Evaluation of Potential anti tumor activity of Echium italicum extract on lung cancer cell_ line, A549

Abstract

Cancer causes significant morbidity and mortality and is a major public health problem worldwide. Lung cancer has the biggest mortality rate among other types of cancer in the world. According to American Cancer Society (ACS) in 2007, 31% all of cancer death in males and 26% in females, were related to lung cancer. Plant-derived compounds have been an important source of several clinically useful anti-cancer agents. In the current study we aimed to assess cytotoxic and possible anti cancer effect of Echium italicum, a traditionally used herbal medicine, on A549 cell line. Materials and Methods In this study, we studied the growth inhibitory effect of E. italicum on human lung cancer cell line, A549. The cells were exposed to n-hexane extract at different concentration and for different time durations. Along with imaging technique for revealing the treatments outcome, MTT assay were carried out to characterize the cytotoxicity of the extract used. Expression of apoptosis related genes such as Bcl-xL, Bax, p53, caspase-3 and EGFR as well as -actin housekeeping gene was studied using reverse transcriptase-PCR. Results Our results demonstrated that n-hexane extract of the root of E. italicum greatly inhibited A549 cell proliferation in a concentration and time-dependent manner. Cytotoxicity of the extract after 24 h in 10, 20 and 50 إg/ml wells was 6, 35 and 60 percent respectively. In 48 h post exposure, the extract at the concentration of 50 إg/ml showed significant toxicity (the highest inhibitory effect) on A549 cells and reduced the cell viability to about 2.91% of un-treated control cells. Also 70% growth inhibition occurs at the concentration of 20 إg/ml. The 10 إg/ml concentration treatment in 48 h showed a cytotoxicity of 22 percent. Data was also confirmed by trypan blue exclusion test. Upon treatment with extract, a clear difference was observed in cellular morphology; the cells acquired more attenuated architecture. A change in expression of some apoptosis related genes was observed. Taken together, the down-regulation of Bcl-xL along with up-regulation of P53, Bax and caspase-3 (at 50 إg/ml) confirms the hypothesis that multiple apoptotic pathways can be considered as potential mechanism of anti-proliferative action of the EIRHE on human adenocarcinoma A549 cell-line. Certainly, significant reduction in expression of EGFR (at 10 and 20 إg/ml) also, expresses the role of cell growth in modulation of A549 cell proliferation. Discussion Our results, for the first time, demonstrate the anti-tumor activity of E. italicum root extract in vitro. The results show that the extract could be considered as a suitable anti cancer candidate for further analysis.