Determination of fluoroquinolones, sulfonamides, and tetracyclines multiresidues simultaneously in porcine tissue by MSPD and HPLC-DAD

An efficient method is provided to detect simultaneously some important veterinary drugs from different classes in highly complex animal tissue matrix. This method using matrix solid-phase dispersion (MSPD) and high performance liquid chromatography (HPLC) with diode array detection (DAD) is developed to effectively determine two fluoroquinolones (enoxacin and lomefloxacin), two sulfonamides (sulfanilamide and sulfamethoxazole) and one tetracycline (tetracycline) simultaneously in porcine tissues. In the process, MSPD methodology was used to treat samples, washed by n-hexane to remove lipid, eluted the analytes with acetonitrile–dichloromethane (1:1, v/v). Solvent acetonitrile and solvent acetic acid (0.1%) were combined in a gradient. HPLC–DAD analysis of the tissue samples was performed within 15 min at a flow rate of 1.0 mL/min. The results showed that a recovery at 0.1, 0.5 and 1.0 μg/g fortification levels ranged from 80.6% to 99.2% with satisfactory relative standard deviations (RSDs) (below 6.1%, n=3) and the limits of quantitation (LOQ) ranged from 7 μg/kg to 34 μg/kg in porcine tissues. Utilization of the method in successfully simultaneous analysis of porcine tissue incurred with veterinary drug multiresidues is described.

Simultaneous quantification of five major active components in capsules of the traditional Chinese medicine 'Shu-Jin-Zhi-Tong' by high performance liquid chromatography

A simple and reliable high performance liquid chromatography (HPLC) method has been developed for the simultaneous quantification of five major bioactive components in ‘Shu-Jin-Zhi-Tong’ capsules (SJZTC), for the purposes of quality control of this commonly prescribed traditional Chinese medicine. Under the optimum conditions, excellent separation was achieved, and the assay was fully validated in terms of linearity, precision, repeatability, stability and accuracy. The validated method was applied successfully to the determination of the five compounds in SJZTC samples from different production batches. The HPLC method can be used as a valid analytical method to evaluate the intrinsic quality of SJZTC.

Cloud-point extraction and reversed-phase high performance liquid chromatography for analysis of phenolic compounds and their antioxidant activity in Thai local wines

A cloud-point extraction (CPE) was developed for the determination of 12 phenolic compounds (i.e. gallic acid, procatechuic acid, p-hydroxybenzoic acid, vanillic acid, caffeic acid, syringic acid, p-coumaric acid, ferulic acid, guaiacol, p-cresol, o-cresol and 3,5-xylenol) using reversed-phase high performance liquid chromatography (RP-HPLC) with photodiode array (PDA) detection. The optimum CPE conditions were 2.0% (w/v) Triton X-114, 3.0% (w/v) Na2SO4 and 20-min equilibrated at 45 °C. The surfactant-rich phase was then analyzed by HPLC using a Symmetry C18 column, gradient mobile phase of acetonitrile and 1% (v/v) acetic acid, and PDA detection at 280 nm. Under the optimum condition, the target phenolic compounds were separated within 25 min. CPE gave higher enrichment factor up to 15-fold compared to that of direct analysis. The proposed method showed good analytical performances with limits of detection in the range 0.01-0.1 mg L(-1) and precisions with relative standard deviation (RSD) lower than 5% for retention time and 10% for peak area. The method was successfully applied to the analysis of phenolic compounds in Thai local wine samples. Gallic acid, procatechuic acid, and vanillic acid were the highest phenolics found in the studied wines with the contents up to 172.4, 99.1, and 26.6 mg L(-1), respectively. The recovery of the spiked wine samples (0.5, 1.0, and 2.0 mg L(-1)) were obtained in the range of 90.4-110%. High total phenolic content, total flavonoids, and antioxidant activity (DPPH method) in the studied wines were also observed.

