Cytotoxicity effects of amiodarone on cultured cells.

Amiodarone is a potent anti-arrhythmic drug used for the treatment of cardiac arrhythmias. Although, the effects of amiodarone are well characterized on post-ischemic heart and cardiomyocytes, its toxicity on extra-cardiac tissues is still poorly understood. To this aim, we have monitored the cytotoxicity effects of this drug on three cultured cell lines including hepatocytes (HepG2), epithelial cells (EAhy 926) and renal cells (Vero). We have investigated the effects of amiodarone on (i) cell viabilities, (ii) heat shock protein expressions (Hsp 70) as a parameter of protective and adaptive response and (iii) oxidative damage.Our results clearly showed that amiodarone inhibits cell proliferation, induces an over-expression of Hsp 70 and generates significant amount of reactive oxygen species as measured by lipid peroxidation occurrence. However, toxicity of amiodarone was significantly higher in renal and epithelial cells than in hepatocytes. Vitamin E supplement restores the major part of cell mortalities induced by amiodarone showing that oxidative damage is the predominant toxic effect of the drug.Except its toxicity for the cardiac system, our findings demonstrated that amiodarone can target other tissues. Therefore, kidneys present a high sensibility to this drug which may limit its use with subjects suffering from renal disorders.

Cytotoxic effects exerted by polyarylsulfone dialyser membranes depend on different sterilization processes.

Polyarylsulfone group is one of the most important polymeric materials used in the biomedical field, due to its excellent properties, such as good thermal, chemical, and mechanical stability. There are three important polyarylsulfone polymers, all of which have excellent electrical properties: polysulfone (PSu), polyarylsulfone (PAS) and polyarylethersulfone (PAES). All these polymers have excellent creep, radiation and high temperature resistance. In this study, we aimed to determine the effect of three sterilization processes (steam, ethylene oxide and gamma rays) on cytotoxicity of polyarylsulfone dialysis membranes. Ten long-term dialysis patients and ten age-matched healthy controls were enrolled in our study. We analysed (1) serum effect on cultured endothelial cell viability using MTT assay and (2) lipid peroxidation assessed by serum malondialdehyde (MDA) formation at the beginning (T0), the middle (T2) and the end (T4) of haemodialysis (HD) session. Our results clearly showed that steam-sterilized membranes improve endothelial cell viability when compared to ethylene oxide or gamma rays-sterilized ones. Moreover, there is a increased generation of MDA in patients sera during HD session. The serum MDA concentration was about 3, 6 and 10 times higher, respectively, for steam, ethylene oxide and gamma rays sterilization procedures when compared to the MDA amount in healthy subject sera. We concluded that using steam instead of ethylene oxide or gamma rays for sterilization may improve the biocompatibility of polyarylsulfone membranes.

Cytotoxicity and genotoxicity induced by aflatoxin B1, ochratoxin A, and their combination in cultured Vero cells.

Aflatoxin B1 (AFB1) and ochratoxin A (OTA) are important food-borne mycotoxins that have been implicated in human health. In this study, independent and combinative toxicities of AFB1 and OTA were tested in cultured monkey kidney Vero cells. The experiments reported here were conducted to evaluate the effect of these toxins on cell viability followed by the determination of cell death pathways, using the quantification of DNA fragmentation and the expression of p53 and bcl-2 protein levels. Our results showed that AFB1 and OTA caused a marked decrease of cell viability in a dose-dependent manner. Under the same conditions, these mycotoxins increased fragmented DNA levels. In addition, p53 was activated in response to DNA damage and the expression of the antiapoptotic factor bcl-2 decreased significantly. According to these data, AFB1 and OTA seemed to be involved in an apoptotic process. Moreover, combined AFB1 and OTA induced all the toxicities observed with the mycotoxins separately. Therefore, this combination was classified as an additive response of the two mycotoxins.