Current Pharmaceutical Biotechnology - Volume 16, Issue 6, 2015

Active or passive immunotherapy is expected to slow or stop the pathological process of Alzheimer’s disease (AD). Immunotherapy for AD has demonstrated that targeting beta-amyloid (Aβ) or tau protein with vaccines or antibodies can reduce AD pathologies. Active anti-Aβ immunization for AD includes using AN1792 and second generation vaccines such as ACC-001, CAD106 and AFFITOPE vaccines, while antibodies for passive immunization include monoclonal antibodies and intravenous immunoglobulin (IVIG). Preclinical trials have shown powerful evidence of significant advances for more than a decade; however, there are still issues that need to be addressed in clinical trials. In the phase IIa AN1792 trial, 6% of patients who received the vaccination were diagnosed with meningoencephalitis as an adverse effect. There was a high incidence of amyloid-related imaging abnormalities (ARIA) in patients treated with some monoclonal antibodies. Moreover, several phase 3 clinical trial findings of immunization targeting Aβ were negative. These issues require attention in order to improve the safety and efficacy of immunization strategies in AD. Prevention studies and other novel immunization strategies have the potential to dramatically impact AD care. Herein we review the recent advances in clinical trials involving immunotherapy for AD.

Regeneration in the central nervous system (CNS) of adult mammalian after traumatic injury is limited, which often causes permanent functional motor and sensory loss. After spinal cord injury (SCI), the lack of regeneration is mainly attributed to the presence of a hostile microenvironment, glial scarring, and cavitation. Besides, inflammation has also been proved to play a crucial role in secondary degeneration following SCI. The more prominent treatment strategies in experimental models focus mainly on drugs and cell therapies, however, only a few strategies applied in clinical studies and therapies still have only limited effects on the repair of SCI. Recently, the interests in immunotherapy strategies for CNS are increasing in number and breadth. Immunotherapy strategies have made good progresses in treating many CNS degenerative disorders, such as Alzheimer’s disease (AD), Parkinson’s disease (PD), stroke, and multiple sclerosis (MS). However, the strategies begin to be considered to the treatment of SCI and other neurological disorders in recent years. Besides anti-inflamatory therapy, immunization with protein vaccines and DNA vaccines has emerged as a novel therapy strategy because of the simplicity of preparation and application. An inflammatory response followed by spinal cord injury, and is controled by specific signaling molecules, such as some cytokines playing a crucial role. As a result, appropriate immunoregulation, the expression of pro-inflammatory cytokines and anti-inflammatory cytokines may be an effective therapy strategy for earlier injury of spinal cord. In addition, myelinassociated inhibitors (MAIs) in the injured spinal cord, such as Nogo, myelin-associated glycoprotein (MAG) and oligodendrocyte- myelin glycoprotein (OMgp) are known to prevent axonal regeneration through their co-receptors, and to trigger demyelinating autoimmunity through T cell-mediated harmful autoimmune response. The antagonism of the MAIs through vaccinating with protein or DNA vaccines targeting Nogo, MAG, OMgp, and their co-receptors, may be an effective strategy for the treatment of SCI. However, immunotherapy such as anti-inflammtory therapy or vaccine targeting MAIs or their receptors, accompanied with the potential in risking autoimmune diseases. As a result, in order to optimize the anti-inflammtory therapy and design of protein or DNA vaccines for their use in the future clinical application, we need to further understand the possible mechanisms of neuroprotective immunity. This review presents recent advances in the development of immunotherapy strategies for the treatment of axonal degeneration and demyelination, and improvement of motor function after SCI.

Gymnema sylvestre R. Br. is one of the most important medicinal plants that grows in tropical forests in India and South East Asia. Its active ingredients and extracts of leaves and roots are used in traditional medicine to treat various ailments and they are present in the market for pharmaceutical and parapharmaceutical products. Commercial products based on substances of plant origin that are generally connoted as natural have to be subjected to monitoring and evaluation by health authorities for their potential impacts on public health. The monitoring and evaluation of these products are critical because the boundary between a therapeutic action and a functional or healthy activity has not yet been defined in a clear and unambiguous way. Therefore, these products are considered borderline products, and they require careful and rigorous studies, in order to use them as complement and/or even replacement of synthetic drugs that are characterized by side effects and high economic costs. This review explores the traditional uses, chemical composition and biological activity of G. sylvestre extracts, providing a general framework on the most interesting extracts and what are the necessary studies for a complete definition of the range of activities.

