Mini Reviews in Medicinal Chemistry - Volume 19, Issue 13, 2019

Nature offers tremendous potential in the medicine field. Natural antioxidant molecules inhibit or quench free radical reactions and delay or inhibit cellular damage. In the last few years, researchers have been focusing on the health benefits of natural products. Particularly some dietary nutrients, such as curcumin, crocin, resveratrol, quercetin, coenzyme Q10, vitamin C, as well as some polysaccharides have been evaluated for their numerous and unique therapeutic properties. This review focuses on examples of pharmaceutical applications of natural anti-oxidants, with special regards to their encapsulation in micro- and nano- delivery systems. In vitro and in vivo studies have been conducted to investigate the physicochemical and pharmacological properties of different delivery systems containing antioxidant molecules. For instance, ethosomes, organogels, monoolein aqueous dispersions and solid lipid nanoparticle have been considered. It was found that micro and nanoencapsulation strategy can improve the solubility of lipophilic molecules and the chemical stability of labile antioxidants, thus prolonging their efficacy. In vitro and in vivo studies have highlighted that antioxidant encapsulation prolongs release kinetics, bioavailability and antioxidant effects. Noticeably, some encapsulated antioxidants effectively inhibit cancer cell proliferation, cell migration and colony formation, thus suppressing cancer progression.

Accumulating evidence has shown that the incidence of atrial fibrillation (AF) is higher in patients with diabetes, especially those with poor glycemic control or long disease duration. Nonenzymatic glycation of amino acids of proteins, lipids, and nucleic acids has progressed under normal aging process and/or diabetic condition, which could lead to the formation and accumulation of advanced glycation end products (AGEs). AGEs not only alter the tertiary structure and physiological function of macromolecules, but also evoke inflammatory and fibrotic reactions through the interaction of cell surface receptor for AGEs (RAGE), thereby being involved in aging-related disorders. In this paper, we briefly review the association of chronic hyperglycemia and type 1 diabetes with the risk of AF and then discuss the pathological role of AGE-RAGE axis in AF and its thromboembolic complications.

Aim: The clinical management of OLP represents a considerable challenge for the oral physician. The aim of this review is to assess the main intervention used in the management of OLP and the efficacy of every type of treatment. Materials and Methods: We searched and analyzed PubMed database for articles on OLP management. Only randomized controlled trials, comparing an active treatment with placebo, or between different active treatments, were considered in this systematic review. Only patients with symptomatic OLP were included and interventions of all types were considered (topical treatment, systemic drugs, non pharmacological intervention). Results: A total of 25 randomized controlled trials were examined and included in this review. Steroids are the most frequently employed drug in the treatment of OLP and their efficacy and safety are demonstrated. Also calcineurin inhibitors and photo-dynamic therapy are used in different studies for OLP management, with positive results. Conclusion: Topical steroids remain the first-line treatment for symptomatic OLP, however, many different pharmacological and non-pharmacological therapies would represent a valid alternative for its management, but, nowadays they require further investigations.

Over the past two decades, many researchers have concluded that a diet rich in polyphenolic compounds plays an important therapeutic role in reducing the risk of cancer, cardiovascular disease, inflammation, diabetes, and other degenerative diseases. Polyphenolic compounds have been reported to be involved in neutralization of reactive oxygen species and charged radicals, and have anticarcinogenic effects, hepatoprotective effects, low-glycaemic response, and other benefits. The benefits of fruits and vegetables may be partly attributable to polyphenolic compounds, which have antioxidant and free radical scavenging properties. Fruits such as apples contain a variety of phytochemicals, including (+)-catechin and (-)-epicatechin, phlorizin, phloretin quercetin, cyanidin-3-Ogalactoside, chlorogenic acid, and p-coumaric acid, all of which are strong antioxidants. Phloretin, a natural phenolic compound, is a dihydrochalcone, which is present in the apple. It exhibits a wide variety of activities such as antioxidative, anti-inflammatory, anti-microbial, anti-allergic, anticarcinogenic, anti-thrombotic, and hepatoprotective, besides being involved in the activation of apoptotic associated gene expression and signal transduction in molecular pathways. Despite a multitude of clinical studies, new efforts are needed in clinical research to determine the complete therapeutic potential of phloretin.

