Copper-based compounds are promising entities for target-specific next-generation anticancer and NSAIDS therapeutics. In lieu of this, benzimidazole scaffold plays an important role, because of their wide variety of potential functionalizations and coordination modes. Herein, we report three copper complexes 1 – 3 with benzimidazole-derived scaffolds, a biocompatible molecule, and secondary ligands viz, 1–10-phenanthroline and 2,2′-bipyridyl. All the copper complexes have been designed, synthesized and adequately characterized using various spectroscopic techniques. In-vitro , human serum albumin (HSA) binding was also carried out using fluorescence technique and in-silico molecular modeling studies, which exhibited significant binding affinities of the complexes with HSA. Furthermore, copper complexes 1 – 3 were tested for biological studies, i.e., anticancer as well as NSAIDS. In vitro cytotoxicity results were carried out on cultured MCF-7 cell lines. To get the insight over the mechanism of action, GSH depletion and change in lipid peroxidation were tested and thus confirmed the role of ROS generation, responsible for the cytotoxicity of the complexes 1 – 3 . Moreover, the copper complexes 1 – 3 were tested for potential to act as NSAIDS on albino rats and mice in animal studies in-vivo . Additionally, we also predicted the mechanism of action of the copper complexes 1 – 3 using molecular modeling studies with COX-2 inhibitor.

The mechanism of interaction between imipenem and HSA was investigated by various techniques like fluorescence, UV.vis absorbance, FRET, circular dichroism, urea denaturation, enzyme kinetics, ITC, and molecular docking. We found that imipenem binds to HSA at a high affinity site located in subdomain IIIA (Sudlow's site I) and a low affinity site located in subdomain IIA.IIB. Electrostatic interactions played a vital role along with hydrogen bonding and hydrophobic interactions in stabilizing the imipenem.HSA complex at subdomain IIIA, while only electrostatic and hydrophobic interactions were present at subdomain IIA.IIB. The binding and thermodynamic parameters obtained by ITC showed that the binding of imipenem to HSA was a spontaneous process (ΔGD⁰(D)= -32.31 kJ mol(-1) for high affinity site and ΔGD⁰(D) = -23.02 kJ mol(-1) for low affinity site) with binding constants in the range of 10(4)-10(5) M(-1). Spectroscopic investigation revealed only one binding site of imipenem on HSA (Ka∼10(4) M(-1)). FRET analysis showed that the binding distance between imipenem and HSA (Trp-214) was optimal (r = 4.32 nm) for quenching to occur. Decrease in esterase-like activity of HSA in the presence of imipenem showed that Arg-410 and Tyr-411 of subdomain IIIA (Sudlow's site II) were directly involved in the binding process. CD spectral analysis showed altered conformation of HSA upon imipenem binding. Moreover, the binding of imipenem to subdomain IIIA (Sudlow's site II) of HSA also affected its folding pathway as clear from urea-induced denaturation studies.

Nuxia oppositifolia is traditionally used in diabetes treatment in many Arabian countries; however, scientific evidence is lacking. Hence, the present study explored the antidiabetic and antioxidant activities of the plant extracts and their purified compounds. The methanolic crude extract of N. oppositifolia was partitioned using a two-solvent system. The n-hexane fraction was purified by silica gel column chromatography to yield several compounds including katononic acid and 3-oxolupenal. Antidiabetic activities were assessed by α-amylase and α-glucosidase enzyme inhibition. Antioxidant capacities were examined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) scavenging assays. Further, the interaction between enzymes (α-amylase and α-glucosidase) and ligands (3-oxolupenal and katononic acid) was followed by fluorescence quenching and molecular docking studies. 3-oxolupenal and katononic acid showed IC50 values of 46.2 μg/mL (101.6 µM) and 52.4 μg/mL (119.3 µM), respectively against the amylase inhibition. 3-oxolupenal (62.3 µg/mL or 141.9 μM) exhibited more potent inhibition against α-glucosidases compared to katononic acid (88.6 µg/mL or 194.8 μM). In terms of antioxidant activity, the relatively polar crude extract and n-butanol fraction showed the greatest DPPH and ABTS scavenging activity. However, the antioxidant activities of the purified compounds were in the low to moderate range. Molecular docking studies confirmed that 3-oxolupenal and katononic acid interacted strongly with the active site residues of both α-amylase and α-glucosidase. Fluorescence quenching results also suggest that 3-oxolupenal and katononic acid have a good affinity towards both α-amylase and α-glucosidase enzymes. This study provides preliminary data for the plant’s use in the treatment of type 2 diabetes mellitus.

Due to the lack of efficient therapeutic options and clinical trial limitations, the FDA-approved drugs can be a good choice to handle Coronavirus disease (COVID-19). Many reports have enough evidence for the use of FDA-approved drugs which have inhibitory potential against target proteins of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Here, we utilized a structure-based drug design approach to find possible drug candidates from the existing pool of FDA-approved drugs and checked their effectiveness against the SARS-CoV-2. We performed virtual screening of the FDA-approved drugs against the main protease (Mpro) of SARS-CoV-2, an essential enzyme, and a potential drug target. Using well-defined computational methods, we identified Glecaprevir and Maraviroc (MVC) as the best inhibitors of SARS-CoV-2 Mpro. Both drugs bind to the substrate-binding pocket of SARS-CoV-2 Mpro and form a significant number of non-covalent interactions. Glecaprevir and MVC bind to the conserved residues of substrate-binding pocket of SARS-CoV-2 Mpro. This work provides sufficient evidence for the use of Glecaprevir and MVC for the therapeutic management of COVID-19 after experimental validation and clinical manifestations.

The continuously increasing incidence rates of cancer and infectious diseases are open threats to the sustainable survival of animals and humans.