气,FID检测器,测定米非司酮中残留的丙酮、二氯甲烷、异丙醚、四氢呋喃、环己烷。结果溶媒对残留溶剂测定无干扰,线性关系良好。结论顶空气相色谱法测定米非司酮中残留溶剂分离效果好,方法灵敏、准确。     

原料药泛昔洛韦中残留溶剂测定方法研究

目的:建立原料药泛昔洛韦中残留溶剂甲醇,乙酸乙酯,二氯甲烷和正己烷限度检查的含量测定方法。方法:顶空气相色谱法,氢火焰离子化检测器,以水为溶剂,丁酮为内标,色谱柱为石英毛细管色谱柱:HP-1(30m×0.32mm,膜厚1.05μm)。结果:4种残留溶剂在对应于限度的50%～150%浓度范围内有良好的线性关系(r=0.9974～0.9999),平均回收率为82.0%～113.0%。结论:方法简单、可靠、精确,可用于原料药残留溶剂含量控制。     

气相色谱法测定扎来普隆中二氯甲烷和N,N-二甲基甲酰胺的残留量

 目的建立毛细管气相色谱法测定扎来普隆中二氯甲烷和N,N-二甲基甲酰胺的残留量。方法采用DB-624熔融石英毛细管柱(30 m×0.32 mm,1.8μm);载气:氮气;分流比:60∶1。二氯甲烷的测定:以N,N-二甲基甲酰胺为溶剂;氯仿为内标;柱温:40℃,保持15 min,以40℃·min^-1的速率升温至180℃,保持10 min;气化室温度:180℃;检测器温度:200℃(FID)。N,N-二甲基甲酰胺的测定:以二氯甲烷为溶剂;甲苯为内标;柱温:85℃;气化室温度:200℃;检测器温度:200℃(FID)。结果二氯甲烷在15.02～150.2 mg·L^-1内线性关系良好,r=0.999 7(n=5),最低检出限为4.5 mg·L^-1,连续进样精密度RSD为1.8%,回收率为99.48%(RSD=0.9%)。N,N-二甲基甲酰胺在22.02～264.2 mg·L^-1内线性关系良好,r=0.999 7(n=5),最低检出限为4.4 mg·L^-1,连续进样精密度RSD为1.2%,回收率为99.55%(RSD=2.7%)。结论本方法可用于测定扎来普隆中二氯甲烷和N,N-二甲基甲酰胺的残留量。     

Evaluation of concentration procedures of mutagenic metabolites from urine of diesel particulate-treated rats

Several concentration procedures of mutagenic metabolites contained in the urine of diesel particulate-treated rats were compared. Mutagenicity was monitored by the Salmonella/microsome assay. The procedures tested were: lyophilization; filtration on XAD-2, XAD-7 or Sephadex LH-20 matrices; ultrafiltration; and extraction with organic solvents. Urine extraction with dichloromethane (DCM) gave almost quantitative recovery of activity while leaving salts and other polar compounds in the aqueous phase, and is the method recommended.     

Analgesic, anti-inflammatory and antioxidant properties of Buddleja globosa, Buddlejaceae

ETHNOPHARMACOLOGICAL RELEVANCE: Buddleja globosa, known as "matico", is employed in Chile for wound healing. AIM OF THE STUDY: To validate the traditional use of the crude drug through in vivo and in vitro evaluation of the anti-inflammatory, analgesic and antioxidant properties of its extracts. MATERIALS AND METHODS: Sequential hexane, dichloromethane, methanol and total methanol extracts were studied using bioguided fractionation. The following activities were investigated: analgesic (writhing test), oral and topic anti-inflammatory (paw- and ear-induced edema), free radical scavenging and antioxidant activities (1,1-diphenyl-2-picrylhydrazyl, DPPH, superoxide anion, lipid peroxidation and xanthine oxidase inhibition). Sodium naproxen, nimesulide, indomethacin were used as reference drugs for in vivo, quercetin and allopurinol for in vitro assays. RESULTS: A mixture of alpha- and beta-amyrins was isolated from the hexane extract that showed 41.2% of analgesic effect at 600 mg/kg, inhibited by 47.7 and 79.0% the arachidonic acid (AA) and 12-deoxyphorbol-13-decanoate (TPA)-induced inflammation at 3mg/20 microL/ear, respectively. A mixture of beta-sitosterol, stigmasterol, stigmastenol, stigmastanol and campesterol was isolated from the fraction CD4-N and beta-sitosterol-glycoside from the fraction CD5-N, reducing TPA-induced inflammation by 78.2 and 83.7% at 1mg/20 microL/ear, respectively. The fraction CD4-N at 300 mg/kg also showed analgesic activity (38.7%). The methanol extract at 600mg/kg per os showed anti-inflammatory effect (61.4%), topic anti-inflammatory (56.7% on TPA) and analgesic activity (38.5%). Verbascoside and luteolin-7-O-glucoside were the major components of the methanol extract; apigenin 7-O-glucoside was also detected. Inhibition of superoxide anion, lipoperoxidation, and DPPH bleaching effect was found in the methanol serial and global extracts. CONCLUSIONS: The present report demonstrate the analgesic and anti-inflammatory properties of Buddleja globosa and validate its use in Chilean traditional medicine.     

