Pretreatment of Blumea lacera leaves ameliorate acute ulcer and oxidative stress in ethanol-induced Long-Evan rat: A combined experimental and chemico-biological interaction.

Blumea lacera (Burm.f.) DC. is described as a valuable medicinal plant in various popular systems of medicine. The aim of the experiment reports the in vivo antiulcer activity of methanol extract of Blumea lacera (MEBLL) and in silico studies of bioactive constituents of MEBLL. In this study, fasted Long-Evans rat treated with 80 % ethanol (0.5 mL) to induce gastric ulcer, were pretreated orally with MEBLL at different doses (250 and 500 mg/kg, p.o., b.w) and omeprazole (20 mg/kg, p.o.) and distilled water were used as a reference drug and normal control respectively. In silico activity against gastric H+-K+ATPase enzyme was also studied. The findings demonstrated that the treatment with MEBLL attenuated markedly ulcer and protected the integrity of the gastric mucosa by preventing the mucosal ulceration altered biochemical parameters of gastric juice such total carbohydrate, total protein and pepsin activity. Additionally, the experimental groups significantly (p < 0.001) inhibited gastric lesions and malondealdehyde (MDA) levels and upregulated antioxidant enzymes level. Furthermore, nine compounds were documented as bioactive, displayed good binding affinities to against gastric H+-K+ATPase enzyme while these compounds illustrated inhibitory effect. From these studies, it is established MEBLL has ulcer healing property as unveiled by in vivo and in silico studies.

A fully derivatized 4-chlorophenylcarbamate-ß-cyclodextrin bonded chiral stationary phase for enhanced enantioseparation in HPLC.

This paper reports an effective approach for the fabrication of a per-4-chlorophenylcarbamate-ß-cyclodextrin (ß-CD) bonded chiral stationary phase (CPCDP) in high-performance liquid chromatography. The morphology and structure of the ligand and the chiral stationary phase (CSP) were characterized by scanning electron microscopy, transmission electron microscopy, solid state 13C nuclear magnetic resonance spectra, fourier transform infrared spectra, elemental analysis and thermogravimetric analysis. Because CPCDP was a kind of multimode enantioseparation materials, the enantioseparation of chiral compounds including twelve azole antifungal agents, five proton pump inhibitors and five dihydropyridine calcium antagonists were studied in both reversed-phase and normal-phase chromatography. All analytes were obtained enantiomeric separation. Especially, the resolution of azoles was excellent. The selectivity and resolution of voriconazole reached 15.41 and 16.80, which was an exciting achievement for the enantioseparations by ß-CD based chiral stationary phases. Compared with the commercial 3,5-dimethylphenyl carbamate-ß-CD based chiral stationary phase (DMP), enhanced enantioselectivities for all the above compounds (except ilaprazole) were obtained on CPCDP column, which indicated that the 4-chlorophenylcarbamate group was conducive to the chiral recognition. Chromatographic studies elucidated that enhancement of analyte-chiral substrate interactions were attributed to the inclusion complexation, π-π stacking interaction, hydrogen-bonding, dipole-dipole interaction and steric hindrance. For further study, we also prepared semi-preparative chromatographic columns to obtain a single enantiomer. In addition to excellent chromatographic performance, the prepared CD-based column is stable and much cheaper than commercial columns, which can reduce the cost of test and has a good application prospect in chiral drug analysis.

A new strategy for extraction and depuration of pantoprazole in rat plasma: Vortex assisted dispersive micro-solid-phase extraction employing metal organic framework MIL-101(Cr) as sorbent followed by dispersive liquid-liquid microextraction based on solidification of a floating organic droplet.

Dispersive micro-solid-phase extraction (DMSPE) combined with dispersive liquid-liquid microextraction based on the solidification of a floating organic droplet (DLLME-SFO) was successfully developed for extraction and depuration of pantoprazole in rat plasma. The remarkable metal organic framework (MOF), MIL-101(Cr) was used as DMSPE adsorbent. The detection of pantoprazole was performed by convenient HPLC-UV. In the extraction of pantoprazole from plasma samples, small molecule compounds, including the target and abundant impurities, were easily admitted into the porous structure of MIL-101 (Cr) material in DMSPE; while, macromolecular compounds were handily excluded from the adsorbent. Next, the depuration process was achieved by removal of small polar impurities in DLLME-SFO. Influential factors were systematically optimized for ideal enrichment and depuration efficiency. Under the optimal conditions, a satisfactory linearity range from the lower limit of quantification (LLOQ, 100 ng/L) to 10 000 ng/L with the correlation coefficients (r) of 0.9934 was obtained. The LLOQ was 100 ng/mL and the relative recoveries were ≧ 73.2 ±â€¯4.8%. The approving reproducibility, acceptable accuracy, and stability were all within the acceptance limits. This proposed method presented the advantages of environment-friendly, low-cost, recyclable, low impurity, and preferable applicability. It could offer a new idea for the pretreatment and pharmacokinetic study of pantoprazole in rat plasma.

