Luciferase Assay

A B S T R A C T Gene reporter technology (GRT) has opened several new avenues for monitoring biological events including the activation of transcription factors, which are central to the study of nutrigenomics. However, this technology relies heavily on the insertion of foreign plasmid DNA into the nuclei of cells (i.e., transfection), which can be very challenging and highly variable among cell types. The objective of this study was to investigate the optimal conditions to generate reliable GRT assay data on bovine immortalized cell lines, Madin Darby Bovine Kidney (MDBK) and bovine mammary epithelial alveolar (MACT) cells. Results are reported for two experiments. In Experiment 1, using 96 well-plate and a robotic inverted fluorescent microscope, we compared transfection efficiency among commercially available transfection reagents (TR) Lipofectamine® 3000 (Lipo3), Lipofectamine® LTX (LipoLTX), and TransIT-X2® (TransX2), three doses of TR (i.e., 0.15, 0.3, and 0.4 μL/well), and three doses of Green Fluorescent Protein plasmid DNA (i.e., 10, 25, and 50 ng/well). Transfection efficiency and mortality rate were analyzed using CellProfiler software. Transfection efficiency increased until the end of the experiment (20 h post-transfection) at which point MACT had greater transfection than MDBK cells (16.3% vs. 2.2%). It is unclear the reason for the low transfection in MDBK cells. Maximal transfection efficiency was obtained with 0.3 μL/well of LipoLTX plus 25 ng/well of plasmid DNA (ca. 29.5 ± 1.9%) and 0.15 μL/well of LipoLTX plus 25 ng/well of plasmid DNA (ca. 4.0 ± 0.4%) for MACT and MDBK cells, respectively. The higher amount of TR and DNA was generally associated with higher cell mortality. Using high, medium, and low transfection efficiency conditions determined in Experiment 1, we performed a GRT assay for peroxisome proliferator-activated response element (PPRE) luciferase in MACT and MDBK cells treated with 10 nM or 100 nM of synthetic Peroxisome Proliferator-activated Receptor β/σ (PPARβ/σ) agonist. The GRT assay was unaffected by poor transfection in MACT cells although the high transfection hampered the possibility of detecting differences between 10 and 100 nM of the PPARβ/δ agonist. In MDBK cells, low transfection efficiency (< 2.0%) failed to detect any differences with GRT assay. The level of transfection was positively associated with a lower coefficient of variation of GRT data. Overall, our data indicates that results of GRT assays are affected by transfection efficiency and a minimum transfection of 2% is required. Thus, factors such as TR type, TR amount, and DNA plasmid amount need to be optimized for a specific cell type before performing GRT assays.

A series of 1-phenyl-4-glycosyl-dihydropyridines (4–17 and 19–21) were prepared by the one pot multicomponent reaction of glcosyl aldehyde, β-keto compounds and aniline or substituted aniline in the presence of TBAHS as catalyst. The compounds were screened in vitro and in vivo for their antileishmanial activities. Most of the compounds exhibited moderate to good activity against amastigotes and promastigotes of Leishmania donovani. The compounds 4, 11, 12, 13, and 17 exhibited potent in vivo activity with selectivity index (SI) values 7.43–18.93. Molecular docking studies with these compounds revealed L. donovani PTR1 as the possible target to show antileishmanial activities.

A series of 1-phenyl-4-glycosyl-dihydropyridines (4–17 and 19–21) were prepared by the one pot multicomponent reaction of glcosyl aldehyde, β-keto compounds and aniline or substituted aniline in the presence of TBAHS as catalyst. The compounds were screened in vitro and in vivo for their antileishmanial activities. Most of the compounds exhibited moderate to good activity against amastigotes and promastigotes of Leishmania

Antileishmanial activities of 16 synthetic oximino benzocycloalkyl azoles against Leishmania donovani were evaluated in vitro against extracellular promastigotes and intracellular amastigotes. Based on SI (Selectivity Index), five compounds were tested further in vivo in hamster model. Out of these, three compounds have shown medium activity (53–58%) and one has shown significant inhibition of parasite multiplication (70%). Despite the fact that