Current Pharmaceutical Biotechnology - Volume 16, Issue 1, 2015

The application of the general model of the law of mass action itself, of the achievement of dynamic, statistical equilibria, has led to great successes in describing the theory of single-molecule biophysics and biochemistry based on individually and freely diffusing molecules in dilute liquid and crowded living cells. For example, anomalous diffusion is a general phenomenon in living cells. There is solid evidence for analyzing fluorescence correlation and dual color fluorescence crosscorrelation spectroscopy data (FCS and dual color FCCS) in cellular applications by equations based on anomalous subdiffusion. Using equations based on normal diffusion causes artifacts of the fitted biological system response parameters and of the interpretations of the FCS and dual color FCCS data in the crowded environment of living cells. Equations based on normal diffusion are not valid in living cells. The original article embraces the status of the experimental situation and touches obstacles that still hinder the applications of single molecules in the cellular environment.

Nicotinic acid (NA) decreases low density lipoprotein (LDL) cholesterol and increases highdensity lipoprotein (HDL) cholesterol at pharmacological doses 500-2000 mg/day, which further inhibits the progression of atherosclerosis and cardiovascular morbidity. However, some effects of NA may be mediated through lipid-independent pathways. NA participates in the regulation of glucose metabolism and the NAD-sirtuin pathway, which may relate to the altered mitochondrial biogenesis. NA exerts its anti-atherosclerotic or side effects via binding to GPR109A and receptor TRPV1. NA may regulate lipid metabolism via adipokines, especially TNFα and adiponectin. NA participates in several cellular pathways, including forkhead transcription factors, sirtuins, and protein kinase B. Though much progress on the regulatory effect of NA has been obtained, much remains to be determined about the exact cellular signal pathways on the regulatory mechanism. To reveal the mechanisms of excessive fatty deposition diseases, it is necessary to investigate the signaling pathways in the muscle, liver, and adipose tissue by which NA controls lipid metabolism. In this paper, we will review recent data on the pharmacological effects of NA and discuss how NA might be harnessed to regulate glucose and lipid metabolism through lipid-independent pathways.

Fragment-based drug discovery (FBDD) has caused a revolution in the process of drug discovery and design, with many FBDD leads being developed into clinical trials or approved in the past few years. Compared with traditional high-throughput screening, it displays obvious advantages such as efficiently covering chemical space, achieving higher hit rates, and so forth. In this review, we focus on the most recent developments of FBDD for improving drug discovery, illustrating the process and the importance of FBDD. In particular, the computational strategies applied in the process of FBDD and molecular-docking programs are highlighted elaborately. In most cases, docking is used for predicting the ligand–receptor interaction modes and hit identification by structurebased virtual screening. The successful cases of typical significance and the hits identified most recently are discussed.

Every year more than 12,000 people in US alone suffer from spinal cord injury. However, complete recovery of physical function is difficult due to multiple factors involved in disease progression. Currently available therapeutic regimens do not address all the factors concerned with the disease progression. The present review focuses mainly on the role of immune cells in progression of spinal cord injury and the drugs that target these immune cells. Literature search shows that inflammatory reactions and subsequent reactions that follow direct injury to spinal cord are sometimes responsible for the severity of the disease. Therefore, for design of proper treatment regimen a deep understanding in this area is required. Understanding the pathophysiology will help in creating delivery system that can target multiple factors involved in progression of spinal cord injury. A combination of various treatment strategies is required to reduce the disability in patients with spinal cord injury.

Xylitol is an important polyalcohol suitable for use in odontological, medical and pharmaceutical products and as an additive in food. The first studies on the efficacy of xylitol in the control and treatment of infections started in the late 1970s and it is still applied for this purpose, with safety and very little contribution to resistance. Xylitol seems to act against microorganisms exerting an anti-adherence effect. Some research studies have demonstrated its action against Gram-positive and Gram-negative bacteria and yeasts. However, a clear explanation of how xylitol is effective has not been completely established yet. Some evidence shows that xylitol acts on gene expression, down-regulating the ones which are involved in the microorganisms’ virulence, such as capsule formation. Another possible clarification is that xylitol blocks lectin-like receptors. The most important aspect is that, over time, xylitol bypasses microbial resistance and succeeds in controlling infection, either alone or combined with another compound. In this review, the effect of xylitol in inhibiting the growth of a different microorganism is described, focusing on studies in which such an anti-adherent property was highlighted. This is the first mini-review to describe xylitol as an anti-adherent compound and take into consideration how it exerts such action.

The significant role of microRNAs (miRNAs) in stem cell development has been expansively discussed in recent publications and they are noticed to be involved in post transcriptional regulation of gene expression by its affinity towards the 3′UTR of target mRNA. Since the expression of miR-21 was high in cells that were derived from MSCs, recent evidence indicates that miR-21 plays a vital role in mesenchymal stem cells (MSCs) differentiation. Despite the fact that miR-21 can be considered as a powerful biomarker for MSCs differentiation, the number of studies related to the above scenario is very limited. This review highlights the recent publications related to the importance of miR-21 specifically in differentiation of MSCs.

