Mini Reviews in Medicinal Chemistry - Volume 18, Issue 3, 2018

The Machine Learning (ML) is one of the fastest developing techniques in the prediction and evaluation of important pharmacokinetic properties such as absorption, distribution, metabolism and excretion. The availability of a large number of robust validation techniques for prediction models devoted to pharmacokinetics has significantly enhanced the trust and authenticity in ML approaches. There is a series of prediction models generated and used for rapid screening of compounds on the basis of absorption in last one decade. Prediction of absorption of compounds using ML models has great potential across the pharmaceutical industry as a non-animal alternative to predict absorption. However, these prediction models still have to go far ahead to develop the confidence similar to conventional experimental methods for estimation of drug absorption. Some of the general concerns are selection of appropriate ML methods and validation techniques in addition to selecting relevant descriptors and authentic data sets for the generation of prediction models. The current review explores published models of ML for the prediction of absorption using physicochemical properties as descriptors and their important conclusions. In addition, some critical challenges in acceptance of ML models for absorption are also discussed.

Diabetes is a chronic metabolic disorder characterized by increased level of glucose in the blood due to defects in insulin action, insulin secretion or both. The effective management of diabetes is extremely important, otherwise, chronic uncontrolled diabetes could lead to diabetes late complications namely neuropathy, retinopathy, cardiomyopathy and nephropathy. The survey has shown that diabetes mellitus is one of the five leading causes of death all over the world. The therapeutic agents in clinical practice are facing the challenge of several unwanted effects, ineffectiveness in a large population and patient compliance therefore, new effective therapies are most warrant. In this connection, the natural product could be the best option as already accepted therapeutic modality since time immemorial. This review encounters various plant derived glycosides with antidiabetic effects; mediated through different mechanism(s). It is concluded that focusing glycosides as antidiabetic therapy could lead to the discovery of some new effective therapeutic agents.

1,3,4-Oxadiazole derivatives are found to have a wide range of pharmacological activities and attracting the researchers to work on this nucleus. Literature survey indicates that many 1,3,4- oxadiazoles have been synthesized with the aim to get compounds of significant anti-inflammatory and analgesic activities with reduced adverse effects. The purpose of this review is to compile the reports on 1,3,4-oxadiazole derivatives possessing anti-inflammatory and analgesic activities. The review also includes the reports on 1,3,4-oxadiazole derivatives of existing NSAIDs in the last ten years.

Inflammatory bowel disease (IBD), commonly represented by ulcerative colitis and Crohn's disease, is a form of chronic inflammatory disorders of the gastrointestinal system. Its current drug treatment includes the use of antibiotics, 5-aminosalicylates, corticosteroids, immune-modifying agents and biologics such as anti-TNF agents and adhesion molecules blockers. These drugs have inherent problems of efficacy as many IBD sufferers need surgical intervention at some stage, high cost especially for the protein-based drugs, loss of efficacy and unwanted side effects. The discovery of novel drugs including those from natural sources that overcome the above mentioned drawbacks of the current therapy is therefore of great interest. While the flavonoid quercetin with proven antiinflammatory effect failed to show activity in vivo, its glycoside rutin has recently proven to possess a significant IBD therapeutic potential in experimental animals. In this communication, the pharmacological and pharmacokinetic profiles of rutin along with its ability to serve as a prodrug that deliver the bioactive quercetin close to the IBD site are discussed. Potential mechanisms of action far beyond antioxidant effects such as suppression of proinflammatory mediators' release and expression of inflammatory proteins (e.g. adhesion molecules, cyclooxygenase, nitric oxide synthase, etc.) are also scrutinized.