Combined α-thalassemia and Hemoglobin J-Iran (β77 His → Asp). A Family Study in southern Iran

We report a 23-year-old man and three members of his family with Hb J-Iran confirmed by electrophoresis, chain separation by high performance liquid chromatography and sequencing. Alpha thalassemia was also confirmed in two family members. The substitution at β77 led to a higher negative charge of the βJ-Iran subunit, which enhanced its electrostatic attraction for the normal positively-charged α subunit. Therefore, more Hb J-Iran than Hb A forms in the red blood cells of heterozygotes. In α-thalassemia, the more attractive βJ-Iran subunit outcompetes βA subunits in forming assemblies with deficient α subunits, so even more Hb J-Iran was formed.

Simultaneous determination of 12, 13-dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture by high performance liquid chromatography

A reversed phase high performance liquid chromatography (HPLC) method was established for the simultaneous determination of 12, 13-dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture. A Grace Apollo C₁₈ column (250 mm×4.6 mm, 5 μm) was used as the stationary phase and the mobile phase was composed of acetonitrile and aqueous phosphoric acid (0.2%, v/v). Gradient elution was carried out at the flow rate of 1.0 mL/min and the column temperature was 30 °C. An ultraviolet (UV) detector was used with a selected wavelength of 240 nm. Calibration curves were linear within the concentration range of 4.6-45.75 μg/mL for 12, 13-dihydroxyeuparin (r>0.9999) and 106.9-1068.9 μg/mL for glycyrrhizic acid (r>0.9999), respectively. Recoveries were 102.18% for 12, 13-dihydroxyeuparin and 101.17% for glycyrrhizic acid. The method developed could be applied to the simultaneous determination of 12, 13-dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture.

Cation Exchange High Performance Liquid Chromatography for Diagnosis of Haemoglobinopathies

BACKGROUND

Cation exchange high performance liquid chromatography (HPLC) is emerging as the method of choice for initial screening and diagnosis of haemoglobinopathies. The use of alkaline and acid gel electrophoresis in the developing countries may result in incorrect diagnosis of haemoglobinopathies. The aim of the study is to assess the accuracy and precision of diagnosis of haemoglobinopathies by HPLC and its possible advantage over conventional techniques.

METHODS

Over a two year period, 955 patients presenting with anaemia were evaluated by HPLC for diagnosis of haemoglobinopathies. All cases showing 'unknown peaks' and other rare haemoglobin variants on HPLC were further analyzed by agar gel electrophoresis at alkaline pH (8.6) and at acid pH (6.0).

RESULT

A total of 137 (14.3%) patients showed different abnormal haemoglobins variants. Of these 91 (66.4%) were diagnosed to have beta - heterozygous thalassaemia based on high level of HbA2 (>3.9%), five (3.7%) as beta - homozygous thalassaemia (HbF 25 - 91%), 15 (10.9%) as sickle cell trait, two (1.5%) as compound heterozygous state of sickle - β(+) thalassaemia and three (2.2%) patients as homozygous sickle cell anaemia (HbSS). One (0.7%) patient had unknown peak on HPLC with retention time of 4.78 minutes, constituting 16.8% of total haemoglobin. Sickling test was negative. He was diagnosed as HbQ - India heterozygous. Thirteen (9.5%) patients were diagnosed as HbE syndrome and were further sub classified as HbE trait (five cases) and HbE disease (eight cases). Seven (5.1%) patients were diagnosed as Hb - D Punjab heterozygous.

