Current Medicinal Chemistry - Volume 25, Issue 9, 2018

Background: Gut microbiota play a vital role not only in the digestion and absorption of nutrients, but also in homeostatic maintenance of host immunity, metabolism and the gut barrier. Recent evidence suggests that gut microbiota alterations contribute to the pathogenesis of metabolic disorders. Objective and Method: In this review, we discuss the association between the gut microbiota and metabolic disorders, such as obesity, type 2 diabetes mellitus and non-alcoholic fatty liver disease, and the contribution of relevant modulating interventions, focusing on recent human studies. Results: Several studies have identified potential causal associations between gut microbiota and metabolic disorders, as well as the underlying mechanisms. The effects of modulating interventions, such as prebiotics, probiotics, fecal microbiota transplantation, and other new treatment possibilities on these metabolic disorders have also been reported. Conclusion: A growing body of evidence highlights the role of gut microbiota in the development of dysbiosis, which in turn influences host metabolism and disease phenotypes. Further studies are required to elucidate the precise mechanisms by which gut microbiota-derived mediators induce metabolic disorders and modulating interventions exert their beneficial effects in humans. The gut microbiota represents a novel potential therapeutic target for a range of metabolic disorders.

Background: Sirtuin1 is an epigenetic enzyme involved in histone and nonhistone protein deacetylation. It acts primarily as a metabolic sensor, which responses to changing energy status by deacetylating crucial transcription factors and cofactors. In this way, Sirtuin1 regulates mitochondrial function and biogenesis, oxidative stress, inflammation, apoptosis and cellular senescence. Disturbance of all of these phenomena promotes the pathogenesis of diabetic complications. These disorders are inseparably connected with chronic hyperglycemia, which possesses a strong epigenetic determinant. Objective: To summarize the contemporary knowledge regarding the role of Sirtuin1 in the development, progression and therapy of diabetic complications. Methods: We extensively searched literature describing the importance of Sirtuin1 in pathophysiology and treatment of all kinds of diabetic complications till September 2017. We focused on the examples of synthetic and natural compounds-mediated Sirtuin1 upregulation along with Sirtuin1-associated epigenetics. Results: Reduction of Sirtuin1 is implicated in endothelial dysfunction and metabolic memory, underlying the development of micro- and macrovascular complications. Declined Sirtuin1 also participates in diabetic testicular and erectile dysfunction. Sirtuin1 is elevated by naturally occurring anti-oxidant and anti-inflammatory compounds such as resveratrol, trans-δ-viniferin, vitamin D and more. Similarly, Sirtuin1 level increases after treatment with standard antihyperglycemic (metformin, exenatide, liraglutide), antihypertensive (sartans), lipid-lowering (fibrates, statins) and anticoagulant (fidarestat) drugs. Regarding epigenetics, a number of miRNAs trigger Sirtuin1 decrease, which further contributes to histone acetylation of Sirtuin1-regulated and relevant for diabetes genes. Conclusion: Evidence strongly suggest that Sirtuin1 upregulation may serve as a potent therapeutic approach against development and progression of diabetic complications.

Background: Geissoschizine methyl ether (GM) is one of the indole alkaloids in Uncaria hook, and an active ingredient of yokukansan (YKS) that improves behavioral and psychological symptoms of dementia (BPSD) in patients with several types of dementia. The pharmacological action of GM has been related to various serotonin (5-HT) receptor subtypes. Objective: The aim of this article is to review the binding characteristics of GM to the 5-HT receptor subtypes in the brains using our own data and previous findings. Method: Competitive receptor-binding and agonist/antagonist activity assays for several 5-HT receptor subtypes were performed. Moreover, the articles describing pharmacokinetics and brain distribution of GM were searched in PubMed. Results: GM bound the following 5-HT receptor subtypes: 5-HT1A, 5-HT1B, 5-HT2A, 5-HT2B, 5-HT2C, 5- HT4, 5-HT5A, 5-HT6, and 5-HT7. Among these receptors, GM had partial agonistic activity for 5-HT1A receptors and antagonistic activity for 5-HT2A, 5-HT2B, 5-HT2C, and 5-HT7 receptors. Also, GM was metabolized by various CYP isoforms, mainly CYP3A4. Parent/unchanged GM was detected in both the blood and brain of rats after oral administration of YKS. In the brains, GM was presumed to bind to 5- HT1A, 5-HT2A, 5-HT2B, 5-HT2C, and 5-HT7 receptors on neuron-like large cells mainly in the frontal cortex. Conclusion: These results suggest that GM is a pharmacologically important alkaloid that regulates various serotonergic activities or functions by binding to multiple 5-HT receptor subtypes. Thus, this review provides recent 5-HT receptor-related evidence that GM is partly responsible for pharmacological effects of YKS.

