Reflex of oleandrin production and molecular changes on the Nerium oleander L. cell suspension culture under UV-A radiation stress effect.

THE AIM of this study is to determine the oleandrin concentrations in the Nerium oleander cell suspension culture after being exposed to UV-A (365nm), at different time intervals (0 controls, 5, 10, 15, 20, 25, 30, 35, 40, 45 and 50min). The results showed that the maximum time limits for carrying N. oleander cells suspension culture to exposure of UV-A is 30min.The present study also aims at investigating changes of the protein bands, peroxidase isozyme and oleandrin concentration at the same condition. Oleandrin was separated and quantified by HPLC. The investigation of protein changes was conducted using SDS PAGE electrophoresis techniques. The results revealed that the changes of the protein bands depend on different time intervals of exposure to A-UV radiation. Thus, the changes of the oleandrin production were consequent to gene expression changes. Peroxidase isozyme analysis, showed that exposure to UV-A for the 5, 15 and 20min had a clear impact on the peroxidase isozyme, but the greatest impact was in the sample exposed to UV-A for a period of 15 minutes (0.093±0.01) μg/ml, the same sample showed the highest concentration of oleandrin compared to the control (0.022±0.001) μg/ml. However, the other samples were less affected by the exposure to UV-A.