Protective Effects Of Chinese Herb Medicine Huqi Extractum Against Radiation Injury In Mouse Thymocytes

Objective: To explore the influence of Chinese herb medicine Huqiextractum on viability and apoptosis in mouse thymocytes against60Co and todetect whether Huqi extractum has effect to alleviate the oxidative injuryinduced by60Co radiation in mice thymocytes.Methods: Thymocytes which were isolated from4-8week health maleKunming mice were incubated for4hours and then were divided into controlgroup (CG), irradiation group (IG), irradiation plus low-dose Huqi extractumgroup (ILHEG), irradiation plus medium-dose Huqi extractum group(IMHEG) and irradiation plus high-dose Huqi extractum group(IHHEG).Other three experimental groups were added same volume Huqiextractum solution in accord with their respective groups except for controland irradiation groups. In addition to control, other groups were exposedradiation with a single dose of5Gy γ-rays delivered by60CO sources afterincubation for10hours.(1).At the12th,24th,36th and48th hour afterirradiation, changes of thymocytes viability of each group was detected withAbsorbance A and measured by MTT colorimetric assay. Changes ofthymocytes morphology were observed by light microscope at the10th and24th hour after irradiation. And thymocytes apoptosis were assessd by PI andAnnexin-V staining with flow cytometry (FCM) at the10th hour and DNAdamage were measured by agarose gel electrophoresis at the24th hour.(2).After irradiation intra-cellular ROS intensity and contents of superoxide ineach group was measured by FCS and superoxide assay kit within30minutes.Results:(1).Viability in control and irradiation group were in declineduring the12th to24th hour after irradiation, while viability in irradiationplus low-dose、 medium-does and high-does groups all went up. Thethymocytes viability level in CG was higher than the IG. After the24th hourthymocytes viability in all groups showed an downward trend, but cellviability in irradiation plus low-dose、medium-does and high-does Huqiextractum groups were higher than the CG and IG. The effect of Huqiextractum showed a does-dependent manner. At the36th hour the differenceof cell viability among groups was statistically significant (p＜0.05). Both apoptotic and necrotic morphological changes were observed under the lightmicroscope among experimental groups after irradiation, especially in IG. Atthe10th hour after irradiation the early apoptosis rate in ILHEG、IMHEG andIHHEG were lower than irradiation group, difference between CG andIHHEG was statistically significant (p＜0.05). At the24th hour afterirradiation clear DNA ladder fragments were found in electrophoresis in allgroups except for control. But ILHEG、IMHEG and IHHEG were lessapparent than IG, especially in IHHEG.(2). intra-cellular ROS intensity andcontents of superoxide in ILHEG、IMHEG and IHHEG all descend atdifferent level compare to IG. Difference between IG and IMHEG, IG andIHHEG were statistically significant（p＜0.01）.Conclusions: Chinese herb medicine Huqi extractum is helpful tomaintain viability and reduce apoptosis of mouse thymocytes exposed to the60CO radiation. At the same time Huqi extractum is useful to lower theintra-cellular ROS and reduce the oxidative injury induced by irradiation.