Radioprotective potential of Lagenaria siceraria extract against radiation-induced gastrointestinal injury.

The cucurbits (prebiotics) were investigated as novel agents for radio-modification against gastrointestinal injury. The cell-cycle fractions and DNA damage were monitored in HCT-15 cells. A cucurbit extract was added to culture medium 2 h before irradiation (6 Gy) and was substituted by fresh medium at 4 h post-irradiation. The whole extract of the fruits of Lagenaria siceraria, Luffa cylindrica, or Cucurbita pepo extract enhanced G2 fractions (42%, 34%, and 37%, respectively) as compared with control (20%) and irradiated control (31%). With cucurbits, the comet tail length remained shorter (L. siceraria, 28 µm; L. cylindrica, 34.2 µm; C. pepo, 36.75 µm) than irradiated control (41.75 µm). For in vivo studies, L. siceraria extract (2 mg/kg body weight) was administered orally to mice at 2 h before and 4 and 24 h after whole-body irradiation (10 Gy). L. siceraria treatment restored the glutathione contents to 48.8 µmol/gm as compared with control (27.6 µmol/gm) and irradiated control (19.6 µmol/gm). Irradiation reduced the villi height from 379 to 350 µm and width from 54 to 27 µm. L. siceraria administration countered the radiation effects (length, 366 µm; width, 30 µm, respectively) and improved the villi morphology and tight junction integrity. This study reveals the therapeutic potential of cucurbits against radiation-induced gastrointestinal injury.

Dietary Pectin Increases Intestinal Crypt Stem Cell Survival following Radiation Injury.

Gastrointestinal (GI) mucosal damage is a devastating adverse effect of radiation therapy. We have recently reported that expression of Dclk1, a Tuft cell and tumor stem cell (TSC) marker, 24h after high dose total-body gamma-IR (TBI) can be used as a surrogate marker for crypt survival. Dietary pectin has been demonstrated to possess chemopreventive properties, whereas its radioprotective property has not been studied. The aim of this study was to determine the effects of dietary pectin on ionizing radiation (IR)-induced intestinal stem cell (ISC) deletion, crypt and overall survival following lethal TBI. C57BL/6 mice received a 6% pectin diet and 0.5% pectin drinking water (pre-IR mice received pectin one week before TBI until death; post-IR mice received pectin after TBI until death). Animals were exposed to TBI (14 Gy) and euthanized at 24 and 84h post-IR to assess ISC deletion and crypt survival respectively. Animals were also subjected to overall survival studies following TBI. In pre-IR treatment group, we observed a three-fold increase in ISC/crypt survival, a two-fold increase in Dclk1+ stem cells, increased overall survival (median 10d vs. 7d), and increased expression of Dclk1, Msi1, Lgr5, Bmi1, and Notch1 (in small intestine) post-TBI in pectin treated mice compared to controls. We also observed increased survival of mice treated with pectin (post-IR) compared to controls. Dietary pectin is a radioprotective agent; prevents IR-induced deletion of potential reserve ISCs; facilitates crypt regeneration; and ultimately promotes overall survival. Given the anti-cancer activity of pectin, our data support a potential role for dietary pectin as an agent that can be administered to patients receiving radiation therapy to protect against radiation-induces mucositis.

Study on the effects of Guiqi Oral Liquid in promoting recovery of hematopoiesis in acute irradiation injured mice.

OBJECTIVE: To explore the effects and possible mechanisms of Guiqi Oral Liquid (GQOL) on the recovery of hematopoiesis in acute irradiation injured mice. METHODS: The acute irradiation injured mice were randomly divided into 2 groups: the treated group and the control group, and also a normal control group was set up with 6 mice in it receiving no treatment. After the mice in the former two groups were irradiated by 6.0 Gy (60)Co gamma-ray, every one of them was given 0.4 ml GQOL or saline in equal volume through a gastric tube twice a day for 14 days. On the 4th, 8th and 14th day after irradiation, the bone marrow mononuclear cells (BMMNC) and megakaryocytes in bone marrow tissues of the mice were counted, the proportion of hematopoietic tissues (by area) was measured, and the expression of adhesion molecules, CD44 and CD54, in bone marrow were estimated by immunochemistry. The colony forming unit of spleen (CFU-S) in the mice were counted on the 8th day after irradiation. RESULTS: On the 4th, 8th, 14th day after irradiation, the count of BMMNC and megakaryocyte, and the proportion of hematopoietic tissues in the treated group were higher than those in the control group (P < 0.01 or P < 0.05). CD44 and CD54 expression in the treated group were higher than those in the control group on the 4th and 8th day (P < 0.01), but near normal on the 14th day (P < 0.01). On the 8th day, CFU-S count in the treated group was higher than that in the control group (P < 0.01). CONCLUSION: GQOL can regulate the expression of adhesion molecules, CD44 and CD54, in the bone marrow of the acute irradiation injured mice, which may be one of the mechanisms of GQOL in accelerating the early phase hematopoiesis recovery of mice.

[Food fibers--blockers and decontaminants of the radionuclides cesium and strontium]. / Pishchevye volokna--blokatory i dekorporanty radionuklidov tseziia i strontsiia.

The Chernobyl accident and its resultant radioactive pollution of enormous areas led to long-term entrance of radionuclides into the human habitat. Among more than 200 radionuclides, the products of uranium fission in the reactor of the atomic power station, the isotopes of iodine, cesium, and strontium present the highest hazard. If iodine-131 virtually decayed by August, 1986, the long-lived isotopes of cesium and strontium will still stir the world public and scientists for many years. The authors' result show that new types of dietary cellulose and composite food additives based on alfalfa polymers have rather pronounced antiradioactive properties against Cs-137 and Sr-85. This makes it necessary to organize the manufacture of these food additives whose daily dose of 12-20 should be supplemented into human diet every day.

[Comparative evaluation of radiation protective efficiency of regimens with various content of calcium, potassium and iron]. / Sravnitelnaia otsenka radioprotektornoi éffectivnosti ratsionov s razlichnym soderzhaniem kaltsiia, kaliia i zheleza.

Calcium deficit in ration of rats considerable reduced radioprotective potential of animals. The enrichment of ration for calcium, potassium, and iron improved radioprotection by changing velocity of accumulation and excretion of cesium.