Thiazolyl Blue is a membrane-permeable yellow dye that is reduced by mitochondrial reductases in living cells to form the dark blue product. The net positive charge on Thiazolyl Blue appears to be the predominant factor involved in their cellular uptake via the plasma membrane potential. Thiazolyl Blue is used as a direct indicator of cytotoxicity (such as for screening cancer drugs), proliferation and apoptosis. Thiazolyl Blue is also an electron acceptor used for studying NADP-dependent dehydrogenases. Thiazolyl Blue reduction is associated not only with mitochondria, but also with the cytoplasm and with nonmitochondrial membranes including the endosome/lysosome compartment and the plasma membrane. Biological Applications: cell viability assay; microbial growth assays; DNA quantification assays; tissue viability assays; detecting enzymes; measuring membrane potential; treating Alzheimer’s disease, asthma, cancer. Because Thiazolyl Blue forms an insoluble formazan it has usually been applied in endpoint assays.

PIK-75 is a specific inhibitor of the p110 α isoform of phosphatidylinositol-3-kinase, an enzyme which is upregulated in several human cancers. PIK-75 is a p110α inhibitor with IC50 of 5.8 nM (200-fold more potently than p110β), it is also an inhibitor of CDK9. Cell-based assays revealed that PIK-75 potently and dose dependently inhibits in vitro and in vivo production of TNF-alpha and IL-6, diminishes the induced expression of human endothelial cell adhesion molecules (E-selectin, ICAM-1, and VCAM-1), and blocks human monocyte-endothelial cell adhesion. Most importantly, PIK-75, when administered orally in a therapeutic regimen, significantly suppresses the macroscopic and histological abnormalities associated with dextran sulfate sodium-induced murine colitis. The efficacy of PIK-75 in attenuating experimental inflammation is mediated, at least in part, due to the downregulation of pertinent inflammatory mediators in the colon. Collectively, these results provide first evidence that PIK-75 possesses anti-inflammatory potential. Given that PIK-75 is known to exhibit anti-cancer activity, the findings from this study thus reinforce the cross-therapeutic functionality of potential drugs.