黄芩苷灌肠对大鼠放射性直肠纤维化的治疗作用探讨

Therapeutic effect of baicalin enema on radioactive rectal fibrosis in rats

目的探讨黄芩苷灌肠对大鼠放射性直肠纤维化的治疗作用。方法90只SD雄性大鼠随机分为5组:空白对照组、单纯放疗组、放疗+黄芩苷低剂量组[50 mg/(kg·d)]、放疗+黄芩苷中剂量组[100 mg/(kg·d)]、放疗+黄芩苷高剂量组[150 mg/(kg·d)],每组18只。除空白对照组外其余所有大鼠均予以X线16 Gy单次盆腔照射,给药组大鼠自放疗次日起每日予黄芩苷灌肠1次,连续14 d。分别于放疗后第4周、8周、12周处死大鼠,记录直肠组织的损伤情况并评分,HE及Masson染色评估直肠组织纤维化情况,免疫组化法检测黄芩苷灌肠对直肠组织Ⅰ型胶原蛋白表达的影响。结果与单纯放疗组相比,放疗+黄芩苷高剂量组大鼠直肠组织损伤明显减轻。HE染色结果显示12周时单纯放疗组黏膜下层增厚最明显。各给药组中,以高剂量组对黏膜下层厚度的减轻作用最显著(P<0.05)。Masson染色结果提示黄芩苷中、高剂量组在整体上均比单纯放疗组的胶原纤维沉积程度轻,以黄芩苷高剂量组最轻。黄芩苷可降低大鼠放疗后直肠组织中Ⅰ型胶原蛋白的表达。结论黄芩苷灌肠可以减少放射线造成的大鼠直肠组织损伤,减轻大鼠放射性直肠纤维化的程度,其中以黄芩苷高剂量组的治疗作用最显著。

Objective To determine the therapeutic effect of baicalin enema on radiation-induced rectal fibrosis in rats.Methods Ninety SD male rats were randomly divided into a blank control group,a radiotherapy group,a radiotherapy+baicalin low dose group[50 mg/(kg·d)],a radiotherapy+baicalin medium dose group[100 mg/(kg·d)],and a radiotherapy+baicalin high dose group[150 mg/(kg·d)],with 18 rats in each group.All rats except the blank control group were irradiated with a single 16 Gy pelvic irradiation,and baicalin enema was administered once daily for 14 days starting from after the radiotherapy.The rats were sacrificed after the radiotherapy at week 4,week 8 and week 12.The gross damage of rectal tissue was scored,and the rectal fibrosis was assessed by HE and Masson staining.Effect of baicalin on typeⅠcollagen expression was determined.Results Compared with those in the radiotherapy group,the rats in the baicalin high dose group had the least rectal tissue damage.HE staining showed the most obvious thickening of the submucosa in the radiation group at week 12.Among the groups with different dose of baicalin,the most significant reduction in submucosal thickness was in the high dose group(P<0.05).Masson staining suggested that both the baicalin medium and high dose groups had less collagen fibre deposition than the radiation group overall,especially in the baicalin high dose group.Baicalin also reduced the expression of typeⅠcollagen.Conclusion Baicalin enema can reduce the damage of rectal tissue caused by radiation and reduce the degree of radiation-induced rectal fibrosis in rats.Baicalin high dose group shows better therapeutic effect.