Current Medicinal Chemistry - Volume 25, Issue 21, 2018

Group IV cytosolic phospholipase A2 (cPLA2α) plays a critical role in inflammatory processes. It produces arachidonic acid which is the main source of the pro-inflammatory eicosanoids mediators that are important in innate immune system. In some cases, these proinflammatory mediators cause damages to the host tissues and therefore promote autoimmune diseases. Consequently, development of potent inhibitors against cPLA2α could improve the therapy of inflammatory diseases. In the last two decades, intense efforts have been done to find potent cPLA2α inhibitors. Several scaffolds have been developed with the use of structureactivity relationship (SAR) studies, and potent inhibitors have been obtained. The poor absorption of these compounds from intestine was the main challenge for clinical application. This review illustrates the search for cPLA2α inhibitors, their SAR studies and biological effects.

Within the different applications of nanomedicine currently being developed, nanogene delivery is appearing as an exciting new technique with the possibility to overcome recognised hurdles and several biological and medical needs. The central component of all delivery systems is the requirement for the delivery of genetic material into cells, and for them to eventually reside in the nucleus where their desired function will be exposed. However, genetic material does not passively enter cells; thus, a delivery system is necessary. The emerging field of nano-gene delivery exploits the use of new materials and the properties that arise at the nanometre-scale to produce delivery vectors that can effectively deliver genetic material into a variety of different types of cells. The novel physicochemical properties of the new delivery vectors can be used to address the current challenges existing in nucleic acid delivery in vitro and in vivo. While there is a growing interest in nanostructure-based gene delivery, the field is still in its infancy, and there is yet much to discover about nanostructures and their physicochemical properties in a biological context. We carried out an organised and focused search of bibliographic databases. Our results suggest that despite new breakthroughs in nanostructure synthesis and advanced characterization techniques, we still face many barriers in producing highly efficient and non-toxic delivery systems. In this review, we overview the types of systems currently used for clinical and biomedical research applications along with their advantages and disadvantages, as well as discussing barriers that arise from nano-scale interactions with biological material. In conclusion, we hope that by bringing the far reaching multidisciplinary nature of nano-gene delivery to light, new targeted nanotechnology-bases strategies are developed to overcome the major challenges covered in this review.

The paradoxical role of ER stress in malignant diseases is only just being unraveled and remains incompletely understood. A particular challenge is the complex interplay between spaciotemporal and locoregional microenvironmental constraints in solid tumors and stress responses upon treatment; thus, the potential for new combinatorial therapeutic options to foster the coincidence of ER stress-related deadly events is likely to be underestimated. Without claiming this review to be complete, we present a comprehensive overview of the signaling mechanisms associated with the unfolded protein response (UPR) and the molecular link to cell survival and death mechanisms. We (i) delineate the mechanistic scenario and outcome of the UPR; (ii) discuss the role of ER stress in cancer development and progression; (iii) highlight the impact of various environmental conditions and stress stimuli, such as nutrient limitation and tumor hypoxia, in this context; and (iv) attempt to shed some light on the putative link between DNA damage, irradiation, and ER stress to emphasize the potential of therapeutic targeting of ER stress pathways for combined cancer treatments.

Background: Since the first isolation of antimicrobial peptides (AMPs) they have attracted extensive interest in medicinal chemistry. However, only a few AMP-based drugs are currently available on the market. Despite their effectiveness, biodegradability, and versatile mode of action that is less likely to induce resistance compared to conventional antibiotics, AMPs suffer from major issues that need to be addressed to broaden their use. Notably, AMPs can lack selectivity leading to side effects and cytotoxicity, and also exhibit in vivo instability. Several strategies are being actively considered to overcome the limitations that restrain the success of AMPs. Methods: In the current work, recent strategies reported for improving AMPs in the context of drug design and delivery were surveyed, and also their possible impact on patients and the environment was assessed. Results: As a major advantage AMPs possess an easily tunable skeleton offering opportunities to improve their properties. Strategic structural modifications and the beneficial properties of cyclic or branched AMPs in term of stability have been reported. The conjugation of AMPs with nanoparticles has also been explored to increase their in vivo stability. Other techniques such as the coupling of AMPs with specific antibodies aim to increase the selectivity of the potential drug towards the target. These strategies were evaluated for their effect on the environment highlighting green technologies. Conclusion: Although further research is needed taking into account both environmental and human health consequences of novel AMPs, several of these compounds are promising drug candidates for use in sustainable medicine.

Background: LAAOs (EC 1.4.3.2) are found in concentrations that vary according to each species of snakes; Viperidae, Crotalidae and Elapidae contain 1-9% of this enzyme in their venoms. Methods: This review focuses on an update on molecular mechanisms, platelet activities, antimicrobial, antiprotozoal, induction of apoptosis and inflammatory potential underlying the actions of SVLAAOs. Results: Snake venom LAAOs (SV-LAAOs) have become an interesting subject for pharmacological, structural and molecular studies. Conclusion: Although the mechanisms of action of these enzymes are not well understood they are a subject of a variety of studies, because LAAOs are multifunctional enzymes exhibiting a wide range of pharmacological effects, including the inhibition or induction of platelet aggregation, hemolysis and hemorrhage, in addition to the stimulation of apoptosis, the activation of leukocytes and the formation of edema. Moreover, SV-LAAOs play an important role in bactericidal, cytotoxic, anti-parasitic, anti-tumor, and antiviral activities.