Carbon Chain Length Determines Inhibitory Potency of Perfluoroalkyl Sulfonic Acids on Human Placental 3β-Hydroxysteroid Dehydrogenase 1: Screening, Structure-Activity Relationship, and In Silico Analysis / 生物医学与环境科学（英文）

OBJECTIVE@#This study aimed to compare 9 perfluoroalkyl sulfonic acids (PFSA) with carbon chain lengths (C4-C12) to inhibit human placental 3β-hydroxysteroid dehydrogenase 1 (3β-HSD1), aromatase, and rat 3β-HSD4 activities.@*METHODS@#Human and rat placental 3β-HSDs activities were determined by converting pregnenolone to progesterone and progesterone secretion in JEG-3 cells was determined using HPLC/MS-MS, and human aromatase activity was determined by radioimmunoassay.@*RESULTS@#PFSA inhibited human 3β-HSD1 structure-dependently in the order: perfluorooctanesulfonic acid (PFOS, half-maximum inhibitory concentration, IC 50: 9.03 ± 4.83 μmol/L) > perfluorodecanesulfonic acid (PFDS, 42.52 ± 8.99 μmol/L) > perfluoroheptanesulfonic acid (PFHpS, 112.6 ± 29.39 μmol/L) > perfluorobutanesulfonic acid (PFBS) = perfluoropentanesulfonic acid (PFPS) = perfluorohexanesulfonic acid (PFHxS) = perfluorododecanesulfonic acid (PFDoS) (ineffective at 100 μmol/L). 6:2FTS (1H, 1H, 2H, 2H-perfluorooctanesulfonic acid) and 8:2FTS (1H, 1H, 2H, 2H-perfluorodecanesulfonic acid) did not inhibit human 3β-HSD1. PFOS and PFHpS are mixed inhibitors, whereas PFDS is a competitive inhibitor. Moreover, 1-10 μmol/L PFOS and PFDS significantly reduced progesterone biosynthesis in JEG-3 cells. Docking analysis revealed that PFSA binds to the steroid-binding site of human 3β-HSD1 in a carbon chain length-dependent manner. All 100 μmol/L PFSA solutions did not affect rat 3β-HSD4 and human placental aromatase activity.@*CONCLUSION@#Carbon chain length determines inhibitory potency of PFSA on human placental 3β-HSD1 in a V-shaped transition at PFOS (C8), with inhibitory potency of PFOS > PFDS > PFHpS > PFBS = PFPS = PFHxS = PFDoS = 6:2FTS = 8:2FTS.

Study on the mechanism of curcumin in the treatment of periodontitis through network pharmacology and mole-cular docking / 华西口腔医学杂志

OBJECTIVES@#This study aims to explore the therapeutic targets of curcumin in periodontitis through network pharmacology and molecular docking technology.@*METHODS@#Targets of curcumin and periodontitis were predicted by different databases, and the protein-protein interaction (PPI) network constructed by String revealed the interaction between curcumin and periodontitis. The key target genes were screened for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Molecular docking was performed to analyze the binding potential of curcumin to periodontitis.@*RESULTS@#A total of 672 periodontitis-related disease targets and 107 curcumin-acting targets were obtained from the databases, and 20 key targets were screened. The GO and KEGG analyses of the 20 targets showed that curcumin might play a therapeutic role through the hypoxia-inducible factor (HIF)-1 and parathyroid hormone (PTH) signaling pathways. Molecular docking analysis showed that curcumin had good binding potential with multiple targets.@*CONCLUSIONS@#The potential key targets and molecular mechanisms of curcumin in treating periodontitis provide a theoretical basis for new drug development and clinical applications.

Identification of Suitable Natural Inhibitor against Influenza A (H1N1) Neuraminidase Protein by Molecular Docking

