METHODS: MTT assay, DNA fragmentation, ELISA and cell cycle analysis were carried out.
RESULTS: Nordamnacanthal and damnacanthal at IC50 values of 1.7 μg/mL and10 μg/mL, respectively. At the molecular level, these compounds caused internucleosomal DNA cleavage producing multiple 180-200 bp fragments that are visible as a "ladder" on the agarose gel. This was due to the activation of the Mg2+/Ca2+-dependent endonuclease. The induction of apoptosis by nordamnacanthal was different from the one induced by damnacanthal, in a way that it occurs independently of ongoing transcription process. Nevertheless, in both cases, the process of dephosphorylation of protein phosphates 1 and 2A, the ongoing protein synthesis and the elevations of the cytosolic Ca2+ concentration were not needed for apoptosis to take place. Nordamnacanthal was found to have a cytotoxic effect by inducing apoptosis, while damnacanthal caused arrest at the G0/G1 phase of the cell cycle.
CONCLUSION: Damnacanthal and nordamnacanthal have anticancer properties, and could act as potential treatment for T-lymphoblastic leukemia.
OBJECTIVE: The antioxidant, cytotoxic, and protective effects of a series of synthesized 2- trifluoromethylquinazolines (2, 4, and 5) and quinazolinones (6-8) in lipopolysaccharide (LPS)- murine microglia (BV2) and hydrogen peroxide (H2O2)-mouse neuroblastoma-2a (N2a) cells were investigated.
METHOD: The antioxidant activity of synthesized compounds was evaluated with ABTS and DPPH assays. The cytotoxic activities were determined by MTS assay in BV2 and N2a cells. The production of nitric oxide (NO) in LPS-induced BV2 microglia cells was quantified.
RESULTS: The highest ABTS and DPPH scavenging activities were observed for compound 8 with 87.7% of ABTS scavenge percentage and 54.2% DPPH inhibition. All compounds were noncytotoxic in BV2 and N2a cells at 5 and 50 μg/mL. The compounds which showed the highest protective effects in LPS-induced BV2 and H2O2-induced N2a cells were 5 and 7. All tested compounds, except 4, also reduced NO production at concentrations of 50 μg/mL. The quinazolinone series 6-8 exhibited the highest percentage of NO reduction, ranging from 38 to 60%. Compounds 5 and 8 possess balanced antioxidant and protective properties against LPS- and H2O2-induced cell death, thus showing great potential to be developed into anti-inflammatory and neuroprotective agents.
CONCLUSION: Compounds 5 and 7 were able to protect the BV2 and N2a cells against LPS and H2O2 toxicity, respectively, at a low concentration (5 μg/mL). Compounds 6-8 showed potent reduction of NO production in BV2 cells.
RESULTS: In this study, L-cells were isolated from a primary intestinal cell line to create suitable target cells for insulin expression studies. The isolated cells displayed L-cell properties and were therefore used as an L-cell surrogate. Next, the isolated L-cells were transfected with the recombinant plasmid consisting of an insulin gene located downstream of the GLP-1 promoter. The secretion tests revealed that an increase in glucose concentration from 5 mM to 25 mM induced insulin gene expression in the L-cells by 2.7-fold. Furthermore, L-cells quickly responded to the glucose stimulation; the amount of insulin protein increased 2-fold in the first 30 minutes and then reached a plateau after 90 minutes.
CONCLUSION: Our data showed that L-cells efficiently produced the mature insulin protein. In addition, the insulin protein secretion was positively regulated with glucose induction. In conclusion, GLP-1 promoter and L-cell could be potential candidates for diabetes gene therapy agents.