Study On The Mechanism That Sesamin Inhibits Proliferation Of HepG2 Cells

Sesame, which has long been regarded as a traditional tonic, is also hepatoprotective, antioxidant, senile-resistant, sedative and so on. Thus it is named as "microcapsule" which is beneficial for health and nutrition. Sesamin is the main active ingredient of sesame, having wonderful attributes such as oxidation resistance, and effective against hypertension, hyperlipidemia as well as cancer. Although there are many reports about the therapeutic effects of sesamin on cancer, little is known about its related mechanism. Taking human HepG2 cell line as the test material, this thesis explains the aititumour mechanism of sesimin, by using the molecular biology tools MTT, RT-PCR and Western blotting. Important results of this study include:1. Sesamin inhibited human HepG2 cell line's proliferation in a dose- and time- dependent manner. Maximum inhibitory effect of sesamin was observed when the HepG2 cells were treated for 48 hours. The OD values gradually decreased with the increase in sesamin concentration, which means that sesamin inhibits the proliferation of cancer cells in a dose-dependent manner.2. Study of the cell-cycle progression showed that the anti-proliferative effect of sesamin was associated with an increase in the G2 phase of HepG2 cells. RT-PCR and Western blotting results indicate that sesamin-induced G2 phase arrest was mediated through inhibition of cyclin-regulated signaling pathway. In fact sesamin inhibited cyclin A and cyclin B expression in HepG2 cells.3. Expression of p53, p21, Bax and Bcl-2 gene was detected by semi-quantitative RT-PCR.From these results, it is clearly evident that the expression level of pro-apoptotic proteins p53, p21 as well as Bax gene was up-regulated by sesamin, but it did not have any significant effect on the expression level of Bcl-2 gene.In conclusion, this study successfully determined that sesamin significantly inhibits the proliferation of human HepG2 cells. With the further understanding of apoptosis on HepG2 cell, this research can provide new idea and methods for supplying better anti-tumor treatment.