Mini Reviews in Medicinal Chemistry - Volume 19, Issue 1, 2019

Colorectal cancer (CRC) is one of the most common cancers in both men and women. Approximately one-third of patients do not survive five years from diagnosis, which indicates the need for treatment improvement, also through new ways of drug delivery. A possible strategy to increase treatment efficacy is the use of liposomal formulation, which allows delivering both hydrophobic and hydrophilic compounds with better biocompatibility and reduced side-effects. Liposomal formulations showed better antitumor activity, longer drug accumulation and no cytotoxic effect on normal cells when compared to free drugs. In this review, we will present liposomal preparations studied in CRC in vitro and in vivo. We will focus on the advantages of liposomal delivery over conventional therapy as well as modifications which increase specificity, drug accumulation and efficacy. Moreover, we will discuss formulations investigated in clinical trials. Liposomal delivery has a great potential in overcoming current limitations of cancer therapy and development of this system gives new perspectives in CRC treatment.

Since candidiasis is so difficult to eradicate with an antifungal treatment and the existing antimycotics display many limitations, hopefully new sulfone derivatives may overcome these deficiencies. It is pertinent to study new strategies such as sulfone derivatives targeting the virulence attributes of C. albicans that differentiate them from the host. During infections, the pathogenic potential of C. albicans relies on the virulence factors as follows: hydrolytic enzymes, transcriptional factors, adhesion, and development of biofilms. In the article we explored how the above-presented C. albicans fitness and virulence attributes provided a robust response to the environmental stress exerted by sulfones upon C. albicans; C. albicans fitness and virulence attributes are fungal properties whose inactivation attenuates virulence. Our understanding of how these mechanisms and factors are inhibited by sulfones has increased over the last years. As lack of toxicity is a prerequisite for medical approaches, sulfones (non-toxic as assessed in vitro and in vivo) may prove to be useful for reducing C. albicans pathogenesis in humans. The antifungal activity of sulfones dealing with these multiple virulence factors and fitness attributes is discussed.

Ryanodine receptors (RyRs) are calcium channels located on the endo(sarco)plasmic reticulum of muscle cells and neurons. They regulate the release of stored intracellular calcium and play a critical role in muscle contraction. The N-terminal part of these receptors accounts for roughly 80% and contains the binding sites for diverse RyRs modulators. The C-terminal domain contains the transmembrane region. This review summarizes the current knowledge about the molecular biology of insect RyRs, chemicals targeting mammal or insect RyRs, and the reasons for mammal RyR-related diseases and diamides resistances. It may lay the foundation for effective management of mammal RyR-related diseases and diamides resistances.

Radix Bupleuri has been used in traditional Chinese medicine for thousands of years, with confirmed curative effects. This plant is also used in healthy food and cosmetics. A recent increase in studies of Radix Bupleuri's chemical constituents (mainly comprising flavonoids, lignins, phenyl propanol derivatives, triterpenoid saponins, and volatile oils) and pharmacological effects motivates the aim of the present study: to review the chemical components and pharmacological effects of Radix Bupleuri. Our review found that Radix Bupleuri exhibits diverse pharmacological effects. More than 281 components have been isolated from Radix Bupleuri, including 15 flavonoids, 430 lignins, 12 phenyl propanol derivatives, 66 triterpenoid saponins, and 158 volatile oils.

Arboviruses have been spreading rapidly throughout the Western Hemisphere in recent decades. Among the arboviruses with high morbidity and mortality are the members of the Alphavirus and Flavivirus genera. Within the first genus, Chikungunya Virus (CHIKV) is considered one of the most challenging human arboviral infection worldwide, against which there is no specific antivirals. Flaviviruses are some of the main viruses responsible for encephalitis, haemorrhagic disease and developmental defects. Dengue virus (DENV), Japanese Encephalitis Virus (JEV), West Nile Virus (WNV) and Zika Virus (ZIKV) are examples of flaviviruses without clinically approved antiviral agents. Thus, the search for new antivirals becomes highly important. One of the strategies that can be employed to obtain new drugs is the identification and utilization of privileged structures. Isatin is an example of a privileged molecular framework, displaying a broad spectrum of biological activities, including antiviral action. Obtaining and studying the antiviral properties of isatin derivatives have helped to identify important agents with potential activity against different arboviruses. This article reviews some of these isatin derivatives, their structures and antiviral properties reported against this important group of viruses.