CONCLUSION

The simplicity of the sample preparation, superior resolution of the method and accurate quantitation of haemoglobin concentration, combined with complete automation, makes this an ideal methodology for diagnosis of haemoglobinopathies.

by high performance liquid chromatography

Swertia spp. (Gentianaceae) grow widely in the eastern and southern Asian countries and are used as traditional medicine for gastrointestinal disorders. Swerchirin, one of the xanthones in Swertia spp., has many pharmacological properties, such as, antimalarial, antihepatotoxic, and hypoglycemic effects. Because of the pharmacological importance of Swerchirin in this investigation, it was purified from Swertia longifolia Boiss. as one of the main components and quantified by means of a validated high performance liquid chromatography (HPLC) technique. Aerial parts of the plant were extracted with acetone 80%. Phenolic and non-phenolic constituents of the extract were separated from each other during several processes. The phenolic fraction was injected into the semi-preparative HPLC system, which consisted of a C₁₈ column and a gradient methanol: 0.1% formic acid mode. Using this method, we were able to purify six xanthones from the plant, in order to use them as standard materials. The analytical method was validated for Swerchirin as one of the most important components of the plant, with more pharmacological activities according to the validation parameters, such as, selectivity, linearity (r² > 0.9998), precision (≤3.3), and accuracy, which were measured by the determination of recovery (98-107%). The limits of detection and quantization were found to be 2.1 and 6.3 μg/mL, respectively. On account of the speed and accuracy, the UV-HPLC method may be used for quantitative analysis of Swerchirin.

Effects of leptin on the content of triglyceride and the expression of peroxisome proliferator activated receptor α and carnitine palmitoyltransferase-I in human hepatocytes with fatty degeneration

AIM: To the influence of leptin on lipid degeneration of hepatocytes and its mechanism.

METHODS: The model of hepatocyte fatty degeneration was prepared using human L-02 liver cells. This experiment included the following groups: normal hepatocytes group, fatty degeneration model group, positive control group (treated with gemfibrozil), and leptin treatment groups I, II and III (using 10^-8, 10^-7 and 10^-6 mol/L leptin, respectively). After 24-hour incubation, cell morphology and the formation of intracellular lipid droplets were observed by oil red O staining and the content of intracellular triglyceride (TG) was detected through high performance liquid chromatography (HPLC). Besides, the mRNA expression levels of peroxisome proliferator activated receptor α (PPARα) and its target gene carnitine palmitoyltransferase-I (CPT-I) were detected by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS: The intracellular lipid droplets were increased in the model group and leptin group I as compared with those in the other groups. The contents of intracellular TG were 1.063 ± 0.146, 0.648 ± 0.023 and 0.553 ± 0.045 mmol/g protein respectively when leptin was used at concentrations of 10^-8, 10^-7 and 10^-6 mol/L. In comparison with that in the positive control group, the mRNA expression of PPARα was increased significantly in the leptin groups II or III (P < 0.01); but PPARα mRNA expression was not remarkably different between the leptin group I and the positive control group. There was no marked difference between the model group and the normal group in CPT-I mRNA expression, but it was significantly elevated after leptin treatments (P < 0.01).

CONCLUSION: Leptin decreases the content of TG in human L-02 hepatocytes with fatty degeneration in a dose-dependent manner, and its mechanism may be related to the up-regulation of PPARα and its target genes.

Measurement of plasma total homocysteine levels in liver failure patients

AIM: To investigate the relationship between plasma total homocysteine (tHcy) levels and liver failure.

METHODS: Plasma tHcy in 96 liver failure patients, 37 non-failure patients and 55 healthy controls were measured by high performance liquid chromatography (HPLC). Serum ALT, AST, TBIL, CHE, ALB, PALB, GLU, Cr and amino acid levels in liver failure patients were also detected, and meanwhile, their relationship with plasma tHcy was analyzed.

RESULTS: The levels of plasma tHcy in liver failure and non-failure patients were significantly higher than those in the healthy controls (14.38 ± 5.85, 12.44 ± 5.39 µmol/L vs 10.29 ± 1.96 µmol/L; P = 0.000, 0.042), and 60.24%, 40.54% of the patients showed significantly higher tHcy levels. Plasma tHcy levels in the acute-on-chronic liver failure patients were a little higher than those in the chronic liver failure patients. There were weak correlations between plasma tHcy levels and ALT, AST, ALB, TBIL, PALB, Cr, and BCAA/AAA, but there was significantly positive correlation between tHcy and methionine (r = 0.297, P < 0.05). The level of tHcy had no marked relation between survivors and the dead.

