ePO 35 – The threat of valproic acid as an aquatic pollutant: growth inhibition on duckweed lemna minor
Beatriz Machado1, Piedade Barros2, Ricardo Ferraz3, Cristina Prudêncio4
1 Escola Superior de Saúde – Instituto Politécnico do Porto, 2 LAQV/REQUIMTE – Escola Superior de Saúde – Instituto Politécnico do Porto, 3 LAQV-REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4 TBIO- Escola Superior de Saúde – Instituto Politécnico do Porto
THE THREAT OF VALPROIC ACID AS AN AQUATIC POLLUTANT: GROWTH INHIBITION ON DUCKWEED LEMNA MINOR
Introduction
The consumption of antiepileptic drugs (AEDs), commonly prescribed for the treatment of epilepsy and other psychiatric disorders, has been increasing. AEDs are frequently found in aquatic environments, mainly due to the low removal efficiency of wastewater treatment plants, affecting animal, human and environmental health. Some studies have reported harmful effects of several AEDs in aquatic organisms, such as growth inhibition, alterations of chlorophyll content, and malformations. Valproic acid (VPA) is a widely prescribed antiepileptic drug that has been detected in aquatic environments and has well-documented effects in humans and small mammals; however, there is still limited knowledge regarding its biological effects on aquatic organisms.
This study aimed to assess the effect of valproic acid on the growth of Lemna minor, a duckweed commonly used as a bioindicator in water quality studies
Methods
Acute growth inhibition tests were conducted using OECD Guideline 221. Lemna minor was exposed to six concentrations of VPA for 7 days; the number of fronds, growth rate, root length and chlorophylls content were analyzed.
Results and discussion
Valproic acid affected all parameters analyzed. At higher concentrations VPA caused a decrease in the number of fronds, growth rate, root length, and chlorophyll content. The loss of pigmentation was also observed at the higher concentrations of VPA. The inhibitory effects of VPA found in this study have also been reported to be caused by other pharmaceuticals.
Conclusions
VPA clearly showed a significant inhibitory effect on the growth and viability of Lemna minor. The effects of VPA are of significant concern, highlighting the need for further research to elucidate its toxic mechanisms and to develop efficient strategies for its removal from aquatic environments.