background: alpinia galanga l. belonging to the family zingiberaceae is widely grown in the state of kerala, india. they are effective antioxidant and free radical scavenger under both in vitro and in vivo condition. the efficacy of the isolated flavonoids in conferring protection from radiation induced damages to genomic dna was studied. materials and methods: the bioflavonoids, galangin and k...

Background: DNA damage is one of the major consequences of radiation exposure onto the biological systems. A series of compounds including flavanoids were found to render DNA protection against radiation damage. In this study we elucidated the potential of rutin and rutin hydrate to protect plasmid DNA against damage induced by irradiation. Materials and Methods: DPPH and hydroxyl radical scave...

background: dna damage is one of the major consequences of radiation exposure onto the biological systems. a series of compounds including flavanoids were found to render dna protection against radiation damage. in this study we elucidated the potential of rutin and rutin hydrate to protect plasmid dna against damage induced by irradiation. materials and methods: dpph and hydroxyl radical scave...

The current study describes a method for assessing the oxidative potential of common environmental stressors (ambient air particulate matter), using a plasmid relaxation assay where the extract caused single-strand breaks, easily visualised through electrophoresis. This assay utilises a miniscule amount (11 µg) of particulate matter (PM) extract compared to other, cell‑based methods (~3,000 µg)...

A series of carbocyclic analogues of netropsin were synthesized and evaluated for their capacity to inhibit human topoisomerases I and II in vitro. The compounds are oligopeptides containing 1,4-di- and 1,2,5-trisubstituted benzene rings and unsubstituted N-terminal NH2 groups. Compounds 4-7 consist of two netropsin-like units linked by aliphatic (tetra- and hexamethylene) chains. In the topois...

Dihydrotanshinone I induced topoisomerase I-mediated DNA cleavage in vitro as strongly as camptothecin, but topoisomerase II-mediated DNA cleavage was not affected. In a DNA relaxation assay using calf thymus DNA topoisomerase I and supercoiled pBR322 plasmid DNA, dihydrotanshinone I reduced topoisomerase I-mediated DNA relaxation in a dose-dependent manner. Heat treatment (65°C) of the reactio...

PURPOSE Peganum harmala L. (Zygophyllaceae) seeds extract is one of the main components of an ethnobotanical preparation used in the treatment of neoplasms in Iran. Cytotoxic effects of P. harmala extract on cancerous cell-lines have been reported before. beta-carbolines like harmaline and harmine are the major alkaloids present in the seeds of the P. harmala. Considering reports concerning DNA...

Protein-deoxyribonucleic acid relaxation complexes have been demonstrated for six Staphylococcus aureus plasmids out of sixteen examined. Four of these encode stretomycin resistence, have molecular weights of about 2.7 x 10(6), and are isolated as supercoiled molecules that are virtally 100% relaxable by treatment with sodium dodecyl sulfate. It is probable that these four isolates represent a ...