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ABSTRACT: Curcumin is a popular plant medicine that is extracted from turmeric dry rhizomes of Curcuma longa Linn. The study of curcumin is well established and is currently becoming a centre of attention.
To develop a steady and simple assay for curcumin determination at the nanogram level based on the intense resonance light scattering (RLS) enhancement due to the interaction between curcumin and phosphodiesters quaternary ammonium salt (PQAS).
PQAS, a new kind of Gemini zwitterionic surfactant, was used as the probe for the determination of curcumin by the RLS technique. A series of validation experiments was also performed.
A linear relationship was constructed between the ΔI(RLS) and the concentration of curcumin. The linear regression equation was presented as ΔI(RLS) = 8.37 + 44.92c (µg/mL) with the regression coefficient r = 0.9987 (n = 12) and the linear range was 0.08-60.0 µg/mL. The detection limit (3σ) was 2.6 ng/mL.
The proposed method can be used to detect the content of curcumin in human urine samples and this new assay using PQAS as a probe was more sensitive and displayed a wider linear range than that reported previously.
Phytochemical Analysis 12/2011; 23(5):456-61. · 2.63 Impact Factor
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ABSTRACT: To identify a proliferation-inducing ligand (APRIL) expression profile in tumor tissue and sputum of lung cancer, and evaluate the possibility of an assistant diagnosis of lung cancer by real-time fluorescence quantitative polymerase chain reaction (RTQ-PCR) in sputum as well, the authors analyzed the expression of APRIL mRNA in 75 tissue samples and 71 corresponding sputum samples of lung cancer by RTQ-PCR and analyzed their correlation. APRIL protein expression was also observed in tumor tissues by Western blot and immunohistochemistry. The expression analysis revealed APRIL expression was elevated in non-small cell lung cancer (NSCLC) and the expression of APRIL protein was located in the membrane and cytoplasm of tumor cells by immunohistochemiscal staining. Compared to benign pulmonary disease and healthy volunteers, the expression of APRIL mRNA in sputum of lung cancer was elevated (both P <. 001). When cut-off values for positivity were set at the mean + 2SD of mRNA expression in healthy volunteers, the positive rate for APRIL mRNA expression was 81.7% (58/71) in sputum samples of lung cancer, 3.2% (2/62) in benign pulmonary disease, and 1.5% (1/65) in healthy volunteers. The correlation was evident between the expression level of APRIL mRNA of tissue samples and that of sputum samples (P <. 001, r =. 702). These results support the possibility that the APRIL gene may play a key role in lung cancer, especially in NSCLC. The elevated expression level of APRIL mRNA in sputum of NSCLC suggested that APRIL mRNA may serve as an effective and convenient diagnostic biomarker for NSCLC.
Experimental Lung Research 08/2009; 35(6):486-500. · 1.22 Impact Factor
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ABSTRACT: APRIL, a member of the TNF superfamily, can induce cell proliferation and is overexpressed in most tumor tissues or cells. Nevertheless, it is still unknown about the effect of decreased levels of APRIL expression on tumor cells. In this study, we analyzed APRIL and HSPG expression in the colon carcinoma cell line, SW480 by Western blot and RT-PCR. And the up-regulation of APRIL and HSPG expression was found in SW480. We also observed that knockdown of APRIL levels in SW480, prominently reversed cell proliferation and partially resulted in senescence phenotypes. Furthermore, cellular senescence due to a decreased level of APRIL expression was associated with engagement of HSPG. Thus, our results suggest that low levels of APRIL play an essential role in cellular senescence via a HSPG-dependent signaling pathway in SW480.
Pathology & Oncology Research 06/2009; 15(4):693-701. · 1.37 Impact Factor
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ABSTRACT: A novel free-probe assay of dextrin was established based on the resonance light scattering (RLS) enhancement in aqueous solution due to the self-aggregation of dextrin. The RLS intensity was well proportional to the concentration of dextrin over the wide range 0.2-14microg mL(-1) and a detection limit 0.02microg mL(-1) was obtained in the optimum conditions. The effect factors such as pH, buffer medium, holding time, ionic strength and temperature were studied in detail. Little or no interference was presented in the detection when adding coexisting substances including various metal ions and some saccharine in the solution. The assay proposed owns the advantages of easy operation, rapidity, sensitivity and practicability. Three synthetic samples and three kinds of medicine samples were analyzed with satisfactory results.
