High-performance liquid chromatography determination and pharmacokinetics of coumarin compounds after oral administration of Samul-Tang to rats.

BACKGROUND: Samul-tang has been traditionally used for the treatment of cardiovascular, gynecologic, cutaneous, and chronic inflammation disorders. Although coumarin compounds do have various pharmacological activities and the same may be present in Samul-tang, however there is little information about it. OBJECTIVE: A simple and sensitive high-performance liquid chromatography (HPLC) method has been developed for the determination of nodakenin, nodakenetin, decursin, decursinol, and decursinol angelate in rat plasma. To obtain a better understanding for pharmacological properties of Samul-tang, pharmacokinetic study of coumarin compounds was performed after oral administration of Samul-tang in rats. MATERIALS AND METHODS: Chromatographic separation of the analytes was successfully achieved on a Phenomenex Luna C18 column (4.6 mm×250 mm, 5 µm) using a mobile phase composed of acetonitrile water with a gradient elution at a flow rate of 1 mL/min. Noncompartmental analysis was performed. RESULTS: Calibration curves for all analytes had good linearity (r(2) <0.999) in a wide linear range. The lower limit of quantification (LLOQ) ranged from 0.05 to 0.1 µg/mL. The variation of intra- and interday assay was less than 15%. Nodakenin, nodakenetin, and decursinol were determined in rat plasma after oral administration of Samul-tang. CONCLUSION: This developed and validated HPLC method was successfully applied to the pharmacokinetic study of three coumarin compounds in rats, given as a single oral administration of Samul-tang. These pharmacokinetic data of the nodakenin, nodakenetin, and decursinol could offer a new point of view to evaluate the pharmacological effects of Samul-tang.

Effects of berberine and hwangryunhaedok-tang on oral bioavailability and pharmacokinetics of ciprofloxacin in rats.

Hwangryunhaedok-Tang (HR) and berberine-containing single herbs are used to treat bacterial infection and inflammatory diseases in eastern Asia. The combination of berberine-containing herbal medicines and ciprofloxacin can be an excellent antibacterial chemotherapy against multidrug resistance bacteria. To evaluate the pretreatment effect of berberine and HR, vehicle, berberine (25 and 50 mg/kg/day), and HR (1.4 g/kg/day) were daily administered to rats for five consecutive days. On day 6, ciprofloxacin was administered (10 mg/kg, i.v. and 20 mg/kg, p.o.) to rats. To assess cotreatment effect of berberine and ciprofloxacin, berberine (50 mg/kg) and ciprofloxacin (20 mg/kg) were coadministered by single oral gavage. Pharmacokinetic data were estimated by noncompartmental model. Compared with ciprofloxacin alone (control group), coadministration of berberine (50 mg/kg) and ciprofloxacin significantly decreased C(max) of ciprofloxacin (P < 0.05). In addition, the pretreatment of berberine (50 mg/kg/day) and HR (1.4 g/kg/day) significantly decreased C(max) and AUC(0→∞), compared with control group (P < 0.05). The oral bioavailability of ciprofloxacin was reduced by cotreatment of berberine and pretreatment of berberine and HR. Our results suggest that the expression of P-glycoprotein and organic anion and/or organic cation transporters (OAT/OCT) could take a role in reduced oral bioavailability of ciprofloxacin by berberine and HR.

Food- and gender-dependent pharmacokinetics of paeoniflorin after oral administration with Samul-tang in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Samul-tang (Si-Wu-tang in Chinese, Shimotsu-to in Japanese), widely used in eastern Asia, is composed of Angelica gigas (Angelicae Gigantis Radix), Cnidium officinale (Cnidii Rhizoma), Paeonia lactiflora (Paeonia Radix) and Rehmannia glutinosa (Rehmanniae Radix Preparata). Paeoniflorin, one of active components in Samul-tang has anti-platelet, anti-inflammation, anti-cancer and neuroprotective properties. However, there is no information about the effects of gender and food intake on the pharmacokinetics of paeoniflorin till now. AIM OF THE STUDY: This study was conducted to investigate whether food and gender could influence pharmacokinetic profiles of paeoniflorin after oral administration of Samul-tang. MATERIALS AND METHODS: Male and female rats were administered with a single oral dose of Samul-tang equivalent to 80 mg/kg of paeoniflorin. Plasma concentrations of paeoniflorin were measured by high-performance liquid chromatography. The statistical differences of each group were evaluated using the analysis of variance (ANOVA) or Student t-test. RESULTS: The pharmacokinetic parameters of paeoniflorin were not significant different by gender difference. However, the maximum plasma concentration (C(max), 0.47±0.29 µg/mL versus 1.10±0.35 µg/mL), area under the concentration-time curve (AUC(0→∞), 1.41±0.89 h · µg/mL versus 3.12±1.61 h · µg/mL) and relative bioavailability (F(rel)=2.21) of fed rats were significantly increased in comparison with those of fasted rats (P<0.05). CONCLUSION: Taken together, food intake can affect both the rate and extent of absorption of paeoniflorin when Samul-tang was administered orally. Furthermore, this study demonstrates a readily preparative HPLC method in the research of traditional herbal medicine.