Diverse antimalarials from whole-cell phenotypic screens disrupt malaria parasite ion and volume homeostasis.

Four hundred structurally diverse drug-like compounds comprising the Medicines for Malaria Venture's 'Pathogen Box' were screened for their effect on a range of physiological parameters in asexual blood-stage malaria (Plasmodium falciparum) parasites. Eleven of these compounds were found to perturb parasite Na+, pH and volume in a manner consistent with inhibition of the putative Na+ efflux P-type ATPase PfATP4. All eleven compounds fell within the subset of 125 compounds included in the Pathogen Box on the basis of their having been identified as potent inhibitors of the growth of asexual blood-stage P. falciparum parasites. All eleven compounds inhibited the Na+-dependent ATPase activity of parasite membranes and showed reduced efficacy against parasites carrying mutations in PfATP4. This study increases the number of chemically diverse structures known to show a 'PfATP4-associated' phenotype, and adds to emerging evidence that a high proportion (7-9%) of the structurally diverse antimalarial compounds identified in whole cell phenotypic screens share the same mechanism of action, exerting their antimalarial effect via an interaction with PfATP4.

Liquid chromatographic ligand-exchange chiral stationary phases based on amino alcohols.

Liquid chromatographic ligand-exchange chiral stationary phases (CSPs) have been developed for the resolution of racemic compounds, which can be used as bidentate or tridentate ligands. In this paper, we review the development of liquid chromatographic ligand-exchange CSPs based on amino alcohols or their derivatives coated dynamically on octadecylsilica gel or bonded covalently to silica gel and their applications to the resolution of α-amino acids, ß-amino acids, α-hydroxycarboxylic acids and proton pump inhibitors (PPIs). The relationship between the structures of CSPs and chromatographic resolution behaviors is discussed. In particular, a rational approach to the development of improved ligand-exchange CSPs based on amino alcohols derived from α-amino acids is followed.

Prescription drugs associated with false-positive results when using faecal immunochemical tests for colorectal cancer screening.

BACKGROUND: The most common side effect in population screening programmes is a false-positive result which leads to unnecessary risks and costs. AIMS: To identify factors associated with false-positive results in a colorectal cancer screening programme with the faecal immunochemical test (FIT). METHODS: Cross-sectional study of 472 participants with a positive FIT who underwent colonoscopy for confirmation of diagnosis between 2013 and 2014. A false-positive result was defined as having a positive FIT (≥20µg haemoglobin per gram of faeces) and follow-up colonoscopy without intermediate/high-risk lesions or cancer. RESULTS: Women showed a two-fold increased likelihood of a false-positive result compared with men (adjusted OR, 2.3; 95%CI, 1.5-3.4), but no female-specific factor was identified. The other variables associated with a false-positive result were successive screening (adjusted OR, 1.5; 95%CI, 1.0-2.2), anal disorders (adjusted OR, 3.1; 95%CI, 2.1-4.5) and the use of proton pump inhibitors (adjusted OR, 1.8; 95%CI, 1.1-2.9). Successive screening and proton pump inhibitor use were associated with FP in men. None of the other drugs were related to a false-positive FIT. CONCLUSION: Concurrent use of proton pump inhibitors at the time of FIT might increase the likelihood of a false-positive result. Further investigation is needed to determine whether discontinuing them could decrease the false-positive rate.

Cytoprotective and Anti-secretory Effects of Azadiradione Isolated from the Seeds of Azadirachta indica (neem) on Gastric Ulcers in Rat Models.

Azadirachta indica is well known medicinal plant mentioned in ancient herbal texts. It has been extensively used in Ayurvedic, Unani and Homoeopathic medicine and has become a luminary of modern medicine. As part of our drug discovery program we isolated azadiradione from the ethanolic extract of seeds of A. indica and evaluated for in-vivo antiulcer activity in cold restraint induced gastric ulcer model, aspirin induced gastric ulcer model, alcohol induced gastric ulcers model and pyloric ligation induced ulcer model. Azadiradione exhibited potent antiulcer activity through the inhibition of H+ K+-ATPase (proton pump) activity via its cytoprotective effect and also via its antisecretory effect. This combined effect has valuable potential in the future treatment of peptic ulceration.

Development of an improved ligand exchange chiral stationary phase based on leucinol for the resolution of proton pump inhibitors.