Sildenafil ameliorates aortic relaxations in apolipoprotein E knockout (apoE) mice. Now, we tested the hypothesis that endothelial dysfunction (ED) in this model is characterized by contractile hyperresponsiveness to phenylephrine (PE) and that this abnormality may be repaired using sildenafil. The aortic rings were evaluated in apoE mice treated with sildenafil (apoE-sil, 40 mg/kg/day) and compared with apoE and wild-type (WT) mice administered with vehicle (veh). The apoE-veh mice exhibited an imbalance of nitric oxide and reactive oxygen species (NO/ROS) levels and an increased maximum response (Rmax, 20%) and sensitivity (7%) to PE, which were not modified by endothelial removal. Under the prostanoids blockade, vasocontraction was decreased more in apoE-veh (-37%) than in WT (-27%) and apoE-sil (-30%) mice. NADPH-oxidase blockade abolished the enhanced contractile responsiveness in apoE-veh (-33%), without effects in WT and apoE-sil groups. The atherosclerotic lesions and the imbalance of NO/ROS were reduced (40%) in apoE-sil mice. In conclusion, ED in apoE mice was characterized by decreased NO-bioavailability and contractile hyperresponsiveness, due to thromboxane and oxidative stress, and was normalized by sildenafil. The beneficial effects of this phosphodiesterase-5 inhibitor on ED and lipid deposition provide new insights for its use as adjuvant in the treatment of atherosclerosis.

Diabetes is a major cause of cardiovascular morbidity and mortality and its prevalence is rapidly increasing worldwide. Despite clear advances in developing effective glucose-lowering drugs, clinical trials have recently shown that intensive glycemic control failed to reduce cardiovascular events in the diabetic population. These findings support the concept that the hyperglycemic environment may be remembered in the cardiovascular system. This phenomenon has been recently defined as “metabolic memory” and may contribute to explain the progression of diabetic vascular complications despite achievement of target HbA1c levels. In this regard, epigenetic changes of DNA/histone complexes are emerging as important modulators of oxidant and inflammatory genes, thus leading to persistent cardiac and vascular dysfunction. Over the last few years, the rapid development of many compounds (i.e. histone deacetylase and histone acetyltransferase inhibitors) able to erase adverse chromatin signatures led to the perception that reverting hyperglycemic damage might be possible and represents an attractive challenge. Here we critically discuss recent evidence supporting the concept that chromatin alterations are key drivers of cardiovascular disease and describe the emerging potential of chromatin modifying agents for the reprogramming of detrimental epigenetic signatures in patients with cardiometabolic disturbances.

Exploration of possible pharmacological effects along with characterisation of the bioactive compounds present in peels may have a key role in converting the fruit waste materials into therapeutic value added products. Extracts prepared from the Citrus limetta fruit peels were studied for antioxidant and anti- inflammatory activity using in-vitro bioassays. Among all, ClEt an ethanol extract of Citrus limetta fruit peels has shown promising anti-oxidant and anti-inflammatory activity. ClEt was further validated to ensure its safety evaluation at 2000mg/kg and anti-malarial efficacy at 100, 250, 500 mg/kg body weight with special reference to inflammatory mediators involved in malaria pathogenesis. In-vivo study revealed that ClEt was safe at higher dose and showed promising anti-malarial activity by inhibiting the parasitaemia and inflammatory mediators (IFN-γ, TNF-α, IL-6) involved in malaria pathogenesis, able to improve the haemoglobin and glucose level and increase the survival time. Chemical fingerprint of ClEt revealed the presence of flavonoids. Results suggested the suitability of ClEt, a flavonoid rich fraction of Citrus limetta fruit peels as a candidate for further investigation towards the management of malaria pathogenesis.