Optical imaging of MMP expression and cancer progression in an inflammation-induced colon cancer model.

The purpose of this study was to use a near-infrared (NIR) fluorescent cyclic His-Try-Gly-Phe peptide to characterize and image the expressions of matrix metalloproteinases (MMPs), which are correlated with cancer promotion, in an inflammation-induced colorectal cancer (ICRC) model. We explored the relationship between the development of colon cancer and the expression of MMPs at the same colonic sites in ICRC models. To develop ICRC models, mice were administered a single intraperitoneal dose (10 mg/kg) of azoxymethane (AOM) and exposed orally to 2% dextran sodium sulfate (DSS) for one week. MMP-2 expression and ß-catenin activation in colonic lesions were characterized by immunohistochemical (IHC) staining. After being treated with inducers for some time, cancerous lesions were found to express high ß-catenin and MMP-2. The profiles of MMP expression were correlated with ß-catenin activation in the colonic lesions. c(KAHWGFTLD)NH(2) (C6) peptide was prepared by standard Fmoc peptide synthesis to target MMPs. Molecular weight of Cy5.5-C6 was 1,954.78 g/mol (calculated MW = 1955.23 g/mol). The in vitro characterization of Cy5.5-C6 showed MMP binding specificity in a cell experiment. In vivo NIRF imaging showed high accumulation of Cy5.5-C6 in tumors with associated expression of MMP-2 in colonic lesions after intravenous injection. The MMP-2 specificity of Cy5.5-C6 was confirmed by successful inhibition of probe uptake in the tumor due to the presence of excess C6 peptide. The use of Cy5.5-C6 to target MMP-2 has the potential to be developed into an effective molecular imaging agent to monitor ICRC progress.

Effect of molecular imaging on validation of developed anti-hVEGFR2 therapeutic antibody.

Vascular endothelial growth factor receptor type 2 (VEGFR2)-targeted tumor treatment is an antiangiogenic therapeutic strategy. The human sodium iodide symporter (hNIS) gene is a useful reporter gene for tumor imaging and radiotherapy. In this study, we investigated the evaluation of therapeutic efficacy in hNIS gene-transfected tumor xenografts using a gamma imaging system after treatment with an anti-VEGFR2 antibody. Human breast cancer MDA-MB-231 cells transfected with the hNIS gene were injected subcutaneously into the right flanks of BALB/c nude mice. Therapy was initiated when the tumor volume reached approximately 130-180 mm(3). The animals were intravenously injected with 50, 100, or 150 µg of antibody every 3 days for 16 days. Gamma imaging was performed 1 and 2 weeks after the first injection to monitor the effects of tumor therapy. Mice were sacrificed 2 weeks after the first injection of antibody and the tumors were removed for CD31 staining and reverse transcription-polymerase chain reaction (RT-PCR) assay. All groups of mice that were treated with anti-hVEGFR2 antibody showed markedly reduced tumor growth compared to control mice. In vivo gamma imaging results showed that, at 1 week after the first injection of the anti-hVEGFR2 antibody, (125)I uptake of a tumor treated with 150 µg of antibody was 24.5% lower than that in the controls. At 2 weeks, (125)I uptake in the tumor treated with 150 µg of antibody was as low as 44.3% of that in the controls. CD31 staining and RT-PCR assays showed that blood vessel formation and expression of the hNIS gene were reduced with increased treatment doses. This study demonstrated the feasibility of molecular imaging and the therapeutic efficacy of developing therapeutic antibody anti-hVEGFR2 using a gamma imaging system in hNIS gene-transfected tumor xenograft mice.