CONCLUSION: The level of plasma tHcy is obviously elevated in liver failure patients, but it can not be used to evaluate the prognosis of liver failure.

Identification of differential HLA-binding peptide between two hepatoma cell lines HepG2 and HepG2.2.15

AIM: To screen the differential HLA-binding peptides between HepG2 and HepG2.2.15 cell lines, and to find some HLA-binding peptides correlated with hepatitis B virus (HBV) infection.

METHODS: HepG2 and HepG2.2.15 cells were harvested (108 cells), and the peptides were isolated from the cell membrane by mild acid elution, respectively. Then the mixture of peptides was fractionated by high performance liquid chromatography (HPLC) and the differential fractions only expressed in HepG2.2.15 cell line were identified by nanoESI-MS/MS analysis. Bioinformatic analysis and MASCOT index were used to investigate the sequence and source of the peptides. Finally the expression of mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS: HPLC fractions were markedly different between HepG2 and HepG2.2.15 cells. A peptide, SPDDPSRYISPDQ, from enolase 1 (ENO1) was obtained, which was only expressed in HepG2.2.15 cells, by nanoESI-MS/MS analysis. The result of RT-PCR confirmed that ENO1 expression was significantly higher in HepG2.2.15 cells than that in HepG2 cells.

CONCLUSION: A human peptide SPDDPSRYISPDQ from ENO1 can be presented on the surface of HepG2.2.15 cells by HLA, and ENO1 mRNA expression is significantly higher in HepG2.2.15 than that in HepG2, suggesting that HBV infection may cause the up-regualtion of ENO1 expression.

Role of andrographolide in the permeability of intestinal tract of cirrhosis rats and its clinical significance

AIM: To detect the impact of andrographolide on the permeability of intestinal tract of cirrhosis rats by high performance liquid chromatography and to probe its clinical significance.

METHODS: The discharge rate of mannitol (M) and lactulose (L) in cirrhosis rats was detected by high performance liquid chromatography (HPLC) and compared with the standard curve.

RESULTS: The lactulose/mannitol (L/M) discharge rate in cirrhosis rats was significantly higher than that in normal rats (0.036 ± 0.012 vs 0.026 ± 0.009, P < 0.05) and significantly lower in the andrographolide and norfloxacin intervention group than that in the control group (0.022 ± 0.010, 0.022 ± 0.007 vs 0.036 ± 0.012, P < 0.05).

CONCLUSION: The permeability of intestinal tract of cirrhosis rats is significantly higher than that of normal rats and significantly lower in the andrographitis and norfloxacin intervention group than that in the control group.

Comparison of protocatechuic aldehyde in Radix Salvia miltiorrhiza and corresponding pharmacological sera from normal and fibrotic rats by high performance liquid chromatography

AIM: To observe the effect of protocatechuic aldehyde on the proliferation of hepatic stellate cells (HSCs).

METHODS: Liver fibrosis was induced in rats by carbon tetrachloride (CCl₄). Then normal and fibrotic drug sera were extracted from rats. The effects of protocatechuic aldehyde, raw Radix Salvia miltiorrhiza and drug sera of Salvia miltiorrhiza on HSC growth were determined by CCK-8. The protocatechuic aldehyde was separated by high performance liquid chromatography (HPLC) in a Alltima C18 column (250 mm × 4.6 mm, 5 μm) with a mobile phase of acetonitrile-4% glacial acetic acid solution (gradient elution) at the wavelength of 281 nm.

