Repeated vertebral compression fractures in young adult may imply functional adrenal tumor.

BACKGROUND: Patients with adrenal Cushing's syndrome (ACS) typically present with central obesity, hirsutism, hypertension, or glucose intolerance, which can be easily identified by a clinical physician. However, recognizing those with subclinical CS or those with less common symptoms and signs is challenging to the subspecialist, which can lead to delayed diagnosis and treatment. We report a case who presented with repeated vertebral fractures in 6 months. Typical physical appearance of CS was not shown so that suspicions were not raised until severe osteoporosis was demonstrated from bone marrow density study. From our case report, endocrine tests and image survey should always be considered in young patients with repeat vertebral fractures. CASE PRESENTATION: A 48-year-old man presented with severe back pain for 3 months. Second and fifth lumbar spine (L2 and L5) vertebral compression fractures were noted from X-ray and magnetic resonance imaging (MRI), and vertebroplasty was performed by orthopedic surgeons. After 1 month, a newly developed compression fracture of the ninth to twelfth thoracic spine and L4-L5 were noted. Severe osteoporosis was noted from the hip bone mineral density test, and he was referred to an endocrinologist for analysis. Serial endocrine tests confirmed hypercortisolism, and subsequent abdomen MRI showed a left adrenal tumor. ACS was diagnosed. Left laparoscopic adrenalectomy was performed, and the patient received cortisol supplement for 12 months. Thereafter, no new fractures were identified. CONCLUSIONS: ACS should be considered and carefully verified in middle-aged adults who present with severe osteoporosis and repeated vertebral compression fracture.

Design, Synthesis, and Evaluation of Dihydropyranopyrazole Derivatives as Novel PDE2 Inhibitors for the Treatment of Alzheimer's Disease.

Phosphodiesterase 2 (PDE2) has been regarded as a novel target for the treatment of Alzheimer's disease (AD). In this study, we obtained (R)-LZ77 as a hit compound with moderate PDE2 inhibitory activity (IC50 = 261.3 nM) using a high-throughput virtual screening method based on molecular dynamics. Then, we designed and synthesized 28 dihydropyranopyrazole derivatives as PDE2 inhibitors. Among them, compound (+)-11h was the most potent PDE2 inhibitor, with an IC50 value of 41.5 nM. The molecular docking of PDE2-(+)-11h reveals that the 4-(trifluoromethyl)benzyl)oxyl side chain of the compound enters the H-pocket and forms strong hydrophobic interactions with L770/L809/F862, which improves inhibitory activity. The above results may provide insight for further structural optimization of highly potent PDE2 inhibitors and may lay the foundation for their use in the treatment of AD.

Licochalcone B, a chalcone derivative from Glycyrrhiza inflata, as a multifunctional agent for the treatment of Alzheimer's disease.

Licochalcone B (LCB), an extract from the root of Glycyrrhiza inflate, has the same caffeic acid scaffold as curcumin (Cur), which is known as an anti-Alzheimer's disease (AD) agent. However, there is no relevant research about anti-AD activity of LCB. In this study, the anti-AD activity of LCB was investigated. LCB could inhibit amyloid beta (Aß42) self-aggregation (IC50 = 2.16 ± 0.24 µM) and disaggregate pre-formed Aß42 fibrils, reduce metal-induced Aß42 aggregation through chelating metal ions. Molecular docking further revealed that LCB inhibited Aß42 self-aggregation through forming two hydrogen bonds with Lys28 to block the salt bridge interaction at the C-terminus of Aß42. Anti-oxidant property of LCB was also observed by DCFH-DA assay. In addition, LCB did show neuroprotective activity against H2O2-induced cell death in SH-SY5Y cells. In general, our results demonstrate that LCB, as a multifunctional agent, is likely to be promising therapeutics for AD.

Literature Review and Meta-Analysis of Transcutaneous Electrical Nerve Stimulation in Treating Chronic Back Pain.

