Effects of AF3442 [N-(9-ethyl-9H-carbazol-3-yl)-2-(trifluoromethyl)benzamide], a novel inhibitor of human microsomal prostaglandin E synthase-1, on prostanoid biosynthesis in human monocytes in vitro

Inhibitors of microsomal prostaglandin (PG) E synthase-1 (mPGES-1) are being developed for the relief of pain. Redirection of the PGH₂ substrate to other PG synthases, found both in vitro and in vivo, in mPGES-1 knockout mice, may influence their efficacy and safety. We characterized the contribution of mPGES-1 to PGH₂ metabolism in lipopolysaccharide (LPS)-stimulated isolated human monocytes and whole blood by studying the synthesis of prostanoids [PGE₂, thromboxane (TX)B₂, PGF_2α and 6-keto-PGF_1α] and expression of cyclooxygenase (COX)-isozymes and down-stream synthases in the presence of pharmacological inhibition by the novel mPGES-1 inhibitor AF3442 [N-(9-ethyl-9H-carbazol-3-yl)-2-(trifluoromethyl)benzamide]. AF3442 caused a concentration-dependent inhibition of PGE₂ in human recombinant mPGES-1 with an IC₅₀ of 0.06 μM. In LPS-stimulated monocytes, AF3442 caused a concentration-dependent reduction of PGE₂ biosynthesis with an IC₅₀ of 0.41 μM. At 1 μM, AF3442 caused maximal selective inhibitory effect of PGE₂ biosynthesis by 61 ± 3.3% (mean ± SEM, P < 0.01 versus DMSO vehicle) without significantly affecting other prostanoids (i.e. TXB₂, PGF_2α and 6-keto-PGF_1α). In LPS-stimulated whole blood, AF3442 inhibited in a concentration-dependent fashion inducible PGE₂ biosynthesis with an IC₅₀ of 29 μM. A statistically significant inhibition of mPGES-1 activity was detected at 10 and 100 μM (38 ± 14%, P < 0.05, and 69 ± 5%, P < 0.01, respectively). Up to 100 μM, the other prostanoids were not significantly affected. In conclusion, AF3442 is a selective mPGES-1 inhibitor which reduced monocyte PGE₂ generation also in the presence of plasma proteins. Pharmacological inhibition of mPGES-1 did not translate into redirection of PGH₂ metabolism towards other terminal PG synthases in monocytes. The functional relevance of this observation deserves to be investigated in vivo.     

The permeability of large molecular weight solutes following particle delivery to air-interfaced cells that model the respiratory mucosa

The transepithelial transport rates of compounds after deposition as aerosolised particles onto respiratory cell layers and allowing dissolution in the cell surface secretions has not been reported in a comprehensive manner to date. Here, the twin-stage impinger (TSI) was used to deposit potentially respirable particles (aerodynamically <6.4 μm) of varying molecular weight dextrans labelled with fluorescein isothiocyanate (FITC-dex) onto Calu-3 cells, a model of the bronchial epithelium. The TSI functioned as a particle size segregator, with >96% of the deposited particles being geometrically <6.4 μm (as measured by microscopy) and the particles being deposited discretely with a uniform distribution. Cell layers tolerated particle deposition at an air flow of 60 L/min. A small reduction in transepithelial electrical resistance (TER) of <10% occurred initially, but the original TER was recovered within 10 min and there was no significant effect on apparent permeability (P_app) of FITC-dex 4 over 4 h. Interleukin 8 (IL-8) secretion in the apical and basolateral directions over 24 h was not increased by exposure to the TSI and particle deposition. The rate of FITC-dex 4 (4 kDa) transport across the cell layer after deposition and dissolution of the particles in the cell surface secretions was ∼20-fold higher (P < 0.05) than if applied as a solution. The volume of cell surface secretions was estimated by tracer dilution (3.44 ± 1.90 μl, mean ± SEM) and this value was used to calculate the P_app of compound once deposited as a particle. The Papp value was found to be similar to that obtained when the compound was applied in solution (P < 0.05). Thus, the increased transport rate was attributable to the differences in donor chamber solute concentration rather than any change in the permeability of the cell layer itself. Following particle deposition, transport of FITC-dex with molecular weights between 4 and 70 kDa correlated well (r² = 0.918) with reported in vivo canine pulmonary clearance after intratracheal instillation of dextrans of similar molecular weight. The use of the TSI and the Calu-3 cell line for the assessment of compound dissolution and transport rates after particle deposition may allow more realistic analyses to be made with respect to the in vivo situation.     