Prostate cancer (PCa) still ranks as the second most frequently diagnosed cancer and metastatic castrationresistant prostate cancer (CRPC) is a foremost cause of men cancer death around the world. The aim of this work was to investigate the selectivity and efficacy of new drug combinations for CRPC. We combined three compounds: paclitaxel (PTX: taxane that inhibits microtubule polymerization); 2-(2,4-Difluoro-phenyl)-4,5,6,7-tetrafluoro-1H-isoindole- 1,3(2H)-dione (CPS49; redox-reactive thalidomide analog with anti-angiogenic properties) and flavopiridol (flavo: semisynthetic flavonoid that inhibits cyclin dependent kinases). We assessed CPS49-flavo or -PTX combinations cytotoxicity in a panel of PCa cell lines and PC3 xenografts. We found that CPS49 enhanced flavo or PTX cytotoxicity in human PCa cell lines while showed resistance in a non-tumor cell line. Furthermore, xenografts generated by inoculation of human prostate carcinoma PC3 cells in nu/nu mice showed that CPS49/flavo administration reduced tumor growth both after 2 weeks of co-treatment and after 1 week of pretreatment with a low dose of flavo followed by 2 weeks of co-treatment. PTX and CPS49 combination did not significantly reduce tumor growth in PC3 xenografts. Histological analysis of xenograft PC3 tumor samples from CPS49/flavo combination showed extensive areas of necrosis induced by the treatment. RT-qPCR array containing 23 genes from PC3 cells or PC3 xenografts exposed to CPS49/flavo combination showed that this treatment shut down the expression of several genes involved in adhesion, migration or invasion. In summary, the antitumor activity of CPS49 or flavopiridol was improved by the combination of these compounds and using half dose of that previously reported. Hence, CPS49-flavo combination is a promising new alternative for PCa therapy.

Glucagon-like peptide-1 (GLP-1) is a short peptide that can significantly reduce blood glucose level. Recombination oral long-acting glucagon-like peptide-1 (rolGLP-1), is a GLP-1 analog generated from site-specific mutation of GLP-1. CTB is a non-toxic portion of the cholera toxin and an ideal protein antigen carrier. In this study, we firstly constructed a vector pET-22b (+)-CTB-10×rolGLP-1 to express a fusion protein composed of CTB and ten tandem repeated rolGLP-1 in BL21 (DE3) line of E.coli. The CTB-10×rolGLP-1 was expressed efficiently in the inclusion bodies. The expression product was analyzed by SDS-PAGE electrophoresis and Western blotting. The inclusion bodies were then denatured, refolded and purified by ion exchange chromatography to obtain a high-purity CTB- 10×rolGLP-1. The therapeutic effect of CTB-10×rolGLP-1 was assessed in comparison with 10×rolGLP-1 alone by daily oral-gavage administration up to 10 days in streptozotocin-induced type 2 diabetic mice. The results showed that the level of blood glucose was reduced more effectively and the oral glucose tolerance of mice was improved more significantly with the administration of CTB-10×rolGLP-1. Our results provided a potentially promising oral biological drug for the treatment of type 2 diabetes.

Benzodiazepines (BZDs), the most commonly prescribed psychotropic drugs with anxiolytic action, may cause hyposalivation. Therefore, this study sought to quantify the acini (N) in parotid glands of Wistar rats treated chronically with two BZDs (Lorazepam and Midazolan) and to verify the action of the pilocarpine when administered with these drugs. Ninety male Wistar rats were distributed in 9 groups according to the administration of: a) S30 - saline solution for 30 days; b) S60 - saline solution for 60 days; c) P60 – pilocarpine for 60 days; d) L30 - Lorazepam for 30 days; e) M30 - Midozolam for 30 days; f) LS60 - Lorazepam for 60 days and, after this period, 30 more days of saline solution; g) MS60 - Midazolam for 30 days and, after this period, 30 more days of saline solution; h) LP60 - Lorazepam and Pilocarpine for 60 days; i) MP60 - Midazolam and Pilocarpine for 60 days. A surgery was performed on the animals to remove the glands. After this, histological cuts were stained by hematoxylin and eosin, from which the N was quantified. The ANOVA and Games-Howell tests were used for statisitical analysis. The L30 and M30 groups presented less N than did the S30 group (p<0.05). The LS60, MS60, and LP60 groups presented less N than did the S60 and P60 groups (p<0.05). No differences could be observed between the MP60 and S60 groups. The chronic administration of Midazolam and Lorazepam reduced acini, which may well have collaborated in the reduction of salivary flow previously verified. The association of Midazolam with Pilocarpine led to the reestablishment of acinar cells, which may have favored the restoration of the salivary flow formerly shown.