Effect of Celastrus orbiculatus extract on growth and apoptosis-related protein expressions of human gastric adenocarcinoma SGC-7901 cell xenografts in nude mice / 中草药

ABSTRACT

To explore the effects of Celastrus orbiculatus extract (COE) on the expressions of apoptosis-related proteins and growth of human gastric adenocarcinoma SGC-7901 cell xenografts in nude mice. Thirty-five mice with subcutaneous xenografts of a gastric cancer cell line (SGC-7901) were randomly divided into five groups a negative control group, a positive control group (xeloda), and low-dose, medium-dose, and high-dose COE groups (10, 20, and 40 mg/kg, respectively). There were seven mice in each group. Tumor volume, tumor weight, and body weight were measured to draw up tumor growth curves and the tumor weight inhibition rates were calculated. The apoptosis rates were measured by TUNEL staining method and the expressions of p53, Bcl-2, and Bax proteins were detected by immunohistochemical staining and Western blotting assay. The COE could inhibit the growth of SGC-7901 xenografts in a dose-dependent manner. The tumor inhibitory rates were 33.3%, 46.8%, and 57.7% when treated with 10, 20, and 40 mg/kg COE, respectively. TUNEL assay showed that COE presented with apparently more apoptosis than the negative control group. The results of immunohistochemical staining showed the expressions of p53 and Bax proteins had a trend of up-regulation, while the expression of Bcl-2 protein had a trend of down-regulation in nude mice after treatment with COE. Compared with the negative control group, the expressions of p53 and Bax were significantly up-regulated, while the expression of Bcl-2 was down-regulated in the high-dose COE group. Western blotting analysis showed the similar results to immunohistochemical staining. COE could significantly inhibit the growth of SGC-7901 cell xenografts in nude mice, which might be related with the up-regulation of the expressions of p53 and Bax and down-regulation of the expression of Bcl-2.