Therapeutic effect of Aloe vera and silver nanoparticles on acid-induced oral ulcer in gamma-irradiated mice

Abstract Radiation combined injury, a life-threatening condition, has higher mortality than simple radiation injury. The aim of the present study was to analyze the efficiency of Aloe vera and silver nanoparticles in improving the healing of ulcerated oral mucosa after irradiation. Thirty male Albino mice were divided into five groups: control, radiation, Aloe vera (AV), silver nanoparticles (NS), and AV+NS. The mice were exposed to whole body 6Gy gamma-radiation. After one hour, 20% acetic acid was injected into the submucosal layer of the lower lip for ulcer induction. The animals received topical treatment with the assigned substances for 5 days. Lip specimens were subjected to hematoxylin and eosin and anti alpha-smooth muscle actin immunohistochemical staining. Results demonstrated occurance of ulcer three days post irradiation in all groups except in the AV+NS group where only epithelial detachment was developed. After seven days, data revealed persistent ulcer in radiation group, and almost normal epithelium in the AV+NS group. A significant reduction of epithelial thickness was detected in all groups at the third day as compared to control. At the seventh day, only the AV+NS group restored the epithelial thickness. Area percent of alpha-smooth muscle actin expression was significantly decreased in radiation group at the third day followed by significant increase at the seventh day. However, all treatment groups showed significant increase in alpha-smooth muscle actin at the third day, which decreased to normal level at the seventh day. Our study demonstrated the efficiency of Aloe vera and silver nanoparticles in enhancing ulcer healing after irradiation.

摘要 复合放射损伤是一种危及生命的病症，其死亡率高于单纯放射损伤。本研究旨在分析芦荟（Aloe vera）与银纳米颗粒（silver nanoparticles）对放射照射后口腔黏膜溃疡愈合的改善效果。将30只雄性白化小鼠分为5组：对照组、放射组、芦荟（Aloe vera，AV）组、银纳米颗粒（silver nanoparticles，NS）组以及AV+NS联合组。对所有小鼠实施全身6Gy γ射线照射。照射1小时后，向小鼠下唇黏膜下层注射20%乙酸以诱导溃疡形成。随后对小鼠进行为期5天的指定药物局部给药治疗。采集唇部标本，进行苏木精-伊红（hematoxylin and eosin，HE）染色及抗α-平滑肌肌动蛋白（alpha-smooth muscle actin，α-SMA）免疫组织化学染色检测。结果显示，照射后第3天，除AV+NS联合组仅出现上皮脱落外，其余各组均形成溃疡。照射后第7天，放射组仍存在持续性溃疡，而AV+NS联合组的上皮结构已基本恢复正常。与对照组相比，照射后第3天所有各组的上皮厚度均显著降低；至第7天，仅AV+NS联合组的上皮厚度恢复至正常水平。照射后第3天，放射组的α-平滑肌肌动蛋白表达面积百分比显著降低，而在第7天则显著升高。但各给药组在第3天的α-平滑肌肌动蛋白表达均显著升高，至第7天则回落至正常水平。本研究证实，芦荟与银纳米颗粒可有效促进放射照射后口腔黏膜溃疡的愈合。