Publication details
Investigating the phytotoxic effects of binary mixtures of diclofenac and paracetamol on duckweed - synergistic or antagonistic interaction?
| Authors | |
|---|---|
| Year of publication | 2025 |
| Type | Article in Periodical |
| Magazine / Source | Environmental Pollution |
| MU Faculty or unit | |
| Citation | |
| web | https://www.sciencedirect.com/science/article/pii/S0269749125016690 |
| Doi | https://doi.org/10.1016/j.envpol.2025.127295 |
| Keywords | Non-steroidal anti-inflammatory drugs; Lemna minor; Growth; Photosynthesis; Oxidative stress |
| Description | Mixtures of emerging aquatic contaminants, like diclofenac (DCF) and paracetamol (PCT) commonly occurring in the environment, can exhibit combination effects. Accumulation of drugs in duckweed plants exposed for seven days to DCF + PCT mixtures was similar to that under individual drugs (both 0.2, 2, and 20 mg/L). But the nature of drug interaction in mixtures was ambiguous, even though the toxic impact of DCF was more substantial than that of PCT. Mixtures with a DCF-to-PCT ratio of 1:1 exhibited a synergistic interaction manifested by a decrease (up to 90 %) in plant number, especially in mixtures DCF 2 + PCT 2 and DCF 20 + PCT 20 mg/L. In mixtures with unequal ratios (1:10 or 1:100 with a predominance of DCF or PCT), their interaction attenuated with time to additive or even antagonistic. This finding (shift from synergistic to additive interaction) was supported even by changes in the plants' dry weight, leaf area, or photosynthetic pigment content. Similarly, a negligible decrease in photosynthetic performance in plants exposed to the mixtures with unequal ratios supported the mitigation of the drug mixture effect. Both individual drugs and their mixtures of 2 and 20 mg/L elevated the production of reactive oxygen species. The antioxidant defence mechanism activity was elevated already by low drug doses (0.2 and 2 mg/L), and the highest contamination (20 mg/L) led to its decrease. Utilizing the "number of plants" parameter showed that the nature of drug interaction in the mixture is fluctuating, and the causal factors include the ratio of mixture component concentrations and the length of the exposure period. |