Sacubitril/valsartan promotes white adipose tissue browning in rats with metabolic syndrome through activation of mTORC1.

In addition to their usual use in the treatment of cardiovascular disease, weak evidence is available for the potential of combined use of neprilysin inhibitor (sacubitril) and AT1 receptor antagonist (valsartan) to promote browning of white adipose tissue (WAT) in rats with metabolic syndrome (MetS). This study involved 32 male Wistar albino rats divided into four groups: CTRL-healthy control rats; ENT-healthy rats treated with sacubitril/valsartan; MS-rats with MetS; MS + ENT-rats with MetS treated with sacubitril/valsartan. After finishing the experimental protocol, different WAT depots were isolated for further analysis of molecular pathways. Molecular docking and molecular dynamics studies were used for in silico assessment of the binding affinity of sacubitril and valsartan towards subunits of mechanistic target of rapamycin complex 1 (mTORC1). Sacubitril/valsartan treatment markedly diminished morphological changes in adipose tissue, resulting in smaller lipid size and multilocular lipid droplet structure in WAT. We showed significantly higher protein expression of uncoupling protein-1 (UCP-1) and mTORC1 in WAT of MS + ENT rats, correlating with increased relative gene expression of browning-related markers in tissue of rats treated with sacubitril/valsartan compared with MS group of rats. In silico analysis showed that sacubitrilat and valsartan exhibited the highest binding affinity against mTOR and mLST8, forming stable complexes with these mTORC1 subunits. The observed results confirmed strong potential of combined sacubitril/valsartan treatment to increase browning markers expression in different WAT depots in MetS condition and to form permanent complexes with mTOR and mLST8 subunits over the time.

Investigation of the interaction between S-isoalkyl derivatives of the thiosalicylic acid and human serum albumin.

S-isoalkyl derivatives of thiosalicylic acid (isopropyl-(L1), isobutyl-(L2) and isoamyl-(L3)) were selected in order to investigate the binding interaction with the human serum albumin (HSA) using different spectroscopic methods and molecular docking simulation. Association constants and number of binding sites were used to analyze the quenching mechanism. The experimental results showed that the fluorescence quenching of HSA by L1, L2 and L3 occurs because of static quenching and that binding processes were spontaneous, with the leading forces in bonding by hydrogen bonding, hydrophobic interactions, and electrostatic interactions. Fluorescence spectroscopy, UV-Vis spectroscopy and synchronous fluorescence spectroscopy showed that ligands (L1, L2 and L3) can bind to HSA and that the binding of ligands induced some microenvironmental and conformational changes in HSA. The calculated distance between the donor and the acceptor according to fiFörster's theory confirms the energy transfer efficiency between the acceptor and HSA. Results of site marker competitive experiments showed that the tested compounds bind to HSA in domain IIA (Site I). Molecular dynamics and docking calculations demonstrated that L3 binds to the Sudlow site I of HSA with lower values of binding energies compared to L1 and L2, indicating the formation of the most stable ligand-HSA complex. Understanding the binding mechanisms of S-isoalkyl derivatives of the thiosalicylic acid to HSA may provide valuable data for the future studies of their biological activity and application as potential antitumor drugs.Communicated by Ramaswamy H. Sarma.

Synthesis and Investigation of Anti-Inflammatory Activity of New Thiourea Derivatives of Naproxen.

The aim of the study was a synthesis and investigation of the dose-dependent anti-inflammatory effect of new thiourea derivatives of naproxen with selected aromatic amines and esters of aromatic amino acids. The results of the in vivo study indicate that derivatives of m-anisidine (4) and N-methyl tryptophan methyl ester (7) showed the most potent anti-inflammatory activity four hours after injection of carrageenan, with the percentage of inhibition of 54.01% and 54.12%, respectively. In vitro assays of COX-2 inhibition demonstrated that none of the tested compounds achieved 50% inhibition at concentrations lower than 100 µM. On the other hand, the aromatic amine derivatives (1-5) accomplished significant inhibition of 5-LOX, and the lowest IC50 value was observed for compound 4 (0.30 µM). High anti-edematous activity of compound 4 in the rat paw edema model, together with potent inhibition of 5-LOX, highlight this compound as a promising anti-inflammatory agent.

Synthesis, Characterization, and Investigation of Anti-Inflammatory and Cytotoxic Activities of Novel Thiourea Derivatives of Naproxen.

The objective of this study was to synthesize seven novel thiourea derivatives of naproxen (8-14), examine the anti-inflammatory activity of the newly synthesized compounds, investigate the cytotoxic potential of both sets of synthesized compounds (1-7 and 8-14), and select the most promising anti-inflammatory and antitumor drug candidates. The results of the in vivo anti-inflammatory study clearly showed that compounds 8 and 9 were capable of decreasing paw edema, as evident from a high percentage of inhibition (44.83% and 49.29%, respectively). In addition, the results of in vitro enzyme inhibition assays demonstrated that neither of the newly synthesized compounds reached 50% inhibition of 5-LOX at concentrations lower than 100 µM. In terms of antitumor potential, derivatives 3 and 8 exhibited strong cytotoxic effects on the HeLa cell line, suggesting the involvement of the extrinsic pathway of apoptosis. According to the overall results obtained for both sets of synthesized molecules, derivatives 4 and 8 can be underlined as molecules with the strongest anti-inflammatory activity, while derivatives 3 and 8 are the most promising cytotoxic agents.

Virtual screening, drug-likeness analysis, and molecular docking study of potential severe acute respiratory syndrome coronavirus 2 main protease inhibitors.

Due to the length of time required to develop specific antiviral agents, the World Health Organization adopted the strategy of repurposing existing medications to treat Coronavirus disease 2019 infection. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease is possible biological target for potential antiviral drugs. We selected various compounds from PubChem database based on the structure of main protease inhibitors in Protein Data Bank database. Ten compounds showed nontumorigenic and nonmutagenic potential and met Egan's and Lipinski's rules. Molecular docking analysis was performed using AutoDock Vina software. Based on number and type of key binding interactions, as well as docking scores, we selected compounds 6, 8, and 17 that demonstrated the highest binding affinity for the target protein. Molecular dynamics simulations were then carried out on the protein-top docked ligand complexes which were subjected to molecular mechanics/generalized Born and surface area calculations. The molecular dynamics simulation results indicated that protein-top docked ligand complexes showed good conformational stability. Among analyzed molecules, compound 17 emerged as the best in silico hit based on the docking score, MM/GBSA binding energy and MD results.