As an effort to develop improved ligand exchange chiral stationary phases (CSPs) for the resolution of chiral drugs, the residual silanol groups on the silica surface of a CSP based on sodium N-[(S)-1-hydroxymethyl-3-methylbutyl]-N-undecylaminoacetate, a (S)-leucinol derivative, were protected with n-octyl groups. The residual silanol group-protected CSP was applied to the resolution of proton pump inhibitors (PPIs) such as omeprazole, pantoprazole, lansoprazole and rabeprazole. The resolution of PPIs on the residual silanol group-protected CSP was excellent with the separation factors (α) in the range of 4.32-6.42 and the resolution factors (RS) in the range of 6.70-7.15. The improved chiral recognition ability of the residual silanol group-protected CSP was rationalized to be originated from the protection of the non-enantioselective interaction sites on the silica surface and the improved lipophilicity of the stationary phase.

Enantiomeric separation of proton pump inhibitors on new generation chiral columns using LC and supercritical fluid chromatography.

The enantioselectivity of proton pump inhibitors, namely, omeprazole, lansoprazole, rabeprazole, pantoprazole, tenatoprazole, and ilaprazole were studied using new generation chiral packing materials: CHIRALPAK IA, CHIRALPAK IB, and CHIRALPAK IC. Two versatile techniques, HPLC and supercritical fluid chromatography (SFC) were used in this study. CHIRALPAK IC has shown superior selectivity under both LC and SFC conditions, whereas CHIRALPAK IA has shown good selectivity in SFC when compared to LC under primary screening conditions. The chiral recognition ability in LC and SFC modes were found to be in the order CHIRALPAK IC > CHIRALPAK IA > CHIRALPAK IB. In addition to diode array detection, chiral detection was carried out using a laser polarimeter and the elution orders were found to be the same in both LC and SFC elution modes. Mobile phase modifiers and column temperature effects were also studied. In SFC, modifiers (cosolvent) elution strength was found to be in the order ethanol > methanol > 2-propanol > acetonitrile. In both LC and SFC, a decrease in retention and increase in resolution with an increase in temperature was noticed for all the proton pump inhibitors.

Retention behavior of proton pump inhibitors using immobilized polysaccharide-derived chiral stationary phases with organic-aqueous mobile phases.

In the present study, the chromatographic behavior of two immobilized polysaccharide-derived chiral stationary phases (CSPs), the Chiralpak ID-3 and Chiralpak IE-3, under aqueous mobile phases conditions is presented. Four proton pump inhibitors (PPIs) (omeprazole, lansoprazole, pentaprazole and rabeprazole) were selected as test compounds. The effect of the concentration of water in the mobile phase was investigated with respect to its contribution to enantioselectivity and retention. Under acetonitrile-water mobile phase conditions, retention behavior evidenced an interesting pattern. At lower water content, the retention factors decreased with increasing water and at higher water content a reversed trend was observed. These findings support the hypothesis that two retention mechanisms operated successively on the same CSP: the HILIC (with water-poor eluents) and RPLC (with water-rich eluents) modes. The retention factors were minimum in the intermediate region, corresponding to a water concentration of about 20%. Interestingly, the baseline separation of all PPIs investigated was optimized under organic-aqueous mobile phases containing a high water content (from about 50 to 65%). Thus, the dual retention behavior of the PPIs on the Chiralpak ID-3 and Chiralpak IE-3 made it possible to reach greener and harmless enantioselective conditions in a short analysis time.

The H+/K+-ATPase inhibitory activities of Trametenolic acid B from Trametes lactinea (Berk.) Pat, and its effects on gastric cancer cells.

Trametenolic acid B (TAB), the bioactive component in the Trametes lactinea (Berk.) Pat, was reported to possess cytotoxic activities and thrombin inhibiting effects. This study was performed to investigate the effects of TAB on H(+)/K(+)-ATPase and gastric cancer. The H(+)/K(+)-ATPase inhibitory activity was determined by gastric parietal cells. Compared to the normal control group, TAB (10, 20, 40 and 80 µg/mL) inhibited the H(+)/K(+)-ATPase activity by 15.97, 16.96, 24.86 and 16.25%, respectively. In the study, 36 Kunming mice were randomly divided into six groups: control, model, TAB-L (TAB, 5 mg/kg/day, i.g.), TAB-M (TAB, 20 mg/kg/day, i.g.), TAB-H (TAB, 40 mg/kg/day, i.g.) and omeprazole (OL, 10 mg/kg/day, i.g.). All mice except the control group were administrated with anhydrous alcohol (5.0 mL/kg, i.g.) for induced gastric-ulcer 1h after the 5th day. At the same time, the control mice were given the same volume of physiological saline. After 4h, TAB was evaluated for H(+)/K(+)-ATPase inhibitory activities of ulcerative gaster, gastric ulcer index and ulcer inhibition. In vitro, the anti-proliferation effect of TAB to gastric cancer cell (HGC-27) in acid environment was detected by MTT, and the apoptosis morphological changes were also observed by Hoechst 33258 dye assay. The results indicated that TAB inhibited moderately H(+)/K(+)-ATPase activity in vitro. Compared to the model group, TAB showed anti-ulcer effects in gastric tissue with the dosages of 20 and 5 mg/kg in vivo. Apart from that, TAB could selectively inhibit gastric cancer cell viability and reduce cell apoptosis against HGC-27 cells at low doses in acid environment.

