Experimental study on tea polyphenols against irradiation-induced apoptosis of submandibular glands cell / 中华放射医学与防护杂志

ABSTRACT

Objective To explore the protective effect of Tea polyphenols(TP) on radiation injury in submandibular glands. Methods Sixty rats were randomly divided into radiation group(R-group) and tea polyphenols combined radiation group (TPR-group), both groups were irradiated with a single exposure of 15 Gy γ-rays delivered to the head and neck area. The rats were intragastrically administered with normal sodium or TP from 14 days before radiation to the experiment ended. On day 3, day 6 and day 30 after radiation, ten submandibular glands glands were taken from each groups. TUNEL method was used to examine the apoptosis of submandibular glands cells and immunohistochemical technique was used to detect the Bcl-2 and the Bax expression in the glands. The morphologic changes of submandibular glands were observed by transmission electron microscopy. Results Apoptosis index in the cell of submandibular glands were significant decreased on days 3, days 6 and days 30 after irradiation, compared with R-group ( F = 56.383, P ＜ 0.01 ). Expression of Bcl-2 and Bax were not significant difference between the two groups. The lesions of submandibular glands in TPR-group were lighter and the apoptosis in cell nuclear were not typical than that of R-group from electron microscope study. Conclusion TP could protect the sumandibular glands against radiation injuries and the mechanism might be realized with the anti-apoptosis in the glands cell.