No abstract

Ochratoxin A (OTA) is a highly toxic mycotoxin found worldwide in cereals, foods, animal feeds and different drinks. Based on previous studies, OTA is one of the major causes of the chronic tubulointerstitial nephropathy known as Balkan endemic nephropathy (BEN) and exerts several other adverse effects shown by cell and/or animal models. It is a well-known fact that OTA binds to various albumins with very high affinity. Recently, a few studies suggested that reducing the bound fraction of OTA might reduce its toxicity. Hypothetically, certain drugs can be effective competitors displacing OTA from its albumin complex. Therefore, we examined 13 different drug molecules to determine their competing abilities to displace OTA from human serum albumin (HSA). Competitors and ineffective chemicals were identified with a steady-state fluorescence polarization-based method. After characterization the competitive abilities of individual drugs, drug pairs were formed and their displacing activity were tested in OTA-HSA system. Indometacin, phenylbutazone, warfarin and furosemide showed the highest competing capacity but ibuprofen, glipizide and simvastatin represented detectable interaction too. Investigations of drug pairs raised the possibility of the presence of diverse binding sites of competing drugs. Apart from the chemical information obtained in our model, this explorative research might initiate future designs for epidemiologic studies to gain further in vivo evidence of long-term (potentially protective) effects of competing drugs administered to human patients.

In this work the interaction between alkali metal ions and graphene surface with the absence and the presence of external electric field applied perpendicular to the surface was investigated. M05-2X/6-31G(d) DFT calculations were performed to describe the adsorption properties. Results show that the electric field pushes closer the positively charged ion to the graphene, where the charge transfer between the alkali metal cations and the electron rich graphene surface increases. At a species-dependent certain strength of the electric field the excess electrons cause negative charge on the alkali metal ion. This effect will promote the removal of the ion from the surface.