Caffeine ameliorates radiation-induced skin reactions in mice but does not influence tumour radiation response.

Intramuscular administration of caffeine at a dose of 80 mg kg(-1) body weight to the gastrocnemius muscles of Swiss mice 5 min prior to local irradiation (35 Gy) of the leg delayed the progression of radiation-induced skin reactions in such animals. While 90% epilation with reddening of the skin was noted in animals treated with radiation alone, animals pretreated with caffeine suffered only partial hair loss with slight reddening of the skin on the 16th and 20th days post-irradiation. Beyond the 28th day, damage scores in irradiated feet for both the groups were similar (score 3) and remained unchanged until the 32nd day and then decreased and disappeared completely in both treatment groups by the 40th day after irradiation. In addition, the effect of caffeine on the radiation response of a mouse fibrosarcoma was investigated. Results showed that intratumoral administration of caffeine at a dose of 80 mg kg(-1) body weight 5 min prior to local exposure of tumours to 10 Gy of 60Co gamma-rays did not influence the response of tumours to radiation. The present study thus showed that although caffeine ameliorated radiation-induced skin reactions in the mouse leg, it did not affect the tumour radiation response, indicating its potential application in cancer radiotherapy.     

5,7-Dihydroxychromone-2-carboxylic acid and it's transition-metal (Mn and Zn) chelates as non-thiol radioprotective agents

5,7-Dihydroxychromone-2-carboxylic acid (DHCCA) and its related complexes with manganese and zinc were prepared and evaluated for radioprotection activity against gamma irradiation in mice. The LD(50) values were found to be more than 1500 and 1000 mg/kg for DHCCA and it's complexes, respectively. For studying radioprotective effects, 1.0 mmol/kg and 0.5 mmol/kg doses of compounds were administrated subcutaneously 24 h prior to 8.2 Gy gamma irradiation. The percentages of 30-day survival of mice for these compounds were 26%-50%. DHCCA exhibited significant action in delaying deaths as well as effective protection against gamma rays-induced mortality compared to reference drug amifostine. Amifostine provides effective radiation protection when administrated immediately prior to radiation exposure, but administration of DHCCA, even 24 h prior to gamma irradiation, provides a significant protection.     

Influence of seed extract of Syzygium Cumini (Jamun) on mice exposed to different doses of gamma-radiation

The radioprotective activity of the hydroalcoholic extract of jamun seeds (SCE) was studied in mice exposed to different doses of gamma radiation. The mice were injected with 0, 5, 10, 20, 40, 60, 80, 100, 120, 140 or 160 mg/kg body weight of SCE, before exposure to 10 Gy of gamma radiation, to select the optimum dose of radiation protection. The 80 mg/kg SCE was found to offer highest protection, therefore, further studies were carried out using this dose. The drug was more effective when administered through the intraperitoneal route at equimolar doses than the oral route. Since higher survival was observed for the i.p. route (50%), than the oral route (29.2%), all other studies were carried out by injecting SCE intraperitoneally. The mice treated with 80 mg/kg body weight SCE intraperitoneally before exposure to 6, 7, 8, 9, 10 and 11 Gy of gamma radiation showed reduction in the symptoms of radiation sickness and mortality at all exposure doses and caused a significant increase in the animal survival when compared with the concurrent double distilled water (DDW) + irradiation group. The SCE treatment protected mice against the gastrointestinal as well as bone marrow deaths and the DRF was found to be 1.24.     

In vivo radioprotection of mice by 3-methyl-1-phenyl-2-pyrazolin-5-one (edaravone; Radicut), a clinical drug

Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one; Radicut) is a brain-protecting agent used clinically to treat acute ischemic stroke with a reaction mechanism of free radical scavenging. Since the initial stage of radiation damage involves the formation of free radicals, edaravone is expected to be effective in preventing lethal damage from ionizing radiation. In the present study, we used mice to examine in vivo the radioprotective effect of edaravone on whole body X-ray irradiation. A solution of edaravone was administered intraperitoneally to C3H mice (male, 10 weeks old), and they were irradiated with a total dose of 8.0 Gy. Edaravone exhibited dose-dependent and injection time-dependent radioprotection. When injected 30 min before the X-ray irradiation, it had the greatest radioprotective effect, whereas an injection after the irradiation showed no protective effect. The LD(50/30) was about 8.8 Gy for edaravone-injected mice and 6.6 Gy for control mice, yielding a DRF for edaravone (450 mg/kg bw) of 1.3. Edaravone decreased the body temperature transiently about 3-6C, but this did not seem to be responsible for the radioprotection. Since the radioprotection was observed only when the reagent was administered before the irradiation, the primary action of edaravone might be the quenching of free radicals with a short lifetime generated by the irradiation.     

