Erythrina alkaloids and a pterocarpan from the bark of Erythrina subumbrans

Three new erythrina alkaloids, (+)-10,11-dioxoerythratine (1), (+)-10,11-dioxoepierythratidine (2), and (+)-10,11-dioxoerythratidinone (3), and a new pterocarpan, 1-methoxyerythrabyssin II (4), were isolated from the bark of Erythrina subumbrans, together with seven known pterocarpans, erythrabyssin II, erybraedin A, erystagallin A, erycristagallin, erythrabissin-1, eryvarin A, and hydroxycristacarpone, three flavanones, 5-hydroxysophoranone, abyssinone V, and lespedezaflavanone B, three triterpenes, sophoradiol, soyasapogenol B, and lupeol, and one isoflavanone, vogelin C. Their structures were elucidated on the basis of spectroscopic data. Some isolates were tested for antiplasmodial, antimycobacterial, and cytotoxic activities.     

Physicochemical and Microbiological Stability of the Extemporaneous Sildenafil Citrate Oral Suspension

Sildenafil is a potent and selective phosphodiesterase-5 inhibitor that is effectively used in the treatment of pulmonary arterial hypertension. In several countries, hospital pharmacists prepare the drug in an extemporaneous liquid preparation as there are no liquid formulations available for pediatric and adult uses. The purpose of this study was to evaluate the stability of an extemporaneous sildenafil citrate oral suspension for 90 days, according to the ASEAN guideline on stability studies of drug products. The results showed that the preparation was a white suspension with a sweet taste. It was a viscous and weakly acidic mixture with pseudoplastic behavior. The drug content was in the range between 99.23% and 102.23%, and the microbial examination met the general requirements throughout the study period. Therefore, the extemporaneously compounded sildenafil suspensions were physically, chemically, and microbiologically stable for at least 90 days when stored at 30° and 40°C. Furthermore, the in-use stability study showed that the preparations had acceptable attributes at least 14 days after the first-time use. This might provide an alternative option when the commercial suspension is unavailable.     

Mechanisms of Vasorelaxation Induced by Hexahydrocurcuminin Isolated Rat Thoracic Aorta

This study was designed to examine the vasorelaxant effects of hexahydrocurcumin (HHC), one of the major natural metabolites of curcumin from Curcuma longa, on rat isolated aortic rings, and the underlying mechanisms. Isometric tension of the aortic rings was recorded using organ bath system. HHC (1 nM to 1 mM) relaxed the endothelium‐intact aortic rings pre‐contracted with PE and KCl in a concentration‐dependent manner. Removal of the endothelium did not alter the effect of HHC‐induced relaxation. In Ca²⁺‐free Krebs solution, HHC significantly inhibited the CaCl₂‐induced contraction in high K⁺ depolarized rings and suppressed the transient contraction induced by PE and caffeine in a concentration‐dependent manner. HHC was also observed to relax phobal‐12‐myristate‐13‐acetate (PMA), an activator of protein kinase C (PKC), precontracted aortic rings in a concentration‐dependent manner with EC₅₀ values equivalent to 93.36 ± 1.03 μM. In addition, pre‐incubation with propranolol (a β‐adrenergic receptor blocker) significantly attenuated the HHC‐induced vasorelaxation. These results suggest that the vasorelaxant effect of HHC is mediated by the endothelium‐independent pathway, probably because of the inhibition of extracellular Ca²⁺ influx through voltage‐operated Ca²⁺ channels and receptor‐operated Ca²⁺ channels, the inhibition of Ca²⁺mobilization from intracellular stores, as well as inhibition of PKC‐mediated Ca²⁺‐independent contraction. Moreover, HHC produces vasorelaxant effects probably by stimulating the β‐adrenergic receptor. Copyright © 2015 John Wiley & Sons, Ltd.     

