Effect of Natural products on Apoptotic Changes Related to Irradiation-Induced Mucositis in Rats

Furthermore, exposure of rats to ionizing radiation caused an elevation in MPO activity and enhanced the production of TNF-α. The serum level of DAO, a specific marker reflecting intestinal damage, was also increased. These changes were largely prevented by pre-treatment with APE and STW 5. Based on the present findings it could be concluded that: 1- Exposure of rats to single radiation dose levels produced dose-dependent extents of intestinal mucositis. 2- Single radiation exposure induced a more pronounced intestinal damage than that induced by the same exposure dose given in a fractionated manner. 3- Radiation-induced apoptosis was confirmed histologically by transmission electron microscopy and biochemically by the increase in the cytosolic calcium content, decrease in the mitochondrial contents of Bcl-2, cytochrome c, and complex I activity. 4- Exposure to radiation caused oxidative stress as evidenced by an increase in the tissue contents of TBARS and a corresponding decrease in GSH, as well as an increase in NOx. 5- Radiation-induced mucositis was associated with the release of the pro-inflammatory cytokine, TNF-α, an increased level of tissue and MPO activity, as well as a rise in serum DAO. 6. Both AEP and STW 5 protects to a large extent against the mucosal changes induced by radiation on the intestinal tract and to counteract the derangement in nearly all the associated relevant parameters. 7- Apoptosis was also counteracted by both AEP and STW 5, albeit by higher doses in the present experimental setting. Smaller doses given over a longer time before and after irradiation may prove just as effective. This is currently still under investigation. 8. The anti-apoptotic effects of both AEP and STW 5 and their general protective effects against intestinal radiation damage could pave the way to discover new measures for avoiding the occurrence of mucositis following radiation exposure.