Current Medicinal Chemistry - Volume 24, Issue 33, 2017

Background: The taxane drugs paclitaxel and docetaxel, widely used on cancer chemotherapy, are currently dosed mainly based on body-surface area. This approach is associated with wide interindividual variability in drug exposure, leading to suboptimal dosing for many patients. Methods: The available evidence supporting dose individualization strategies for paclitaxel and docetaxel were reviewed, focusing mainly on the application of therapeutic drug monitoring by a priori pharmacogenetic data or a posteriori drug measurements in biological fluids. The PubMed database was searched, in the period of 1987-2017, using the keywords pharmacogenetics, metabolic genotyping, dose individualization, therapeutic drug monitoring, personalized medicine, taxanes paclitaxel and docetaxel, either alone or in combination. Results: The current knowledge of pharmacology of the taxane drugs paclitaxel and docetaxel, mainly its pharmacokinetics and the proteins responsible for their biotransformation and transport, along with the genetic polymorphism responsible for variations in the activities of these proteins, opens new opportunities for dose selection for individual patients. Conclusion: Considering the relation between systemic exposure to these drug and clinical responses, a posteriori TDM, with measurement of drug concentrations in plasma of treated patients, is currently the most straightforward approaches for dose individualization of paclitaxel and docetaxel.

Background: Renal disease is a serious health problem, with increasing incidence and prevalence. Oxidative stress and inflammation play a key role in the pathogenesis and progression of renal disease. Therefore, therapeutic approaches to decrease oxidative stress should be of interest. Objective: This review aims to provide a comprehensive and updated overview of the protective mechanisms mediated by Nrf2 (nuclear factor erythroid 2–related factor 2), a description of novel compounds that target Nrf2, its effectiveness to prevent renal disease and the on-going clinical trials for this pathological condition. Methods: We undertook a structured search of bibliographic databases for peer-reviewed research in literature about Nrf2 activators and renal disease. Results: The transcription factor Nrf2 is an emerging regulator of cellular resistance to oxidants and inflammation. Nrf2 controls the basal and induced expression of a couple of cytoprotective and antiinflammatory genes that regulate the physiological and pathophysiological outcomes of oxidant exposure. We have analyzed numerous findings showing that Nrf2 induction protects against oxidative stress and modulates inflammation in acute kidney injury and chronic kidney disease progression. However, few clinical trials have been performed in humans. Recent studies suggested that renoprotective effects of Nrf2 activation are observed at low doses, whereas harmful effects appear at higher concentrations. Conclusion: The findings of this review confirm that novel studies are necessary to address whether Nrf2-targeting may be a safe therapeutic approach to decrease renal disease progression in humans.

Background: Parasitic diseases caused by protozoan parasites of the genus Trypanosoma and Plasmodium cause some of the deadliest and disabling human infections in tropical and subtropical areas. Diphenyl-based bis(2-phenylimino)imidazolidines and bisguanidines are extremely potent antiparasitic agents against Trypanosoma brucei (etiological agent of African trypanosomiasis) and Plasmodium falciparum (etiological agent of severe malaria). Many of these compounds are also curative in mouse models of stage 1 African trypanosomiasis representing promising leads for the development of antitrypanosomal drugs. In addition, different classes of bis(2-iminoimidazolidines) and bisguanidines have been shown to have antimicrobial activity against other pathogens (e.g. bacteria, fungi, parasitic worms). Due to their structural and physicochemical properties, these dibasic compounds, which are dications at physiological pH, are prone to bind to the minor groove of DNA at AT-rich sites. In several cases, such interaction is thought to be responsible for their antimicrobial activity. Results: In this review, we give a comprehensive view of the synthetic methods used to introduce the 2-aminoimidazoline scaffold in a molecule. Synthetic routes that give access to these cyclic guanidines (i.e. unsubstituted, 1-, 4-, and 5-substituted 2-aminoimidazolines) are detailed. The in vitro and in vivo antiprotozoal activity of bis(2-aminoimidazolines) and bisguanidines against kinetoplastid parasites (T. brucei, T. cruzi, Leishmania), Plasmodium spp. and other pathogens (e.g. ESKAPE bacteria, Candida spp., M. tuberculosis, E. multilocularia) is also reviewed. Finally, the targets that are involved in the antimicrobial activity (e.g. DNA) or other biological activities (e.g. α-adrenergic receptors, imidazoline binding sites, kinases) of this class of dicationic compounds are discussed.

Background: The main aim of synthesizing permanently charged opioids is to ensure that they do not enter the central nervous system. Such drugs can provide analgesic activity with reduced sedation and other side effects on the central nervous system. Methods: We undertook a search of bibliographic databases for peer-reviewed research literature and also summarized our published results in this field. Results: The present review focuses on the characterization of permanently charged opioids by various physicochemical methods, and in vitro as well as in vivo tests. The basicity and lipophilicity of opioid alkaloids are discussed at the microscopic, speciesspecific level. Glucuronide conjugates of opioids are also reviewed. Whereas the primary metabolite morphine-3-glucuronide does not bind to opioid receptors with high affinity, morphine-6-glucuronide is a potent analgesic, at least, partly due to its unexpectedly high lipophilicity. We discuss the quaternary ammonium opioid derivatives of a permanent positive charge, detailing their antinociceptive activity and effects on gastrointestinal motility in various in vivo animal tests and in vitro studies. Compounds with antagonistic activity are also reviewed. The last part of our study concentrates on sulfate conjugates of morphine derivatives that display unique pharmacological properties because they carry a negative charge at any pH value in the human body. Conclusion: In conclusion, the findings of this review confirm the importance of permanently charged opioids in the investigated fields of pharmacology.

Background: Migraine is a primary headache disorder. Despite numerous studies conducted with the aim to understand the pathophysiology of migraine, several aspects are still unclear. The trigeminovascular system plays a key role. Neurogenic inflammation is presumed to be an important factor in migraine pathophysiology, mediated by the activation of primary neurons, leading to the release of various pro-inflammatory neuropeptides and neurotransmitters such as Calcitonin Gene-Related Peptide (CGRP), substance P (SP), and vasoactive intestinal peptide (VIP). Nitric oxide (NO), Pituitary adenylate cyclase-activating polypeptide (PACAP) and Glutamate (Glu) also play an important role in the modulation of inflammatory mechanisms. Objective: To review the literature focusing on novel therapeutic targets in migraine, related to neurogenic inflammation. Method: A systematic literature search in the database of PUBMED was conducted regarding therapeutic strategies in migraine, focusing on substances and cytokines released during neurogenic inflammation, published until January 2017. Results: Ongoing phase III clinical studies with monoclonal antibodies against CGRP and CGRP receptors offer promising novel aspects for migraine treatment. Preclinical and clinical studies targeting SP and nitric oxide synthase (NOS) were all terminated with no significant results compared to placebo. New promising therapeutic goal could be PACAP and its receptor (PAC1), and kynurenic acid (KYNA) analogues. Conclusion: Current migraine treatment offers pain relief only for a small proportion of migraine patients and might not be adequate for patients with cardiovascular comorbidity due to side effects. Better understanding of migraine pathophysiology might, therefore, lead to novel therapeutic lines both in migraine attack treatment and prophylaxis.