Beneficial effects of transcatheter closure of atrial septal defects not only in young adults

Objectives: To compare cardiac events and remodeling effects after transcatheter closure of atrial septal defects (ASD) in pediatric, adult, and older adult patients. Methods: A retrospective review was conducted of 353 patients who underwent transcatheter ASD closure between February 1999 and December 2007 at Siriraj Hospital. The patients were divided into 3 groups according to age: children (<18 years; n = 99); adults (18–50 years; n = 169); and older adults (>50 years; n = 85). Cardiac events at 1 year, and changes in left and right ventricular dimensions between preprocedure and 6 months and 1 year postprocedure were compared between groups. Results: Of the 353 patients, the average size of ASD was 22.1 ± 6.6 mm. Device: ASD diameter was 1.25 ± 0.28 mm. At 1 year postprocedure, the prevalence of chest discomfort and atrial fibrillation (AF) was higher in older adult patients, compared to the other age groups. Device embolization, cardiac erosion, pericardial effusion, syncope, migraine, thrombus formation, and residual shunt did not differ between groups. Within the first 6 months, the right ventricular (RV) dimension tended to dramatically decrease, while the left ventricular (LV) dimension increased in all age groups. These changes leveled off in children and in older adults, but in the adult group (18–50 years), RV shrinkage and LV expansion continued for 1 year. A low rate of early and late complications was noted. Conclusion: Transcather closure of ASD can cause cardiac remodeling, regardless of the patient's age at the time of the procedure. For older adult patients, the long‐term risk of AF continuation and chest discomfort is likely. (J Interven Cardiol 2012;25:382–390)     

Protective effect of diarylheptanoids from Curcuma comosa on primary rat hepatocytes against t-butyl hydroperoxide-induced toxicity

Context: Curcuma comosa Roxb. (Zingiberaceae) has traditionally been used as an anti-inflammatory agent in liver, and recent study has shown its hepatoprotective effect against CCl₄-induced liver injury in vivo.

Objective: This study further assesses the protective effect of C. comosa extracts and its isolated compounds against tert-butyl hydroperoxide (t-BHP)-induced hepatotoxicity in isolated primary rat hepatocytes.

Materials and methods: Isolated primary hepatocytes were pretreated with either ethanol (5–50?μg/ml) or hexane extract (1–50?μg/ml), or two diarylheptanoids (4–35?μM): compound D-91 [1-(4-hydroxyphenyl)-7-phenyl-(6E)-6-hepten-3-ol] and compound D-92 [(3S)-1-(3,4-dihydroxyphenyl)-7-phenyl-(6E)-6-hepten-3-ol], from C. comosa for 2?h prior to exposure to 1.5?mM t-BHP for 15 and 30?min. Their hepatoprotective activities were then determined.

Results: t-BHP markedly caused the formation of MDA and ALT leakage from the hepatocytes. Pretreatment with the C. comosa ethanol extract showed greater protective effect than the hexane extract, and the effect was concentration related. Treating the hepatocytes with compound D-92 provided greater protective effect than compound D-91. IC₅₀ values of compounds D-91, D-92, and silymarin for the protection of ALT leakage at 30?min were 32.7?±?1.1, 9.8?±?0.7, and 160?±?8?μM, respectively. Further investigation showed that compound D-92 was more effective in maintaining the intracellular glutathione content in the t-BHP treated group, whereas the reduction in antioxidant enzymes, glutathione peroxidase and glutathione-S-transferase activities, were not improved.

Discussion and conclusion: Results suggest that diarylheptanoids are the active principles that provide protection against t-BHP-induced injury. Their ability to maintain intracellular glutathione content is the main mechanisms underlying the protective action.     