Reduction of stimulated sodium iodide symporter expression by estrogen receptor ligands in breast cancer cells.

PURPOSE: The sodium iodide symporter (NIS) mediates active iodide uptake in lactating breast tissue, and when its levels are enhanced by all-trans retinoic acid (atRA), NIS has been proposed as a target for the imaging and radiotherapy of breast cancer. Importantly, the estrogen receptor α (ERα) is an important regulator of atRA induced NIS gene expression in breast cancer cells. In this study, we investigated the effect of an ER agonist (17ß-estradiol, E(2)) or antagonist [trans-hydroxytamoxifen (TOT) or raloxifene (RAL)] treatment on the regulation of NIS gene expression and iodide uptake in an ERα-positive breast cancer (MCF-7) model. METHODS: NIS functional activity was measured in vitro by (125)I uptake assay after incubation with E(2) (from 10(-15) to 10(-5) M), TOT (from 5×10(-8) to 5×10(-6) M), or RAL (from 5×10(-8) to 5×10(-6) M) in the presence or absence of atRA (10(-7) M). Under the same conditions, NIS mRNA expression was examined by reverse transcriptase polymerase chain reaction. Athymic mice with MCF-7 xenograft tumors were treated with atRA alone or atRA together with E(2) to evaluate the change of (125)I uptake in tumor tissues in vivo. RESULTS: In the iodide uptake study in cells, E(2), TOT, or RAL treatment alone did not stimulate (125)I uptake. However, when iodide uptake was stimulated by atRA, cotreatment with E(2), TOT or RAL decreased (125)I uptake in a concentration-dependent manner. The hormone effects on NIS mRNA expression levels in MCF-7 cells were similar. The results of the in vivo biodistribution study showed that (125)I uptake was reduced 50% in tumor tissues of mice treated with atRA/E(2) as compared to tumors treated only with atRA. CONCLUSION: Our results suggest that combination treatment of atRA and ER ligands could limit the functional activity of the NIS gene induced by atRA, thereby compromising its use as a target for diagnosis or radiotherapy in breast cancer.

Oleyl-chitosan nanoparticles based on a dual probe for optical/MR imaging in vivo.

Oleic acid-conjugated chitosan (oleyl-chitosan) is a powerful platform for encapsulating oleic acid-decorated iron oxide nanoparticles (ION), resulting in a good magnetic resonance imaging (MRI) probe. Oleyl-chitosan could self-assemble into core-shell structures in aqueous solution and provide the effective core compartment for loading ION. ION-loaded oleyl-chitosan nanoparticles showed good enhanced MRI sensitivity in a MR scanner. Cy5.5 dye was accessed to the oleyl-chitosan conjugate for near-infrared (NIR) in vivo optical imaging. After intravenous injection of ION-loaded Cy5.5-conjugated oleyl-chitosan (ION-Cy5.5-oleyl-chitosan) nanoparticles in tumor-bearing mice, both NIRF and MR imaging showed the detectable signal intensity and enhancement in tumor tissues via enhanced permeability and retention (EPR) effect. Tumor accumulation of the nanoparticles was confirmed through ex vivo fluorescence images and Prussian blue staining images in tumor tissues. It is concluded that ION-Cy5.5-oleyl-chitosan nanoparticle is highly an effective imaging probe for detecting tumor in vivo.

Surface engineering of quantum dots for in vivo imaging.

The aim of this study was to investigate the effect of gluconic acid (GA) conjugation on the biodistribution of cysteamine-capped quantum dots (amino-QDots) in vivo. Cadmium selenide/zinc sulfide (CdSe/ZnS) was capped with cysteamine through a thiol exchange method, and different amounts of GA were conjugated to the amine groups of cysteamine via the formation of an amide bond. The emission maxima of the synthesized QDots, the amino-QDots and the GA-conjugated amine-QDots (GA-QDots) were located at 720, 600 and 610 nm, respectively. In the cell viability studies, the GA-QDots showed very low toxicity against CHO cells as compared to the cytotoxicity of the amino-QDots. The QDots were next intravenously injected into normal mice and then we performed ex vivo optical imaging. The majority of the amino-QDots were accumulated in the lung. In contrast, the GA-QDots were cleared out of the body through the kidney. Therefore, we expect that the conjugation of GA onto the amino-QDots can create opportunities for using amino-QDots for in vivo imaging.