Chemical composition and potential antioxidant-mediated antigenotoxicity of Polygonum maritimum L. from the south of Portugal

Abstract

The human being is continuously exposed to exogenous agents that perturb the redox homeostasis, contributing to the development of degenerative diseases. These agents include xenobiotics present in food, which when consumed may induce oxidative stress and inflammation in the gastrointestinal tract, increasing the levels of reactive oxygen and nitrogen species [1]. These reactive species can interact with cellular constituents such as the DNA, potentially damaging the genetic material and thus contributing to the development of gastrointestinal tract-related cancers.

The potential damage caused by xenobiotics may be mitigated by the consumption of products rich in (poly)phenols due to their well-recognized antioxidant properties [2]. Halophytes, which are continuously exposed to abiotic stresses, have been associated to high content in (poly)phenols and strong antioxidant capacity, making them promising sources of products that could be included in the human diet to promote health. The halophyte Polygonum maritimum L., also known as sea knotgrass, has been described for its antioxidant capacity [3]; however, to our knowledge there are no reports on its antigenotoxicity.

In this work, the chemical composition and the antioxidant and antigenotoxic activities of the halophyte P. maritimum L. were assessed. For investigation of the chemical composition of the extract, the total phenol, ortho-diphenol and flavonoid contents were measured in vitro by colorimetric assays. The antioxidant potential was also evaluated in vitro, by measuring the scavenging capacity of the radicals 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide. Moreover, the antioxidant and antigenotoxic activities against H2O2 were assessed by viability and dDEL assays, respectively, in the yeast Saccharomyces cerevisiae. The results suggest that the P. maritimum extract is rich in phenolic compounds, which may be linked with the antioxidant activity observed in this work. This antioxidant capacity may mediate the antigenotoxic protection provided against H2O2 assessed with the dDEL assay. These findings suggest that P. maritimum is a (poly)phenol-rich plant that could be consumed or included in food as ingredient to mitigate the oxidative stress and DNA damage with dietary origin in the gastrointestinal tract throughout our lifetime and, in this way, promote human health.