Search results for "Radiation-Protective Agents"
showing 10 items of 12 documents
Prevention from radiation damage by natural products
2018
Abstract Background Radiotherapy is a mainstay of cancer treatment since decades. Ionizing radiation (IR) is used for destruction of cancer cells and shrinkage of tumors. However, the increase of radioresistance in cancer cells and radiation toxicity to normal tissues are severe concerns. The exposure to radiation generates intracellular reactive oxygen species (ROS), which leads to DNA damage by lipid peroxidation, removal of thiol groups from cellular and membrane proteins, strand breaks and base alterations. Hypothesis Plants have to deal with radiation-induced damage (UV-light of sun, other natural radiation sources). Therefore, it is worth speculating that radioprotective mechanisms ha…
The effect of amifostine or IMRT to preserve the parotid function after radiotherapy of the head and neck region measured by quantitative salivary gl…
2008
Purpose: In this retrospective study, two approaches to preserve the parotid function after radiotherapy (RT) were compared: application of the radioprotective agent amifostine during RT and parotid sparing intensity-modulated radiotherapy (IMRT). Patients and methods: Patients were qualified for this analysis if (1) both parotid glands received a radiation dose of P50 Gy using conventional radiotherapy techniques (cRT) or if they received a parotid sparing IMRT as alternative, if (2) salivary gland scintigraphies before and after RT were performed, and if (3) a normal parotid function was present before RT. Quantitative salivary gland scintigraphy was used to assess the parotid gland funct…
Protective effect of amifostine on dental health after radiotherapy of the head and neck.
2000
Abstract Purpose: The cytoprotective agent amifostine has been shown to reduce the radiation-induced acute and chronic xerostomia in head and neck cancer patients. The purpose of this study was to evaluate whether or not amifostine also reduces the incidence of dental caries associated with the radiation-induced xerostomia. Methods and Materials: The dental status before and 1 year after radiotherapy was retrospectively compared in 35 unselected patients treated as part of the prospective randomized and multicenter open-label Phase III study (WR-38) at the University Hospitals of Heidelberg, Freiburg, and Erlangen. The WR-38 study compared radiotherapy in head and neck cancer with and witho…
Prophylaxis of radiogenic sialadenitis and mucositis by coumarin/troxerutine in patients with head and neck cancer--a prospective,randomized, placebo…
2001
To study the efficacy of coumarin/troxerutine for the protection of salivary glands and mucosa during irradiation. Design: Prospective, randomized, placebo-controlled, double-blind trial. Setting: University hospital, Germany. Patients: 48 patients who had radiotherapy to the head and neck. Main outcome measures: Salivary gland scintigraphy and acute side-effects of radiotherapy (Radiation Therapy Oncology Group (RTOG) score). Results: 23 patients (11 experimental, 12 placebo) completed the study. The global efficacy measure combining scintigraphy and RTOG score favoured the experimental arm (P= 0.07). The RTOG score showed significantly fewer acute side-effects of radiation in the experime…
Halloysite/Keratin Nanocomposite for Human Hair Photoprotection Coating
2020
We propose a novel keratin treatment of human hair by its aqueous mixtures with natural halloysite clay nanotubes. The loaded clay nanotubes together with free keratin produce micrometer-thick protective coating on hair. First, colloidal and structural properties of halloysite/keratin dispersions and the nanotube loaded with this protein were investigated. Above the keratin isoelectric point (pH = 4), the protein adsorption into the positive halloysite lumen is favored because of the electrostatic attractions. The ζ-potential magnitude of these core-shell particles increased from -35 (in pristine form) to -43 mV allowing for an enhanced colloidal stability (15 h at pH = 6). This keratin-cla…
Potential use of HMG-CoA reductase inhibitors (statins) as radioprotective agents
2011
HMG-CoA reductase inhibitors (statins) are widely used in the therapy of hypercholesterolemia. Apart from their lipid-lowering activity, they have pleiotropic effects that are attributed to the inhibition of regulatory proteins, including Ras-homologous (Rho) GTPases. Here, we discuss the potential usefulness of statins to prevent normal tissue damage provoked by radiotherapy. Statins reduce the mRNA expression of pro-inflammatory and pro-fibrotic cytokines stimulated by ionizing radiation in vitro and alleviate IR-induced inflammation and fibrosis in vivo. The currently available data indicate that statins accelerate the rapid repair of DNA double-strand breaks and, moreover, mitigate the …
Curcumin and trans-resveratrol exert cell cycle-dependent radioprotective or radiosensitizing effects as elucidated by the PCC and G2-assay
2013
Curcumin and trans-resveratrol are well-known antioxidant polyphenols with radiomodulatory properties, radioprotecting non-cancerous cells while radiosensitizing tumor cells. This dual action may be the result of their radical scavenging properties and their effects on cell-cycle checkpoints that are activated in response to radiation-induced chromosomal damage. It could be also caused by their effect on regulatory pathways with impact on detoxification enzymes, the up-regulation of endogenous protective systems, and cell-cycle-dependent processes of DNA damage. This work aims to elucidate the mechanisms underlying the dual action of these polyphenols and investigates under which conditions…
Melatonin protects rats from radiotherapy-induced small intestine toxicity
2017
Radiotherapy-induced gut toxicity is among the most prevalent dose-limiting toxicities following radiotherapy. Prevention of radiation enteropathy requires protection of the small intestine. However, despite the prevalence and burden of this pathology, there are currently no effective treatments for radiotherapy-induced gut toxicity, and this pathology remains unclear. The present study aimed to investigate the changes induced in the rat small intestine after external irradiation of the tongue, and to explore the potential radio-protective effects of melatonin gel. Male Wistar rats were subjected to irradiation of their tongues with an X-Ray YXLON Y.Tu 320-D03 irradiator, receiving a dose o…
Lung autophagic response following exposure of mice to whole body irradiation, with and without amifostine
2010
Research highlights: {yields} We investigated the effect 6 Gy of WBI on the autophagic machinery of normal mouse lung. {yields} Irradiation induces dysfunction of the autophagic machinery in normal lung, characterized by decreased transcription of the LC3A/Beclin-1 mRNA and accumulation of the LC3A, and p62 proteins. {yields} The membrane bound LC3A-II protein levels increased in the cytosolic fraction (not in the pellet), contrasting the patterns noted after starvation-induced autophagy. {yields} Administration of amifostine, reversed all the LC3A and p62 findings, suggesting protection of the normal autophagic function. -- Abstract: Purpose: The effect of ionizing irradiation on the autop…
A collagen extraction and deuterium oxide stable isotope tracer method for the quantification of bone collagen synthesis rates in vivo.
2021
Abstract The development of safe and practical strategies to prevent weakening of bone tissue is vital, yet attempts to achieve this have been hindered by a lack of understanding of the short‐term (days‐weeks) physiology of bone collagen turnover. To address this, we have developed a method to quantify bone collagen synthesis in vivo, using deuterium oxide (D2O) tracer incorporation techniques combined with gas chromatography pyrolysis isotope‐ratio mass spectrometry (GC‐pyrolysis‐IRMS). Forty‐six male and female rats from a selectively bred model ingested D2O for 3 weeks. Femur diaphyses (FEM), tibia proximal (T‐PRO), and distal (T‐DIS) epiphyses‐metaphyses and tibia mid‐shaft diaphyses (T…