A sensitive fluorigenic substrate for selective in vitro and in vivo assay of leukotriene A4 hydrolase activity

2013 ◽  
Vol 441 (2) ◽  
pp. 152-161 ◽  
Author(s):  
Hervé Poras ◽  
Sophie Duquesnoy ◽  
Marie-Claude Fournié-Zaluski ◽  
Céline Ratinaud-Giraud ◽  
Bernard P. Roques ◽  
...  
Keyword(s):  
Hydrolase Activity ◽  
In Vivo Assay ◽  
Leukotriene A4 Hydrolase ◽  
Leukotriene A4

scholarly journals Identification of Human Leukotriene A4 Hydrolase Inhibitors Using Structure-Based Pharmacophore Modeling and Molecular Docking

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2871
Author(s):  
Suaad A. Audat ◽  
Nizar A. Al-Shar’i ◽  
Buthina A. Al-Oudat ◽  
Amanda Bryant-Friedrich ◽  
Mel F. Bedi ◽  
...  
Keyword(s):  
Epoxide Hydrolase ◽  
3D Structure ◽  
Pharmacophore Model ◽  
Pharmacophore Modeling ◽  
Leukotriene B4 ◽  
Hydrolase Activity ◽  
Lipid Mediator ◽  
Leukotriene A4 Hydrolase ◽  
Leukotriene A4

Leukotriene B4 (LTB4) is a potent, proinflammatory lipid mediator implicated in the pathologies of an array of inflammatory diseases and cancer. The biosynthesis of LTB4 is regulated by the leukotriene A4 hydrolase (LTA4H). Compounds capable of limiting the formation of LTB4, through selective inhibition of LTA4H, are expected to provide potent anti-inflammatory and anti-cancer agents. The aim of the current study is to obtain potential LTA4H inhibitors using computer-aided drug design. A hybrid 3D structure-based pharmacophore model was generated based on the crystal structure of LTA4H in complex with bestatin. The generated pharmacophore was used in a virtual screen of the Maybridge database. The retrieved hits were extensively filtered, then docked into the active site of the enzyme. Finally, they were consensually scored to yield five hits as potential LTA4H inhibitors. Consequently, the selected hits were purchased and their biological activity assessed in vitro against the epoxide hydrolase activity of LTA4H. The results were very promising, with the most active compound showing 73.6% inhibition of the basal epoxide hydrolase activity of LTA4H. The results from this exploratory study provide valuable information for the design and development of more potent and selective inhibitors.

Evaluation of the Skin Sensitization Potential of Silica nanoparticles using in vitro and in vivo assay

2021 ◽  
Vol 350 ◽  
pp. S72
Author(s):  
D.H. Lee ◽  
S.-H. Kim ◽  
J.H. Lee ◽  
J.-Y Yang ◽  
H.-S. Shin ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Skin Sensitization ◽  
In Vivo Assay

scholarly journals Antiplasmodial Quinones from the Rhizomes of Kniphofia Foliosa

2013 ◽  
Vol 8 (9) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Martha Induli ◽  
Meron Gebru ◽  
Negera Abdissa ◽  
Hosea Akala ◽  
Ingrid Wekesa ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Methyl Ether ◽  
Spectroscopic Data ◽  
Antimalarial Activity ◽  
In Vivo Assay

Extracts of the rhizomes of Kniphofia foliosa exhibited antiplasmodial activities against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum with IC50 values of 3–5 μg/mL. A phenyloxanthrone, named 10-acetonylknipholone cyclooxanthrone (1) and an anthraquinone-anthrone dimer, chryslandicin 10-methyl ether (2), were isolated from the rhizomes, along with known quinones, including the rare phenylanthraquinone dimers, joziknipholones A and B. The structures of these compounds were determined based on spectroscopic data. This is the second report on the occurrence of the dimeric phenylanthraquinones in nature. In an in vitro antiplasmodial assay of the isolated compounds, activity was observed for phenylanthraquinones, anthraquinone-anthrone dimers and dimeric phenylanthraquinones, with joziknipholone A being the most active. The new compound, 10-acetonylknipholone cyclooxanthrone, also showed anti-plasmodial activity. In an in vivo assay, knipholone anthrone displayed marginal antimalarial activity.

scholarly journals An in vivo assay for the reverse transcriptase of human retrotransposon L1 in Saccharomyces cerevisiae.

