Zhongjiefeng Protection Preliminary Experimental Study Of The Parotid Gland Radiation Damage

Objective To study the effect of Sarcandra glabra extracts on superoxide anion free radical(O₂·^-)and hydroxy free radical(HO·).Methods Spectrophotometry(wave length 322nm and 510nm)was used to observe the effects of Sarcandra glabra extracts on superoxide anion free radical and hydroxy free radical.To study scavenging effect of hydroxy free radical in different presence of Sarcandra glabra extracts,we applied 1,10-Phenanthroline-Fe²⁺oxidative to assay it produced by H₂O₂/Fe.²⁺,and applied autoxidation of pyrogallol to assay superoxide anion free radical,in order to know the effect of Sarcandra glabra extracts on it.Results In the presence of Sarcandra glabra extracts 0.01 mg.ml^-1in vitro, the generation of O₂·^-was inhibited by -76.84%,and in the presence of Sarcandra glabra extracts 0.2,0.4,0.6,1.2 mg·ml^-1in vitro,the level of HO·was reduced by 0.89,17.52,49.35,89.89%,respectively.It has dose-effect relationship between groups.Conclusion Sarcandra glabra extracts can greatly scavenge HO·,and enhance the production of O₂·^-. Objective To discuss whether Sarcandra glabra had protective effect against irradiation-induced injury to salivary gland,as well as analyzed the possible molecular mechanism.Methods 48 male guinea pigs were randomly divided into four groups: control group,in which animals received 0.9%normal sodium alone;irradiation group,in which animals received 0.9%normal sodium before irradiation; medicine group,in which animals received Sarcandra glabra extracts but were not irradiated;medicine+irradiation group,in which animals received Sarcandra glabra extracts before irradiation.The animals were intragastrically administered with drug or 0.9%normal sodium from three days before irradiation until experiment ended.Irradiation group and medicine+irradiation group were irradiated with a single exposure dose of 15 Gy gamma rays delivered to the head and neck region.24 hours after the irradiated procedure, the animals were sacrificed without anaesthesia.The total activities of superoxide dismutase(SOD)and the content of malonaldehyde(MDA)of salivary gland were measured and compared the difference among the groups, respectively.Results The content of salivary gland MDA were 2.99,4.34,0.74,1.3 nmol/mg of protein in control group,irradiation group,medicine group and medicine+irradiation group,respectively(P＜0.01).The medicine group and medicine+irradiation group of MDA content were observed obviously reduction compared with the other two(P＜0.01).The activities of salivary gland total SOD were 249.6,223.02,262.23,165.05 U/mg of protein in the four groups, respectively.The medicine+irradiation group resulted in a significant reduction of the total SOD activities compared with the other three(P＜0.01).While,no significant difference were observed among the control group,irradiation group and medicine group(P＞0.05).There was no linear relationship between total SOD activities and MDA content(R=0.07).Conclusion Sarcandra glabra can reduce salivary gland MDA content of irradiated and non-irradiated guinea pigs and shows a potential radioprotective impact against gamma-irradiation-induced oxidative stress and injury to salivary gland;it maybe have a potential inhibitory action on total SOD activities of salivary gland after irradiation. Objective To investigate the ability to ameliorate the early radiation damage on salivary gland pretreated with Sarcandra glabra extracts in a guinea-gig model,which received conventional radiotherapy on head-neck region,and promote gland recovery as continued administration after radiation, as well as analyzed the possible mechanism.Methods Guinea-pigs divided into normal control,radiation control (radio-control)and medicine radiation group(med-group).Fractionated radiation delivered to head-neck region were applied in two radiation groups.According to different radiation dose and observation time,5 observation groupsⅠ,Ⅱ,Ⅲ,ⅣandⅤwere set up at total dose 20,30,40,50Gy and 60 day after 50Gy,respectively.Med-groups administered Sarcandra glabra extracts for 7 days before radiation until each experiment group ended,whereas the radio-control served as 0.9%normal sodium concurrently.The body weight, gland weight,histopathologic change,remaining gland areas and inflammatory cell counts of parotid gland were compared between 2 radiation groups of each observation points,respectively.Results The body weight of med-group increased persistently,while the radio-control groups grew slowly after the body transient weight loss in the initial stage of radiation.But the average body weight and growth rate of radio-control were lower than that med-groups(P＜0.01).The gland weigh of all med-groups were higher than correspondent radio-control ones,but only groupⅢandⅤhad significant difference(P＜0.05).The histomorphology of med-groups were significantly better than that of radio-control groups,which prominent reflected in the number of gland amount,structure and morphous and so on during the later period of radiation to different extent and after radiation ended.For varying degrees of decline was occurrence of remaining gland areas after radiation.,The average salivary gland areas was normal control group, med-group and radio-control group in turn from high to low(P＜0.05).Med-GroupⅢtoⅤwere higher than that correspondent radio-control groups(P＜0.05).The med-groupⅠwas the highest one in med-groups, while groupⅣwas the lowest one,groupⅤwas higher than groupⅣ(P＜0.05),but there was no difference among groupⅡ,Ⅲ,Ⅴ(P＞0.05)。The average salivary gland areas declined gradually with the irradiation dosage upgrade in radio-control groups,groupⅠwas the highest one and groupⅣandⅤwas the lowest one,there was no difference between them(P＞0.05)。The inflammatory cell counts of groupⅣandⅤof radio-control were higher than the other dose groups and correspondent med-groups(P＜0.01),and the groupⅡandⅢof med-group were higher than the other dose groups and correspondent radio-control(P＜0.01). Conclusion Sarcandra glabra extracts can protect early damage induced by irradiation on parotid gland in guine-pig model;it can help to the gland recovery as continued administration after radiation;alleviating the inflammatory reaction induced by irradiation may be one of mechanisms of radioprotection.