Cytotoxicity investigations of biogenic tellurium nanorods towards PC12 cell line.

The authors evaluated the cytotoxicity underlying mechanisms of biogenic tellurium (Te) nanorods (NRs) produced by the Pseudomonas pseudoalcaligenes strain Te on the PC12 cell line. The half-maximal inhibitory concentration (IC₅₀) value was estimated at 5.05 ± 0.07 ng/ml for biogenic Te NRs and 2.44 ± 0.38 ng/ml for K₂TeO₃, respectively. The viability of PC12 was inhibited concentration dependent at doses of 1, 2.5, 5, 10, and 20 ng/ml. Te NRs principally induced late apoptosis or necrosis at IC₅₀ concentration, without effect on caspase-3 activities. Furthermore, Te NRs reduced glutathione and enhanced malondialdehyde levels, and also reduced superoxide dismutase and catalase activities. These findings revealed that biogenic Te NRs were less toxic than K₂TeO₃. Additionally, they induced cytotoxity towards the PC12 cell line through the activation of late apoptosis independent of the caspase pathway, and may also enhance oxidative stress in the nervous system.