Good response to methotrexate is associated with a decrease in the gene expression of ABCG2, a drug transporter, in patients with rheumatoid arthritis.

OBJECTIVES: Methotrexate (MTX) is used as an anchor drug in the treatment of rheumatoid arthritis (RA), although more than a half of the patients with RA require additional treatments. We designed a prospective study involving two medical centers in Japan to examine the association between the expression of MTX-related genes including a drug transporter ATP-binding cassette sub-family G member 2 (ABCG2) gene and the clinical response to MTX in MTX-naive patients with RA. METHODS: The primary endpoint of this study was good response based on the European League Against Rheumatism (EULAR) response criteria by Disease Activity Score using 28-joint count (DAS28). We evaluated the association between the baseline expression of six genes involved in the intracellular pharmacokinetics of MTX, including ABCG2, as well as their temporal changes, and the clinical response at week 12 from the initiation of MTX. RESULTS: Based on the clinical response at 12 weeks after the initiation of MTX, 24 patients were classified into good responders (n = 9) and non-good responders (n = 15; 10 moderate responders and 5 non-responders) groups. A univariate logistic regression analysis of the baseline gene expression levels to predict the EULAR good response at week 12 showed a significant association with ABCG2 expression alone. Furthermore, the rate of baseline expression of ABCG2 mRNA above the cut-off value determined using a receiver operating characteristic curve was higher in good responders than in non-good responders (p = .012). Moreover, ABCG2 expression decreased in almost all good responders, but not in non-good responders, after MTX treatment for 12 weeks (median -76% vs. +41% from baseline, respectively; p = .011). The ABCG2 expression level did not correlate with DAS28 at baseline or week 12. CONCLUSIONS: Our study revealed that good response to MTX is associated with a decrease in the expression of ABCG2 in patients with RA.

Two novel steroidal alkaloid glycosides from the seeds of Lycium barbarum.

Two novel steroidal alkaloid glycosides, lycioside A (1) and lycioside B (2) were isolated from the seeds of Lycium barbarum. Their structures were determined by various spectroscopic analyses. Compounds 1 and 2 showed inhibitory activities with the IC(50) values of 75.3 and 72.8 µM against rat intestinal sucrase, and 63.4 and 59.1 µM against rat intestinal maltase.

Triterpenoid saponins from Rubus ellipticus var. obcordatus.

Ten new triterpenoid saponins (1-10), named rubusides A-J, and 21 known saponins (11-31) were isolated from the roots of Rubus ellipticus var. obcordatus. The structures of 1-10 were established on the basis of spectroscopic analyses, mainly NMR and MS, and chemical degradations. The compounds demonstrated inhibitory activities against alpha-glucosidase with IC50 values in the range 0.65-3.09 mM.

Retrospective cohort study of the efficacy and safety of dabigatran: real-life dabigatran use including very low-dose 75 mg twice daily administration.

BACKGROUND: Dabigatran is a direct thrombin inhibitor and an anticoagulant that is prescribed to prevent ischemic stroke and systemic embolism in non-valvular atrial fibrillation. Dabigatran (150 mg twice daily) is non-inferior to warfarin for the prevention of stroke and systemic embolism. A dose reduction to 110 mg twice daily should be considered for patients with decreased renal function, elderly patients, and those with a history of gastrointestinal bleeding. A small number of patients are prescribed 75 mg twice daily; however, excessive dose reduction below that indicated on the package insert may decrease the effectiveness of dabigatran. In this study, we investigated the incidence of thromboembolic events and hemorrhagic complications in patients receiving different doses of dabigatran, including patients receiving the very low-dose of 75 mg twice daily. METHODS: Five hospitals in Meguro and Setagaya areas of Tokyo were included in this study. The subjects were patients receiving dabigatran in the hospitals from March 2011 to February 2014. Thromboembolic events (stroke, systemic embolism, and transient cerebral ischemic attack) and hemorrhagic complications occurring before December 2014 were retrospectively evaluated. RESULTS: A total of 701 subjects received dabigatran during the study period: 187 patients (26.7%) received 150 mg twice daily (normal dose), 488 patients (69.6%) received 110 mg twice daily (low-dose), and 26 patients (3.7%) received 75 mg twice daily (very low-dose). Thromboembolism occurred in 4 (2.1%), 11 (2.3%), and 3 patients (11.5%), in the normal dose, low-dose, and very low-dose groups, respectively. The odds ratio of the 75 mg dose to the 150 and 110 mg doses was 5.73 (95% CI, 1.55-21.2; p = 0.009), and the incidence with the 75 mg dose was higher than that with the other doses. Although the number of events was limited, it should be noted that 3 patients in the very low-dose group had thromboembolic events. CONCLUSIONS: The results suggest that sufficient anticoagulation efficacy may not be maintained when the dabigatran dose is excessively reduced to 75 mg twice daily.

