Suppressing the oxidation of LDL and DNA strand breakage of bioactives in dehulled and hull fraction of lentils

Hull/seed coat contains various plant cells that are responsible for sustaining the life of seeds in which phenolics perform significant roles in supporting their functions. In the present study, inhibitory activities against the oxidation of LDL and DNA of soluble- and insoluble-bound phenolics in the dehulled and hull fractions of lentils were determined. In addition, their α-glucosidase inhibitory activity was also assessed. The hulls possessed much higher levels of phenolics in both the soluble- and insoluble-bound forms than dehulled grain fractions, and this led to their potent activities in suppressing the oxidation of LDL and DNA and inhibiting α-glucosidase activity. The high bioactivities of hulls might be due to the existence of various types of cells such as palisade and parenchyma cells containing numerous phenolics for sustaining their functions. This study may help in a better understanding of the localization of soluble- and insoluble-bound phenolics in the structure of lentil.

Topoisomerase Inhibitors and Targeted Delivery in Cancer Therapy

DNA topoisomerases are enzymes that catalyze the alteration of DNA topology with transiently induced DNA strand breakage, essential for DNA replication. Topoisomerases are validated cancer chemotherapy targets. Anticancer agents targeting Topoisomerase I and II have been in clinical use and proven to be highly effective, though with significant side effects. There are tremendous efforts to develop new generation of topoisomerase inhibitors. Targeted delivery of topoisomerase inhibitors is another way to reduce the side effects. Conjugates of topoisomerases inhibitors with antibody, polymer, or small molecule are developed to target these inhibitors to tumor sites.

Comet Assay: A Strong Tool for Evaluating DNA Damage and Comprehensive Guidelines for Plant Cells

Heavy metals affect plant system in various toxic ways including morphophysiological alterations and genotoxic damages inside a plant cell. The extent of DNA damage under any genotoxic agents can be effectively measured in single cells applying comet assay approach. Comet assay primarily measures DNA strand breakage in single cells and its use has increased in different areas: clinical applications, human monitoring, radiation biology and genetic ecotoxicology. This paper is a review of the detailed protocol and precautions to be taken while performing comet assay and may have been slightly modified from other original protocols according to the plant, organ, cell type, etc. In conclusion, the study reviewed in this paper demonstrate that the comet assay application in plants provides a reliable, sensitive and rapid system for the study of environmental genotoxicity caused by heavy metals.

8-oxoG DNA Glycosylase-1 Inhibition Sensitizes Neuro-2a Cells to Oxidative DNA Base Damage Induced by 900 MHz Radiofrequency Electromagnetic Radiation

Background/Aims: The purpose of this study was to explore the in vitro putative genotoxicity during exposure of Neuro-2a cells to radiofrequency electromagnetic fields (RF-EMFs) with or without silencing of 8-oxoG DNA glycosylase-1 (OGG1). Methods: Neuro-2a cells treated with or without OGG1 siRNA were exposed to 900 MHz Global System for Mobile Communication (GSM) Talk signals continuously at a specific absorption rate (SAR) of 0, 0.5, 1 or 2 W/kg for 24 h. DNA strand breakage and DNA base damage were measured by the alkaline comet assay and a modified comet assay using formamidopyrimidine DNA glycosylase (FPG), respectively. Reactive oxygen species (ROS) levels and cell viability were monitored using the non-fluorescent probe 2, 7-dichlorofluorescein diacetate (DCFH-DA) and CCK-8 assay. Results: Exposure to 900 MHz RF-EMFs with insufficient energy could induce oxidative DNA base damage in Neuro-2a cells. These increases were concomitant with similar increases in the generation of reactive oxygen species (ROS). Without OGG1 siRNA, 2 W/kg RF-EMFs induced oxidative DNA base damage in Neuro-2a cells. Interestingly, with OGG1 siRNA, RF-EMFs could cause DNA base damage in Neuro-2a cells as low as 1 W/kg. However, neither DNA strand breakage nor altered cell viability was observed. Conclusion: Even if further studies remain conducted we support the hypothesis that OGG1 is involved in the process of DNA base repair and may play a pivotal role in protecting DNA bases from RF-EMF induced oxidative damage.