Facts and myths about columns packed with sub-3 μm and sub-2 μm particles

Increasing the separating efficiency enhances the separation power. The most popular solution for improving chromatographic performance is to employ columns packed with small particle diameters (i.e., sub-2 μm particles) to induce a simultaneous improvement in efficiency, optimal velocity and mass transfer, albeit the cost of pressure. In this study a systematic evaluation of the possibilities and limitations of the separations obtained with 5 cm long narrow bore columns packed with 1.5–3.0 μm particles is presented. Several commercially available different sub-3 μm and sub-2 μm packed columns were evaluated by using van Deemter, Knox and kinetic plots. Theoretical Poppe plots were constructed for each column to compare their kinetic performance. Data are presented on different polar neutral real life analytes, to show that the separation time is not obviously shorter if the particle size is reduced. Comparison of low-molecular weight compounds (one steroid and one non-steroid hormone, with molecular weights lower than 500) and a high-molecular weight one (MW ∼ 1000) was conducted. Same efficiency can be achieved with columns packed with 1.9–2.1 μm particles as with smaller particles. The column packed with 3 μm particles had the lowest reduced plate height minimum (h = 2.2) while the column with the smallest particles (1.5 μm) gave the highest reduced plate height minimum (h ∼ 3.0). According to this study, the theoretically expected efficiency of very fine particles (diameter <2 μm) used in practice today is compromised. Investigation of this phenomenon is presented.     

Shell and small particles; Evaluation of new column technology

The performance of 5 cm long columns packed with shell particles was compared to totally porous sub-2 μm particles in gradient and isocratic elution separations of hormones (dienogest, finasteride, gestodene, levonorgestrel, estradiol, ethinylestradiol, noretistherone acetate, bicalutamide and tibolone). Peak capacities around 140–150 could be achieved in 25 min with the 5 cm long columns. The Ascentis Express column (packed with 2.7 μm shell particles) showed similar efficiency to sub-2 μm particles under gradient conditions. Applying isocratic separation, the column of 2.7 μm shell particles had a reduced plate height minimum of approximately h = 1.6. It was much smaller than obtained with totally porous particles (h ≈ 2.8). The impedance time also proved more favorable with 2.7 μm shell particles than with totally porous particles. The influence of extra-column volume on column efficiency was investigated. The extra-column dispersion of the chromatographic system may cause a shift of the HETP curves.     

Development of a high performance liquid chromatography method for quantification of PAC-1 in rat plasma

A sensitive and specific high performance liquid chromatography method with UV detection was developed and validated for the determination of PAC-1 in rat plasma. After extraction with ethyl acetate, the chromatographic separation was carried out on a Diamonsil C₁₈ column (150 mm × 4.6 mm i.d., 5 μm particle size, Zhonghuida) protected by a ODS guard column (10 mm × 4.6 mm i.d., 5 μm particle size), using acetonitrile–methanol–phosphate buffer (pH 3.0, 30 mM) (31:3:66, v/v/v) as mobile phase at a flow rate of 1.0 mL/min, and wavelength of the UV detector was set at 281 nm. No interference from any endogenous substances was observed during the elution of PAC-1 and internal standard (IS, indapamide). The calibration curve was linear over the range of 0.05–20 μg/mL (r > 0.99). The lower limit of quantification was evaluated to be 50 ng/mL. The method was successfully applied to the pharmacokinetic study of PAC-1 after intravenous and oral administration in rats, respectively.     