Objective: the aim of the work was to evaluate the effect of moderate physical exercise on the response of circulating phagocytes to the antineoplastic drug NSC 631570. Methods: Eight healthy adult men aged 23 ± 2 years were recruited to participate in the study; NSC 631570 was administered i.v. in a single therapeutic dose; blood samples were collected before and after the drug administration; the moderate physical exercise programme included 50 slow squats; total leukocyte, neutrophil and lymphocyte counts were determined using the haematological analyser; intracellular ROS generation and phagocytic activity of circulating monocytes and granulocytes were analysed by flow cytometry; PPAR-γ protein expression was evaluated by Western blot. Results: introduction of NSC 631570 in an inpatient setting was associated with a decrease in phagocyte endocytic activity along with an increase in ROS generation. Drug injection in an outpatient setting was accompanied by a significant increase in monocyte and granulocyte phagocytosis along with a decrease in the daily mean of ROS generation as well as by a decrease in monocyte reactivity reserve after stimulation in vitro. PPAR-γ expression in circulating monocytes was significantly decreased after the drug administration in an inpatient setting and was slightly increased in active participants after the drug injection. Conclusion: NSC 631570 causes M1 (N1) shift of phagocytes after in vivo introduction. Moderate physical exercise exerts a negative effect on the immunomodulatory action of NSC 631570 by abrogating M1 (N1) shift of circulating phagocytes. One of the reasons for such an effect could be an increase in PPAR-γ expression by phagocytes.

Recently, the inhibitor dipeptidyl peptidase-4 has been reported to be beneficial in the treatment of type 1 diabetes mellitus. For the first time, this study evaluates the effect of vildagliptin on β -cell neogenesis and lipid homeostasis in a later phase of type 1 diabetes. In Fischer rats, diabetes was induced with alloxan. After confirmation of diabetic status, the animals received no treatment for 30 days to establish a late phase of the disease these animals. After this period, the animals were treated with vildagliptin via gavage for 30 consecutive days. Fasting blood glucose, serum insulin, lipid profile and pancreatic histology were evaluated. Treatment with vildagliptin increased serum levels of insulin, improved beta cell function and improved the lipid profile. Histological analyses revealed that this treatment increased the populations of pancreatic β-cells in the diabetic animals. The treatment was effective in improving the mass and function of β-cells and contributed to lipid homeostasis, in an experimental model of type 1 diabetes.

Achyrobichalcone is a biflavonoid recently found in Achyrocline satureioides. This substance has unprecedented chemical structure and occurrence, but resembles other bioactive bichalcones, which have important pharmacological properties, such as anticancer activity. The major challenge for evaluation of the physicochemical and biological properties of this new molecule is the isolation step, which affects the purity and yield of the isolated product. Thus, the objective of this work was to develop a semi-preparative method for achyrobichalcone isolation from Achyrocline satureioides by high-speed countercurrent chromatography. The high-speed countercurrent chromatography separation was achieved in two steps. In the first step, an enriched fraction of achyrobichalcone from the freeze-dried extract was obtained, using the solvent system hexane-ethyl acetate-methanol-water 0.8:1:0.8:1, v/v. The purification of achyrobichalcone from the enriched fractions was achieved by further high-speed countercurrent chromatography fractionation with hexane-ethyl acetate-methanol-water 0.9:0.9:0.8:1, v/v. The final isolated product was obtained using preparative thin layer chromatography and crystallization procedure. A yellow semi-crystalline solid with purity close to 90% was obtained as the final product. The mass recovery of achyrobichalcone isolation was near 67%. The structural identification from spectroscopic and chromatographic techniques confirmed the achyrobichalcone structure. This is the first report of achyrobichalcone isolation on a semi-preparative scale by high-speed countercurrent chromatography. This method afforded achyrobichalcone in good yield and purity for further biopharmaceutical studies.

VARV-CrmB is a TNF binding protein of variola virus. VARV-CrmB protein was previously shown to be active as a TNF-antagonist in a number of in vivo and in vitro models. Here we investigated the epicutaneous effect of recombinant VARV-CrmB protein using an experimental model of muTNFinduced migration of skin leukocytes as well as colony forming activity of bone marrow cells (BMC). Epiсutaneous applications of muTNF enhanced the number of cells migrating from skin flaps of BALB/c mice, whereas subsequent applications of VARV-CrmB protein in 30 min after muTNF, abolished that effect. Epicutaneously applied muTNF influenced the activity of committed hematopoietic progenitors causing a reduction of erythroid (BFUe+CFUe) colonies and increase of granulocyte-macrophage (CFU-GM) colonies in the colony-forming tests. VARV-CrmB, applied in combination with muTNF, demonstrated an ability to reverse this effect, namely, to increase BFUe+CFUe and reduce CFU-GM back to the control levels. Taking together, these data demonstrate the TNF-blocking properties of VARV-CrmB in vivo at epicutaneous applications. As effective TNF antagonist VARV-CrmB protein might be conceded as a beneficial candidate for future research and development of therapeutic approaches in the field of inflammatory skin diseases.

The Chinese citrus fruit fly, Bactrocera minax is one of the most economically important and aggressive pests threatening the Chinese citrus industry. In order to provide some recommendations for the improvement of integrated pest management of this species, the authors evaluated the toxicity of 6 insecticides on the second stage larvae, fourth stage larvae, and adult flies from multiple geographical B. minax populations. In addition, the influences of each pesticide on pupation and emergence were examined for one population, from Hanzhong. The 6 reagents displayed a wide range of toxicity on various stages of B. minax. Abamectin and Dichlorphos displayed the highest and lowest toxicities, respectively. All of the insecticides had negative effects on pupation and emergence of B. minax from Hanzhong, while Chlorpvrifos had the strongest impact on pupation, and Phoxim had the strongest influence on emergence. Though Phoxim and Chlorpvrifos were both effective, these insecticides belong to the class of organophosphorus pesticides, and their use should be reduced in orchards because of their high toxicity and long residual period.