Radioprotective Effects of ON 01210.Na upon Oral Administration

ON 01210.Na (Ex-RAD), a chlorobenzylsulfone derivative was investigated for its pharmacologic and radioprotective properties when administered via oral and subcutaneous (SC) routes. The goals of the study were to assess the comparative bioavailability of ON 01210.Na when administered by oral versus SC routes and to demonstrate that the oral drug delivery of ON 01210.Na afforded survival advantage similar to SC dosing. Pharmacokinetics was studied after two doses, 24 h apart, of ON 01210.Na (500 mg/kg) administered to male C3H/Hen mice (7-9 weeks) via SC injection or oral route. The dose response (100 to 750 mg/kg) and survival advantage of ON 01210.Na administered at 24 h and 15 min prior to 7.5 or 8 Gy whole body irradiation from a ¹³⁷Cs source (dose rate 1 Gy/min) were studied in these mice. Effects on the hematopoietic system were investigated by complete blood count and granulocyte-macrophage colony forming unit assay. A significant survival advantage and hematopoietic protection were observed after prophylactic oral ON 01210.Na and results were comparable to SC administration. These findings correlated well with pharmacokinetic data. Both SC and oral ON 01210.Na showed significant survival advantage against radiation toxicity and ON 01210.Na mediated hematopoietic protection plays key role in enhanced survival of mice. Oral administration holds better clinical promise as an effective countermeasure not only for early-responders in a nuclear accident, but also for the at-risk civilian population.     

Heat-treated mineral-yeast as a potent post-irradiation radioprotector

In vivo radioprotection of C3H mice by i.p. administration of Zn-, Mn-, Cu-, or Se-containing heat-treated Saccharomyces serevisiae yeast sample was examined. The 30-day survival of the group treated 30 min before 7.5 Gy whole-body X-irradiation with mineral-containing yeast powders suspended in 0.5% methylcellulose was significantly higher than that of control group. When mineral-yeast was administered immediately after irradiation, the survival rate was even higher and Zn- or Cu-yeast showed the highest rate (more than 90%). Although treatment with simple yeast showed a high survival rate (73%), it was significantly lower than that obtained by the Zn-yeast treatment. The effects of Zn-yeast were studied further. When the interval between irradiation and administration was varied, the protective activity of Zn-yeast decreased gradually by increasing the interval but was still significantly high for the administration at 10 h post-irradiation. The dose reduction factor of Zn-yeast (100 mg/kg, i.p. administration immediately after irradiation) was about 1.2. When the suspension of Zn-yeast was fractionated by centrifugation, the insoluble fraction showed a potent effect, while the soluble fraction had only a moderate effect. In conclusion, mineral-yeast, especially Zn-yeast, provides remarkable post-irradiation protection against lethal whole body X-irradiation. The activity is mainly attributable to the insoluble fraction, whereas some soluble components might contribute to the additional protective activity.     

Eugenol as an in vivo radioprotective agent

In the present work, an attempt has been made to evaluate the possible in vivo radioprotection by eugenol. Swiss albino mice were administered different doses of eugenol (75,150 and 300 mg/kg) before exposure to 1.5 Gy of gamma radiation. The micronucleus test was carried out to determine the genetic damage in bone marrow. Our results demonstrated significant reduction in the frequencies of micronucleated polychromatic erythrocytes (MnPCEs) with all three eugenol doses. Eugenol (150 mg/kg) was also tested against different doses of radiation (0.5, 1, 1.5, and 2 Gy) and was found to afford significant radioprotection. Reduction in the incidence of MnPCEs could be noticed up to 72 h postirradiation (1.5 Gy). Moreover, the level of peroxidative damage and the specific activities of lactate dehydrogenase (LDH) and methylglyoxalase I (Gly I) were observed in the liver of mice treated with eugenol for seven days in comparison to untreated mice. The results revealed that eugenol exerted significant protection against oxidative stress. This possibility was further supported by the enhanced response of Gly I and the lowered activity of LDH. The present findings suggested that eugenol has a radioprotective potential.     