Development and validation of an HPLC-DAD method for bis(12)-hupyridone and its application to a pharmacokinetic study

A rapid and simple method of high performance liquid chromatography with UV detection for the quantification of bis(12)-hupyridone in rat blood has been developed and validated. Chromatographic separation was carried out in an Agilent Extend C₁₈ 5 μm column (length, 250 mm; inner diameter, 4.6 mm) using a mixture of water–acetonitrile–trifluoroacetic acid (81:19:0.04, v/v/v) as the mobile phase at a flow rate of 1 mL/min, with detection at 229 nm. The method used for the bis(12)-hupyridone quantification showed linearity for concentration range of 0.1–7.5 μg/mL with r² = 0.9991. The limit of detection and quantification of this method were 0.05 μg/mL and 0.1 μg/mL, respectively. The intra- and inter-day variations of the analysis were less than 4.22% with standard errors less than 13.3%. The developed method was successfully applied to the pharmacokinetic study of bis(12)-hupyridone after intravenous administration of 5 mg/kg and intraperitoneal administration of 10 and 20 mg/kg in rats.     

High-throughput determination of faropenem in human plasma and urine by on-line solid-phase extraction coupled to high-performance liquid chromatography with UV detection and its application to the pharmacokinetic study

An automated system using on-line solid-phase extraction and HPLC with UV detection was developed for the determination of faropenem in human plasma and urine. Analytical process was performed isocratically with two reversed-phase columns connected by a switching valve. After simple pretreatment for plasma and urine with acetonitrile, a volume of 100 μl upper layer of the plasma or urine samples was injected for on-line SPE column switching HPLC-UV analysis. The analytes were retained on the self-made trap column (Lichrospher C₁₈, 4.6 mm × 37 mm, 25 μm) with the loading solvent (20 mM NaH₂PO₄ adjusted pH 3.5) at flow rate of 2 ml min⁻¹, and most matrix materials were removed from the column to waste. After 0.5 min washing, the valve was switched to another position so that the target analytes could be eluted from trap column to analytical column in the back-flush mode by the mobile phase (acetonitrile–20 mM NaH₂PO₄ adjusted pH 3.5, 16:84, v/v) at flow rate of 1.5 ml min⁻¹, and then separated on the analytical column (Ultimate™ XB-C₁₈, 4.6 mm × 50 mm, 5 μm).The complete cycle of the on-line SPE preconcentration purification and HPLC separation of the analytes was 5 min. Calibration curves with good linearities (r = 0.9994 for plasma sample and r = 0.9988 for urine sample) were obtained in the range 0.02–5 μg ml⁻¹ in plasma and 0.05–10 μg ml⁻¹ in urine for faropenem. The optimized method showed good performance in terms of specificity, linearity, detection and quantification limits, precision and accuracy. The method was successfully utilized to quantify faropenem in human plasma and urine to support the clinical pharmacokinetic studies.     

Formulation of pyrazinamide-loaded large porous particles for the pulmonary route: Avoiding crystal growth using excipients

We have designed a novel formulation of pyrazinamide (PZA), an antitubercular drug within large porous particles intended for deep lung delivery. By simply spray-drying PZA, we have obtained crystalline particles of the δ polymorph of PZA that were unstable and not adapted for lung administration. Several excipients were added to the formulation to obtain stable large porous particles with a median size above 5 μm and a low tap density. Although a combination of leucine and ammonium bicarbonate (AB) allowed to reduce tap density and to increase particle size, these excipients were not sufficient to prevent crystallization and promote stability. The addition of hyaluronic acid (HA) in combination with dipalmitoylphosphatidylcholine (DPPC) allowed to obtain stable partially crystalline spherical particles adapted for deep lung delivery. The optimized formulation obtained by spray-drying 0.9 g/L PZA, 0.6 g/L leucine, 0.2 g/L HA, 0.3 g/L DPPC and 2 g/L AB in a mixture of ethanol–water (70/30, v/v) possesses a median size of 5.8 ± 0.1 μm and a tap density around 0.09 ± 0.01 g/cm³. The estimated aerodynamic diameter is around 1.75 μm and the powder is stable for more than 4 weeks of storage.     

