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Introduction: Natural products can be used as radioprotector agents because of containing phenolic compounds and several flavonoids with antioxidant properties. When the normal cells are exposed to ionizing radiation, they generate free radicals and reactive oxygen species that can cause damage in DNA, which leads to cellular dysfunction or even cell death. However, it is necessary to identify new radioprotective agents to protect normal cells. Ferulago angulata (F.angulata), a medicinal plant, can be used as a new radioprotective agent. Purpose: The antioxidant activity of F.angulata was assayed using FRAP and DPPH methods. Then, the human blood samples were incubated with F.angulata at different concentrations (25, 50, 100 and 200 μM) and subsequently exposed to IR at a dose of 2Gy. The radioprotective effectof F.angulata on the exposed cells was assessed by micronucleus (MN) method. Also, biomarkers of oxidative stress in the exposed cells were evaluated by malondialdehyde (MDA) and superoxide dismutase (SOD) methods. Methods: The antioxidant activity of F.angulata was assayed using FRAP and DPPH methods. Then, the human blood samples were incubated with F.angulata at different concentrations (25, 50, 100 and 200 μM) and subsequently exposed to IR at a dose of 2Gy. The radioprotective effectof F.angulata on the exposed cells was assessed by micronucleus (MN) method. Also, biomarkers of oxidative stress in the exposed cells were evaluated by malondialdehyde (MDA) and superoxide dismutase (SOD) methods. Results: Our findings showed that F. angulata reduced the frequency of MN induced by IR in exposed cells. At 200μM concentration of F. angulata, maximum reduction in the frequency of MN (63.11%) was observed that demonstrated a high degree of radioprotection. Afterward, pretreatment at 200μM concentration of F.angulata inhibited oxidative stress in irradiated lymphocytes, leading to a reduction in MN frequency and MDA levels while SOD activity was enhanced in the exposed cells. Conclusion: F. angulata as a natural radioprotective agent can protect normal cells against reactive oxygen species and genetic damage induced by IR.

Introduction: The ionizing radiation exposure of the normal cell causes damage to DNA, which leads to cell dysfunction or even cell death. However, it is necessary to identify new radio protectives in order to protect normal cells. Sulindac sulfide (SS) is a metabolite of sulindac (a non-steroidal anti-inflammatory drug) known as a cyclooxygenase inhibitor. Free radicals and reactive oxygen species are generated in the IR-exposed cells. Also, the induced inflammation process causes damage in DNA. Purpose: In this research, the radioprotective effect of SS was investigated against genotoxicity and lipid peroxidation induced by ionizing radiation in the human blood lymphocytes. Methods: In this study, the human blood samples were pretreated with SS at different concentrations (10, 25, 50, 100 and 250 μM) and then were exposed to IR at a dose of 1.5 Gy. The micronucleus (MN) assay was used to indicate the radioprotective effects of SS on exposed cells. Total antioxidant activity of the SS was measured by using FRAP and DPPH assay. Also, the malondialdehyde (MDA) levels and the activity of superoxide dismutase (SOD) on the exposed cells were evaluated. Results: It was found that SS decreased the percentage of MN induced by IR in exposed cells. Maximum reduction in the frequency of MN was observed at 250 μM of SS (87%) that provides the highest degree of protection against IR. On the other hand, pretreatment at 250 μM of SS inhibited IR-induced oxidative stress, which led to a decrease in the MN frequencies and MDA levels, while SOD activity showed an increase in the exposed cells. Conclusion: It could be concluded that SS as a good radioprotective agent protects the human normal cells against the oxidative stress and genetic damage induced by IR.

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Background:The use of electronic portal imaging devices (EPIDs) is a method for the dosimetric verification of radiotherapy plans, both pretreatment and in vivo. The aim of this study is to test a 2D EPID-based dosimetry algorithm for dose verification of some plans inside a homogenous and anthropomorphic phantom and in vivo as well.Materials and Methods:Dose distributions were reconstructed from EPID images using a 2D EPID dosimetry algorithm inside a homogenous slab phantom for a simple 10 × 10 cm2 box technique, 3D conformal (prostate, head-and-neck, and lung), and intensity-modulated radiation therapy (IMRT) prostate plans inside an anthropomorphic (Alderson) phantom and in the patients (one fraction in vivo) for 3D conformal plans (prostate, head-and-neck and lung).Results:The planned and EPID dose difference at the isocenter, on an average, was 1.7% for pretreatment verification and less than 3% for all in vivo plans, except for head-and-neck, which was 3.6%. The mean γ values for a seven-field prostate IMRT plan delivered to the Alderson phantom varied from 0.28 to 0.65. For 3D conformal plans applied for the Alderson phantom, all γ1% values were within the tolerance level for all plans and in both anteroposterior and posteroanterior (AP-PA) beams.Conclusion:The 2D EPID-based dosimetry algorithm provides an accurate method to verify the dose of a simple 10 × 10 cm2 field, in two dimensions, inside a homogenous slab phantom and an IMRT prostate plan, as well as in 3D conformal plans (prostate, head-and-neck, and lung plans) applied using an anthropomorphic phantom and in vivo. However, further investigation to improve the 2D EPID dosimetry algorithm for a head-and-neck case, is necessary.