Experimental accumulation and depuration kinetics and natural occurrence of microcystin-LR in basil (Ocimum basilicum L.)

Wannes Hugo R Van Hassel; Mohamed F Abdallah; Maria Gracia Guzman Velasquez; Christopher O Miles; Ingunn A Samdal; Julien Masquelier; Andreja Rajkovic

doi:10.1016/j.envpol.2024.123715

Experimental accumulation and depuration kinetics and natural occurrence of microcystin-LR in basil (Ocimum basilicum L.)

Environ Pollut. 2024 Apr 15:347:123715. doi: 10.1016/j.envpol.2024.123715. Epub 2024 Mar 8.

Authors

Wannes Hugo R Van Hassel¹, Mohamed F Abdallah², Maria Gracia Guzman Velasquez³, Christopher O Miles⁴, Ingunn A Samdal⁵, Julien Masquelier⁶, Andreja Rajkovic⁷

Affiliations

¹ Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Gent, 9000, Belgium; Sciensano, Chemical and Physical Health Risks, Organic Contaminants and Additives, Leuvensesteenweg 17, Tervuren, 3080, Belgium; InBios- Centre for Protein Engineering, Department of Life Sciences, University of Liège, Allée du six Août 11, Liège, 4000, Belgium. Electronic address: wannes.vanhassel@sciensano.be.
² Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Gent, 9000, Belgium; Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Assiut University, Assiut, 71515, Egypt.
³ Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Gent, 9000, Belgium; Sciensano, Chemical and Physical Health Risks, Organic Contaminants and Additives, Leuvensesteenweg 17, Tervuren, 3080, Belgium.
⁴ Biotoxin Metrology, National Research Council Canada, Halifax, NS, B3H 3Z1, Canada; Norwegian Veterinary Institute, Postboks 64, 1431, Ås, Norway.
⁵ Norwegian Veterinary Institute, Postboks 64, 1431, Ås, Norway.
⁶ Sciensano, Chemical and Physical Health Risks, Organic Contaminants and Additives, Leuvensesteenweg 17, Tervuren, 3080, Belgium.
⁷ Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Gent, 9000, Belgium.

PMID: 38462191
DOI: 10.1016/j.envpol.2024.123715

Abstract

Microcystin-LR (MC-LR) is a hepatotoxic metabolite that naturally occurs during some cyanobacterial blooms in eutrophic waterbodies, and irrigation of edible plants with MC-LR-contaminated water causes bioaccumulation of the toxin. However, sufficient information about accumulation and depuration mechanics in hydroculture-grown herb plants is still lacking. This work aimed at 1) investigating bioaccumulation and depuration of MC-LR in basil, 2) verifying the possible MC-LR detoxification mechanisms in the plant, and 3) detecting the natural occurrence of MC-LR in basil (n = 50) collected from the Belgian market. Basil plants grown in a hydroculture were exposed to MC-LR (5, 20, and 50 μg L^-1) spiked in a Hoagland solution for seven days. MC-LR depuration was also studied by transferring the plants to a non-contaminated Hoagland solution after exposure to MC-LR for another seven days. MC-LR concentrations in Hoagland solution, basil leaves, and roots were quantified using a validated UHPLC-MS/MS method. In addition, ELISA and LC-HRMS (only basil leaves) were used for confirmation. The results showed an increase in the accumulated levels of MC-LR at higher exposure doses, with higher MC-LR levels in roots than in leaves for all the treatment conditions. For MC-LR depuration, significant reductions were observed in all the treatment conditions for roots only. No MC-LR conjugates, potentially related to metabolism, were detected by LC-HRMS. Finally, MC-LR was detected in one store-bought basil sample, representing the first occurrence of cyanotoxins in an edible crop from Belgium.

Keywords: Accumulation; Basil; Depuration; Food safety; MC-LR; Microcystins; UHPLC-MS/MS.

MeSH terms

Cyanobacteria Toxins
Marine Toxins*
Microcystins / toxicity
Ocimum basilicum* / metabolism
Tandem Mass Spectrometry

Substances

cyanoginosin LR
Microcystins
Cyanobacteria Toxins
Marine Toxins