Olive Mill Wastewater Extract: In Vitro Genotoxicity/Antigenotoxicity Assessment on HepaRG Cells

Int J Environ Res Public Health. 2024 Aug 9;21(8):1050. doi: 10.3390/ijerph21081050.

Abstract

Olive mill wastewater (OMWW), with its high level of phenolic compounds, simultaneously represents a serious environmental challenge and a great resource with potential nutraceutical activities. To increase the knowledge of OMWW's biological effects, with an aim to developing a food supplement, we performed a chemical characterisation of the extract using the Liquid Chromatography-Quadrupole Time-of-flight spectrometry (LC-QTOF) and an in vitro genotoxicity/antigenotoxicity assessment on HepaRG ™ cells. Chemical analysis revealed that the most abundant phenolic compound was hydroxytyrosol. Biological tests showed that the extract was not cytotoxic at the lowest tested concentrations (from 0.25 to 2.5 mg/mL), unlike the highest concentrations (from 5 to 20 mg/mL). Regarding genotoxic activity, when tested at non-cytotoxic concentrations, the extract did not display any effect. Additionally, the lowest tested OMWW concentrations showed antigenotoxic activity (J-shaped dose-response effect) against a known mutagenic substance, reducing the extent of DNA damage in the co-exposure treatment. The antigenotoxic effect was also obtained in the post-exposure procedure, although only at the extract concentrations of 0.015625 and 0.03125 mg/mL. This behaviour was not confirmed in the pre-exposure protocol. In conclusion, the present study established a maximum non-toxic OMWW extract dose for the HepaRG cell model, smoothing the path for future research.

Keywords: comet assay; olive by-products; phenolic compounds; viability assay.

MeSH terms

  • Cell Line
  • DNA Damage* / drug effects
  • Humans
  • Mutagenicity Tests
  • Mutagens / toxicity
  • Olea* / chemistry
  • Phenols / analysis
  • Phenols / toxicity
  • Plant Extracts / chemistry
  • Plant Extracts / toxicity
  • Wastewater* / chemistry
  • Wastewater* / toxicity

Substances

  • Wastewater
  • Plant Extracts
  • Phenols
  • Mutagens

Grants and funding

This research received no external funding.