The comparison of apoptosis-related protein expressions in neurotoxin-based in vitroParkinson’s Disease models

Programmed cell death (apoptosis) is mainly responsible for neuronal damage in neurodegenerative diseases. Thus, inhibition of apoptosis could represent an effective strategy in the prevention of these diseases. in this study, we aimed to compare the apoptotic responses of neurotoxins that are widely used to induce neuronal damage incell culture studies and help to decide the most suitable experimental model for drug studies that target apoptosis. Cell viability analyses were performed by MTT assay following 1-methyl-4-phenylpyridinium (MPP+), 6-hydroxydopamine (6-OHDA), rotenone andparaquat treatments at three different time points(12, 24, 48h). Pro-apoptotic (Bax, Bad, Bak), anti-apoptotic (Bcl-2, Bcl-xl) protein levels and total caspase-3 protein levels were determined by Western Blotting technique following treatments. As expected, all neurotoxins managed to trigger cell death and apoptotic pathway. on the other hand, each neurotoxin was found to enhance and/or reduce the levels of different proteins that are associated with apoptosis. Due to different responses of apoptosis related proteins to neurotoxins, it can be concluded that the determination of target proteins with a number of protein-binding assays prior to cell culture studies and then deciding an in vitro model are essential while screening newly synthesized drugs that target apoptosis

Potential Cytotoxic Activity of Psephellus pyrrhoblepharus Extracts

Many species of Psephellus and Centaurea genuses have pharmacological activities including antiinflamatory, antipyretic, cytotoxic etc. Psephellus pyrrhoblepharus (Boiss.) Wagenitz (Centaurea pyrrhoblephara), an endemic plant, was collected from Elazığ, Turkey. Liver cancer is affecting millions of people all over the world. Recent days interest in use of plant-derived compounds for therapeutic purposes in cancer is increasing. So any approach to treat liver cancer is extremely valuable. We aimed to evaluate the cytotoxic potential of extracts (methanol:water 1:1, chloroform and n-hexane) of aerial parts of P. pyrrhoblepharus using human liver cancer cell (HepG2) by utilizing the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay in different concentrations (50,100,200 µg/mL) and time points (6, 12, 24 h). Regarding the cytotoxicity, cell viability was decreased following extract exposures at different time points. However, the highest cytotoxic activity was observed in 100 µg/mL concentrations of chloroform extract at 24 h. Chloroform extract of plant showed the highest cytotoxic activity in 200 µg/mL concentrations when compared to methanol:water and n-hexane extracts at 12 h. It can be suggested that used extracts of P. pyrrhoblepharus exert cytotoxic effect in HepG2 carcinoma cells in a dose- and time-dependent manner. Generally, results provide information regarding the threshold concentrations of P. pyrrhoblepharus extracts that might be used in different applications without toxicity hazards