Study On Preventive Effects Of Tannins From Dioscoreae Cirrhosae On Acute Radiation Enteritis

Objective:By observing the effect of tannins from Dioscoreae cirrhosae on morphology andinflammatory cytokines of the intestinal tissue in mice with acute radiation enteritis andits free radical scavenging activity. Explore the protective effect and its possiblemechanism. This experiment explores the tannins’ protective effect on acute radiationenteritis and its possible mechanism.Method:1Ultrasound-assisted ethanol/methanol extraction method was suse to prepare tanninfrom Dioscorea Cirrhosae Lour that was identified with thin-layer chromatography andultraviolet and visible spectrophotometer；DPPH assay was used to evaluate the freeradical scavenging activity.2Forty male Chinese Kunming mice were randomly divided into non-radiation group,radiation group without drugs, radiation group with tea polyphenols, radiation groupwith tannins from Dioscoreae Cirrhosae and radiation group with tannins from Gallachinensis. The radiation groups were irradiated with a single exposure0f8.0Gy γ raysfrom60Co. The mice were intragastrically administered2h before radiation and weredone18h after radiation．The30-day livability, the mean survival time and theprotective coefficients were characterized.3Forty male Chinese Kunming mice were randomly divided into non-radiation group,radiation group without drugs, radiation group with tannins from Dioscoreae Cirrhosae100mg/(kg·d)、200mg/(kg·d)and400mg/(kg·d).After7days of continuousadministration,the mice were radiated under X-ray of a16Gy dose,3days later，the mice were killed.Light microscope was used to observe the pathological changes of themice’s intestinal tissue and immunohistochemical method was adopted to assay theexpression of TGFβ1and ICAM-1in intestinal mucosa. The intestinal SOD activity andMDA concentration was detected by Biochemical Assay Kit.Results：1The yield of tannins from Dioscorea Cirrhosae Lour is21.09%, and the tanninpresented a strong absorption capability at221nm. The tannin could scavenge DPPHfree radical evidently and its EC50is0.171mg/ml.2All the mice of radiation group without drugs died in16d after exposure, and theirmean survival time was (12.0±2.45) d, while the radiation groups with tannins fromDioscoreae Cirrhosae, with tannins from Galla chinensis and with tea polyphenols were(26.25±7.13) d,(21.88±8.89) d and (23.25±9.33) d respectively. There was a significantdifference in comparison with radiation group without drugs(P <0.05or P <0.05).3Compared with the non-radiation group,pathologic changes appeared in intestinalmucosa in the radiation group without drugs,such as mucosa becoming obviousdropsical,and the villus turning thicker,shorter and,varied in length or defecting,necrotic,shedding.Damage of jejunum in therapy group were relatively minor compared to themodel group with less edema,necrosis,et al.The level of TGFβ1and ICAM-1in thetherapy group mice gut mucosa were lower than those of model groups (p<0.05,p<0.01),the SOD activity increased and the MDA content reduced in radiation group withtannins from Dioscoreae Cirrhosae.Conclusion：1The tannin was extracted from Dioscorea Cirrhosae Lour, which showed a very goodradical scavenging activity.2The tannins from Dioscoreae Cirrhosae and Galla chinensis could increase the mean survival time of the mice exposed to8.0Gy γ rays from60Co and could present asignificant protection on radiation injuries.3The tannins from Dioscoreae Cirrhosae may decrease the X-ray radiation damage onintestinal,reduce the expression of TGFβ1and ICAM-1,as well as decrease theoxidative damage.