Type 2 diabetes mellitus and cardiovascular diseases (CVD) have become the main cause of morbidity and death worldwide. In addition, current anti-diabetic and cardiovascular therapy is based on conventional drugs that have limited effectiveness and adverse side effects. In this regard, the role of medicinal herbs as a complementary or an alternative medicine is of great interest. Urtica dioica L. (Urticaceae), which is the focus of this review, has been widely used in traditional medicine to treat a variety of ailments, including, diabetes, hypertension and prostate cancer. The aim of this article is to review current knowledge related to the anti-diabetic and cardiovascular properties of U. dioica, with particular emphasis on the bioactive compounds, the plant parts used, and the action mechanism behind lowering blood glucose level and reducing risk of CVD. We also discuss the chemical composition and toxicological properties of the plant. From this review, it was suggested that the anti-diabetic and the cardiovascular effects of U. dioica are attributed to different classes of compounds, such as polyphenols, triterpens, sterols, flavonoids, and lectin which reduce the blood glucose level and the risk of CVD by their antihypertensive, antioxidant and anti-inflammatory properties and/or by interfering with different cellular signalization pathways, including increase of NO, inhibition of α-amylase and α-glycosidase, modulation of GLUT4 and protection of pancreatic β-cells, among others. The identification of the plant constituents and the understanding of their exact action mechanisms are necessary to prove the efficacy of the plant and develop it as pharmacological drug.

Background: Currently, there is no conclusive cure for Alzheimer's disease (AD) and existing treatments mainly offer symptomatic relief. Dysfunction of the cholinergic system plays an important role in the pathogenesis of AD. Tacrine (1, 2, 3, 4-tetrahydroacridin-9-amine, III) was the first approved agent for the palliative therapy of AD but its use is associated with some complications. Development of novel multi target derivatives of Tacrine with lower complications is strongly warranted. In this study, new aminobenzothiazole (1-5, with many useful biological and pharmacological properties) analogues (IV-VIII) were synthesized by changing of amine moiety of III. Then, the effects of these new compounds on learning and memory impairment in scopolamine-induced model of amnesia were studied and the outcomes were compared with control and Tacrine groups in rat. Material and Methods: The rats received Tacrine or its derivatives (IV-VIII) i.p. for two weeks at a dose of 10 mg/kg. For induction of amnesia, scopolamine at a dose of 1 mg/kg was daily administered i.p. started on day-8 till the end of the study. Behavioral experiments including Y-maze, novel object recognition (discrimination) and passive avoidance paradigms were conducted at week 2. Results: Data analysis showed that some Tacrine derivatives, especially VII with 2-amino, 6-nitrobenzothiazole moiety, could markedly and significantly improve alternation score, discrimination ratio and step through latency compared to control and Tacrine groups. Conclusion: These findings indicated that some of these derivatives (especially compounds VI and VII) are capable to mitigate learning and memory deficits in scopolamine-induced model of amnesia in rats and may have potential benefit in management of patients with AD.

Background: Several biologically active indole alkaloids have been isolated from marine organisms over the previous few years. Many scientsts interested in synthesis of the marine azepinoindole alkaloids due to their wide range of bioliogical activies. Objective: We interested herein to synthesize a new series of some analogues of new naturally occurring azepinoindole alkaloids. Method: A novel series of [1,2,4,5]tetrazepino[6,7-b]indoles, Marine natural product Hyrtioreticuline C and D analogues, were synthesized via the reaction of 3-hydrazonoindolin-2-one with hydrzaonoyl chlorides in basic medium. Results: The spectral data of the products proved their structure. All new derivatives were tested against two carcinoma cell lines ((A-549 & HepG2)) in comparison with the well-known anticancer standard drug (cisplatin) and two derivatives from the tested compounds showed activity more potent than the reference drug. Conclusion: We succeeded in synthesis of new antitumor active azepinoindole alkaloids.