Background & Objective: Six novel complexes of transition metal namely, [CoLCl2(H2O)2]0.5H2O, [NiLCl2(H2O)2]0.5H2O, [CuLCl2]0.5H2O, [ZnLCl2], [PdLCl2]H2O and [CdLCl2]H2O, where L is benzocycloheptenone thiosemicarbazone ligand, have been obtained. The confirmation of the structures of the obtained metal chelates depends on the different spectral and physicochemical techniques including CHN analysis, infrared spectra, molar conductivity measurement, UV-vis, thermogravimetric analysis and magnetic moment. The infrared spectral results ascertained that the ligand behaved as neutral bidentate connecting the metal centers via N and S atoms of C=N and C=S groups, respectively. Methods: The UV-Vis, molar conductivity and magnetic susceptibility results implied that the geometrical structures of the metal chelates are octahedral for Co(II) & Ni(II) complexes, tetrahedral for Zn(II) & Cd(II) complexes and square planar for Cu(II) & Pd(II) complexes which have been confirmed by molecular modeling studies. Conclusion: Moreover, the mode of interaction between some chosen metal complexes towards SSDNA has been thoughtful by UV-Vis spectra and viscosity measurements. The value of the intrinsic binding constant (Kb) for the examined compounds has been found to be lower than the binding affinity of the classical intercalator ethedium bromide. Also, the viscosity measurements of the complexes proved that they bind to DNA, most likely, by a non-intercalative mode like H-bonding or electrostatic interactions.

Background: Increased rate of mortality due to the development of resistance to currently available antimicrobial and anticancer agents initiated the need to develop new chemical entities for the treatment of microbial infections and cancer. Objective: The present study was aimed to synthesize and evaluate antimicrobial and anticancer activities of Schiff bases of 2-mercaptobenzimidazole. Methods: The Schiff bases of 2-mercaptobenzimidazole were synthesized from 4-(2-(1H-benzo[d]- imidazol-2-ylthio)acetamido)benzohydrazide. The synthesized compounds were evaluated for antimicrobial and anticancer activities by tube dilution method and Sulforhodamine-B (SRB) assay, respectively. Results: Compounds 8 (MICpa, an = 2.41, 1.20 μM/ml), 10 (MICse, sa = 2.50 μM/ml), 20 (MICec = 2.34 μM/ml) and 25 (MICca = 1.46 μM/ml) showed significant antimicrobial activity against tested bacterial and fungal strains and compounds 20 (IC50 = 8 μg/ml) and 23 (IC50 = 7 μg/ml) exhibited significant anticancer activity. Conclusion: In general, the synthesized derivatives exhibited moderate antimicrobial and anticancer activities. Compounds 8 and 25 having high antifungal potential among the synthesized compounds may be taken as lead molecules for the development of novel antifungal agents.

Background & Objective: New diaryl-substituted pyrimidinedione compounds, their thioxo derivatives as well as their bicyclic thiazole compounds were synthesized and characterized. Methods: The glycosylamino derivatives of the synthesized disubstituted derivatives of the pyrimidine scaffold were also prepared via reaction of the N3-amino derivatives with a number of monosaccharides followed by acetylation. Results: The anticancer activity of the synthesized compounds was studied against human liver cancer (HepG2) and RPE-1cell lines. Compounds 2a, 2b, 3a and 12 showed potent activities with IC50 results comparable to that of doxorubicin. Conclusion: Docking investigations into Cyclin-dependent kinase 2 (CDK-2) enzyme, a potential target for cancer medication, were also reported showing the possible binding interaction into the enzyme active site to support their activity behavior.