Lack of UDS activity in the livers of mice and rats exposed to dichloromethane

Dichloromethane (DCM) has been evaluated for its ability to initiate unscheduled DNA synthesis (UDS) in the livers of male mice and rats in vivo. Two types of experiment were conducted. In the first, Alpk:AP rats were exposed by oral gavage to 100, 500, or 1,000 mg/kg DCM and hepatocytes assessed for UDS via autoradiography 4 and 12 hours later. In the second, Fischer F344 rats or B6C3F1 mice were exposed by inhalation to either 2,000 or 4,000 ppm of DCM for either 2 or 6 hours, and hepatocytes assessed for UDS immediately after exposure. The dose levels and strains of rodent employed in the latter protocol correspond to those employed in a recent cancer bioassay of DCM conducted by the U.S. National Toxicology Program. DCM failed to induce UDS in any of the experiments. These data are discussed within the context of other evidence indicating DCM to be nongenotoxic in vivo, despite its reported carcinogenicity in the mouse.     

DNA adducts and oxidative DNA damage induced by organic extracts from PM2.5 in an acellular assay

The genotoxic activities of complex mixtures of organic extracts from the urban air particles collected in various localities of the Czech Republic, which differed in the extent and sources of air pollution, were compared. For this purpose, PM2.5 particles were collected by high volume samplers in the most polluted area of the Czech Republic - Ostrava region (localities Bartovice, Poruba and Karvina) and in the locality exhibiting a low level of air pollution - Trebon - a small town in the non-industrial region of Southern Bohemia. To prepare extractable organic matter (EOM), PM2.5 particles were extracted by dichloromethane and c-PAHs contents in the EOMs were determined. As markers of genotoxic potential, DNA adduct levels and oxidative DNA damage (8-oxo-7,8-dihydro-2′-deoxyguanosine, 8-oxodG, levels) induced by EOMs in an acellular assay of calf thymus DNA coupled with ³²P-postlabeling (DNA adducts) and ELISA (8-oxodG) in the presence and absence of microsomal S9 fraction were employed. Twofold higher DNA adduct levels (17.20 adducts/10⁸ nucleotides/m³ vs. 8.49 adducts/10⁸ nucleotides/m³) were induced by EOM from Ostrava-Bartovice (immediate proximity of heavy industry) compared with that from Ostrava-Poruba (mostly traffic emissions). Oxidative DNA damage induced by EOM from Ostrava-Bartovice was more than fourfold higher than damage induced by EOM from Trebon (8-oxodG/10⁸ dG/m³: 0.131 vs. 0.030 for Ostrava-Bartovice vs. Trebon, respectively). Since PM2.5 particles collected in various localities differ with respect to their c-PAHs content, and c-PAHs significantly contribute to genotoxicity (DNA adduct levels), we suggest that monitoring of PM2.5 levels is not a sufficient basis to assess genotoxicity of respirable aerosols. It seems likely that the industrial emissions prevailing in Ostrava-Bartovice represent a substantially higher genotoxic risk than mostly traffic-related emissions in Ostrava-Poruba. B[a]P and c-PAH contents in EOMs are the most important factors relating to their genotoxic potential.