石花制剂对小鼠急性辐射损伤的防护作用

目的 考察不同剂量、不同给药时间、不同给药途径和不同方法制备的石花制剂对小鼠急性辐射损伤的防护作用,探讨石花制剂治疗小鼠急性辐射损伤的最佳给药方案。方法 小鼠在照射前腹腔注射10mg/kg、20mg/kg、40mg/kg、80mg/kg石花制剂,进行⁶⁰Coγ射线一次性全身照射,照射剂量为9 Gy,观察小鼠的30d活存率和保护系数;照前15min、30min、1h、2h、4h腹腔注射石花制剂,观察30d活存率和保护系数;照前肌肉注射和口服给予石花制剂,观察30 d活存率和保护系数;照前腹腔注射醇提和水提的石花制剂,观察30d活存率和保护系数。结果 石花制剂在一定剂量范围内(20~80 mg/kg)可显著提高受照小鼠的30d活存率和平均活存天数;照前15min至1h腹腔注射石花制剂对受⁶⁰Coγ射线照射小鼠的辐射损伤均有显著的治疗作用;照前肌肉注射石花制剂时,防护效果略逊于腹腔注射给药,而同样剂量口服给药时,则防护作用不显著;水提取的石花制剂在照前不同时间腹腔注射给药,防护效果与50%乙醇提取的石花制剂近似。结论 石花制剂对小鼠急性辐射损伤有一定的防护作用,最佳给药方案为照前30min腹腔注射40mg/kg的石花制剂。     

Modulation of gamma radiation-inflicted damage in Swiss albino mice by an alcoholic fraction of Podophyllum hexandrum rhizome

A partially characterized extract of Podophyllum hexandrum rhizomes was studied for its radioprotective potential in mice. A major portion of the podophyllotoxin was obtained from the extract by further fractionation. Acute toxicity and maximum tolerated dose (MTD) of a single intraperitoneal dose of the extract were studied in mice to evaluate the toxicity of the extract, if any. Radioprotective efficacy was determined in terms of survival against 10 Gy whole-body irradiation (WBI), protection against 1 Gy-induced chromosomal aberration (CA), and estimation of dose reduction factor (DRF) in irradiated and extract pretreated mice. The MTD was observed to be 60 mg/kg of body weight, whereas a dose of 90 mg/kg of body weight yielded 50% death in mice within 72 hours of intraperitoneal administration of the extract. A dose range of 15-20 mg/kg of body weight administered 2 hours before 10 Gy WBI of mice yielded 66% survival, while administration of 10-15 mg/kg of body weight of the extract 1 hour before WBI yielded more than 90% survival. A DRF of 1.625 was estimated for 10 and 15 mg/kg of body weight of the extract administered 1 hour before WBI. Further studies on modulation of 1 Gy-induced CA revealed significant radioprotective efficacy of the extract in mouse bone marrow cells. Partial removal of podophyllotoxin was useful in reducing toxicity of the extract without altering its radioprotective efficacy.     

Radioprotection by Rhodiola imbricata in mice against whole-body lethal irradiation

Rhodiola imbricata, an Indian medicinal plant, was investigated for protection against whole-body lethal gamma irradiation (10 Gy)-induced mortality in Swiss albino strain "A" mice. The maximum tolerance dose values for aqueous (RD-I) and aqua-alcoholic (RD-II) extracts were 1,100 and 1,300 mg/kg of body weight, respectively. Pre-irradiation administration of RD-I produced >90% survival, while RD-II produced >83% survival beyond the 30-day observation period. The optimal radioprotective dose for RD-I as well as RD-II was 350 mg/kg of body weight; the aqua-alcoholic extract, however, had an advantage over the aqueous extract at lower as well as at higher doses. The optimal time interval between administration of extract and irradiation was 30 minutes for both RD-I and RD-II. The number of colony-forming units per spleen in irradiated mice was 1.91 +/- 0.15, while in mice given RD-I or RD-II, 30 minutes before irradiation (10 Gy), it increased to 17.3 +/- 0.67 and 15.6 +/- 0.61, respectively. These findings have important implications in the development of a suitable radioprotector of herbal origin.     