BACKGROUND AND OBJECTIVES: This study is a meta-analysis of randomized controlled trials comparing the efficacy of transcutaneous electrical nerve stimulation (TENS) to a control and to other nerve stimulation therapies (NSTs) for the treatment of chronic back pain. METHODS: Citations were identified in MEDLINE, the Cochrane Library, Google Scholar, and ClinicalTrials.gov through June 2014 using the following keywords: nerve stimulation therapy, transcutaneous electrical nerve stimulation, back pain, chronic pain. Control treatments included sham, placebo, or medication only. Other NSTs included electroacupuncture, percutaneous electrical nerve stimulation, and percutaneous neuromodulation therapy. RESULTS: Twelve randomized controlled trials including 700 patients were included in the analysis. The efficacy of TENS was similar to that of control treatment for providing pain relief (standardized difference in means [SDM] = -0.20; 95% confidence interval [CI], -0.58 to 0.18; P = 0.293). Other types of NSTs were more effective than TENS in providing pain relief (SDM = 0.86; 95% CI, 0.15-1.57; P = 0.017). Transcutaneous electrical nerve stimulation was more effective than control treatment in improving functional disability only in patients with follow-up of less than 6 weeks (SDM = -1.24; 95% CI, -1.83 to -0.65; P < 0.001). There was no difference in functional disability outcomes between TENS and other NSTs. CONCLUSIONS: These results suggest that TENS does not improve symptoms of lower back pain, but may offer short-term improvement of functional disability.

Development and characterization of docetaxel-loaded lecithin-stabilized micellar drug delivery system (LsbMDDs) for improving the therapeutic efficacy and reducing systemic toxicity.

In the present study, we attempted to develop a lecithin-stabilized micellar drug delivery system (LsbMDDs) for loading docetaxel (DTX) to enhance its therapeutic efficacy and minimize systemic toxicity. A novel DTX-loaded LsbMDDs was optimally prepared by a thin-film hydration method and then hydrated with a lecithin nanosuspension while being subjected to ultrasonication. Physical characteristics of the optimized DTX-loaded LsbMDDs formulations were examined and found to have a mean size of <200 nm, an encapsulation efficiency of >90%, and drug loading of >6% with stability at room temperature and at 4 °C being longer than 2 and 7 days, respectively. The in vitro release of DTX from the DTX-loaded LsbMDDs was slower than that from the generic product of DTX (Tynen®). A cell viability assay demonstrated that the LsbMDDs showed better cytotoxicity than Tynen® against CT26 cancer cells. The in vivo antitumor efficacy of the DTX-loaded LsbMDDs was observed to be better than that of Tynen® in a CT26 tumor-bearing mice model. A high-dose regimen of the DTX-loaded LsbMDDs formulation showed greater inhibition of DU145 tumor growth than did Tynen®, but with less to similar systemic toxicity. An in vivo study also showed that a greater amount of drug was able to accumulate in the tumor site with the DTX-loaded LsbMDDs, and its maximal tolerable doses for single and repeated injections were 2-2.5-fold higher than those of Tynen®. In conclusion, the LsbMDDs could be a promising high drug-loaded nanocarrier for delivering hydrophobic chemotherapeutic agents that can enhance the efficacy of chemotherapy and reduce systemic toxicity.

Discovery of novel purine nucleoside derivatives as phosphodiesterase 2 (PDE2) inhibitors: Structure-based virtual screening, optimization and biological evaluation.

Phosphodiesterase 2 (PDE2) has received much attention for the potential treatment of the central nervous system (CNS) disorders and pulmonary hypertension. Herein, we identified that clofarabine (4), an FDA-approved drug, displayed potential PDE2 inhibitory activity (IC50 = 3.12 ±â€¯0.67 µM) by structure-based virtual screening and bioassay. Considering the potential therapeutic benefit of PDE2, a series of purine nucleoside derivatives based on the structure and binding mode of 4 were designed, synthesized and evaluated, which led to the discovery of the best compound 14e with a significant improvement of inhibitory potency (IC50 = 0.32 ±â€¯0.04 µM). Further molecular docking and molecular dynamic (MD) simulations studies revealed that 5'-benzyl group of 14e could interact with the unique hydrophobic pocket of PDE2 by forming extra van der Waals interactions with hydrophobic residues such as Leu770, Thr768, Thr805 and Leu809, which might contribute to its enhancement of PDE2 inhibition. These potential compounds reported in this article and the valuable structure-activity relationships (SARs) might bring significant instruction for further development of potent PDE2 inhibitors.

