Malfunctioning of some dna repair pathways predisposes to certain types of cancer. impaired base excision repair, nucleotide excision repair, mismatch repair and recombination are implied in human tissues. these repair pathways are engaged very quickly in the cell when the external (chemical carcinogens) and internal (lipid peroxidation products) compounds react directly with dna. this reaction...

Development of radioprotective agents has been a subject of intense research to ameliorate the aftermath of exposure to radiation exposure. The aim of the study was to determine the antioxidant and radioprotective potentials of the fruit extract of Oroxylum indicum (L.) Vent. Free radical scavenging activity of O. indicum fruit extracts was determined through DPPH and superoxide assays. Ascorbi...

Ionizing radiation is encountered in our natural environment and is also generated and used by mankind, e.g., for medical uses. A better understanding of the biological effects of ionizing radiation will lead to better use of and better protection from radiation. In this chapter, the response of cells to radiation will be described and discussed. Some basic concepts of ionizing radiation will b...

During its life cycle Leishmania spp. face several stress conditions that can cause DNA damages. Base Excision Repair plays an important role in DNA maintenance and it is one of the most conserved mechanisms in all living organisms. DNA repair in trypanosomatids has been reported only for Old World Leishmania species. Here the AP endonuclease from Leishmania (L.) amazonensis was cloned, express...

Crude oil is enriched in polycyclic aromatic hydrocarbons (PAHs). Many PAH analogs have proved to potentially damage DNA. DNA damage can be assessed using various biomarkers to find out the degree of genotoxicity of pollutants following in vitro exposure. In this research the comet assay and micronucleus (MN) test were used to detect DNA damages and cytogenetic changes following crude oil expos...

Electron transfer (ET) reactions are important for their implications in both oxidative and reductive DNA damages. The current contribution investigates the efficacy of caffeine, a xanthine alkaloid in preventing UVA radiation induced ET from a carcinogen, benzo[a]pyrene (BP) to DNA by forming stable caffeine-BP complexes. While steady-state emission and absorption results emphasize the role of...

Disulfiram/Radioprotector/Comet assay/Lipid peroxidation. Disufiram (a drug used for the treatment of alcoholism) protected microsomal membranes and plasmid DNA against damages induced by gamma-radiation. The peroxidation of membrane lipids increased linearly with the radiation dose up to 600 Gy, and the presence of disulfiram inhibited membrane lipid peroxidation as assayed by the presence of ...

Characteristic of damage introduced in DNA by ionizing radiation is the induction of a wide range of lesions. Single-strand breaks (SSBs) and base damages outnumber double-strand breaks (DSBs). If unrepaired, these lesions can lead to DSBs and increased mutagenesis. XRCC1 and DNA polymerase beta (polbeta) are thought to be critical elements in the repair of these SSBs and base damages. XRCC1-de...

Among various DNA damages, double-strand breaks (DSBs) are considered as most deleterious, as they may lead to chromosomal rearrangements and cancer when unrepaired. Nonhomologous DNA end joining (NHEJ) is one of the major DSB repair pathways in higher organisms. A large number of studies on NHEJ are based on in vitro systems using cell-free extracts. In this paper, we summarize the studies on ...

Ultra Violet (UV) radiation induces reactive oxygen species (ROS) production, DNA oxidation and single strand breaks (SSBs), which will eventually lead to skin cell damages or even skin cancer. Here, we tested the potential activity of gremlin, a novel vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) agonist, against UV-induced skin cell damages. We show that gremlin activated VEGF...