Optimization and validation of a high performance liquid chromatography method for rapid determination of sinafloxacin,a novel fluoroquinolone in rat plasma using a fused-core C18-silica column

A novel, simple and rapid high performance liquid chromatographic method has been developed and validated for the determination of sinafloxacin, a new fluoroquinolone, in rat plasma using 96-well protein precipitation, fused-core C₁₈-silica column (4.6 mm × 50 mm, 2.7 μm) packed with a new solid support, which is made of 2.7 μm particles that consist of a 1.7 μm solid core covered with a 0.5 μm thick shell of porous silica.The chromatographic separation was achieved with a mobile phase of 20:80 (v/v) of acetonitrile and phosphate buffer (pH = 3.0) at a flow rate of 1 ml min⁻¹. Fluorescence detection was employed with λ_ex 295 nm and λ_em 505 nm. Lomefloxacin was used as internal standard (IS). The total analysis time was as short as 3 min. The method was sensitive with a limit of detection (LOD) of 2 ng ml⁻¹, with good linearity (R² = 0.9996) over the linear range of 5–500 ng ml⁻¹. The intra-day and inter-day precision was less than 5.8% and accuracy ranged from 100.3% to 103.5% for quality control (QC) samples at three concentrations of 10, 50 and 400 ng ml⁻¹.The fused-core C₁₈-silica column method offered high sample throughput, low injection volume and low consumption of organic solvents. The method was successfully employed in the pharmacokinetic study of sinafloxacin formulation product after tail vein injection to healthy rats.     

Internal mouthpiece designs as a future perspective for enhanced aerosol deposition. Comparative results for aerosol chemotherapy and aerosol antibiotics

Background

In an effort to identify factors producing a finest mist from Jet-Nebulizers we designed 2 mouthpieces with 4 different internal designs and 1–3 compartments.

Materials and methods

Ten different drugs previous used with their “ideal” combination of jet-nebulizer, residual-cup and loading were used. For each drug the mass median aerodynamic diameter size had been established along with their “ideal” combination.

Results

For both mouthpiece, drug was the most important factor due the high F-values (F_large = 251.7, p < 0.001 and F_small = 60.1, p < 0.001) produced. The design affected the droplet size but only for large mouthpiece (F_large = 5.99, p = 0.001, F_small = 1.72, p = 0.178). Cross designs create the smallest droplets (2.271) so differing from the other designs whose mean droplets were greater and equal ranging between 2.39 and 2.447. The number of compartments in the two devices regarding the 10 drugs was found not statistically significant (p-values 0.768 and 0.532 respectively). Interaction effects between drugs and design were statistically significant for both devices (F_large = 8.87, p < 0.001, F_small = 5.33, p < 0.001).

Conclusion

Based on our experiment we conclude that further improvement of the drugs intended for aerosol production is needed. In addition, the mouthpiece design and size play an important role in further enhancing the fine mist production and therefore further experimentation is needed.     

Methylated N-(4-N,N-dimethylaminocinnamyl) chitosan-coated electrospray OVA-loaded microparticles for oral vaccination

The purpose of this study was to prepare microparticles entrapping ovalbumin (OVA) as a model antigen to induce immune responses in mice following oral vaccination. In this study, calcium-alginate and calcium-yam-alginate microparticles were prepared by crosslinking alginate with calcium chloride solution using an electrospraying technique. 0.1% (w/v) of methylated N-(4-N,N-dimethylaminocinnamyl) chitosan (TM₆₅CM₅₀CS) was used to coat microparticles entrapping an initial OVA of 20% w/w to polymer. The results indicated that the coated microparticles were spherical and had a smooth surface, with an average size of 1–3 μm, and were positively charged. In addition, the particles demonstrated a greater swelling and mucoadhesive properties than did uncoated microparticles. The in vitro release from the microparticles indicated that the coated microparticles resulted in more sustained release than uncoated microparticles. The cytotoxicity results showed that all of the formulations were safe. The in vivo oral administration demonstrated that at the same amount of 250 μg OVA, coated microparticles exhibited the highest in vivo adjuvant activity in both IgG and IgA immunogenicity.     