The discovery, complex crystal structure, and recognition mechanism of a novel natural PDE4 inhibitor from Selaginella pulvinata.

Phosphodiesterase-4 (PDE4) is an important drug target for treatment of inflammation-related diseases. Till now, natural PDE4 inhibitors are rare and their co-crystal structures with PDE4 are hardly available. In the present study, selaginpulvilins K and L (1 and 2), two novel fluorene derivatives, were isolated from a traditional Chinese medicine Selaginella pulvinata and exhibited remarkable inhibition against phosphodiesterase-4D (PDE4D) at IC50 11nM and 90nM, respectively. Compound 1 also showed a good selectivity across PDE families with the selective fold ranging from 30 to 909. To understand the recognition mechanism of selaginpulvilins towards PDE4, the crystal structure of PDE4D bound with 1 was successfully determined by the X-ray diffraction method and presented an unusual binding mode in which the stretched skeleton of the inhibitor bound shallowly to the active site but had interactions with multi sub-pockets, such as Q, HC, M, and S, especially strong interaction with the metal region. Assisted with molecular modeling, the structure-activity relationship and the selectivity of selaginpulvilins were also well explored, which would facilitate the future rational inhibitor design or structural optimizations.

Discovery of Novel Phosphodiesterase-2A Inhibitors by Structure-Based Virtual Screening, Structural Optimization, and Bioassay.

Phosphodiesterase-2A (PDE2A) is a potential therapeutic target for treatment of Alzheimer's disease and pulmonary hypertension. However, most of the current PDE2A inhibitors have moderate selectivity over other PDEs. In the present study, we described the discovery of novel PDE2A inhibitors by structure-based virtual screening combining pharmacophore model screening, molecular docking, molecular dynamics simulations, and bioassay validation. Nine hits out of 30 molecules from the SPECS database (a hit rate of 30%) inhibited PDE2A with affinity less than 50 µM. Optimization of compound AQ-390/10779040 (IC50 = 4.6 µM) from the virtual screening, which holds a novel scaffold of benzo[cd]indol-2(1H)-one among PDE inhibitors, leads to discovery of a new compound LHB-8 with a significant improvement of inhibition (IC50 = 570 nM). The modeling studies demonstrated that LHB-8 formed an extra hydrogen bond with Asp808 and a hydrophobic interaction with Thr768, in addition to the common interactions with Gln859 and Phe862 of PDE2A. The novel scaffolds discovered in the present study can be used for rational design of PDE2A inhibitors with high affinity.

Natural phosphodiesterase-4 inhibitors from the leaf skin of Aloe barbadensis Miller.

The ethanolic extract of Aloe barbadensis Miller leaf skin showed inhibitory activity against phosphodiesterase-4D (PDE4D), which is a therapeutic target of inflammatory disease. Subsequent bioassay-guided fractionation led to the isolation of two new anthrones, 6'-O-acetyl-aloin B (9) and 6'-O-acetyl-aloin A (11), one new chromone, aloeresin K (8), together with thirteen known compounds. Their chemical structures were elucidated by spectroscopic methods including UV, IR, 1D and 2D NMR, and HRMS. All of the isolates were screened for their inhibitory activity against PDE4D using tritium-labeled adenosine 3',5'-cyclic monophosphate ((3)H-cAMP) as substrate. Compounds 13 and 14 were identified as PDE4D inhibitors, with their IC50 values of 9.25 and 4.42 µM, respectively. These achievements can provide evidences for the use of A. barbadensis leaf skin as functional feed additives for anti-inflammatory purpose.

Prenylated coumarins: natural phosphodiesterase-4 inhibitors from Toddalia asiatica.

