In vitro evaluation of inorganic and methyl mercury mediated cytotoxic effect on neural cells derived from different animal species
Jing Tong , Youwei Wang , Yuanan Lu
DOI:10.1016/j.jes.2015.04.036
Received February 02, 2015,Revised March 24, 2015, Accepted April 15, 2015, Available online September 25, 2015
Volume 28,2016,Pages 138-145
To extend the current understanding of the mercury-mediated cytotoxic effect, five neural cell lines established from different animal species were comparatively analyzed using three different endpoint bioassays: thiazolyl blue tetrazolium bromide, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay (MTT), neutral red uptake assay (NRU), and Coomassie blue assay (CB). Following a 24-hr exposure to selected concentrations of mercury chloride (HgCl2) and methylmercury (II) chloride (MeHgCl), the cytotoxic effect on test cells was characterized by comparing their 50% inhibition concentration (IC50) values. Experimental results indicated that both these forms of mercury were toxic to all the neural cells, but at very different degrees. The IC50 values of MeHgCl among these cell lines ranged from 1.15 ± 0.22 to 10.31 ± 0.70 渭mol/L while the IC50 values for HgCl2 were much higher, ranging from 6.44 ± 0.36 to 160.97 ± 19.63 渭mol/L, indicating the more toxic nature of MeHgCl. The IC50 ratio between HgCl2 and MeHgCl ranged from 1.75 to 96.0, which confirms that organic mercury is much more toxic to these neural cells than inorganic mercury. Among these cell lines, HGST-BR and TriG44 derived from marine sea turtles showed a significantly high tolerance to HgCl2 as compared to the three mammalian neural cells. Among these neural cells, SK-N-SH represented the most sensitive cells to both chemical forms of mercury.