A search for hepatoprotective activity of aqueous extract of Rhus coriaria L. against oxidative stress cytotoxicity

The protective effects of different concentrations of aqueous extract of Rhus coriaria L. fruit (75 and 100 μg/ml) and also gallic acid (100 μM) as one of its main components were examined against oxidative stress toxicity induced by cumene hydroperoxide (CHP) in isolated rat hepatocytes. Both extract concentrations and gallic acid (100 μM) significantly (P < 0.05) protected the hepatocyte against all oxidative stress markers including cell lysis, ROS generation, lipid peroxidation, glutathione depletion, mitochondrial membrane potential decrease, lysosomal membrane oxidative damage and cellular proteolysis. Aqueous extracts of Rhus coriaria L. (75 and 100 μg/ml) were more effective than gallic acid (100 μM) in protecting hepatocytes against CHP induced lipid peroxidation (P < 0.05). On the other hand gallic acid (100 μM) acted more effective than aqueous extracts of Rhus coriaria L. (75 and 100 μg/ml) at preventing hepatocyte membrane lysis (P < 0.05). In addition H₂O₂ scavenging effect of both extract concentrations (75 and 100 μg/ml) were determined in hepatocytes and compared with gallic acid (100 μM). Gallic acid (100 μM) was more effective than aqueous extracts of Rhus coriaria L. (75 and 100 μg/ml) at H₂O₂ scavenging activity (P < 0.05).     

Separation and determination of nimesulide related substances for quality control purposes by micellar electrokinetic chromatography

A micellar electrokinetic chromatography (MEKC) method has been developed and validated for the determination of nimesulide related compounds in pharmaceutical formulations. Electrophoretic separation of six European Pharmacopoeia (EP) impurities (A–F) was performed using a fused silica capillary (L_eff. = 50 cm, L_tot. = 57 cm, 50 μm i.d.) with a background electrolyte (BGE) containing 25 mM borate buffer (pH 9.5), 30 mM sodium dodecyl sulphate and φ = 3% (v/v) acetonitrile. The influence of several factors (surfactant and buffer concentration, pH, organic modifier, applied voltage, capillary temperature and injection time) was studied. The method was suitably validated with respect to linearity, limit of detection and quantification, accuracy, precision and selectivity. The calibration curves obtained for the six compounds were linear over the range 5–12 μg ml⁻¹ (0.05–0.12%). The relative standard deviations (s_r) of intra- and inter-day experiments were less than 5.0%. The detection limits ranged between 0.7 and 1.6 μg ml⁻¹ depending on the impurity. The proposed method was applied successfully to the quantification of nimesulide impurities in its pharmaceutical formulation.     

Microfluidic one-step synthesis of Fe3O4-chitosan composite particles and their applications

This paper demonstrates a simple and easy approach for the one-step synthesis of Fe₃O₄-chitosan composite particles with tadpole-like shape. The length and diameter of the particles were adjustable from 638.3 μm to ca. 798 μm (length), and from 290 μm to 412 μm (diameter) by varying the flow rate of the dispersed phase. Mitoxantrone was used as the model drug in the drug release study. The encapsulation rate of the drug was 71% for chitosan particles, and 69% for magnetic iron oxide-chitosan particles, respectively. The iron oxide-chitosan composite particles had a faster release rate (up to 41.6% at the third hour) than the chitosan particles (about 24.6%). These iron oxide-chitosan composite particles are potentially useful for biomedical applications, such as magnetic responsive drug carriers, magnetic resonance imaging (MRI) enhancers, in the future.     