Assessment of cellular and molecular changes in the rat brain after gamma radiation and radioprotection by anisomycin

The objective of the study was to describe cellular and molecular markers of radioprotection by anisomycin, focusing on the changes in rat brain tissue. Two-month-old Wistar rats were exposed to a ⁶⁰Co radiation source at a dose of 6 Gy, with or without radioprotection with anisomycin (150 mg/kg) administered subcutaneously 30 min before or 3 or 6 h after irradiation. Survivors were analyzed 30 days after treatment. Astroglial and microglial responses were investigated based on the expression of glial markers assessed with immunohistochemistry, and quantitative changes in brain biomolecules were investigated by Raman microspectroscopy. In addition, blood plasma levels of pro-inflammatory (interleukin 6 and tumor necrosis factor α) and anti-inflammatory (interleukin 10) cytokines were assessed. We found that application of anisomycin either before or after irradiation significantly decreased the expression of the microglial marker Iba-1. We also found an increased intensity of Raman spectral bands related to nucleic acids, as well as an increased level of cytokines when anisomycin was applied after irradiation. This suggests that the radioprotective effects of anisomycin are by decreasing Iba-1 expression and stabilizing genetic material by increasing the level of nucleic acids.     

Protective effects of soybean isoflavone against gamma-irradiation induced damages in mice

In the present work, we investigated the radioprotective efficacy of soybean isoflavone (SI) in mitigating gamma-irradiation-induced oxidative damage to the livers and blood systems of adult Swiss albino mice. We administered various doses of SI (50 mg/kg b.wt, 100 mg/kg b.wt, and 400 mg/kg b.wt) to the mice for seven consecutive days before exposing them to a single dose of 4.56 Gy 60Co-gamma whole-body irradiation. The irradiated mice continued to receive SI for two or seven days before sacrifice. The SI treatments significantly elevated liver catalase (CAT) and glutathione peroxidase (GPx) enzyme activities and mRNA abundances, and decreased the malonaldehyde (MDA) levels. The SI treatments also accelerated the recovery of circulating white blood cells (WBCs) and reticulocytes (RETs) seven days following irradiation. These effects were dose-dependent, and the strongest effect on most biomarkers (but not on histopathology) was seen with an intermediate dose. Our results provide useful information for future investigations, and strongly implicate a clinical application for SI.     

褪黑素对小鼠淋巴细胞电离辐射损伤的防护作用

目的 探讨褪黑素(MLT)对小鼠淋巴细胞电离辐射损伤的防护作用及其机制。方法 采用流式细胞术和荧光分光光度法在离体和整体条件下分别检测小鼠淋巴细胞凋亡小体百分率和DNA裂解率。在此基础上,腹腔注射MLT,观察2 Gy X射线全身照射后24 h小鼠胸腺、脾脏淋巴细胞数量及胸腺细胞³H-TdR掺入率和Con A、LPS诱导的脾T、B淋巴细胞转化率的变化。结果 离体研究中,小鼠胸腺和脾脏淋巴细胞体外接受0.5~6.0 Gy照射后,凋亡小体百分率、DNA裂解率均呈剂量依赖性增加,而照射前预先加入2 mmol/L MLT,细胞凋亡小体百分率、DNA裂解率与单纯照射组比较均显著降低。整体研究中,2Gy全身照射前腹腔注射MLT,小鼠胸腺和脾脏淋巴细胞凋亡小体百分率和DNA裂解率显著低于单纯照射组,接近或低于假照水平,MLT剂量在0.1~2.5 mg/kg范围内均有作用,但无明显剂量依赖性。小鼠胸腺、脾脏淋巴细胞数量、胸腺细胞³H-TdR掺入率及有丝分裂原诱导的脾脏T、B淋巴细胞转化率在2 Gy全身照射后均显著低于假照组(P <0.001)。0.5~10 mg/kgMLT预先腹腔注射,胸腺、脾脏淋巴细胞数显著高于0 mg/kg体重组(单纯照射),其中0.5 mg/kg体重组增高最显著;胸腺细胞³H-TdR掺入率显著增高(P <0.01或P <0.001),以0.5 mg/kg体重组增高最显著;Con A诱导的T细胞转化率显著增高,也以0.5 mg/kg体重组为著;LPS诱导的B细胞转化率增高,以10mg/kg体重组最显著。结论 MLT在体内和体外均可减轻电离辐射诱导的小鼠淋巴细胞损伤,对免疫功能具有保护作用。     

Caffeine promotes ethanol drinking in rats. Examination using a limited-access free choice paradigm.

