茶多酚拮抗放射性颌下腺细胞凋亡的实验研究

目的 探讨茶多酚(TP)对放射性颌下腺损伤的防护作用。方法 将Wistar大鼠60只随机分为照射组(R)、茶多酚+照射组(TPR),照射前14 d至标本提取当天分别予以生理盐水和茶多酚灌胃,采用⁶⁰Co γ射线15 Gy 一次性照射大鼠头颈部。照射结束后3、6和30 d,每组各取10只大鼠颌下腺,原位末端标记法(TUNEL法)检测腺体细胞和导管细胞凋亡,免疫组织化学方法检测腺体Bcl-2﹑Bax的表达,透射电镜观察组织细胞超微结构改变。结果 茶多酚可以使照射后3﹑6和30 d 的颌下腺腺泡细胞及导管细胞凋亡指数降低,与照射组相比,差异有统计学意义(F =56.383, P <0.01);Bcl-2和Bax的表达组间差异无统计学意义;电镜下TPR组损伤较轻,细胞核凋亡改变不典型。结论 茶多酚可以对放射性颌下腺损伤起到一定防护作用,其机制可能是通过拮抗细胞凋亡实现的。

Experimental study on tea polyphenols against irradiation-induced apoptosis of submandibular glands cell

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.