Capreomycin inhalable powders prepared with an innovative spray-drying technique

The aim of the work was to produce inhalable capreomycin powders using a novel spray-drying technology. A 2³ factorial design was used to individuate the best working conditions. The maximum desirability was identified at the smallest mean volume diameter (d_v) and span, and the highest yield. Powders were characterized for size, morphology, flowability and aerodynamic properties. Mathematical models showed a good predictivity with biases lower than 20%. The maximum conformity with desirability criteria was obtained spraying a 10 mg/mL bacitracin solution at 111 °C with the 4 μm pore size membrane. By processing capreomycin sulfate with the parameters optimized for bacitracin, an inhalable powder was obtained (i.e., yield of 82%, d_v of 3.83 μm, and span of 1.04). By further optimization, capreomycin sulfate powder characteristics were improved (i.e., yield, ∼71%; d_v, 3.25 μm; span, 0.95). After formulation with lactose, emitted dose and respirable fraction of 87% and ∼27% were obtained, respectively. Two capreomycin sulfate powders with suitable properties for inhalation were produced using the nano spray-dryer B-90.     

Development and validation of an ion-pair RP-HPLC method for the determination of oligopeptide-20 in cosmeceuticals

Oligopeptide-20 is a growth-factor mimicking peptide used in cosmeceuticals. This article describes the development and validation of an ion-pair reversed-phase liquid chromatography method that allows, after liquid-liquid extraction, the quantification of oligopeptide-20 in cosmetic creams. Chromatographic separation was achieved on a cyanopropyl Hypersil analytical column (100 mm × 2.1 mm i.d., 5 μm particle size), using a mobile phase of acetonitrile-heptafluorobutyric acid (pH = 2.5, 9.0 mM) (70:30, v/v) containing 0.045% diethylamine at a flow rate of 0.50 mL min⁻¹. Ultraviolet (UV) spectrophotometric detection at 225 nm was used. The method had linear calibration curve over the range 1.35-4.95 μg mL⁻¹ for oligopeptide-20. The intra- and inter-day RSD values were less than 3.3%, while the relative percentage error, %E_r, was less than 1.9. The developed method was applied successfully to the quality control of a cosmetic cream containing 0.003% (w/w) oligopeptide-20.     

Ultra high-pressure liquid chromatographic assay of moxifloxacin in rabbit aqueous humor after topical instillation of moxifloxacin nanoparticles

The present report describes a rapid and sensitive ultra high-pressure liquid chromatography (UHPLC) method with UV detection to quantify moxifloxacin in rabbit aqueous humor. After deproteinisation with acetonitrile, gradient separation of moxifloxacin was achieved on a Waters Acquity BEH C18 (50 mm × 2.1 mm, 1.7 μm) column at 50 °C. The mobile phase consisted of 0.1% trifluoroacetic acid in water and acetonitrile at a flow rate of 0.4 ml/min. Detection of moxifloxacin was done at 296 nm. Method was found to be selective, linear (r = 0.9997), accurate (recovery, 97.30–99.99%) and precise (RSD, ≤1.72%) in the selected concentration range of 10–1000 ng/ml. Detection and quantitation limit of moxifloxacin in aqueous humor were 0.75 and 2.5 ng/ml, respectively. The aqueous humor levels of moxifloxacin after single topical instillation in three formulations, i.e. moxifloxacin solution (Moxi-SOL), anionic nanoparticles (Moxi-ANP) and cationic nanoparticles (Moxi-CNP) were investigated. A fourfold increase in the relative bioavailability was observed with the Moxi-CNP (AUC_0→t, 3.14 μg h/ml) compared with Moxi-SOL (AUC_0→t, 0.79 μg h/ml) and Moxi-ANP (AUC_0→t, 0.72 μg h/ml) formulation. The results indicate that the cationic nanoparticle increases ocular bioavailability of moxifloxacin and prolong its residence time in the eye.     