Bioassay-guided fractionation of the ethanolic extract of the roots of Toddalia asiatica led to the isolation of seven new prenylated coumarins (1-7) and 14 known analogues (8-21). The structures of 1-7 were elucidated by spectroscopic analysis, and their absolute configurations were determined by combined chemical methods and chiral separation analysis. Compounds 1-5, named toddalin A, 3‴-O-demethyltoddalin A, and toddalins B-D, represent an unusual group of phenylpropenoic acid-coupled prenylated coumarins. Compounds 1-21 and four modified analogues, 10a, 11a, 13a, and 17a, were screened by using tritium-labeled adenosine 3',5'-cyclic monophosphate ([3H]-cAMP) as substrate for their inhibitory activity against phosphodiesterase-4 (PDE4), which is a drug target for the treatment of asthma and chronic obstructive pulmonary disease. Compounds 3, 8, 10, 10a, 11, 11a, 12, 13, 17, and 21 exhibited inhibition with IC50 values less than 10 µM. Toddacoumalone (8), the most active compound (IC50=0.14 µM), was more active than the positive control, rolipram (IC50=0.59 µM). In addition, the structure-activity relationship and possible inhibitory mechanism of the active compounds are also discussed.

Natural phosphodiesterase-4 (PDE4) inhibitors from Crotalaria ferruginea.

Bioassay-guided fractionation of the ethanol extract of the Chinese folk medicine Crotalaria ferruginea led to the isolation of a new isoflavonoid, 4'-hydroxy-2'-methylalpinum-isoflavone (1), and eight known analogs (2-9). Their structures were elucidated by spectroscopic analysis. Compounds 1, 2, 5, and 8 showed inhibitory activities against phosphodiesterase-4 (PDE4), a therapeutic target of asthma, with IC50 values ranging from 2.57 to 8.94 µM. The possible action mechanism and the structure-activity relationship (SAR) of the active isoflavonoids were explored by using molecular docking and molecular dynamics (MD) simulation methods. Our study herein may explain the anti-inflammatory function of this plant in Chinese folk medicine.

Chemical constituents of Aloe barbadensis Miller and their inhibitory effects on phosphodiesterase-4D.

Aloe barbadensis Mill has been used as food and medicine for a long time. In order to investigate the chemical constituents of A. barbadensis and their inhibitory activities towards phosphodiesterase-4D (PDE4D), 70% methanol extract of the dried A. barbadensis powder was employed. Phytochemical investigation has led to the isolation of three new chromones, 5-(hydroxymethyl)-7-methoxy-2-methylchromone (4), 5-((4E)-2'-oxo-pentenyl)-2-hydroxymethylchromone (6), and 7-hydroxy-5-(hydroxymethyl)-2-methylchromone (7), together with eighteen known compounds. Their chemical structures were determined based on spectroscopic methods including UV, IR, 1D and 2D NMR, and HRMS spectrometry. In addition, their inhibition against PDE4D was evaluated using tritium-labeled adenosine 3',5'-cyclic monophosphate ((3)H-cAMP) as the substrate. Inhibition was calculated by the variation of radioactivity after the reaction, and compounds 1-4, 10, and 21 exhibited certain inhibitory activities towards PDE4D, which can provide an explanation why A. barbadensis can serve as anti-inflammatory agents.

MEMS microwell and microcolumn arrays: novel methods for high-throughput cell-based assays.

Although the cell-based assay is becoming more popular for high throughput drug screening and the functional characterization of disease-associated genes, most researchers in these areas do not use it because it is a complex and expensive process. We wanted to create a simple method of performing an on-chip cell-based assay. To do this, we used micro-electro-mechanical systems (MEMS) to fabricate a microwell array chip comprised of a glass substrate covered with a photoresist film patterned to form multiple microwells and tested it in two reverse transfection experiments, an exogenous gene expression study and an endogenous gene knockdown study. It was used effectively in both. Then, using the same MEMS technology, we fabricated a complementary microcolumn array to be used as a drug carrier device to topically apply drugs to cells cultured in the microwell array. We tested the effectiveness of microwell-microcolumn on-chip cell-based assay by using it in experiments to identify epidermal growth factor receptor (EGFR) activity inhibitors, for which it was found to provide effective high throughput and high content functional screening. In conclusion, this new method of cell-based screening proved to be a simple and efficient method of characterizing gene function and discovering drug leads.