The influenza A (H1N1) virus, also known as swine flu is a leading cause of morbidity and mortality since 2009. There is a need to explore novel anti-viral drugs for overcoming the epidemics. Traditionally, different plant extracts of garlic, ginger, kalmegh, ajwain, green tea, turmeric, menthe, tulsi, etc. have been used as hopeful source of prevention and treatment of human influenza. The H1N1 virus contains an important glycoprotein, known as neuraminidase (NA) that is mainly responsible for initiation of viral infection and is essential for the life cycle of H1N1. It is responsible for sialic acid cleavage from glycans of the infected cell. We employed amino acid sequence of H1N1 NA to predict the tertiary structure using Phyre2 server and validated using ProCheck, ProSA, ProQ, and ERRAT server. Further, the modelled structure was docked with thirteen natural compounds of plant origin using AutoDock4.2. Most of the natural compounds showed effective inhibitory activity against H1N1 NA in binding condition. This study also highlights interaction of these natural inhibitors with amino residues of NA protein. Furthermore, among 13 natural compounds, theaflavin, found in green tea, was observed to inhibit H1N1 NA proteins strongly supported by lowest docking energy. Hence, it may be of interest to consider theaflavin for further in vitro and in vivo evaluation.

Bioactive compounds from marine yeast inhibits lung cancer.

Anticancer agents derived from natural products such as various sources like plants, animals and microorganisms. Marine-derived microorganism has become important sources of new bioactive molecules. The products isolated from marine sources possess cytotoxic activities against many cancers. Secondary metabolites as a source of Candida albicans natural drugs many of the medicines prescribed today are natural products obtained from terrestrial plants and microorganisms. The major components (80-90%) of cell wall of are carbohydrates, mannose or polymers of mannose covalently associated with proteins to form glycoproteins. The American Cancer Society has estimated 159,260 deaths due to lung cancer from diagnosis of 224,210 new cases in the United States in 2014. The International Agency for Research on Cancer estimated over 1 million new cancers cases in India in 2012 (10, 14, 934). In this study, we aimed to find new bioactive compounds from crude culture extracts produced by C. albicans as isolated from coastal mangrove ecosystem and docking studies were carried out.

Molecular Characterization of Legionellosis Drug Target Candidate Enzyme Phosphoglucosamine Mutase from Legionella pneumophila (strain Paris): An In Silico Approach

The harshness of legionellosis differs from mild Pontiac fever to potentially fatal Legionnaire's disease. The increasing development of drug resistance against legionellosis has led to explore new novel drug targets. It has been found that phosphoglucosamine mutase, phosphomannomutase, and phosphoglyceromutase enzymes can be used as the most probable therapeutic drug targets through extensive data mining. Phosphoglucosamine mutase is involved in amino sugar and nucleotide sugar metabolism. The purpose of this study was to predict the potential target of that specific drug. For this, the 3D structure of phosphoglucosamine mutase of Legionella pneumophila (strain Paris) was determined by means of homology modeling through Phyre2 and refined by ModRefiner. Then, the designed model was evaluated with a structure validation program, for instance, PROCHECK, ERRAT, Verify3D, and QMEAN, for further structural analysis. Secondary structural features were determined through self-optimized prediction method with alignment (SOPMA) and interacting networks by STRING. Consequently, we performed molecular docking studies. The analytical result of PROCHECK showed that 95.0% of the residues are in the most favored region, 4.50% are in the additional allowed region and 0.50% are in the generously allowed region of the Ramachandran plot. Verify3D graph value indicates a score of 0.71 and 89.791, 1.11 for ERRAT and QMEAN respectively. Arg419, Thr414, Ser412, and Thr9 were found to dock the substrate for the most favorable binding of S-mercaptocysteine. However, these findings from this current study will pave the way for further extensive investigation of this enzyme in wet lab experiments and in that way assist drug design against legionellosis.

In silico analysis of compounds from Stemona tuberosa as an inhibitor for N1 neuraminidase of H5N1 avian virus

The worldwide spread of H5N1 avian influenza has raised concerns that this virus might acquire the ability to pass readily among humans and cause a pandemic.Two anti-influenza drugs currently being used to treat the infected patients are oseltamivir (Tamiflu) and zanamivir (Relenza), both of which target the neuraminidase enzyme of the virus. Reports of the emergence of drug resistance has made the development of new anti-influenza molecules a priority. Various compounds present in Stemona tuberosa a plant belonging to Stemonaceae family was tested for activity against H5N1 neuraminidase. Eight one molecules including stilbenoids, bibenzyls and various others were selected as probable compounds for lead molecules. These lead molecules were tested for toxicity tests and Lipinski rule in Pre ADMET server. Around 33 compounds cleared all these tests. Validated ligand molecules were docked against H5NI Neuraminidase active site residues using AUTODOCK 4 which showed better results in comparison with zanamivir and oseltamivir, anti- influenza drugs.