Arthritis is marked by joint deterioration that affects articular cartilage and subchondral bone. Though cartilage degradation does the major damage during arthritis, subsequent bone degeneration cannot be neglected. Recent progress in arthritis research has identified the clinical importance of bone erosion in destructive arthritis. Studies have showed the key role played by osteoclasts and receptor activator of nuclear factor kappaB ligand (RANKL) signaling in bone erosion. Cathepsins and tartrate resistant acid phosphatase (TRAP) are considered key enzymatic factors contributing to bone erosion. Further, reactive oxygen species (ROS) formed at the ruffled border of osteoclasts also causes bone resorption and matrix degradation. Besides, severe inflammation during arthritis induces bone erosion by aiding in Ca2+ removal and activating osteoclastogenesis. The inflammatory cytokines and ROS influence osteoclast differentiation by regulating osteoclast-lineage cells or by acting on other cells to regulate the expression of RANKL and osteoprotegerin (OPG). The enhanced production of pro-inflammatory cytokines and ROS in arthritis stimulates tissue injury by means of oxidative damage leading to vital organ damage and synovial and circulatory cell apoptosis. Thus, blocking enzymatic and non-enzymatic factors responsible for bone erosion and inflammation is considered a prime strategy in the management of arthritis. In this review we provide an overview of the mechanisms of bone erosion, inflammation and associated oxidative stress/damage during arthritis perpetuation along with shedding light on potential targets. The article also describes the possible natural therapeutic agents that could prevent bone loss and inflammation, and related secondary complications of arthritis.

Viruses are potent pathogens that can effectively deliver the genetic material to susceptible host cells. This capability is beneficially utilized to successfully deliver the genetic material. However, the use of virus mediated gene delivery is considered divisive, because the potentially replicable genomes recombine or integrate with the cell DNA resulting in immunogenicity, ranging from inflammation to death. Thus, the need for potentially effective non-viral gene delivery vehicles arises. Non-viral vectors, protein only particles and virus like particles (VLP) can be constructed which contain all the necessary functional moieties. These resemble viruses and are called artificial or synthetic virus. The artificial virus eliminates the disadvantages of viral vectors but retain the beneficial effects of the viruses. Need for further functionalization can be avoided by this approach because incorporation of requisite agents such as cell ligands, membrane active peptides, etc. into proteins is possible. The protein- DNA complexes resemble bacterial inclusion bodies. Nucleic acids influence conformation of protein units which subsequently result in cell uptake and finally to the cell nucleus. Such tunable systems mimic the activities of infected viruses and are used for the safe and effective delivery of drugs and genetic material in gene therapy. The versatility, stability and biocompatible nature of artificial virus along with high transfection efficacy have made it favorite for gene delivery purposes, in addition to being useful for various biomedical and drug delivery applications.

Background: Chronic lymphocytic leukemia (CLL) is an indolent B-lineage neoplasm, characterized by clonal expansion of CD5 positive B cells with constitutive activation of survival pathways including NF-kB. Pentoxifylline, a xanthine-derivative compound indicated for the treatment of microvascular disturbancies, has been suggested to have anti-proliferative and anti-metastatic activities in various types of cancer. In the present study we extend these data showing one of the potential molecular mechanisms through which Pentoxifylline may promote apoptosis in CLL clonal lymphocytes.

Methods: Peripheral blood mononuclear cells were isolated from 15 CLL patients 0 RAI stage and 15 healthy volunteers and treated for 24 and 48 hours with Pentoxifylline. Apoptosis induction was evaluated through Annexin V and TUNEL assays. Mitochondrial membrane potential depolarization analysis, active Caspase-3 assay, reactive oxygen species generation and Western Blot were assessed to further investigate the alterations induced by Pentoxifylline.

Results: We observed a statistically significant occurrence of apoptosis, DNA fragmentation and active Caspase-3 in lymphocytes from CLL patients compared to healthy volunteers after 48 hours of Pentoxifylline treatment. To clarify the molecular mechanism of the drug, we also evaluated the expression levels of NF-kB/p65 and its related proteins. In treated CLL cells, NF-kB/p65 was significantly decreased in comparison to normal cells, whereas we observed a less marked reduction of Bcl-2 expression. The treatment also induced a decrease of Mcl-1 in CLL cells with a greater down-regulation of the anti-apoptotic alternatively spliced isoform.

Conclusion: These findings showed that Pentoxifylline induced apoptosis in leukemic cells through a molecular mechanism that involves the NF-kB signaling.