Repurposing FDA-approved drugs cetilistat, abiraterone, diiodohydroxyquinoline, bexarotene, and remdesivir as potential inhibitors against RNA dependent RNA polymerase of SARS-CoV-2: A comparative in silico perspective

Abiraterone and Galeterone, Powerful Tools Against Prostate Cancer: Present and Perspective

Due to the high prostate cancer incidence worldwide, the development of different methods of treatment continues to be a hot research topic. Since its first clinical application at the beginning of the 2010s, abiraterone in the form of prodrug abiraterone acetate continues to be the most used hormone derivative in the treatment of castration-resistant prostate cancer. This is the reason behind the publication of many scientific results regarding its synthesis, biological activity, metabolism, novel designed steroid derivatives based on its structure, etc. A similar steroid compound with a heterocycle in the C17 position, called galeterone, also designed to treat prostate cancer, continues to be in clinical studies, which provides further proof of the importance of these steroid derivatives. Besides prostate cancer treatment, abiraterone showed indications for possible clinical application in the treatment of breast, ovarian, lung, kidney, salivary gland, and adrenocortical cancer, congenital adrenal hyperplasia, Cushing's syndrome, and COVID-19, while galeterone is investigated for its use against prostate, pancreatic, and breast cancer. Herein, we report a review comprising methods of synthesis, possible clinical applications, and mechanisms of action, as well as structures and bioactivities of derivatives of these two important steroids.

Study of the binding interaction of salmon sperm DNA with nintedanib, a tyrosine kinase inhibitor using multi-spectroscopic, thermodynamic, and in silico approaches

The study of the intermolecular binding interaction of small molecules with DNA can guide the rational drug design with greater efficacy and improved or more selective activity. In the current study, nintedanib's binding interaction with salmon sperm DNA (ssDNA) was thoroughly investigated using UV-vis spectrophotometry, spectrofluorimetry, ionic strength measurements, viscosity measurements, thermodynamics, molecular docking, and molecular dynamic simulation techniques under physiologically simulated conditions (pH 7.4). The obtained experimental results showed that nintedanib and ssDNA had an apparent binding interaction. Nintedanib's binding constant (Kb) with ssDNA, as determined using the Benesi-Hildebrand plot, was 7.9 × 104 M-1 at 298 K, indicating a moderate binding affinity. The primary binding contact forces were hydrophobic and hydrogen bonding interactions, as verified by the enthalpy and entropy changes (ΔH0 and ΔS0), which were - 16.25 kJ.mol-1 and 39.30 J mol-1 K-1, respectively. According to the results of UV-vis spectrophotometry, viscosity assays, and competitive binding interactions with ethidium bromide or rhodamine B, the binding mode of nintedanib to ssDNA was minor groove. Molecular docking and molecular dynamic simulation studies showed that nintedanib fitted into the B-DNA minor groove's AT-rich region with high stability. This study can contribute to further understanding of nintedanib's molecular mechanisms and pharmacological effects.

Khan R, Kumalo HM. Assessing the Potential Contribution of In Silico Studies in Discovering Drug Candidates That Interact with Various SARS-CoV-2 Receptors

The COVID-19 pandemic has spurred intense research efforts to identify effective treatments for SARS-CoV-2. In silico studies have emerged as a powerful tool in the drug discovery process, particularly in the search for drug candidates that interact with various SARS-CoV-2 receptors. These studies involve the use of computer simulations and computational algorithms to predict the potential interaction of drug candidates with target receptors. The primary receptors targeted by drug candidates include the RNA polymerase, main protease, spike protein, ACE2 receptor, and transmembrane protease serine 2 (TMPRSS2). In silico studies have identified several promising drug candidates, including Remdesivir, Favipiravir, Ribavirin, Ivermectin, Lopinavir/Ritonavir, and Camostat Mesylate, among others. The use of in silico studies offers several advantages, including the ability to screen a large number of drug candidates in a relatively short amount of time, thereby reducing the time and cost involved in traditional drug discovery methods. Additionally, in silico studies allow for the prediction of the binding affinity of the drug candidates to target receptors, providing insight into their potential efficacy. This study is aimed at assessing the useful contributions of the application of computational instruments in the discovery of receptors targeted in SARS-CoV-2. It further highlights some identified advantages and limitations of these studies, thereby revealing some complementary experimental validation to ensure the efficacy and safety of identified drug candidates.