Thermal ink-jet spray freeze-drying for preparation of excipient-free salbutamol sulphate for inhalation

The use of thermal ink-jet spray freeze-drying (TIJ-SFD) to engineer inhalable, excipient-free salbutamol sulphate (SS) particles was assessed. A modified Hewlett-Packard printer was used to atomise aqueous SS solutions into liquid nitrogen. The frozen droplets were freeze-dried. It was found that TIJ-SFD could process SS solutions up to 15% w/v; the porous particles produced had a physical diameter of ca. 35 μm. Next generation impactor (NGI) analysis indicated that the particles had a smaller aerodynamic size (MMAD ranging from 6 to 8.7 μm). Particles prepared from the lowest concentration SS solution were too fragile to withstand aerosolisation, but the 5% w/v solution yielded particles having the best combination of strength and aerodynamic properties. Comparison with a commercial SS formulation (Cyclocap®) showed that the SFD preparation had an almost equivalent FPF_6.4μm when analysed with a twin-stage impinger (TSI; 24.0 ± 1.2% and 26.4 ± 2.2%, respectively) and good performance when analysed with NGI (FPF_4.46μm:16.5 ± 2.0 and 27.7 ± 1.7, respectively). TIJ-SFD appears to be an excellent method to prepare inhalable particles. It is scalable yet allows assessment of the viability of the pulmonary route early in the development since it can be used with very small volumes (<0.5 mL) of solution.     

Paris saponin VII inhibits growth of colorectal cancer cells through Ras signaling pathway

Dysregulation of the Ras signaling pathway plays a key role in the progression of colorectal cancer. When bound to GTP, Ras is activated and stimulates several downstream effectors’ pathways, including the Raf/MEK/ERK kinase cascade, the PI3-kinase/AKT/mTor pathway, and the Ral GTPase pathway. Saponins extracted from Liliaceae family herbs have strong antitumor activities with low toxicity. In this study, Paris saponin VII (PSVII), isolated from Trillium tschonoskii Maxim., was evaluated on human colorectal cancer cells (HT-29 and SW-620), a mouse model of colitis associated colorectal cancer (CACC) and a murine model of xenograft tumor. It was found that PSVII inhibited colorectal cancer cell growth in a concentration-dependent manner. The IC₅₀ values of PSVII for growth inhibition of HT-29 and SW-620 cells were 1.02 ± 0.05 μM and 4.90 ± 0.23 μM. It could induce cell apoptosis, together with cell cycle arrest in G₁ phase, and trigger apoptosis in a caspase-3-dependent manner. PSVII-induced growth inhibitory effect was associated with disturbance of MAPK pathway by down-regulating MEK1/2, ERK1/2 phosphorylation, and suppression of AKT pathway by reducing AKT and GSK-3β phosphorylation. In the CACC mouse model, PSVII protected mice from intestinal toxicities and carcinogenesis induced by 1,2-dimethylhydrazine (DMH) and dextran sodium sulfate (DSS). In the model of xenograft tumor, PSVII remarkably decreased the xenograft tumor size and triggered the apoptosis of tumor cells. Both in vitro and in vivo study showed that PSVII inhibited Ras activity. Taken together, PSVII might be a potential therapeutic reagent for colorectal cancer through targeting Ras signaling pathway.     

Development and validation of UPLC method for quality control of Curcuma longa Linn.: Fast simultaneous quantitation of three curcuminoids

A new reversed phase ultra performance liquid chromatography (UPLC) method was developed for the rapid quantification of three curcuminoids (curcumin (C), desmethoxycurcumin (DMC) and bisdesmethoxycurcumin (BDMC)) in Curcuma longa Linn. (C. longa) using a Waters BEH Shield RP C₁₈, 2.1 mm × 100 mm, 1.7 μm column. The runtime was 2 min. The influence of column temperature and mobile phase on resolution was investigated. The method was validated according to the ICH guideline for validation of analytical procedures with respect to precision, accuracy, and linearity. The limits of detection were 40.66, 49.38 and 29.28 pg for C, DMC and BDMC, respectively. Limits of quantitation for C, DMC and BDMC, were 134.18, 164.44 and 97.50 pg, respectively. Linear range was from 3.28 to 46.08 μg/ml. The mean ± SD percent recoveries of curcuminoids were 99.47 ± 1.66, 99.50 ± 1.99 and 97.77 ± 2.37 of C, DMC and BDMC, respectively. Comparison of system performance with conventional HPLC was made with respect to analysis time, efficiency and sensitivity. The proposed method was found to be reproducible and convenient for quantitative analysis of three curcuminoids in C. longa. This work provided some references for quality control of C. longa.