1994 ◽  
Vol 14 (7) ◽  
pp. 4485-4492 ◽  
Author(s):  
B A Dombroski ◽  
Q Feng ◽  
S L Mathias ◽  
D M Sassaman ◽  
A F Scott ◽  
...  
Keyword(s):  
Reverse Transcriptase ◽  
Consensus Sequence ◽  
Unknown Origin ◽  
Open Reading Frames ◽  
Long Terminal Repeats ◽  
Base Pairs ◽  
In Vivo Assay ◽  
Reading Frames

L1 elements constitute a highly repetitive human DNA family (50,000 to 100,000 copies) lacking long terminal repeats and ending in a poly(A) tail. Some L1 elements are capable of retrotransposition in the human genome (Kazazian, H. H., Jr., C. Wong, H. Youssoufian, A. F. Scott, D. G. Phillips, and S.E. Antonarakis, Nature (London) 332:164-166, 1988). Although most are 5' truncated, a consensus sequence of complete L1 elements is 6 kb long and contains two open reading frames (ORFs) (Scott, A. F., B. J. Schmeckpeper, M. Abdelrazik, C. T. Comey, B. O'Hara, J. P. Rossiter, T. Cooley, P. Health, K. D. Smith, and L. Margolet, Genomics 1:113-125, 1987). The protein encoded by ORF2 has reverse transcriptase (RT) activity in vitro (Mathias, S. L., A. F. Scott, H. H. Kazazian, Jr., J. D. Boeke, and A. Gabriel, Science 254:1808-1810, 1991). Because L1 elements are so numerous, efficient methods for identifying active copies are required. We have developed a simple in vivo assay for the activity of L1 RT based on the system developed by Derr et al. (Derr, L. K., J. N. Strathern, and D. J. Garfinkel, Cell 67:355-364, 1991) for yeast HIS3 pseudogene formation. L1 ORF2 displays an in vivo RT activity similar to that of yeast Ty1 RT in this system and generates pseudogenes with unusual structures. Like the HIS3 pseudogenes whose formation depends on Ty1 RT, the HIS3 pseudogenes generated by L1 RT are joined to Ty1 sequences and often are part of complex arrays of Ty1 elements, multiple HIS3 pseudogenes, and hybrid Ty1/L1 elements. These pseudogenes differ from those previously described in that there are base pairs of unknown origin inserted at several of the junctions. In two of three HIS3 pseudogenes studied, the L1 RT appears to have jumped from the 5' end of a Ty1/L1 transcript to the poly(A) tract of the HIS3 RNA.

Disruption of endocrine function in in vitro H295R cell-based and in in vivo assay in zebrafish by 2,4-dichlorophenol

2012 ◽  
Vol 106-107 ◽  
pp. 173-181 ◽  
Author(s):  
Yanbo Ma ◽  
Jian Han ◽  
Yongyong Guo ◽  
Paul K.S. Lam ◽  
Rudolf S.S. Wu ◽  
...  
Keyword(s):  
Endocrine Function ◽  
In Vivo Assay

scholarly journals Effect of Massoia (Massoia aromatica Becc.) Bark on the Phagocytic Activity of Wistar Rat Macrophages

2018 ◽  
Author(s):  
Triana Hertiani ◽  
Agustinus Yuswanto ◽  
Sylvia Utami Tunjung Pratiwi ◽  
Harlyanti Mashar
Keyword(s):  
Phagocytic Activity ◽  
Wistar Rats ◽  
In Vitro Assay ◽  
Phagocytic Index ◽  
Dependent Manner ◽  
Vitro Assay ◽  
Macrophage Cells ◽  
In Vivo Assay