RESULTS: Protocatechuic aldehyde, raw Radix Salvia miltiorrhiza and drug sera of Salvia miltiorrhiza were found to have inhibitory effects on proliferation of rat HSCs. Raw Radix Salvia miltiorrhiza had a stronger inhibitory effect than the drug sera. The fibrotic drug sera showed a higher suppressive effect than the normal drug sera (P < 0.05). Protocatechuic aldehyde was found in crude materials of both Radix Salvia miltiorrhiza and its corresponding drug sera. The average recovery (n = 6) was 110.5% for raw Salvia miltiorrhiza Bge, 102% for normal drug sera and 105.2% for fibrotic drug sera. The relative standard deviation (RSD) was 0.37%, 1.96% and 1.51%, respectively (n = 6). The contents of protocatechuic aldehyde were 0.22%, 0.15% and 0.19%, respectively (n = 6) (P < 0.05). The RSD was 0.33%, 0.75% and 1.24% (n = 6) for raw material of Radix Salvia miltiorrhiza, normal drug sera and fibrotic drug sera, respectively. The samples were stable for 6 d.

CONCLUSION: Protocatechuic aldehyde can inhibit the growth of HSCs. HPLC is suitable for the determination of virtual bioactive components of Chinese herbal medicines in vitro.

Urinary nucleosides as biological markers for patients with colorectal cancer

AIM: Fourteen urinary nucleosides, primary degradation products of tRNA, were evaluated to know the potential as biological markers for patients with colorectal cancer.

METHODS: The concentrations of 14 kinds of urinary nucleosides from 52 patients with colorectal cancer, 10 patients with intestinal villous adenoma and 60 healthy adults were determined by column switching high performance liquid chromatography method.

RESULTS: The mean levels of 12 kinds of urinary nucleosides (except uridine and guanosine) in the patients with colorectal cancer were significantly higher than those in patients with intestinal villous adenoma or the healthy adults. Using the levels of 14 kinds of urinary nucleosides as the data vectors for principal component analysis, 71% (37/52) patients with colorectal cancer were correctly classified from healthy adults, in which the identification rate was much higher than that of CEA method (29%). Only 10% (1/10) of patients with intestinal villous adenoma were indistinguishable from patients with colorectal cancer. The levels of m1G, Pseu and m1A were positively related with tumor size and Duke’s stages of colorectal cancer. When monitoring the changes in urinary nucleoside concentrations of patients with colorectal cancer associated with surgery, it was found that the overall correlations with clinical assessment were 84% (27/32) and 91% (10/11) in response group and progressive group, respectively.

CONCLUSION: These findings indicate that urinary nucleosides determined by column switching high performance liquid chromatography method may be useful as biological markers for colorectal cancer.

Identification of naturally presented MAGE epitopes from tissues of hepatocellular carcinoma by mass spectrometry

AIM: To detect the naturally processed antigenic peptides of melanoma antigen gene (MAGE) in tissues of hepatocellular carcinoma (HCC) by the technology of mass spectrometry (MS) and the strategy of differential analysis.

METHODS: Epitope prediction was performed to select HLA-A2-restricted protein sequence of MAGE-1 and MAGE-3 (theoretic peptides) to serve as the targets for MS screening. Peptides were isolated by mild acid elution from the surfaces of HCC cells and non-neoplastic liver cells, which were obtained from the same patient with HCC. Then the mixtures of peptides were fractionated by HPLC and a differential comparison was made between the two kinds of cells. Finally, the fractions contained tumor-specific peptides were analyzed by MS.

RESULTS: Eighty target peptides were selected after epitope prediction. Two naturally processed peptides of MAGE antigen were detected from HCC samples: FLWGPRALV (MAGE-3_271-279) and FPSLREAAL (MAGE-1_294-302). They were from peak 45.246 and 34.801, and the m/z was 1 058.49 and 1 003.62 respectively.

CONCLUSION: It is the first evidence that naturally presented peptides of MAGE antigen can be isolated and identified from the tumor tissues. MS-based approach can determine naturally processed peptides of tumor antigen rapidly and precisely, which is important in epitope identification and vaccine designation.