In silico analysis and molecular docking studies of natural compounds of Withania somnifera against bovine NLRP9.

CONTEXT: NLRP9 is a member of nucleotide-binding domain leucine-rich repeat-containing receptors and is found to be associated with many inflammatory diseases. In the current scenario, the identification of promising anti-inflammatory compounds from natural sources by repurposing approach is still relevant for the early prevention and effective management of the disease. METHODS: In the present study, we docked bioactives of Ashwagandha (Withanoside IV, Withanoside V, Withanolide A, Withanolide B, and Sitoindoside IX) and two control drugs against bovine NLRP9 protein. ADME/T analysis was used to determine the physiochemical properties of compounds and standard drugs. Molecular modeling was used to evaluate the correctness and quality of protein structures. In silico docking analysis revealed Withanolide B had the highest binding affinity score of -10.5 kcal/mol, whereas, among control drugs, doxycycline hydrochloride was most effective (-10.3 kcal/mol). The results of this study revealed that bioactives of Withania somnifera could be promising inhibitors against bovine NLRP9. In the present study, molecular simulation was used to measure protein conformational changes over time. The Rg value was found to be 34.77A°. RMSD and B-factor were also estimated to provide insights into the flexibility and mobile regions of protein structure. A functional protein network interaction was constructed from information collected from non-curative sources as protein-protein interactions (PPI) that play an important role in determining the function of the target protein and the ability of the drug molecule. Thus, in the present situation, it is important to identify bioactives with the potential to combat inflammatory diseases and provide strength and immunity to the host. However, there is still a need to study in vitro and in vivo to further support these findings.

Isolation and characterization of opuntiol from Opuntia Ficus indica (L. Mill) and its antiproliferative effect in KB oral carcinoma cells.

In this study, we isolated and characterized a novel bioactive flavonol from the cactus pad of Opuntia Ficus indica Indica (L. Mill) (OFI) by chromatography techniques. The isolated compound was characterized by FT-IR, 1H and 13C NMR spectroscopy. Single-crystal XRD results illustrate that the obtained flavonol was opuntiol (6-hydroxymethyl-4-methoxy-2H-pyran-2-one) and it was found to be near planar except for the H atoms of the methylene and methyl groups. The crystal packing was stabilized by C-H….O and O-H….O intermolecular hydrogen bonds. The isolated opuntiol significantly inhibited KB cells proliferation and its IC50 value was found to be 30 µM. Further, we noticed that opuntiol significantly induced ROS generation and subsequently altered MMP in KB cells. Western blot analysis and morphological observations by fluorescence microscope indicate the apoptotic inducing potential of opuntiol in KB cells.

Crude Cell-Free Extract From Deinococcus radiodurans Exhibit Anticancer Activity by Inducing Apoptosis in Triple-Negative Breast Cancer Cells.

Extremophilic organisms have the potential to tolerate extremely challenging environments of nature. This property can be accredited to its production of novel secondary metabolites that possess anticancer and other pharmaceutical values. The present study was aimed to investigate the anticancer activity of crude secondary metabolite extract (CSME) obtained from the radiation-tolerant bacterium Deinococcus radiodurans in triple-negative human breast carcinoma (MDA-MB-231) cells. The 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay showed the antiproliferative potential of CSME in MDA-MB-231 cells (IC50 = 25 µg/ml) and MCF-7 cells (IC50 = 10 µg/ml). Further, the CSME treatment led to the production of intracellular reactive oxygen species (ROS) and nuclear membrane alterations with the formation of apoptotic bodies in MDA-MB-231 cells. Considerable DNA damage and low antioxidant status were observed in CSME-treated MDA-MB-231 cells. The results also showed that the CSME treatment induced apoptotic markers expression in MDA-MB-231 cells. Western blot results illustrated significant upregulation of p53, caspase-3, and caspase-9 proteins expression. Then, we analyzed the presence of secondary metabolites which may be linked with antiproliferative potential of CSME by gas chromatography-mass spectrometry (GC-MS). The results illustrated the presence of 23 bioactive compounds some of which are already reported to possess anticancer properties. The study indicates that the CSME of D. radiodurans possess anticancer properties and exhibit the potential to be used as an anticancer agent.

Correction to: Understanding the survival mechanisms of Deinococcus radiodurans against oxidative stress by targeting thioredoxin reductase redox system.

The correction does not affect the discussion or conclusions of the article. The correct image is given below.

Understanding the survival mechanisms of Deinococcus radiodurans against oxidative stress by targeting thioredoxin reductase redox system.

The principal objective of this study is to determine the resistance of Deinococcus radiodurans to hydrogen peroxide (H2O2) induced oxidative stress by inhibiting its thioredoxin reductase (TrxR) antioxidant system. Treatment of D. radiodurans with different TrxR inhibitors such as ebselen, epigallocatechin gallate and auranofin displayed this organism sensitivity to H2O2 treatment in a concentration-dependent manner. We observed that D. radiodurans showed greater resistance to H2O2 treatment. Further, it has also been noticed that TrxR redox system was suppressed by TrxR inhibitors and that this response might be associated with the oxidative stress-mediated cell death in D. radiodurans. Thus, TrxR inhibitors affect the resistance of the D. radiodurans through suppression of its thioredoxin redox pathway via the inhibition of TrxR. Results from this study proved that TrxR plays an important role as an antioxidant enzyme by scavenging intracellular ROS, and thus contributing to the resistance of D. radiodurans towards oxidative stress.