Massoia (Massoia aromatica Becc., Lauraceae) bark has been widely used as a component of traditional Indonesian medicine. The indigenous people boil or steam the bark for traditional applications. Our preliminary research revealed the potency of Massoia essential oil and its major compound, C-10 Massoialactone as potential immunomodulator in vitro. However, no scientific evidence regarding its in vivo effects is available. Therefore, this study evaluated the potential immunomodulatory effects of Massoia bark infusion on the nonspecific immune response (phagocytosis) of Wistar rats. The aqueous extract of Massoia bark was obtained by boiling pulverized bark in water, and the C-10 massoialactone content of the extract was determined through Thin Layer Chromatography (TLC) densitometry. For the in vitro assay, macrophages were treated with the freeze-dried infusion at the concentrations of 2.5, 5, 10, 20, or 40 μg/mL media. For the in vivo assay, 2-month-old male Wistar rats were divided into 5 groups. The baseline group received distilled water at the dose of 1 mL/100 g BW with the immunostimulant herbal product “X” administered as the positive control at the dose of 0.54 mL/rat. The treatment groups received the infusion at a dose of 100, 300, or 500 mg/100 g BW. Treatments were given orally every day for 14 days. The ability of macrophage cells to phagocyte latex was determined as phagocytic index (PI) and was observed under microscopy with 300 macrophages. The in vitro study revealed that the phagocytic activity of the infusion-treated macrophages significantly increased in comparison with that of the control macrophages in a concentration-dependent manner. Among all treatment concentrations, the concentration of 40 μg/ml provided the highest activity with a PI value of 70.51% ± 1.11%. The results of the in vivo assay confirmed those of the in vitro assay. The results of the present study indicate that Massoia bark can increase the phagocytic activity of rat macrophage cells. Its potential as a naturally derived immunomodulatory agent requires further study.

scholarly journals Spike protein up-regulates inflammatory axis of both thromboinflammation and leukotriene in severe COVID-19

2020 ◽  
Author(s):  
Xiaopeng Tang ◽  
Mingqian Fang ◽  
Juan Zhang ◽  
Zhiyi Liao ◽  
Ruomei Cheng ◽  
...  
Keyword(s):  
Epoxide Hydrolase ◽  
Leukotriene B4 ◽  
Spike Protein ◽  
Aminopeptidase Activity ◽  
Healthy Control ◽  
Leukotriene A4 Hydrolase ◽  
Inflammatory Drugs ◽  
Anti Inflammatory ◽  
Leukotriene A4

Abstract Hypercytokinemia is a critically fatal factor in COVID-19. However, underlying pathogenic mechanisms are unknown. Here we show that fibrinogen and leukotriene-A4 hydrolase (LTA4H), two of the most potent inflammatory contributors, are elevated by 67.7 and astonishing 227.7% in the plasma of patients infected by SARS-CoV-2 and admitted to intensive care unit in comparison with healthy control, respectively. Conversely, transferrin identified as a fibrinogen immobilizer in our recent work and Spink6 are down-regulated by 40.3 and 25.9%, respectively. Furthermore, we identify Spink6 as the first endogenous inhibitor of LTA4H, a pro-inflammatory enzyme catalyzing final and rating limited step in biosynthesis of leukotriene-B4 that is an extremely inflammatory mediator and a target to design superior anti-inflammatory drugs. Additionally, virus Spike protein is found to evoke LTA4H and fibrinogen expression in vivo. Collectively, these findings identify the imbalance between inflammatory drivers and antagonists, which likely contributes to hypercytokinemia in COVID-19. Spink6 may have superior anti-inflammatory function because it specifically targets epoxide hydrolase of LTA4H to inhibit leukotriene-B4 biosynthesis without effecting LTA4H’s aminopeptidase activity.

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