Analytica chimica acta 04/2009; 635(2):202-6. · 4.31 Impact Factor
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ABSTRACT: A fantastic resonance light scattering (RLS) enhancement phenomenon was found when the interaction between the metal ion Cu (II) and a natural antioxidant curcumin (C(21)H(20)O(6)) occurred in certain conditions. Based on this phenomenon, a novel and convenient assay of curcumin was developed and successfully applied on the determination of curcumin in human urine samples. This assay applied the RLS technique with a common metal ion Cu (II) as the spectral probe. In the pH range of 6.5-7.5, the interaction between Cu (II) and curcumin occurred and the weak RLS intensity of Cu (II) was greatly enhanced by curcumin. The maximum peak was located at 538.5 nm. Under the optimum conditions, the enhanced RLS intensity was proportional to the concentration of curcumin ranging from 0.4 to 60 microg ml(-1) with the detection limit of 0.07 microg ml(-1). The synthetic and human urine samples were determined satisfactorily. Good recoveries (98.8-102.5%) were obtained in the determination of urine samples, which proved that the assay proposed was reliable and applicable in the determination of curcumin in body fluid. In this work, the RLS and fluorescence spectral characteristics of the chemicals, the optimum conditions of the reaction and the influencing factors were investigated.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 12/2008; 72(3):518-22. · 2.10 Impact Factor
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ABSTRACT: A novel method is designed for the direct determination of trace amounts of molybdenum(VI) in tap water, human hair, and Chinese herbal medicine by means of decreasing resonance light scattering (RLS) technique. The characteristics of RLS spectra, the effective factors, and optimum conditions of the reaction were studied. In the medium of hydrochloric acid (pH 2.38), Mo(VI), dibromohydroxyphenylfluorone (DBHPF), and Triton X-100 react to form a complex, resulting in significant decreasing RLS signals of DBHPF-Triton X-100. The decreasing RLS intensity at 583.0 nm is proportional to the concentration of Mo(VI) up to 8.0 ng mL(-1). The detection limit is 0.013 ng mL(-1). The method is simple, reproducible, with reaction rapidity and stability of complexes formed. Moreover, the high selectivity and sensitivity of this method permits its direct determination of molybdenum(VI) in tap water, human hair, and Chinese herbal medicine and the results are in agreement with those obtained by the inductively coupled plasma atomic emission spectrometry (ICP-AES) method.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 08/2008; 70(2):290-6. · 2.10 Impact Factor
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ABSTRACT: A method for the specific determination of an antibacterial quaternary ammonium compound Dequalinium chloride (DQC) was described in this paper. At pH 0.5, the resonance light scattering (RLS) intensity of sodium dodecyl benzene sulfonate (SDBS) remarkably was enhanced by adding DQC. A RLS peak at 392.0 nm was found, and the enhanced intensity of RLS at this wavelength was proportional to the concentration of DQC in the range of 0.096-2.88 microg/mL. The detection limit was 2.98 ng/mL and the correlation coefficient was r=0.9988 (n=9). The method was applied to the analysis of DQC in lozenges and human serum. The results indicated that the method was sensitive, simple, practical and useful in the clinical assay.
Journal of Pharmaceutical and Biomedical Analysis 06/2008; 48(3):946-50. · 2.97 Impact Factor
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ABSTRACT: A novel resonance light scattering (RLS) decrease method was developed to determine rutin with a simple probe manganese sulfate. At pH 7.5, the strong RLS intensity of manganese sulfate was remarkably decreased by the addition of rutin with the maximum peak located at 389.0 nm. Under the optimum conditions, a good linear relationship between the changes of RLS intensities of manganese sulfate with and without rutin and the concentrations of rutin was obtained over the range of 0.49-24.4 microg ml(-1) and a low detection limit (3sigma) 0.42 microg ml(-1) was achieved in the mean time. Based on this approach, a novel method for quantitative analysis of rutin is proposed in this paper. The method proposed was also applied successfully to the determination of rutin in commercial pharmaceutical preparations of compound rutin tablets and human urine samples. The assay is sensitive, rapid, inexpensive, practical and relatively free from interference generated by coexisting substances.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 02/2008; 71(2):344-9. · 2.10 Impact Factor
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ABSTRACT: Manganese chloride can form large particles with nucleic acids by electrostatic forces, which results in strong enhancement of resonance light scattering (RLS) signals. Based on this phenomenon, a novel and very simple assay of DNA was established. The work conditions have been investigated including the concentration of probe, the acidity of solution, the effect of ionic strength and the selectivity. In acidic solution, the enhanced RLS intensity at 389.5 nm was proportional to the concentration of nucleic acids in the range 0.05-10.0 microg ml(-1) for both ctDNA and fsDNA and 1.0-10.0 microg ml(-1) for yRNA. The limits of detection (LOD, 3sigma) were 0.17, 0.13 and 0.53 ng ml(-1) for ctDNA, fsDNA and yRNA, respectively. Synthetic samples were determined satisfactorily.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 11/2007; 68(2):263-8. · 2.10 Impact Factor
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ABSTRACT: A novel assay of DNA at nanogram levels is presented that is based on the measurement of resonance light scattering (RLS)
signals in the presence of norfloxacin. The characteristics of RLS spectra, the effective factors and the optimum conditions
of the reaction have been investigated. In Britton-Robinson buffer (pH 5.87), norfloxacin has a maximum peak at 405.5 nm and
the RLS intensity is greatly enhanced by trace amounts of DNA due to the interaction between norfloxacin and DNA. Mechanistic
studies show that the binding of norfloxacin to DNA forms large particles, which result in the significant enhancement of
RLS intensity. The enhanced intensity of RLS is proportional to the concentration of DNA in the range from 0.01–2.0 µg mL−1 for yeast DNA, and from 0.02 to 2.3 µg mL−1 for calf thymus DNA. The determination limit (3σ) is 0.7 ng mL−1 for yeast DNA and 1.2 ng mL−1 for calf thymus DNA, respectively. Synthetic samples were determined satisfactorily.
