To confirm the demethylation effect of DAC, BGS was performed on treated cell lines

estinal side effects associated with Triptolide Aspirin therapy, especially during high dosage of aspirin administered for treatment of systemic inflammatory ailments including rheumatoid arthritis. Aspirin also elicits effects that are independent of COX inhibition. Prolonged use of NSAIDs has been reported to reduce the risk of malignancies, though their anti-cancer activity has not been fully established. Aspirin induces shedding of GPIba and GPV from platelet surface through activation of the metalloproteinase ADAM17 and cell death. Clinical trials have indicated that chemopreventive properties of NSAIDs could be due to induction of apoptosis. Several mechanisms have been proposed to explain aspirin-induced apoptosis, which include upregulation of pro-apoptotic proteins and oxidative stress. Aspirin has been shown to induce decrement in mitochondrial transmembrane potential and stimulate intrinsic pathway of apoptosis in mouse Neuro 2a cells. There have been few clinical studies to suggest decrease in platelet count in individuals under aspirin medication. Although aspirin has long been considered to be an effective and safe therapeutic regime against cardiovascular disorders, consequences of its proapoptotic attributes on platelets, the key players in thrombogenesis, demand serous investigation. Proteasome, the protein degradation machinery of the cell, cleaves intracellular proteins in order to regulate essential cellular processes like antigen processing, cell cycle, transcription and signal transduction. We have recently demonstrated a central role of proteasome in determination of platelet life span and the factors regulating its enzymatic activity in human Aspirin Delimits Platelet Life Span platelets. In the present study, we have evaluated effect of aspirin on platelet survival in murine as well as human models. Aspirin induced apoptosis PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19661433 in human platelets in a dose-dependent manner, which was associated with concomitant inhibition of platelet proteasomal activity in presence of the drug. Platelet half life was found to be significantly lowered in aspirin-treated mice as compared to control animals. Thus, above observations provide cautionary framework to critically re-evaluate prophylactic and therapeutic dosage regime of aspirin in clinical practice. Despite widespread use of aspirin against cardiovascular ailments, its preventive administration in susceptible individuals on routine basis is not recommended. Aspirin has been reported to be safe for primary prevention at coronary event risk.1.5%/year though it is not recommended due to associated side effects at coronary event risk 0.5%/year. In standard doses aspirin poses less threat of gastrointestinal bleeding; however, the bleeding risk is still twice as high as without aspirin. 0.52.86109/ml. All steps were carried out under sterile conditions and precautions were taken to maintain the cells in resting condition. Proteasome activity assay Platelets were incubated at 37uC for 30 min with aspirin or vehicle and washed twice in buffer A. Cells were pelleted and resuspended in 125 ml of 26 permeabilization buffer followed by addition of 125 ml of 26 proteasome assay buffer. Permeabilized cells were added to the wells of microplates in a fluorescence microplate reader at 37uC. Reaction was started by the addition of Suc-Leu-Leu-Val-Tyr-AMC in DMSO and was monitored for 10 min . Proteasome peptidase activities were determined from SucLLVY-AMC-hydrolyzing activity. Ethics Statement The