There is growing evidence that caffeine may alter the pattern of intake of a variety of drugs. The present study was designed to assess the effect of caffeine pretreatment on voluntary ethanol consumption. The first experiment examined the effect of caffeine on the acquisition of ethanol intake in a limited-access-choice procedure in which water and ethanol were presented concurrently. Male Wistar rats, exposed to food and water ad lib, were presented with a daily 1-h choice session between water and progressively increasing concentrations of ethanol (2-10%). Each ethanol concentration was made available for 4-6 days for a total of 20 days of access to ethanol. Intraperitoneal injections of caffeine (5 or 10 mg/kg) or saline were administered to the rats 30 min prior to each choice session. Caffeine produced a dose-related facilitation in ethanol drinking whereby the lower caffeine dose produced enhancement in ethanol drinking. The second experiment examined the effect of caffeine on the maintenance of established ethanol consumption. Male Wistar rats, initially acclimatized to increasing concentrations of ethanol (2%-10), were presented with an additional 18 ethanol (10%) presentations, comprised of a 6-day baseline period followed by 6 days of treatment where animals were given one of three doses of caffeine (2.5, 5 or 10 mg/kg) or saline prior to ethanol presentation. A final 6-day post-treatment period followed treatment. These results revealed an inverted-U effect of caffeine dose on ethanol ingestion where the low and high caffeine doses produced no effect but the moderate dose of 5 mg/kg enhanced ethanol drinking that persisted throughout the post-treatment period. A third experiment revealed that caffeine did not alter levels of blood ethanol within the time period used for the ethanol drinking session.     

Behavioral desensitization to nicotine is enhanced differentially by ethanol in long-sleep and short-sleep mice

In order to assess the anticonvulsant potency of ethanol, male and female long-sleep (LS) and short-sleep (SS) mice were pretreated with ethanol 7.5 min prior to challenge with an ED80 dose of nicotine (LS: 4.25 mg/kg; SS: 6.25 mg/kg). LS mice were more sensitive to the anticonvulsant effects of ethanol than were SS mice. In order to assess the effect of ethanol on the nicotine-induced behavioral desensitization to nicotine observed previously in these mice, animals were pretreated with saline, nonanticonvulsant doses of ethanol (0.25 g/kg, 0.75 g/kg or 1.5 g/kg), a subseizure-producing dose of nicotine (2.0 mg/kg) or a combination of these two drugs 15 or 30 min prior to nicotine challenge. Ethanol enhanced the nicotine-induced behavioral desensitization in both mouse lines; however, this effect was seen at lower ethanol doses and was more pronounced in LS mice. Ethanol pretreatment did not affect brain nicotine concentrations; therefore, the ethanol effect probably involves changes in brain sensitivity to nicotine.     

Radioprotective effects of citrus extract against gamma-irradiation in mouse bone marrow cells

The radioprotective effects of citrus extract were investigated by using the micronucleus test for anticlastogenic and cell proliferation activity. A single intraperitoneal (i.p.) injection of citrus extract (Citrus aurantium var. amara) at 250, 500, 1000 mg/kg body weight 1 h prior to gamma-ray irradiation (1.5 Gy) reduced the frequencies of micronucleated polychromatic erythrocytes (MnPCE(S)) and normochromatic erythrocytes (MnNCE (S)). All three doses of citrus extract significantly reduced the frequencies of MnPCEs and MnNCEs in mice bone marrow compared to non-drug-treated irradiated control (p < 0.005-0.05). The optimum dose for protection in mouse was 250 mg/kg to protect mice bone marrow 2.2-fold against the side effects of gamma-irradiation with respect to the non-drug-treated irradiated control. The flavonoids were contained in citrus extract, probably to show protective activity, and reduced the clastogenic effect of radiation on mice bone marrow. Therefore fruits and vegetables contain flavonoids to be useful as protective effects under such stress conditions as irradiation.     

