Pretreatment with L-TH antagonizes cisplatin-induced cellular death and modified the radiosensitivity.

<p><b>(A)</b> Vero cells were pretreated with L-TH (120 nM) for different exposure time before incubation with cisplatin (60μM/24h). L-TH protected the cells from cisplatin induced dose-dependent loss of viability and L-TH protected the cells from cisplatin-induced cell death in time-dependent effect. <b>(B)</b> The cells were pretreated with different doses of L-TH two hours before they were IRR with either 2 or 6 Gy dose levels. Cell viability was determined using MTT assay after 24h incubation. Data are expressed as mean (% of control) ± SEM of three independent experiments. (*) indicates significant difference versus CIS-treated or 2Gy-irradiated cells (*<i>P</i>< 0.05).