Arbortristoside-A and 7-O-trans-cinnamoyl-6ß-hydroxyloganin isolated from Nyctanthes arbortristis possess anti-ulcerogenic and ulcer-healing properties.

Nyctanthes arbortristis Linn (Oleaceae) is widely distributed in sub-Himalayan regions and southwards to Godavari, India commonly known as Harsingar and Night Jasmine. In continuation of our drug discovery program on Indian medicinal plants, we isolated arbortristoside-A (AT) and 7-O-trans-cinnamoyl-6ß-hydroxyloganin (6-HL) from the seeds of N. arbortristis. AT and 6-HL exhibited anti ulcer activity in experimentally induced ulcer models including cold restraint stress (CRU), alcohol (AL), pylorus ligation-induced gastric ulcer (PL) models and they also showed ulcer healing effect in chronic acetic acid-induced ulcer model (AC).

Inhibition of H+/K+ ATPase in the gastroprotective effect of Baccharis illinita DC.

Baccharis illinita DC (Compositae) is used in folk medicine to treat gastric disturbances. Preliminary studies with other extracts of B. Illinita showed gastric protection against ethanol-, indometacin- and stress-induced ulcers and the inhibition of gastric secretion. Based on these data, the aim of this study was to verify the pathways involved in the inhibition of gastric secretion. The chloroform extract (CE) of flowers from B. illinita (3, 10, 30 and 100 mg kg(-1) i.p.) tested on rats with pylorus ligature reduced the volume and the total acidity of gastric content by approximately 50% (ED50 = 69 mg kg(-1)). Treatment with CE (100 mg kg(-1) i.p.) reduced the gastric total acidity stimulated by histamine, bethanechol and pentagastrin to 42%, 27% and 57% of that in the stimulated control group, respectively. The CE (10, 30 and 100 microM) inhibited H+/K+ ATPase activity in-vitro, with an IC50 of 37 microM. The isolated flavonoid luteolin (1, 3, 10 and 30 microM) also inhibited H+/K+ ATPase activity by 50%, at a dose of 30 microM. Our results suggest that the reduction in gastric secretion occurs through inhibition of H+/K+ ATPase, which is the final step in acid secretion and therefore one of the most important steps.

Antiulcer and gastric antisecretory effects of Landolphia owariensis extracts in rats.

Water, methanol and chloroform extracts of Landolphia owarensis were investigated for their effects on gastric acid secretion and ulceration in male albino rats. Two models of gastric lesion induced in experimental Wistar rats-HC1/ethanol-induced gastric lesions and Pylorus ligation-induced gastric lesions-were employed. In both models, the antiulcer activity of LA was compared with that of cimetidine (100 mg kg p.o.). In the HCl/Ethanol model, ulcer index and mucus production was determined. In pylorus ligated rat, ulcer index, mucus production, total volume of gastric juice and gastric acidity level were measured. Pre-treatment of animals with the aqueous extracts (100mg/kg and 200mg/kg) orally once daily for two weeks significantly reduced formation of ulcers induced by HCl/ethanol mixture, the percentage inhibition being 43.8 % and 55.27 % respectively. The chloroform extract afforded the least protection with 23.07 % and 14.77 % inhibition. This was also accompanied by significant increases in gastric mucus production. In pylorus ligated rats, total volume of gastric juice and gastric acidity was significantly decreased as compared to control group, to levels comparable to that produced by cimetidine. The results indicate that the leaf extracts of LO contains antiulcer principles.

[Direct enantiomeric separation of pantoprazole sodium by high performance liquid chromatography].

By using the Kromasil CHI-TBB chiral stationary phase, the racemic mixture of pantoprazole sodium was resolved in the normal phase mode. The influences of the composition of the mobile phase, the content of acidic and basic additives and the flow rate on this enantiomer separation were studied. The chiral high performance liquid chromatographic method for the analysis of pantoprazole sodium was established with high efficiency and good repeatability, by using hexane-isopropanol-acetic acid mixture (95:5:0.1, v/v) as the mobile phase at a flow rate of 2.0 mL/min at 25 degrees C.