Effect of aromatase inhibitors on bone mineral density in a Japanese breast cancer population.

We retrospectively analyzed the bone mineral density (BMD) of postmenopausal Japanese women taking an aromatase inhibitor (AI), exemestane, anastrozole or letrozole, and calculated the decrease rate constant of BMD in each individual to compare the influence of the three AIs on BMD. We also aimed to evaluate the preventive effect of bisphosphonates (BPs) on the AI-induced decrease in BMD. The decrease rate constant of BMD (k(e)) in each individual was determined as a slope of linear regression of the relationship between time and logarithm of BMD value in each patient during the AI therapy. To compensate for the age-related change in BMD level, we estimated the age-related decrease rate constant of BMD (ke,0) in healthy Japanese postmenopausal women from the literature. AIs decreased BMD with a ke value of -0.0329 yr(-1), which was 4.7-fold larger than the k(e,0) value of -0.00699 yr(-1). No significant difference was detected in the influence on BMD among AIs. Co-administration of BP ameliorated the ke value to -0.0117 yr(-1), a value similar to k(e,0). The influence of AIs on BMD was quantitatively evaluated by using the decrease rate constant of BMD (k(e)). The present study also suggests that BPs may be useful to prevent the decrease in BMD induced by AIs.

Phenolic glycosides from Agrimonia pilosa.

Phytochemical investigation of the methanolic extract from the aerial parts of Agrimonia pilosa led to the isolation of three compounds, (-)-aromadendrin 3-O-ß-D-glucopyranoside, desmethylagrimonolide 6-O-ß-D-glucopyranoside, and 5,7-dihydroxy-2-propylchromone 7-O-ß-D-glucopyranoside, together with nine known compounds, agrimonolide 6-O-glucoside, takanechromone C, astragalin, afzelin, tiliroside, luteolin, quercetin, isoquercetrin, and quercitrin. Their structures were determined by various spectroscopic analysis and chemical transformations.

Bioassay-guided isolation and quantification of the alpha-glucosidase inhibitory compound, glycyrrhisoflavone, from Glycyrrhiza uralensis.

The EtOAc extract of the roots of Glycyrrhiza uralensis exhibited alpha-glucosidase inhibitory activity. Bioassay-guided fractionation resulted in the isolation of an active prenylflavonoid, glycyrrhisoflavone. Its structure was elucidated by NMR and MS analyses. A simple method to prepare glycyrrhisoflavone from the 95% EtOH extract of the roots of G. uralensis was developed by combination of Diaion HP-20 column chromatography (CC), silica gel CC, and preparative HPLC. An HPLC-PDA method was developed for quantitative determination of glycyrrhisoflavone in the roots of G. uralensis. The sample was extracted with MeOH and analyzed using a reversed-phase column with isocratic elution with CH3CN-H2O (0.06% trifluoroacetic acid) (42:58) at a flow rate of 1.2 mL/min, a column temperature of 40 degrees C, and a detection wavelength of 260 nm. The method allowed the determination of glycyrrhisoflavone in the concentration range of 5-500 microg/mL. The relative standard deviation values of the precision and repeatability were 0.3% and 2.0%, respectively. The limits of detection and quantification were 0.5 microg/mL and 5 microg/mL, respectively. The relative recovery rate was 100.2 +/- 1.8%. Based on the validation results, the HPLC determination method was found to be precise, accurate, and time conservative. This method was applied successfully to nine different root samples of G. uralensis. The amounts of glycyrrhisoflavone in these samples were 15-93 mg/100 g of dried powdered plant material.