Radioprotective potential of an herbal extract of Tinospora cordifolia

A preparation of Tinospora cordifolia (RTc) administered i.p. (200 mg/kg b.w.) to strain "A" male mice 1 h before whole body gamma-irradiation was evaluated for its radioprotective efficacy in terms of whole body survival, spleen colony forming units (CFU), hematological parameters, cell cycle progression, and micronuclei induction. Preirradiation treatment with RTc rendered 76.3% survival (30 days), compared to 100% mortality in irradiated control and prevented radiation induced weight loss. On 10th postirradiation day, the endogenous CFU counts in spleen were decreased with increasing radiation doses 12.0 (5 Gy), 2.16 (7.5 Gy) and 0.33 (10 Gy) but pre-irradiation administration of 200 mg/kg b.w. of RTc increased CFU counts to 31.16, 21.83 and 3.00 respectively. Pre-irradiation RTc treatment could restore total lymphocyte counts (TLC) by the 15th day to normal. It also increased the S-phase cell population that was reduced following 2 Gy irradiation in a time dependent manner. 2 Gy irradiation-induced micronuclei were also decreased by a pre-irradiation administration of RTc from 2.9 to 0.52%. Because the radioprotective manifestation of RTc observed in several systems in experimental animals can be exploited for human applications.     

In vivo gamma-rays induced initial DNA damage and the effect of famotidine in mouse leukocytes as assayed by the alkaline comet assay

Ionizing radiation induces a variety of lesions in DNA, each of which can be used as a bio-indicator for biological dosimetry or the study of the radioprotective effects of substances. To assess gamma ray-induced DNA damage in vivo in mouse leukocytes at various doses and the effect of famotidine, blood was collected from Balb/c male mice after irradiation with 4 Gy gamma-rays at different time intervals post-irradiation. To assess the response, mice were irradiated with doses of gamma-rays at 1 to 4 Grays. Famotidine was injected intra-peritoneally (i.p) at a dose of 5 mg/kg at various time intervals before irradiation. Four slides were prepared from each sample and alkaline comet assay was performed using standard protocols. Results obtained show that radiation significantly increases DNA damage in leukocytes in a dose dependent manner (p < 0.01) when using appropriate sampling time after irradiation, because increasing sampling time after irradiation resulted in a time dependent disappearance of DNA damage. Treatment with only 5 mg/kg famotidine before 4 Gy irradiation led to almost 50% reduction in DNA damage when compared with those animals which received radiation alone. The radioprotective capability of famotidine might be attributed to radical scavenging properties and an anti-oxidation mechanism.     

Protective effect and the therapeutic index of indralin in juvenile rhesus monkeys

The radioprotective effect of indralin in rhesus monkeys was examined over 60 d following gamma irradiation. Male and female rhesus macaques (Macaca mulatta) 2–3-years-old and weighing 2.1–3.5 kg were used. Animals were exposed to total-body gamma irradiation from ⁶⁰Co at a dose of 6.8 Gy (lethal dose, 100% lethality over 30 days). Indralin (40–120 mg kg^–1) was administered intramuscularly 5 min prior to radiation exposure. Indralin taken at a dose of 120 mg kg^–1 protected five out of six monkeys (compared with the radiation control group, in which all 10 animals died). The average effective dose of indralin in the monkeys exposed to gamma irradiation for 30 min was equal to 77.3 (63.3–94.3) mg kg^–1, and the maximum tolerated dose of indralin administered to monkeys was 800 mg kg^–1. Indralin reduced radiation-induced injuries in macaques, thus resulting in a less severe course of acute radiation syndrome. Delayed and less pronounced manifestation of the haemorrhagic syndrome of the disease, and milder forms of both leukopenia and anaemia were also noted. The therapeutic index for indralin, expressed as the ratio of the maximum tolerated dose to the average effective dose_, was equal to 10. Therefore, indralin has a significant radioprotective effect against radiation and has a high therapeutic index in rhesus monkeys.     

硼卡钠对急性辐射损伤小鼠的防护作用

目的 考察硼卡钠(sodium borocaptate,BSH)对急性辐射损伤小鼠的防护作用。方法 以BSH为受试物,用⁶⁰Co γ射线对小鼠进行一次性全身照射,照射剂量为6 Gy,剂量率为0.8 Gy/min。照射后第3天、第14天检测外周血细胞计数,并于照射后第14天检测小鼠脏器指数。结果 照后第3天,BSH高剂量组血小板计数显著增加(P <0.05);照后第14天,与模型组比较,BSH中剂量组血小板计数显著增加(P < 0.01),胸腺指数、脾脏指数均显著升高(P < 0.05)。结论 BSH能显著提高辐照后小鼠的血小板水平,对急性辐射损伤小鼠免疫系统有保护作用。