Development of an assay to assess genotoxicity by particulate matter extract

Abstract

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). The negative impact of air pollution on human health has been extensively recognised. Among the air pollutants, PM plays an eminent role, as reflected in the broad scientific interest. PM toxicity highly depends on its composition (metals and organic compounds), which in turn has been linked to multiple health effects (such as cardiorespiratory diseases and cancer) through multiple toxicity mechanisms; the induction of oxidative stress is considered a major mechanism among these. In this study, the PM levels, oxidative potential, cytotoxicity and genotoxicity of PM in the region of Larissa, Greece were examined using the plasmid relaxation assay. Finally, coffee extracts from different varieties, derived from both green and roasted seeds, were examined for their ability to inhibit PM-induced DNA damage. These extracts also exerted an inhibitory effect on xanthine oxidase and catalase, but had no effect against superoxide dismutase. Overall, this study highlights the importance of assays for assessing the oxidative potential of widespread environmental stressors (PM), as well as the antioxidant capacity of beverages and food items, with the highlight being the development of a plasmid relaxation assay to assess the genotoxicity caused by PM using only a miniscule amount.

Οlive tree blossom polyphenolic extracts exert antioxidant and antimutagenic activities in vitro and in various cell lines

“…Evaluation of the antigenotoxicity of the extracts using the DNA relaxation assay. The DNA relaxation assay has been previously described (18). The principle of this assay is dependent on the conformational changes of the plasmid (pBluescript-Sk+, Fermentas) DNA, which natively exists in the supercoiled conformation but after a single-strand break is converted to an open circular one.…”

Phenolic compounds profile, neuroprotective effect and antioxidant potential of a commercial Turkish coffee

“…After incubation, 10.0% trichloroacetic acid was added and after shaking, 0.1% FeCl 3 was added to the mixture. After 30 minutes, the conversion of Fe 3+ -ferricyanide complex to Fe 2+ was recorded by reading the absorbance at 700nm [25]. The greater the absorbance,the greater the reducing power.…”

Cell‑specific and roasting‑dependent regulation of the Keap1/Nrf2 pathway by coffee extracts

“…However, despite the fact that coffee beans undergo roasting before their consumption, there is not much evidence on the effects of roasting on coffee composition, nor the differences between green and roasted coffee beans regarding their antioxidant activity ( 23 – 25 ). Indeed, it is known that the roasting procedure, which differs between coffee varieties, greatly affects CGAs leading to their breakdown and the formation of products, which may alter the antioxidant capacity of coffee beans ( 23 , 26 , 27 ).…”