Background: MicroRNAs (miRNAs) are frequently dysregulated in cancers and serve as attractive targets for prognostication and therapeutic applications. Besides cancer, the biological functions of miR-149 have been studied in various diseases. This review aims to summarize the reports available in the literature, regarding miR-149 as a molecular target for cancer therapeutics. Methods: An extensive literature search was conducted using the Pubmed database to sieve out articles related to the roles of miR-149 in carcinogenesis and cancer progression, and potential miRNA-based therapies. A total of 89 publications were selected for inclusion in this review. Results: Depending on the cancer type, miR-149 can behave either as a tumor suppressor or as an ‘onco-miR’ that promotes tumorigenesis and cancer spread, suggesting that this miRNA has diverse functions. Potential miRNA-based therapies include the use of miRNA mimics, miRNA inhibitors, demethylating agents and circular RNAs. Conclusion: Although targeting miRNA is an attractive anti-cancer strategy, not all cancers can be treated by the same miRNA-based strategy. A comprehensive understanding of miRNA regulatory mechanism is also necessary to improve the design of miRNA-based therapeutics and there is a need for safe and efficient delivery methods when using this approach for anti-cancer treatment.

Background: Cancer is a major global health issue. It causes extensive individual suffering and gives a huge burden on the health care in society. Despite extensive research and different tools have been developed it still remains a challenge for early detection of this disease. FTIR imaging has been used to diagnose and differentiate the molecular differences between normal and diseased tissues. Methods: Fourier Transform Infrared Spectroscopy (FTIR) is able to measure biochemical changes in tissue, cell and biofluids based on the vibrational signature of their components. This technique enables to the distribution and structure of lipids, proteins, nucleic acids as well as other metabolites. These differences depended on the type and the grade of cancer. Results: We emphasize here, that the FTIR spectroscopy and imaging can be considered as a promising technique and will find its place on the detection of this dreadful disease because of high sensitivity, accuracy and inexpensive technique. Now the medical community started using and accepting this technique for early stage cancer detection. We discussed this technique and the several challenges in its application for the diagnosis of cancer in regards of sample preparations, data interpretation, and data analysis. The sensitivity of chemotherapy drugs on individual specific has also discussed. Conclusion: So far progressed has done with the FTIR imaging in understanding of cancer disease pathology. However, more research is needed in this field and it is necessary to understand the morphology and biology of the sample before using the spectroscopy and imaging because invaluable information to be figured out.

Background: Blood-brain barrier transport is an important process to be considered in drug candidates. The blood-brain barrier protects the brain from toxicological agents and, therefore, also establishes a restrictive mechanism for the delivery of drugs into the brain. Although there are different and complex mechanisms implicated in drug transport, in this review we focused on the prediction of passive diffusion through the blood-brain barrier. Methods: We elaborated on ligand-based and structure-based models that have been described to predict the blood-brain barrier permeability. Results: Multiple 2D and 3D QSPR/QSAR models and integrative approaches have been published to establish quantitative and qualitative relationships with the blood-brain barrier permeability. We explained different types of descriptors that correlate with passive diffusion along with data analysis methods. Moreover, we discussed the applicability of other types of molecular structure-based simulations, such as molecular dynamics, and their implications in the prediction of passive diffusion. Challenges and limitations of experimental measurements of permeability and in silico predictive methods were also described. Conclusion: Improvements in the prediction of blood-brain barrier permeability from different types of in silico models are crucial to optimize the process of Central Nervous System drug discovery and development.