Growth Suppressing Effect of Curcuma Comosa Extract on Male Reproductive Organs in Immature Rats

The effects of Curcuma comosa extracts on the growth of male reproductive organs were investigated in immature rats. Intragastric administration of a hexane extract at a dose of 500 mg/kg BW for 7 consecutive days significantly suppressed weights of testes, epididymis, ventral prostate, seminal vesicle and levator ani muscle, whereas the same dose of ethyl acetate extract did not affect the organ weights. Suppression of the growth of the organs by the hexane extract was dose-dependent. Histological examination revealed regression of the spermatogonium in the seminiferous tubules and necrosis of epithelial cells in the epididymis. All effects of the hexane extract were similar to the effects of estradiol. Concurrent treatment with either hCG or testosterone did not fully abolish the suppressing effects of the extract. The growth-suppressing effect of C. comosa extract on male reproductive organs can be attributed to inhibition of gonadotrophin secretion and subsequent reduction of testosterone production, or to direct action on the male accessory sex organs.     

Antibacterial pterocarpans from Erythrina subumbrans

Seven pterocarpans, erybraedin B (1), erybraedin A (2), phaseollin (3), erythrabyssin II (4), erystagallin A (5), erythrabissin-1 (6) and erycristagallin (7), two flavanones, 5-hydroxysophoranone (8) and glabrol (9), and one isoflavone, erysubin F (10), were isolated from the stems of Erythrina subumbrans (Leguminosae). Their structures were identified by means of spectroscopy. This is the first report of the isolation of the non-alkaloidal compounds from Erythrina subumbrans and the observed dehydration of 6a-hydroxypterocarpans 5 and 6 in CDCl(3) to the corresponding pterocarpenes 11 and 12, respectively. Compounds 8 and 9 were isolated for the first time from the genus Erythrina. Compounds 2 and 4 exhibited the highest degree of activity against Streptococcus strains with an MIC range of 0.78-1.56 microg/ml, whereas compound 7 exhibited the highest degree of activity against Staphylococcus strains, including drug-resistant strains (MRSA and VRSA), with an MIC range of 0.39-1.56 microg/ml. Interestingly, compounds 2, 4, 5 and 7 were more active against several strains of Streptococcus and Staphylococcus than the standard antibiotics vancomycin and oxacillin. Compound 7 showed the highest level of activity against all VRSA strains tested, with an MIC range of 0.39-1.56 microg/ml, which were resistant to both antibiotics. These compounds may prove to be potent phytochemical agents for antibacterial activity, especially against the MRSA and VRSA strains.     

Novel action of the chalcone isoliquiritigenin as a cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor: potential therapy for cholera and polycystic kidney disease

Overstimulation of cAMP-activated Cl(-) secretion can cause secretory diarrhea. Isoliquiritigenin (ISLQ) is a plant-derived chalcone that has a wide range of biological activities. The present study thus aimed to investigate the effect of ISLQ on cAMP-activated Cl(-) secretion in human intestinal epithelium, especially the underlying mechanism and therapeutic application. Short-circuit current analysis of human intestinal epithelial (T84) cell monolayers revealed that ISLQ dose-dependently inhibited cAMP-activated Cl(-) secretion with an IC(50) of approximately 20 μM. ISLQ had no effect on either basal short-circuit current or Ca(2+)-activated Cl(-) secretion. Apical Cl(-) current analysis of T84 cell monolayers indicated that ISLQ blocked mainly the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channels, but not other unidentified cAMP-dependent Cl(-) channels. ISLQ did not affect intracellular cAMP levels or cell viability. ISLQ completely abolished the cholera toxin-induced transepithelial Cl(-) secretion in T84 cells and reduced the cholera toxin-induced intestinal fluid secretion in mouse closed loop models by 90%. Similarly, ISLQ completely inhibited the cAMP-activated apical Cl(-) current across monolayers of Madin-Darby Canine Kidney (MDCK) cells and retarded cyst growth in MDCK cyst models by 90%. This study reveals a novel action of ISLQ as a potent CFTR inhibitor with therapeutic potential for treatment of cholera and polycystic kidney disease.     

Slow fetal heart rate may predict pregnancy outcome in first-trimester threatened abortion

Two hundred forty pregnant women presented with first-trimester threatened abortion were examined by transvaginal ultrasound. Women with a slow fetal heart rate of less than 120 beats per minute may eventually be at increased risk for pregnancy loss.