Microchimica Acta 12/2006; 157(1):107-112. · 3.03 Impact Factor
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ABSTRACT: The interaction between norfloxacin and calf thymus double-stranded DNA (dsDNA) has been studied by a resonance light scattering (RLS) technique with a common spectrofluorometer. The characteristics of RLS spectra, the effective factors and optimum conditions of the reaction have been investigated. In Britton-Robinson (BR) buffer (pH 5.87), norfloxacin has a maximum peak 405.5 nm and the RLS intensity is remarkably enhanced by trace amount of calf thymus dsDNA due to the interaction between norfloxacin and dsDNA. The binding of norfloxacin to DNA forms large particles, which were characterized by RLS spectrum, scanning electron microscopy (SEM), ultraviolet-visible (UV-vis) spectrum, and fluorescence spectrum. Based on the enhanced RLS intensity, a novel method for sensitive determination of calf thymus dsDNA concentration ranging from 0.02 to 2.3 microg ml(-1) was developed. The determination limit (3 sigma) was 1.2 ng ml(-1). The method is simple, rapid, practical and relatively free from interference generated by coexisting substance, as well as much more sensitive than most of the reported methods. Three synthetic samples of ctDNA were determined with satisfactory results.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 12/2006; 65(3-4):919-24. · 2.10 Impact Factor
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ABSTRACT: A novel histidine-selective method has been developed for the determination of histidine in aqueous solutions by resonance light scattering (RLS) technique. At pH 8.0, the weak RLS intensity of tetraphenylporphyrin manganese (III) chloride [MnTPPCl] was greatly enhanced by the addition of histidine with the maximum peak located at 483 nm. Under the optimum conditions, it was found that the enhanced RLS intensity was in proportion to the concentration of histidine in the range 7.8 × 10−7–2.4 × 10−5 mol l−1. Low detection limit of 9.2 × 10-8 mol l−1 has been achieved. The histidine concentrations in synthetic samples and real samples were determined with satisfactory results. The sensitivity and selectivity of this method are high enough to permit the determination of trace amounts of histidine without any significant interference from high levels of other components such as common anions and especially, other amino acids.
Analytica Chimica Acta.
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ABSTRACT: Based on the interaction between nucleic acids and tetraphenyl porphyrinatoiron chloride (FeTPPCl), a novel method for the determination of nucleic acids at the nanogram level has been developed. Under the optimum conditions, the weak resonance light scattering (RLS) intensity of FeTPPCl was greatly enhanced by nucleic acids and the enhanced RLS intensity was proportional to the concentration of nucleic acids in the range 0.02-2.8 microg/mL for calf thymus DNA, 0.05-3.3 microg/mL for fish sperm DNA and 0.07-4.5 microg/mL for yeast RNA. The detection limits (3sigma) were 2.9 ng/mL for calf thymus DNA, 3.9 ng/mL for fish sperm DNA and 5.2 ng/mL for yeast RNA. Almost no interference could be observed from proteins, nucleosides and most of the metal ions. The proposed method showed good reliability, sensitivity, rapidity and reproducibility when applied to the determination of nucleic acids in synthetic and biochemical samples. The time savings make this method suitable for large routine analyses.
Luminescence 22(5):493-500. · 1.73 Impact Factor
